IAQM u GUIDANCE

Construction Dust Monitoring

Institute of
Air Quality
Management

Guidance on Monitoring in the Vicinity of

Demolition and Construction Sites

October 2018 (version 1.1)

www.iaqm.co.uk
 IAQM u GUIDANCE
Construction Dust Monitoring

Contents
1. Introduction 4

2. Background 5

3. Methodology 6

4 Approaches to Monitoring dust 7

5. Glossary of terms 20

6. Case study: Barts and London NHS Trust 21

7. Case study: East Parkside, Greenwich 23

8. Case study: Siting monitors for construction 25

9. Appendix 29

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Acknowledgments

Chair of the Working Group Copyright statement: Copyright of these materials is held
Stephen Moorcroft, Air Quality Consultants by the members of the Working Group. We encourage the
use of the materials but request that acknowledgement of
Members of the Working Group the source is explicitly stated. All design rights are held by the
Michael Bull, ARUP IAQM, unless otherwise stated.
Peter Fleming, AQMC
Daniel Marsh, Kings College, London
Matthew Stoaling, Isopleth Ltd
Will Franklin, RSK

Acknowledgements: IAQM committee & experts who

offered their comments during the preparation of this
document. Richard Maggs at Bureau Veritas for providing the
Case Study for Barts and London NHS Trust, Hugh Datson
at DustScanAQ for providing the Case Study related to East
Editor: Paddy Fowler
Parkside, Greenwich and Daniel Marsh at King’s College
London for providing the case study on siting requirments. Graphic Design: Aoife O’Connell
(aoife.oconnellm@gmail.com)

The Institute of Air Quality Management (IAQM):

IAQM aims to be the authoritative voice for air quality by Contact: IAQM
maintaining, enhancing and promoting the highest standards c/o Institution of Environmental Sciences
of working practices in the field and for the professional 3rd Floor, 140 London Wall. London
development of those who undertake this work. Membership EC2Y 5DN
of IAQM is mainly drawn from practising air quality professionals
working within the fields of air quality science, air quality
T: +44 (0)20 7601 1920
assessment and air quality management.
E: info@the-ies.org

Date: October 2018

Cover image: Tolu Olubode | Unsplash

IAQM Guidance on Air Quality Monitoring in the Vicinity of Demolition and Construction Sites 3
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Construction Dust Monitoring

1. Introduction
1.1 Constructing buildings, roads and other infrastructure can
have a substantial, temporary impact on local air quality. The
most common impacts are increased particulate matter (PM)
concentrations and dust soiling. Depending on the risk of dust
effects occurring, monitoring may need to be carried out during
both demolition and construction activities to ensure that the
applied mitigation measures are effective in controlling dust
emissions, and that there are no significant impacts on the
surrounding environment.

1.2 This guidance on air quality monitoring in the vicinity of

demolition and construction sites provides an update to the
2012 IAQM publication, and takes into account new research,
feedback from users of the 2012 Guidance, and advances in
monitoring technology. The guidance will continue to be updated
as knowledge and experience expands. This guidance has
been produced as a result of the voluntary contribution of the
members of a Working Group, for which IAQM is very grateful.

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2. Background
2.1 Environmental Impact Assessment (EIA) requires the 2.3 This guidance is based on the most up-to-date information
consideration of any impacts associated with the demolition/ available and draws upon the practical experience of the Working
construction phase of a proposed development. Such Group members, and other contributors, over many years.
considerations are also frequently incorporated into a variety
of other air quality assessments. These assessments often need 2.4 This guidance is not intended to be prescriptive with regard
to consider the role of air quality monitoring within the package to the various monitoring techniques that can be used, but
of mitigation measures that is proposed, and such monitoring instead aims to highlight the advantages and disadvantages of
proposals are frequently incorporated into planning conditions each, in order to assist in the selection of the most appropriate
or s106 legal agreements1. method. Where reference has been made to commercially-
available samplers, this is intended to provide additional
2.2 This document provides updated guidance on PM and dust guidance on the method and represents no endorsement or
monitoring in the vicinity of demolition and construction sites. recommendation by IAQM.
It takes account of recent evidence related to Site Action Levels
and quality assurance / quality control procedures that should 2.5 This guidance is focused on monitoring concentrations of
be applied to the operation of certain types of monitoring particulate matter and dust deposition. No consideration is
equipment. It also takes account of feedback from users of the given to measurement of concentrations of other pollutants,
2012 Guidance, and new types of monitoring equipment that are such as nitrogen dioxide, around construction sites, although
now available to the marketplace. It should be read and applied emissions of NOx from these sites may represent an important
in conjunction with the Guidance on the assessment of dust source in urban areas.
from demolition and construction that was published by the
IAQM in February 2014, and specifically Mitigation Measures 9
to 12 that are related to Monitoring.

1
A legal agreement between the local authority and the developer; also known as planning obligations; s106 agreements are drafted when it is considered the
development will have significant impacts that cannot be moderated by conditions attached to the planning approval.

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3. Methodology
3.1 This IAQM guidance has been developed through an on-going as was reasonably possible. As such, this document represents
dialogue within the IAQM and a Working Group established to a recommended approach to monitoring in the vicinity of
develop draft guidance. Suggestions on what should be in the construction sites. It was developed through a collaborative
guidance have been solicited from the Working Group. process involving the Institute of Air Quality Management’s
professional membership.
3.2 Once consensus within the Working Group had been
achieved on the major issues, the guidance was circulated to
IAQM members for their comments, and these comments
have been taken into consideration, and incorporated as far

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4. Approaches to Monitoring Dust

4.1 The approach used to devise an air quality monitoring to fulfil all of these objectives, in all situations. For example,
strategy for a specific construction site should be commensurate quantitative monitoring is not likely to be required on all sites.
with the risk category (“negligible”, “low risk”, “medium risk” Careful consideration of the objectives will assist in devising
or “high risk”) assigned to each of the four potential activities the appropriate monitoring strategy, including the choice of
(demolition, earthworks, construction and trackout) identified monitoring method, the number and location of monitoring
within “STEP 2” of the 2014 IAQM Guidance on the assessment sites, the duration of monitoring, the requirements for a baseline
of dust from demolition and construction, version 1.1. survey, and whether the monitoring sites should remain in a
static position throughout the construction works. In all cases,
4.2 It is possible that different risk categories may be assigned there should be a “nominated representative” responsible for
to different site activities (e.g. “high” risk during demolition, and the dust monitoring surveys, who is a member of the Principal
“low” risk during construction). In addition, on large construction Contractors team.
projects, where the work is carried out in distinct phases, different
risk categories may also be assigned to these different phases. 4.5 In the majority of cases, the principal purpose of the
In such circumstances it may be appropriate to apply different monitoring will be to ensure that the mitigation measures are
air quality monitoring strategies as the works proceed in each effective and to flag up incidents where additional measures,
phase or stage of the works, but considerable care will need or temporary cessation of works, is necessary. Such monitoring
to be taken to ensure that the appropriate monitoring is also provides an important body of evidence on the actual
carried out at the correct time. For this reason, in many cases, impact of site emissions during any reporting of complaints;
it may be deemed more practical, and precautionary, to assign such evidence is likely to beneficial to both the local authority
the highest risk category to the entire period of site works. and the site operator.

Purpose of Air Quality Monitoring 4.6 In other cases, where the construction site is large, the
duration of the works is long, and there are a substantial number
4.3 It is essential to give full and proper consideration to the of sensitive receptors in close proximity to the works, it may
purpose of monitoring during the construction works before any prove necessary to demonstrate that the site emissions do not
strategy is finalised. Monitoring may be carried out in order to contribute to exceedances of the air quality objectives; this has
fulfil a number of objectives2 : important implications in the choice of monitoring methodology
(discussed later in this Section).
• To ensure that the construction activities do not give rise
to any exceedances of the air quality objectives for PM10 Qualitative Monitoring Surveys
and/or PM2.5, or any exceedances of recognised threshold
criteria for dust deposition/soiling;
4.7 At all sites, an inspection for visible dust emissions in
the vicinity of the site boundary (internal and external) should
• To ensure that the agreed mitigation measures to control be conducted at least once on each working day. The results
dust emissions are being applied and are effective; of this inspection should be clearly recorded in a clear and
unambiguous manner.
• To provide an “alert” system with regard to increased
emissions of dust, and a trigger for cessation of site works 4.8 Visual monitoring is likely to involve observation of dust
or application of additional abatement controls; deposition onto a surface and dispersion on and off-site. Whilst
such observations are necessarily influenced by subjective
• To provide a body of evidence to support the likely opinion, the approach is simple to implement, and can be used
contribution of the site works in the event of complaints; and effectively to minimise problems occurring. The monitoring
involves observing both the conditions likely to lead to dust
• To help to attribute any high levels of dust to specific
release (weather and nature of construction activity) in addition
activities on site in order that appropriate action may
to the observation of any effects. Visual monitoring for dust
be taken.
will therefore also include perception of the potential for dust
4.4 These objectives are not mutually exclusive, and in some release and be associated with procedures likely to be described
cases they are complementary; however, it may not be necessary in a Dust Management Plan (DMP) or Construction Environmental

2
Some processes, such as mobile crushing and screening, may be subject to specific guidance for emissions limits and related dust monitoring requirements.
These requirements can be found in the relevant Process Guidance Notes and are not covered within this Guidance.

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Box 1: Directional or deposited dust monitoring – which approach to take?

In theory, passive (unpowered) dust monitoring is quite straightforward. The common methods are used to sample directional
dust (i.e. dust flux) or deposited dust (i.e. dust fall). The instruments are generally quite simple to install and operate. The
samplers don’t require a power source and can generally be left unattended for days, or even weeks, between servicing. But
their apparent simplicity can disguise an important consideration: what method to use, where and why?

There is a range of passive directional and deposited dust sampling methods. No method is perfect and all have advantages
and disadvantages. It is important to appreciate some of the key differences between them and their suitability for the task
when recommending compliance values, designing dust management and monitoring schemes, or evaluating data.

Essentially, dust flux represents the horizontal passage of dust past a point (e.g. between source and receptor) while dust in
deposition represents the vertical passage of dust to a surface (e.g. dust fall at a receptor). Accordingly, a directional (flux)
gauge cannot automatically be used to show what the impact could be at an off-site receptor, whilst a deposition gauge
cannot automatically be used to show where the dust at a receptor originated from. A directional gauge can be used to
indicate the potential source, or sources, of dust (i.e. whose dust is it?), whilst a depositional gauge can be used to indicate
its accumulation (i.e. how much is there?).

Many operators recognise the importance of measuring dust emissions from construction and demolition sites. Where
appropriate, the site operator will pay for (or contribute to the cost of) a dust monitoring programme. However, it can be
difficult to justify provision of passive dust monitoring equipment beyond the site boundary especially if there is a risk that it
cannot realistically be used to discriminate between dust from the site in question and from other sources (e.g. roads, arable
farmland, industrial premises or other construction and demolition sites) or where there is a risk of tampering or interference
with it. Consequently, there is a potential paradox in developing effective dust monitoring programmes for construction and
demolition sites: how to measure, and properly attribute, dust impacts from a site upon the community beyond?

At some sites, the boundary is so close to adjacent receptors that, for all intents and purposes, any dust monitoring method
on it can be effective. In such cases, the site boundary can be considered a receptor in its own right – a proxy for an off-site
receptor. But at other sites, the choice of sampling equipment, and the setting of appropriate compliance values, is much
more critical and requires careful consideration.

Management Plan (CEMP) for the site. Observations should always Visual assessment of any dust release
be recorded in a site log.
4.11 In its most basic form, this assessment will simply involve
Monitoring for conditions likely to the nominated representative surveying the site for evidence
increase the risk of dust release of dust release. This may include, for example, observing the
movement of vehicles, stockpiling and demolition. It should
4.9 There are obvious visual signs that a site will be operating be immediately obvious if such operations are leading to
at an increased risk of dust release. These signs will be related the release of dust emissions and the size and frequency
to: of such releases. Under such circumstances the nominated
representative may need to undertake further mitigation
• Weather (i.e. dry periods with higher wind speeds); and
as defined in the DMP or CEMP for the site. This approach
• Site operations (i.e. activities with increased potential for is well-suited for identifying the occurrence of short-lived
dust release). (acute) dust events and allowing immediate action to prevent
further releases.
4.10 When it is clear that these conditions are occurring, the
nominated representative should increase the frequency of Monitoring of any visible surface soiling
visual assessments of dust release and monitoring of any visible
surface soiling (see below). This is particularly the case if the 4.12 There are likely to be many surfaces on (and around) the
prevailing wind is in a direction towards sensitive receptors. In boundary of a construction or demolition site where it should
some cases there may be an opportunity to modify (or delay) be obvious whether dust is being generated at a level where it
potentially dusty site activities until the risk has reduced. is leading to visible surface soiling. These may include, but are
not limited to:

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Box 2: Which PM Concentration Metric

Should be Measured?
Some monitoring techniques can only measure one metric
(e.g. PM10 or PM2.5) while others can simultaneously measure
several. It is recommended that priority be assigned to the
measurement of PM10, as emissions of dust from construction
sites are predominantly in the coarser fractions, but where
TSP concentrations are also recorded, these may be useful
in identifying source contributions.

Monitoring of PM2.5 concentrations should not normally be

required (but should be reported where available) unless
measurements for comparison with the air quality objectives
are required. Emissions of PM2.5 will be principally related to
NRMM exhausts. It is recommended that PM2.5 should not
be the primary metric.

• Car bonnets and roofs; or dust deposition/soiling rates around the site at nearby
receptors, although, as noted later in this Guidance, this
• Windowsills; and may have resource implications, and an approach based on
continuous PM monitoring may be preferred.
• Street ‘furniture’ (such as lampposts and traffic bollards).
For high risk sites, it will normally be necessary to
4.13 There is also the potential to establish “on-site” surfaces
supplement the monitoring for medium risk sites with
within the site boundary (e.g. a polished sheet of metal) on
monitoring of ambient particulate matter concentrations
which dust deposition may be observed.
(see Box 1 and Box 2).
4.14 Where such visual inspections are carried out,
consideration will need to be given to the periods of time over
Air Quality Monitoring Techniques
which dust can accumulate, and whether the surfaces were 4.16 There are a wide variety monitoring techniques
likely to have been clean before the construction activities available to measure both concentrations of airborne
started. The visual survey should also include access routes particulate matter and dust flux, deposition and soiling
into the site, along which trackout of dust, and subsequent rates. These range from “active” (powered) samplers
resuspension may occur. to measure specific dust fractions (e.g. PM10) to simpler
“passive” (unpowered) samplers that measure dust flux,
Air Quality Monitoring and Risk dust deposition and soiling. Active dust samplers include
Assessment sophisticated, automatic analysers that provide real-time,
high-resolution measurements of airborne particulate
4.15 For negligible and low risk category sites, it should matter concentrations that can be directly compared to the
not normally be necessary to undertake any quantitative air objectives, and other automatic analysers that measure real-
quality monitoring, although in some circumstances it may time concentrations of airborne particulate matter that are
be applicable to undertake occasional surveys (e.g. for TSP or only indicative in comparison to the objectives; there are
for PM10 concentrations) using hand-held monitors during the also non-automatic samplers that measure concentrations
Qualitative Monitoring Surveys as a means of demonstrating of airborne particulate matter (see Box 3). Passive samplers
the efficacy of site controls. An example of the need for include a variety of techniques that can be used to quantify
occasional surveys would be if a site has a low risk status but dust flux and deposition rates, or provide an indication
a lengthy demolition or “high risk” phase; in this instance of dust soiling rates. Some of the most commonly-used
monitoring would be warranted for the high risk phase but techniques are described in more detail in Section 9:
not for the duration of the project. Appendix. The various advantages and disadvantages of
each technique, and the general applicability to construction
For medium risk sites, it should normally be adequate to dust monitoring, is shown in Table 1.
undertake surveys of dust flux over the site boundary, and/

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Box 3: Certification of Analysers and Samplers for the Measurement of Ambient

PM Concentrations
Reference methods

The reference methods for the determination of PM10 and PM2.5 concentrations are set out in EN12341:2014. The reference
methods are based on gravimetric samplers which do not allow continuous online sampling. Defra and the Devolved
Administrations have approved a number of monitoring technologies which are deemed to be equivalent to the reference
methods and can be used in the national network (AURN) to determine compliance with the limit values. These are listed as
“Deemed equivalent by Defra” on the UK-Air website https://uk-air.defra.gov.uk. These instruments can be used to determine
compliance with the air quality objectives, Data Air Quality Indicators and health-based bandings.

Indicative methods

Many types of light-scattering instruments are also available and many of these have been certified by the Environment Agency
under its MCERTS scheme for Indicative ambient particulate monitors. These instruments carry a higher level of uncertainty
than reference-equivalent analysers, and they cannot report concentrations for strict comparison with the objectives.

A list of certified indicative instruments can be found at www.csagroupuk.org/services/mcerts/mcerts-product-certification/

mcerts-certified-products/.

4.17 For those monitoring techniques that require laboratory • Are there reliable meteorological (wind speed and direction)
analysis of samples, this should be conducted by a laboratory that data available that are characteristic of the site? It may be
has appropriate (e.g. UKAS) accreditation for the tests (assuming necessary to set up a local meteorological station at the site.
such accredited tests are available).
4.20 As set out in Table 1, there are other issues that need to be
Selection of Monitoring Techniques carefully considered in selecting the most appropriate monitoring
strategy. For example, whilst methods that measure dust flux
4.18 It is not the purpose of this guidance to be prescriptive in the or soiling can provide a wider site coverage, and are cheaper in
selection of specific samplers or analysers, rather to provide guidance terms of initial set-up costs, they do not provide information in
on the factors that should be taken into account in choosing an real time (so that immediate action cannot be taken to rectify
appropriate technique that will meet the defined objectives. problems) and they are more resource-intensive.
4.19 When quantitative monitoring is necessary, the important Baseline Monitoring
questions that need to be asked in selecting the appropriate
monitoring technique are: 4.21 A period of baseline monitoring prior to the start of
construction activities (including any demolition or site clearance
• Is there a requirement to carry out measurements that can works) may be beneficial. This allows existing conditions to
be directly compared with the objectives? If so, a technique be defined more accurately, and can assist with the setting or
that provides “reference equivalent” concentrations will interpretation of “trigger thresholds”. The longer the period of
usually be needed (see Box 3 and Table 1). Indicative baseline monitoring, the more robust the data will be. Where
instruments (as described in Box 3 and Table 1) may be baseline monitoring is deemed necessary, it will normally be
suitable for demonstrating that the objectives are not being necessary to undertake monitoring for a minimum period of three
exceeded, where measured levels are well below the criteria, months, but careful consideration should be given to seasonal
but it is not possible to determine a threshold for this; variations; for example, a period of baseline monitoring carried
out for three months during a wet, winter period, is unlikely to
• Is there a requirement to carry out real-time monitoring
provide a robust baseline for construction activities carried out
of PM concentrations? If so, an automatic analyser will
during a subsequent hot, dry summer. Under such circumstances,
be required;
the applicability of baseline monitoring will need to be carefully
• Is there access to electrical power and secure sites? Suitable considered and justified. Where baseline monitoring is conducted,
arrangements to provide additional power and security may it should be carried out using the same techniques and same site
be required; and locations as identified for the main study.

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4.22 Baseline monitoring is only likely to be required where of power supply, security and access) to locate the sampling
there is a specific need to determine site-specific Site Action equipment at the construction site boundary. Care should be
Levels, or where there are specific sensitivities with regard to taken to ensure that mains power supplies are available on a
exceedances of the objectives. continual and reliable basis.

4.23 In most situations, baseline monitoring may not be 4.28 Where monitoring is required to measure compliance with
required, e.g. in some urban areas where there is a large the air quality objectives, it is essential that a “reference equivalent”
existing body of monitoring data (and where these sites are method be used (see Box 3; Table 1; and para 4.19). Under such
expected to continue to operate throughout the duration circumstances, it will also be more appropriate to site the monitoring
of the construction works). In other situations it may not be station(s) close to the sensitive receptors3 (where the air quality
practicable to carry out baseline monitoring, e.g. if the risk objectives apply) rather than directly at the site fenceline. Potential
assessment determines that monitoring need only be carried contributions from other (non-site) dust sources (such as roads or
out during a short-duration activity of the works (such as other dusty activities in the area) should be taken into account as
demolition, which may only extend over several weeks). it is important that responsibility for the exceedance of Site Action
Levels (or objective) is allocated appropriately.
4.24 In circumstances where monitoring is only required for
the later stages of the construction works (e.g. the demolition 4.29 The number of monitoring sites that can be practically
and earthworks activities are classified as “low risk”, while established will normally be influenced by the technique that
the construction activities are classified as “high risk”) the is to be used. Where monitoring of PM concentrations is to
baseline monitoring may need to be undertaken before any be carried out, a minimum of two sampling sites should be
site works commence. established; these may be located upwind and downwind of
the site, but in complex urban areas this may be difficult to
Selection of Monitoring Locations determine; in such cases, siting of samplers at opposite sides
of the site, selected with regard to sources and receptors
4.25 In the selection of monitoring locations, a number of issues should be applied. Such an approach allows analyses of
need to be taken into account, including a decision on the number
source contributions to be carried out if necessary (e.g. when
of sites that are to be established, whether they are to remain in
trigger thresholds are exceeded) particularly if wind speed and
a permanent position throughout the entire construction works,
direction data are available, and also allows for coverage during
and whether monitoring is required for direct comparison with
variable weather conditions. Other considerations include
the objectives. There are a number of practical issues that also
the proximity of the closest sensitive receptors to the site
must be considered, such as the availability of electrical power,
boundary, and additional sites may be required to ensure there
access to the monitoring sites, and security.
is adequate coverage over all meteorological conditions. In
4.26 Care needs to be taken with regard to the microenvironment some circumstances it can also be useful to establish additional
in positioning of samplers. For example, sampler inlets should sites along a transect. Data from these additional sites are
be located in a clear, unobstructed position, and some metres useful in assigning source contributions (as the contribution of
away from any large structures (such as walls of buildings) that site dust emissions will fall off with increasing distance from
might interrupt airflow; immediately above should be open to the site boundary).
the sky (free in an arc of at least 270°), with no overhanging trees
4.30 Where local meteorological data are not readily available,
or other structures. To measure airborne dust concentrations,
consideration should be given to installing appropriate wind
the sampler head should ideally be located between 1.5 to 4m
speed and direction sensors at the site. Care should be taken
above ground level as suggested in the 2008 Ambient Air Quality
to ensure that the sensors have a clear and unobstructed air
Directive (2008/50/EC). Examples of good and poor siting of
flow around them. For large or long term sites, consideration
samplers is provided in Section 9: Case Study.
should be given to installing a meteorological station capable of
4.27 In most circumstances, the principal aim of monitoring recording wind speed, direction, humidity and rainfall.
will be to ensure that the agreed mitigation measures are being
4.31 Where monitoring for dust deposition or dust soiling rates is
effectively applied, and that impacts upon the local community
conducted, a minimum of two sites (upwind and downwind of the
are minimised. In such circumstances, monitoring at, or close to,
site, in relation to the prevailing wind) should be established based
the site boundary is recommended as this will record the highest
on the approach described above, but it is always useful to establish
dust emissions. It is also usually more convenient (for reasons
additional sites around the site boundary (and, as described above

3
Samplers may be located directly adjacent to sensitive receptors, or for practical reasons (security, power etc.), at locations which are representative of
sensitive receptors – the latter are sometimes referred to as “proxy receptors”.

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along a downwind transect), and (where applicable) to collocate

PM analysers and dust deposition gauges. For measurement of
dust flux across a site, three samplers may be required in order to
enclose the site boundary. As above, the location of the closest
sensitive receptors may dictate that additional monitoring sites
are included to ensure there is adequate coverage.

4.32 For construction works that extend over a long period, the
work may be carried out in different phases (and as discussed above,
different risk categories may be assigned). In this case, the monitoring
locations may remain unchanged throughout the duration of the
works, or may be relocated as the phasing progresses. There are
potential advantages and disadvantages with both approaches:

• If the sampling locations are relocated, there may be

substantial “downtimes” when the equipment is moved and
re-commissioned (particularly when power supply is required),
and equipment may potentially be damaged, but with careful
planning, such issues can be avoided; and

• If the sampling locations are not relocated:

1. monitoring during some stages of the works may be some

considerable distance from the dust-raising activities and
may not provide adequate information on maximum levels
at the site boundary, or risks of exceedances at off-site
receptors; and

2. as phases of the works proceed, new sensitive receptor

locations may introduced within close proximity to the
revised site boundary.

4.33 It is important that the phasing of the work be

adequately considered, and appropriate monitoring strategies
be implemented to address the above issues.

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Table 1: Summary of advantages and disadvantages of principal dust monitoring techniques

Technique Advantages Disadvantages Applicability for

Construction Site
Monitoring
Airborne particulate matter
TEOM-FDMS Analyser Provides continuous real- Very high capital and Unlikely to be applicable
time data with <1-hour time operational cost. Requires in most situations due
resolution. electrical power and site to cost and stringent
security, careful servicing operational requirements.
Demonstrated to be and maintenance. May be appropriate
equivalent to the reference for very sensitive sites
method (certain versions Experience has where demonstration
only) and concentrations demonstrated that of compliance with the
can be directly compared considerable care needs to objectives is critical.
with the objectives. be taken with instrument
operation and subsequent
data ratification.

Individual analysers may

only measure PM10 or PM2.5
depending on size selective
inlet. Dichotomous
versions are also available
to measure PM2.5 and PM10
concurrently.
TEOM Analyser (without Provides continuous real- Relatively high capital and Unlikely to be applicable
FDMS) time data with 15-miniute operational cost. Requires in most situations due
time resolution. Data can electrical power and site to cost and operational
be corrected for loss of security, careful servicing requirements. May be
semi-volatile material using and maintenance. appropriate for very
the VCM approach (http:// sensitive sites where
www.volatile-correction- Individual analysers can demonstration of
model.info/) to provide only measure PM10 or PM2.5 compliance with the
concentrations that can depending on size selective objectives is desirable.
be compared with the inlet.
objectives.
Beta-attenuation Analysers Provides continuous real- Relatively high capital and Unlikely to be applicable
time data with 1-hour time operational cost. Requires in most situations due
resolution. electrical power and site to cost and operational
security, careful servicing requirements. May be
Demonstrated to be and maintenance. appropriate for very
equivalent to the reference sensitive sites where
method (some instruments Individual analysers can demonstration of
only – see Box 3) and only measure PM10 or PM2.5 compliance with the
concentrations can be depending on size selective objectives is critical.
directly compared with the inlet.
objectives.

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Table 1 Continuation: Summary of advantages and disadvantages of principal dust monitoring techniques.

Technique Advantages Disadvantages Applicability for

Construction Site
Monitoring
Palas FiDAS 200 An optical particle counter Relatively high capital and Unlikely to be applicable
that can measure several operational cost. Requires in most situations due
particle fractions including electrical power and site to cost and operational
PM10 and PM2.5 at the same security, careful servicing requirements. May be
time. Demonstrated to and maintenance. Results appropriate for sensitive
be reference equivalent for unusually heavy or light sites where demonstration
(depending on specific particles may differ from of compliance with the
inbuilt algorithm [PM10] and results obtained with size objectives is critical.
slope correction [PM2.5]). selective inlets.
Instrument can be supplied
in a stand-alone box and so
may have lower capital cost.
Light-scattering monitors These analysers rely on Calculation of PM Analysers can be easily
size selective inlets to concentrations is based deployed at the site
determine the particle upon assumptions about boundary. Real-time
size measured and as such particle characteristics monitoring provides
can only measure one size which may vary from place information on
fraction at a time. to place and from time to effectiveness of mitigation
time, and may be subject measures. Minimal
Relatively lightweight, to “artefacts” Interference requirement for routine
portable and may during foggy conditions servicing and maintenance
be battery operated. may be seen on unheated beneficial to construction
Easily attached at site systems. Concentrations site environments. They
boundary. Relatively low only indicative with regard can be used to identify any
cost (compared to other to the objectives. May periods of unexpectedly
automatic analysers). requires power and site high levels of dust.
Requires little routine security.
servicing and maintenance.
Can be used to provide
real time alters of potential
exceedances
Optical Particle Counters These analysers have the Calculation of PM Analysers can be easily
ability to measure several concentrations is based deployed at the site boundary.
size fractions simultaneously upon assumptions about Real-tim e m o nito ring
(TSP, PM10 and PM 2.5) and particle characteristics provides information on
continuously. Individual which may vary from place effectiveness of mitigation
particles are counted and to place and from time to m e a s u re s . M i n i m al
classified by size. Several size time and may be subject requirement for routine
fractions may be available to “artefacts” Interference servicing and maintenance
and some will also output during foggy conditions beneficial to construction
particle numbers. This may be seen on unheated site environments. They
additional information can be systems. Concentrations can be used to identify any
useful in identifying sources. only indicative with regard to periods of unexpectedly high
the objectives. May require levels of dust.
power and site security.

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Table 1 Continuation: Summary of advantages and disadvantages of principal dust monitoring techniques.

Technique Advantages Disadvantages Applicability for

Construction Site
Monitoring
Filter-based gravimetric One sampler has been Considerable care needs Unlikely to be applicable in
samplers demonstrated to be to be taken with filter most situations. Although
equivalent to the reference selection, storage and some sampler types are
method (Partisol 2025) handling, and with QA/ small and battery powered,
and concentrations can be QC procedures for filter they do not provide real-
directly compared with the weighing. time information, and
objectives. are resource-intensive to
High operating costs operate.
Other samplers (e.g. and intensive resource
MiniVol) are relatively small requirements.
and battery powered, and
can be easily deployed, Time resolution of
but are not reference measurement limited
equivalent. to 24h, and results not
available in real-time.
Hand-held samplers Provide real-time There may be problems Information from hand
information for several size with the detection limit held samplers useful for
fractions simultaneously. of some sampler types. application at some low-
Can be easily deployed for Concentrations only risk sites, and at other sites
walk-over surveys to check indicative. to supplement information
effectiveness of mitigation gathered from permanent
measures. monitoring.
Dust Deposition, Dust Flux and Soiling
Deposit gauges (e.g. Frisbee Relatively low cost. Can Requires subsequent Provides useful information
Gauge) be easily deployed on laboratory analysis of to supplement monitoring
site. Requires no electrical particle mass. Time of PM concentrations (at
power. Can be deployed resolution limited to high risk sites). At other
with other gauges (e.g. several weeks or longer, and sites, provides an indication
sticky pads). cannot provide information of potential loss of
on short-term events. amenity and effectiveness
“Custom and practice” of mitigation measures,
trigger thresholds based although time resolution of
on relatively historic data, monitoring is a significant
and no account taken of disadvantage.
particle colour.

These do not show the

direction of travel so there
is the possibility that results
can be confounded if there
are neighbouring projects.
Resource intensive.

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Table 1 Continuation: Summary of advantages and disadvantages of principal dust monitoring techniques.

Technique Advantages Disadvantages Applicability for

Construction Site
Monitoring
Sticky Pads Relatively low cost. Can Require subsequent Provides useful information
be easily deployed on laboratory analysis of to supplement monitoring
site. Requires no electrical EAC% and or AAC%. Time of PM concentrations
power. Measurement of resolution limited to one (at high risk sites). At
EAC takes account of week (or longer), and other sites, provides an
particle colour. Directional cannot provide information indication of potential
sticky pads can be used to on short-term events. loss of amenity and
quantify dust flux. Exposed Resource intensive. effectiveness of mitigation
pads can be analysed measures, although time
subsequently to determine resolution of monitoring is
the chemistry and/or a disadvantage.
morphology of individual
particles.
Dust Soiling Gauges (e.g. Relatively low cost. Can Require subsequent Provides useful information
glass slides) be easily deployed at large laboratory analysis of to supplement monitoring
number of sites. Requires dust soiling rates. Time of PM concentrations
no electrical power. resolution limited to one (at high risk sites). At
week (or longer), and other sites, provides an
cannot provide information indication of potential
on short-term events. loss of amenity and
These do not show the effectiveness of mitigation
direction of travel so there measures, although time
is the possibility that results resolution of monitoring is
can be confounded if there a disadvantage.
are neighbouring projects.
Resource intensive. May be
subject to under reading
due to “wash-off” of non-
adhered particles

Operation, Data management and QA/ • Equipment maintenance and servicing should be carried out
according to manufacturer’s recommendations;
QC Procedures
4.34 It is essential that suitable and adequately documented • All site servicing should be carried out by appropriately
procedures are applied to all construction site monitoring that trained staff, and records should be kept of all service visits.
is conducted. This should cover the operation of the sampling Site service records from every visit should be provided to
equipment, data management, and Quality Assurance/Quality the data managers as soon as possible, and flow checks
Control (QA/QC). These procedures should be undertaken by should only be conducted with calibrated rotameters;
appropriately qualified and experienced personnel.
• Data verification and ratification for PM concentration
4.35 Guidance on the general principles for operation, data data should be carried out by appropriately trained and
management and QA/QC has been provided by Defra4, and is experienced personnel; and
not reproduced in full within this document. Specific regard
will need to be given to the following: • Arrangements for sample handling, storage and transport

4
Local Air Quality Management Technical Guidance LAQM.TG16 – Chapter 7, Part 2

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should be documented and suitable to avoid sample • Regular download and calibration of data to ensure that
contamination or loss. the instrument is fully operational; and

4.36 In addition to guidance issued by Defra, King’s College has • Routine, between-instrument calibrations to assess for
recently completed a research project to evaluate construction consistency over time, and to identify outlier performance.
site monitoring strategies, with specific focus on the performance This can be achieved by non-working day comparisons.
of light-scattering indicative analysers5. In particular, the
importance of controlling the water content of the aerosol by 4.37 These recommendations are fully endorsed by the
heating was noted to be especially important. In addition, there Working Group that drafted this IAQM Guidance, and should
can be issues with long-term drift due to progressive dirtying be incorporated into all construction dust programmes that use
of optics and clogging of sample flow controls. Basic steps to light-scattering indicative samplers.
maximise data quality were noted to be:
Site Action Levels
• Good quality siting with free movement of air around the 4.38 It is common practice to set Site Action levels for PM
inlet, and clear lines of sight to sources of dust emissions; concentrations and/or dust deposition/flux/soiling rates, as
a mechanism to ensure that dust mitigation measures are both
• Correct configuration of instruments, with specific attention
adequate and are being applied correctly. It can be useful practice
given to ensure that the sample inlet is heated to reduce
for site operators to sign up to daily pollution forecasts so they
interference from water vapour and secondary PM;
become aware if moderate or high PM levels are likely; in these
• Regular visits to change filters and adjust flows as necessary, events additional mitigation may be applied.
and to assess the site environs to ensure that the monitor
4.39 Historically, a Site Action Level of 250 µg/m3, measured as a
and sampling location are fit for purpose;
15-minute mean PM10 concentration, has been widely adopted and
• Regular servicing (according to manufacturer’s this was cited in the 2012 IAQM Guidance. However, this metric
recommendations), either on site or at base, so that cleaning was founded on quite limited data, and was based on a study
and recalibration can be carried out; carried out by King’s College on measurement data collected

5
Fuller, G et al (2016) Implications for construction site monitoring strategies, King’s College London.

IAQM Guidance on Air Quality Monitoring in the Vicinity of Demolition and Construction Sites 17
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Table 2: Site Action Levels for Sticky Pads With Combined EAC/AAC

AAC: Dust Coverage

EAC: Dust Soiling Level 0 Level 1 Level 2 Level 3 Level 4

<80% / 80-95% / 95-99% / 99-100% / 100% over

interval interval interval interval 45° / interval

Level 0 Very Low Very Low Very Low Low Medium

<0.5%/day
Level 1 Low Low Low Medium High

0.5-0.7%/
day
Level 2 Medium Medium Medium High High

0.7-2.0%/
day
Level 3 High High High High Very High

2.0-5.0%/
day
Level 4 Very High Very High Very High Very High Very High

>5.0%/day

As proposed by Datson (2010) and included in AEA (2011)

at Marylebone Road during 1999-2001, and the operation of a • Dust Deposition

single construction site.
{{ Frisbee-type Deposition Gauges: 200 mg/m2/day,
4.40 A more recent report by King’s College has evaluated averaged over a 4-week period
measurement data from nine construction sites . The monitoring
was based on reference-equivalent samplers, and the analysis {{ Glass Slide Deposit Gauges: 25 soiling units (su) per
included 1.8 million data points. The outcome of this research week, measured as a running 4-week average
recommends a Site Action Level of 190 µg/m3, measured as a
{{ Sticky Pads: 5% EAC/day, measured over a 1-week
1-hour mean. This recommendation has been reviewed and
period
is fully endorsed by the Working Group that has drafted this
IAQM Guidance. • Dust flux
4.41 The Site Action Levels set out below are recommended. {{ Sticky pads where both EAC and AAC are measured
These will be reviewed in the future as additional information over a 1-week period as shown in Table 2 below. It is
becomes available. suggested that a Site Action Level is “High” or above.
• PM10 Concentrations: 190 µg/m3 averaged over a 1-hour
period

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Further Reading
AEA (2011). Management, mitigation and monitoring of Defra (2016). Local Air Quality Management: Technical Guidance
nuisance dust and PM10 emissions arising from the extractive (TG16).
industries: an overview. Didcott: AEA Technology plc (AEAT/
ENV/R3141 Issue 1). Font, A and Fuller, G (2016). Re-assessment of the 250 µg m-3
action value: Work Package 1 – Testing PM10 trigger values at
BRE (2003). Controlling particles, vapour and noise pollution
construction sites. King’s College London.
from construction sites - set of five Pollution Control Guides.
Available to purchase from: http://www.brebookshop.com/ Fuller, G et al (2017). Re-assessment of the 250 µg m-3 action
details.jsp?id=144548. value: Work Package 5 – Recommendations for operational air
quality standards.
Environment Agency (2004). Monitoring of particulate matter in
ambient air around waste facilities: Technical Guidance Document
(Monitoring) M17 [online]. Available from: http://publications.
environment-agency.gov.uk/PDF/GEHO1105BJXU-E-E.pdf.

Environment Agency (2011). Technical Guidance Note (Monitoring)

M8: Monitoring Ambient Air [online]. Available from: http://
publications.environment-agency.gov.uk/PDF/GEHO0611BTYA-
E-E.pdf.

IAQM (2014). Guidance on the assessment of dust from

demolition and construction. Available at iaqm.co.uk/guidance.

IAQM Guidance on Air Quality Monitoring in the Vicinity of Demolition and Construction Sites 19
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5. Glossary of Terms
AAC% Absolute Area Coverage The “total” dust PM Particulate Matter
coverage on the sample surface, determined as pixels having
a lower greyscale value than a reference value in a computer- PM10 Particulate matter suspended in ambient air which
scanned image of a “sticky pad” sample as a % of total area. passes through a size-selective inlet with a 50% efficiency cut-
off at 10 µm aerodynamic diameter.
BPG Best Practice Guidelines
PM2.5 Particulate matter suspended in ambient air which
CEMP Construction Environment Management Plan. passes through a size-selective inlet with a 50% efficiency cut-
off at 2.5 µm aerodynamic diameter.
DMP Dust Management Plan; a document that describes the
site-specific methods to be used to control dust emissions. Receptor Location Locations at which dust emissions
from construction activities may have an impact. “Sensitive
Dust Solid particles that are suspended in air, or have receptors” are those receptor locations which may be particularly
settled out onto a surface after having been suspended in air. sensitive to dust impacts (e.g. residential properties etc.). “Proxy
The terms dust and particulate matter are often used fairly receptors” are monitoring locations identified to represent
interchangeably, although in some contexts one term tends to sensitive receptors (for reasons of security, access to power etc.).
be used in preference to the other. In this Guidance the term
“dust” is used to define the particles that may give rise to soiling Reference Samplers Reference methods for the
and to human health and ecological effects. NB: this is different determination of PM10 and PM2.5 are set out in EN12341:2014.
to the definition of “dust” given in BS 6069 Part 2, where dust Defra and the devolved administrations have also approved
refers to particles up to 75 µm diameter. a number of “reference-equivalent” samplers. Only reference
or reference-equivalent instruments can be used to determine
Dust Deposition Rate of dust fallout to a nominally compliance with the air quality objectives, and for comparison
horizontal surface, most usually quantified in terms of mg/m2/ with the Daily Air Quality Index or other health-based bandings.
day in the nominally vertical plane. Normally associated with
measurements conducted using non-directional (deposition) Site Action Levels Threshold above which further
samplers. Dust deposition may also be measured in terms of investigation or action is instigated. This may involve a more
“dust soiling” (see EAC% and Soiling Units) detailed assessment of the monitoring data to determine
the likely contribution of the construction site activities to
Dust Flux The rate of passage of dust on the pathway the threshold exceedance, investigation of site activities and
from emission source to receptor i.e. the horizontal component mitigation, or if appropriate cessation of the works.
of wind-blown dust. Normally associated with directional (flux)
samplers. Although dust flux may be expressed by the same Soiling Units (su) Determined using a gloss meter as the
metric as dust deposition (mg/m2/day), the two are not directly loss of reflectance at 45° to the surface of a glass microscope
comparable or interchangeable. slide. It is normal to express this as a “soiling rate”, e.g. su/
week.
EAC% Effective Area Coverage “ D u st soiling
“ determined by the loss of reflectance using a smoke stain TSP Total Suspended Particulate matter. A term describing
reflectometer, or as a relative difference in greyscale of pixels the mass of airborne particles in ambient air that is measured
in a computer-scanned image of a ”sticky pad” sample. without a size-selective inlet. Includes particles across a wide
range of sizes, approximately in the range <50-100 µm.

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6. Case study: Barts and London NHS

Background The main features of the monitoring protocol are:
Barts and the London NHS Trust sought to upgrade their estate
through the demolition of existing buildings and subsequent It recognises that there is a need to provide evidence
provision of state of the art facilities as provided through a throughout the period of demolition and construction
Public Finance Initiative (PFI). The Trust was required to continue work to ensure that levels of dust at the site are no worse
operating as normal through the entire duration of the demolition than currently exists. This approach acknowledges the
and re-build programme, which was anticipated to take place urban setting of the Royal London in an existing Air Quality
over 10 years’. Management Area, where problems in the attainment of air
quality objectives are known to exist;
The challenge
Concern was expressed by the Trust in relation to patient It recognises the need to monitor the likely occurrence
care and health during the occurrence of demolition and of annoyance in and around the site, in respect of larger
construction where the propensity for uncontrolled dust particles that may be deposited to sensitive locations during
releases was high, particular where works were in close the course of construction work;
proximity to the hospital wards. The aged brick work of some
of the estates had additionally highlighted the potential for It recognises the need to monitoring the potential impact on
Aspergillus spore release. health of the patients located on wards that are maintaining
full operation during the course of the re-development of
The Solution the site;
Mitigation measures were deployed at the sites which sought
to reduce the occurrence of uncontrolled emission releases It recognises the concerns expressed by The Trust in respect
associated with demolition and construction activities. A of ‘other contaminants’ likely to be present at site. Notably,
monitoring programme was implemented which sought to the occurrence of Aspergillus spores arising from demolition
provide the necessary evidence to the contractor – SKANSKA activity, which forms part of the PM10 fraction;
– that mitigation measures were being effective in their
It recognises the need for (almost) real-time information on
suppressing ability.
PM10 occurrence at the site;

Stringent Criteria It recognises the need to undertake simultaneous

The adoption of site-specific criteria was based on frequency measurements on wind speed and wind direction to facilitate
of occurrence of 15-minute average concentrations derived interpretation of data at the site;
from 4 months on-site baseline data and the application
deviations from the maximum value of 15-minute average data It recognises the need to separate the impacts of secondary
(at 100 µg/m3) in steps of 10 units for single occurrence and formation of particles arising from transportation of wider
two consecutive occurrences. This was found to be far more emissions (such as transboundary European episodes)
stringent that default adopted thresholds of 200 – 250 µg/ from those related to the impact of primary emissions (i.e.
m3, and aligned well with the need for additional vigilance in construction activities) at the site;
the hospital environs. Analysis sought to identify the potential
It provides a basis on which The Trust can further react to
for thresholds to lead to a cessation of works and subsequent
determine any possible danger to patients on operational
investigations into the reasons for the alert, which would heavily
wards resulting from the possible occurrence of Aspergillus
influence the overall programme of works relative to the need
spores arising during periods of demolition.
for environmental diligence. That is, too many interruptions to
the programme arising from alerts and the financial penalties
would be too great set against the need to ensure that air
quality remained within safe thresholds for assurance to the
NHS Trust the patient health was not compromised.

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Construction Dust Monitoring Case study

On the basis of the frequency of the following threshold alert corrected. Triggered alerts were additionally used in respect
values were adopted (inclusive of gravimetric correction): of Aspergillus surveys undertaken when localised dust
releases arose.
Early Warning / Lower Threshold: a single occurrence of
15-minute average > 80 µg/m3 SKANSKA were successful in winning a number of awards for
management of the programme, of which the dust monitoring
Upper Threshold: two consecutive 15-minute averages >80 programme contributed. These included:
µg/m3
City of London Considerate Contractor award 2007
Further procedures were implemented to identify the
separation between locally derived alerts – those directly UK Quality in Construction Awards – Corporate Social
attributed to the programme – and those that were attributed Responsibility award 2008
to regional episodes of PM10, or transboundary European
The UK Sustainable City Awards – Sustainable Procurement
events. In the case of the latter, the programme identified award 2009
successfully the impacts of forest fires in Russia and also
the impacts associated with Saharan dust episodes, both The Constructing Excellence UK Awards – Innovation award
of which were beyond the influence of the contractor and 2009
enabled works to continue without interruption, despite alert City of London Considerate Contractor Environmental Award
thresholds being exceeded. 2010

Success
The monitoring provided a successful means of reducing
interruptions to works for SKANSKA whilst ensuring concerns
of the NHS Trust were addressed. Cessation of works and
subsequent investigations identified where mitigation
measures had temporarily failed and were able to be

The following table provided an analysis of the frequency of occurrence for single events and for two consecutive events:

Month 1 Month 2 Month 3 Month 4

Number of 15-minute averages above

>100 0 2 0 8
>90 4 6 1 19
>80 12 9 6 40
>70 23 21 25 71
Number of 2 consecutive 15-minute averages above
>100 0 1 0 1
>90 1 1 0 3
>80 1 1 1 5
>70 3 4 2 7

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7. Case study: East Parkside, Greenwich

Photo credit: Hugh Datson (DustScanAQ)

Nuisance dust emissions from construction and demolition works With this in mind, DustScanAQ Ltd was commissioned by
are common, with fine particles from these sources capable VolkerFitzpatrick Ltd to prepare a dust management and
of being carried long distances from sites, polluting the local monitoring strategy (DMS) for site redevelopment works at
environment and affecting the health of local residents, as well East Parkside, Greenwich. The works were being undertaken
as those working on the site. for Meridian Delta Ltd (the overall site developer) and
comprised reconstruction and provision of infrastructure prior
In addition to legal health and safety requirements, further to development of individual plots on a brownfield site on
regulations now require local authorities to work towards Greenwich Peninsula.
achieving national air quality objectives and construction site
operators will therefore need to demonstrate that both nuisance The DMS was prepared after consultation with Greenwich
dust and fine particle emissions from their sites are adequately Council’s Environmental Protection team and follows construction
controlled and are within acceptable limits. industry best practice and guidance and Greenwich Council’s
own Noise and Dust Protocols.

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Photo credit: Hugh Datson (DustScanAQ)

Fugitive ‘nuisance’ dust emissions were monitored at five locations To assess the risk of fugitive dust from the site affecting nearby
on the site boundary using DustScan DS-100 directional dust residents, directional ‘arcs of significance’ were determined for
gauges. The DS-100 is a passive (i.e. unpowered) dust sampler, the site as ‘any direction where dust propagation might cross
featuring a ‘sticky cylinder’ to sample dust in flux for subsequent the site boundary’. For this, the dust data was summarised as a
quantification. The directional dust monitoring head collects ‘risk factor’ of potential dust nuisance across the site boundary
fugitive dust from 360° around the gauge to indicate potential in five levels ranging from ‘very low’ to ‘very high’.
dust sources and pathways.
Ongoing dust suppression measures are revised and updated
As recommended by DustScanAQ Ltd, directional dust samples according to site conditions and operations.
were taken over seven day intervals. At the end of the monitoring
intervals, each sampling cylinder is removed and placed in a
protective carrying flask and a replacement head fitted. Used
sampling heads are sent to DustScanAQ Ltd for computer analysis.

Directional dust was reported at 15° resolution as Absolute Area

Coverage (AAC%, the presence of dust irrespective of colour)
and Effective Area Coverage (EAC%, the darkness or potential
soiling of dust). The dust monitoring results were tabulated
and shown as ‘directional dust roses’ to show the magnitude of
AAC% at each monitoring location for each sampling interval.

The directional dust monitoring data can be reviewed in

accordance with the London BPG for ‘sticky pad’ dust monitoring
and are summarised in relation to the DustScan AAC% and EAC%
‘dust nuisance risk matrix’.

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Introduction
Construction Dust Monitoring Case study

8. Case study: Siting monitors for

construction
As the understanding of fugitive dust and emissions from It is common for construction sites to have a minimum of two
construction and demolition activities has increased so monitors located at the site boundary to form a transect across
has the requirement for monitoring around the sites to the site in line with the predominant wind direction, with the UK
reduce the risk of human exposure. The actual locations having a prevailing south-westerly wind through the year. Larger
for the monitoring equipment will always be site specific developments may have a requirement for many more monitors
but should be representative of potential exposure to local in order to give representative coverage across the life of the
residents and people working in the surrounding area as well project. The monitoring locations should be approved by the
as any ‘sensitive receptors’, such as schools and hospitals. local planning authority prior to installation and once agreed
they should not be moved without consultation.

Photo credit: Daniel Marsh (King’s College London)

Deciding on the locations for monitoring should be integral to the larger site plan. This monitor was already installed in a
‘well’ with significantly restricted airflow but it was then further boxed in when the subcontractor placed a shipping container
directly in front of it.

Consumption of Scientific Information and the Open Access publishing debate 25

 IES u REPORT Open Access
IAQM uGUIDANCE
Construction Dust Monitoring Case study

Photo credit: Daniel Marsh (King’s College London)

You should avoid installing monitors in the vicinity of trees. This monitor formed part of a long term measurement campaign
around a major area of redevelopment. It may have been installed during the winter months when there was little or no foliage on
the trees. After being in place for several years it was shielded from the construction activity by the surrounding tree canopy.

There are a few basic guidelines as to where the monitors should The following factors should also be taken into account:
be installed which fall in line with the microscale siting criteria
according to European Directive 2008/50/EC, these include: • interfering sources (including site access gates, mist canons
and water suppression);
• the flow around the inlet sampling probe shall be unrestricted
(free in an arc of at least 270°); • security;

• without any obstructions affecting the airflow in the vicinity • safe operator access; and
of the sampler (normally some metres away from buildings, • availability of a permanent electrical power supply.
balconies, trees and other obstacles and at least 0,5 m
from the nearest building in the case of sampling points
representing air quality at the building line);
There are many interpretations of the advice given above;
• in general, the inlet sampling point shall be between 1.5 m included is a gallery of the good, the bad and the ugly! The images
(the breathing zone) and 4 m above the ground; and used have been taken across a number of construction projects
in London and are not representative of any one developer,
• The inlet probe shall not be positioned in the immediate
contractor or supplier of monitoring equipment and services.
vicinity of sources in order to avoid the direct intake of
emissions unmixed with ambient air.

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Introduction
Construction Dust Monitoring Case study

This monitor was

installed inside
Heras security
fencing along the
site boundary. The
contractor had built
an enclosure to
shield the monitor
from the road but
this also significantly
restricted airflow
around the sample
head.
In this case
moving the
monitor up within
the enclosure
or extending
the length of
the sample inlet
would improve
the airflow around
the inlet.

Photo credit:
Daniel Marsh
(King’s College
London)

Monitors should
be located in clear
unobstructed
positions away
from walls or
buildings.
This monitor has
been installed very
low on the lea
side of a building,
shielded from
all construction
related dust.

Photo credit:
Daniel Marsh
(King’s College
London)

Consumption of Scientific Information and the Open Access publishing debate 27

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Construction Dust Monitoring Case study

If there are no
suitable options
for installing a
monitor at the
location where
it is required it is
possible to create
your own using a
cage, which also
provides a safe
working area for
the operator.

Photo credit:
Daniel Marsh
(King’s College
London)

Another correctly
installed monitor
alongside a busy
construction
access road.
This monitor
is mounted at
approx. 2.7m
to prevent any
interference from
the public or site
workers and has a
level area of hard
standing for safe
ladder access.

Photo credit:
Daniel Marsh
(King’s College
London)

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9. Appendix
Summary of Air Quality Monitoring Methods and then through a drier (to remove water) before entering the
TEOM sensor unit where the PM is collected onto a filter and
There is a wide variety of monitoring techniques available to weighed. The analyser samples in this “base cycle” for 6 minutes,
measure both concentrations of airborne particulate matter and during which time there will be losses of semi-volatile particles
dust deposition/soiling rates. Further guidance on monitoring from the filter. The sample flow then switches so that it passes
methods and the appropriate QA/QC procedures that should through a cooled chamber and then through a filter to remove
be applied, can be found in Defra Technical Guidance LAQM. PM from the sample stream; this cooled, scrubbed air is returned
TG16. Some of the most commonly-used techniques are to the sensor unit. During the purge cycle (which also runs for 6
described below: minutes), volatile particles continue to evaporate from the sensor
unit filter, such that the average PM concentration measured
Airborne Particulate Matter
will normally be negative. The FDMS then adjusts the final mass
Concentrations of airborne particulate matter (TSP or less) concentration by reference to any mass change recorded in the
can be carried out using automatic analysers, that provide purge cycle e.g. if a decrease in mass was measured during the
high-resolution measurements in real-time, or by filter-based purge cycle (which is normally the case) this would be added
gravimetric samplers that normally only provide 24-hour mean back to the base cycle measurement recorded. The analyser has
concentrations, and require laboratory determination of the been declared as equivalent to the European reference sampler
particle mass. for both PM10 and PM2.5 measurements. There are a number of
variants of the TEOM-FDMS; users are advised to visit the UK-Air
Some types of analyser are capable of simultaneously measuring website to check which are reference-equivalent.
different size fractions of particulate matter; other analysers use
a specific, size-selective inlet, and can normally only measure one The TEOM
fraction (although there are dichotomous samplers available) – analyser is based on the principle that the frequency of oscillation
and, of course, more than one analyser can be deployed. For of a glass, tapered tube changes by an amount that is directly
monitoring around construction sites, consideration should proportional to the mass of the tube and attached filter. Thus,
normally be given to measurements of the PM10 fraction. any change in mass, due to deposition of particles onto a small
Measurements of the Total Suspended Particulate (TSP) fraction filter affixed to one end, will result in a change in the resonant
may also be useful in identifying source contributions (as dust frequency which is proportional to the additional mass. Due
emissions from demolition and construction activities are to the need to eliminate the effect of changing humidity on
predominantly in the coarser fractions). the mass measurement, the sample filter is held at 50C. This
results in losses of semi-volatile particles, and the TEOM
These are capable of providing high- systematically under-reads PM concentrations when compared
resolution measurements (typically for 15-min or 1-hr averages, with the European reference sampler, and it is necessary to apply
although shorter period measurements can be made, and may a “correction” to the data. An approach to correcting TEOM
be useful in source identification). The instruments are based data has been introduced involving the Volatile Correction
on a number of widely-differing measurement principles. Some Model (VCM) developed by King’s College. A VCM web portal
instruments have been accredited as equivalent to the European (www.volatile-correction-model.info) is available which allows
reference sampler , and the concentrations can be compared users to download geographically-specific correction factors
directly with the air quality objectives/limit values for PM10 and to apply to TEOM PM10 measurements on either a 1-hour or
PM2.5. Other instruments have no such “equivalence status”, and 24-hour basis. VCM-corrected PM10 data can be considered
the recorded concentrations can only provide an indication as to be “reference equivalent”. It should be noted that PM2.5
to whether the objectives/limit values are likely to be exceeded; concentrations measured using the TEOM cannot be corrected
this is only important where it is necessary to compare the in this way.
measured concentrations directly against the objectives/limit
values. Commonly-available automatic samplers include: These devices sample air
onto a paper tape, and the reduction in the transmission of beta
Based on particles from the start to the end of the sampling period is
the TEOM analyser (see below) the TEOM-FDMS independently recorded to determine the PM concentration. These instruments
measures the volatile component of the air sample. The sample can have both heated or unheated inlets, which perform very
stream passes through the size selective inlet (PM10 or PM2.5) differently. The Met-One Smart Heated BAM is reference-

IAQM Guidance on Air Quality Monitoring in the Vicinity of Demolition and Construction Sites 29
 IAQM u GUIDANCE
Construction Dust Monitoring

equivalent for PM10 after correction for slope, by dividing by 1.035; These samplers, often referred to
the instrument is reference-equivalent for PM2.5 without any as “gravimetric samplers” are based on drawing air through a
need for correction. The Met-One BAM (unheated) is reference- filter for a known length of time, and at a known flow rate;
equivalent for PM10 after correcting for slope (multiplication the filter is then weighed in the laboratory to determine the
factor of 0.833). The Met-One BAM (unheated) is not reference- particle mass. Although simple in theory, weighing of filters is
equivalent for PM2.5. FAI produce a number of variants of the fraught with difficulties and particular care needs to be taken
SWAM BAM instrument; users are recommended to visit the to the handling and transport of the filters, and the pre- and
UK-Air website to check which are reference-equivalent, and post-sampling conditioning. The European reference sampler
other specific, operational requirements. The Opsis SM200 can is a filter-based gravimetric sampler; the Partisol 2025 has also
be used to measure PM10 concentrations in beat-attenuation been demonstrated to be “reference equivalent”. There are a
mode with no need for correction, and is reference-equivalent. variety of other samplers that are used, including the MiniVol
portable air sampler. These samplers are only able to report
The Palas FiDAS 200 is an optical particle PM concentrations averaged over a 24-hour period, and there
counter than can measure several particle fractions simultaneously is a delay between the sampling period and the availability of
inlcuding PM10 and PM2.5. Measured values are processed by the result. For these reasons, they are not commonly used
an inbuilt algorithm. The “Method 11” algorithm for PM10 has for monitoring in the vicinity of construction sites. Other
been approved by Defra, and is reference-equivalent. For PM2.5, samplers are available which sample over periods of several
the Method 11 algorithm data need to be adjusted for slope days (depending on battery life). These can only provide long-
by dividing by 1.06; with this correction applied, the data are term average values and are not reference equivalent.
reference-equivalent.
A wide variety of portable hand-held
Indicative optical analysers: There are a number of optical monitors is available for measuring concentrations of ambient
particle monitors that rely on the interaction between airborne particulate matter. Many of these are designed for sampling
particles and visible or infrared laser light. The instruments that in industrial environments, and are often aimed at measuring
utilise light scattering often have the advantage that they can compliance with the much higher Workplace Exposure Limits
report concentrations for a range of particle sizes (total particles, set by HSE. Nonetheless, if they have sufficient sensitivity they
PM10, PM2.5 and PM1) and they are often portable (or semi- can be usefully applied in “walk-over” surveys at demolition
portable) and can be battery-operated; they are also relatively or construction sites, and used to identify whether mitigation
small and lightweight and can be attached to lampposts, fences, measures are being adequately implemented. It should be noted
etc. The principal disadvantage is that they rely on a range of that some portable optical particle counters provide data as
assumptions to calculate the PM mass concentration, the validity particle number as opposed to particle mass.
of which may vary both spatially and temporally, and they can
only provide measurements that are indicative of exceedances of Dust Deposition and Soiling
the objectives. These optical monitors are often used to identify
potential issues surrounding construction works. A number of Measurements of dust deposition, dust flux or dust soiling
these instruments have been certified using the Environment rates can be used to assess the potential for loss of amenity
Agency’s Indicative Instrument certification scheme. Users are in the local community. Such measurements can also be used
recommended to visit the relevant website to check the latest to determine whether the dust mitigation measures are being
certification details. These instrumentsts may be of two types applied effectively. It is important to note that dust deposition
and dust flux are different. A depositional gauge is used to
1. Light scatter instruments which us the light scatter from a measure dust deposition; a directional gauge is used to measure
“cloud” of particles to estimate PM values. In most cases these dust flux. Whilst dust deposition and dust flux may be expressed
require a size selective inlet to determine size fraction. by the same metric (mg/m2/day), it is not possible to convert
measurements of dust flux to dust deposition (e.g. by adding
2. Optical Particle counters which count and classify (by size) the directional components together).
individual particles. Algorithms are then used to estimate particle
mass from particle size and therby estimate mass values for a This can be measured using a variety of
range of particle sizes. Some OPCs can also output values for techniques that collect the deposited dust into containers or
particle numbers. onto “sticky pads”. The “Frisbee gauge” is one of the most

30
 IAQM u GUIDANCE
Construction Dust Monitoring

widely used deposit gauges, and its use has superseded that
of the original “British Standard” gauge. Dust is collected
onto a “Frisbee-type” collector; the dust is then washed into a
bottle. The mass of the collected material is then determined
by subsequent laboratory analysis and the results expressed in
terms of mg/m2/day. Sampling is normally carried out over a
period of several weeks to a month. The Frisbee Gauge can also
be adapted to include a vertically-mounted cylindrical sticky
pad to permit directional sampling (see below).

Sticky pad gauges are founded on the principle that the deposited
dust becomes trapped onto the surface. Instead of weighing the
mass of the collected dust, the analysis is carried out optically
to determine the Effective Area Coverage (EAC%), which takes
account of the “darkness” of the particles and the discoloration
caused, or the Absolute Area Coverage (AAC%) which records the
percentage dust coverage of the surface, regardless of the colour.

Sticky pads configured in the form of a cylinder provide

a directional component of both EAC and AAC. Some samplers
allow configurations of both horizontal (dust deposition) and
cylindrical (dust flux) to be used , and in conjunction with a PM10
sampler if required. Samples are normally collected over a one-
week period. The BS 1747 Part 5 “CERL” directional gauge is no
longer recommended due to its limited collection efficiency.

Measurements of dust soiling rates can be carried out

using the “glass slide deposit gauge”. Glass slide deposit gauges
consist of cleaned glass microscope slides that are left exposed
for one week at a time. The reduction in surface gloss when
measured by a gloss-meter (Rendel Dust Meter) is proportional
to the amount of dust soiling on the slide after exposure. The
intention is that the slides act as surrogates for surfaces where
soiling may cause a nuisance, such as windowsills and car
paintwork. The results are presented as a soiling rate, expressed
in soiling units averaged over one week (su/week), rounded to
the nearest whole number. One soiling unit is equivalent to a
one percent reduction in reflectance.

IAQM Guidance on Air Quality Monitoring in the Vicinity of Demolition and Construction Sites 31
 IAQM
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