AIR POLLUTION INDICATOR
AIR POLLUTION
Air pollution is contamination of the indoor or outdoor environment by
any chemical,physical or biological agent that modifies the natural
characteristics of the atmosphere.
Household combustion devices, motor vehicles, industrial facilities and
forest fires are common sources of air pollution. Pollutants of major public
health concern include particulate matter, carbon monoxide, ozone, nitrogen
dioxide and sulfur dioxide. Outdoor and indoor air pollution cause
respiratory and other diseases and are important sources of morbidity and
mortality.
WHO data show that almost all of the global population (99%) breathe air
that exceeds WHO guideline limits and contains high levels
of pollutants, with low- and middle-income countries suffering from the
highest exposures.
Air quality is closely linked to the earth’s climate and ecosystems globally.
Many of the drivers of air pollution (i.e. combustion of fossil fuels) are also
sources of greenhouse gas emissions. Policies to reduce air pollution,
therefore, offer a win-win strategy for both climate and health, lowering the
burden of disease attributable to air pollution, as well as contributing to the
near- and long-term mitigation of climate change.
Causes of Air Pollution:
Burning of fossil fuels:
. Fossil fuel emits harmful gases such as sulfur dioxide and
carbon monoxide into the air.
Automobiles :
The emission of harmful gases is caused by the excessive use of
automobiles.
Agricultural Activities:
Various processes take place during agricultural activities such as
the emission of ammonia, overuse of insecticides, pesticides, and
fertilizers. Ammonia is a typical byproduct of agriculture and one of
the most dangerous gases in the atmosphere.
Farmers also set fire to the fields and old crops to clear them up for
the new cycle of sowing. According to reports, burning to clean up
fields pollutes the air by emitting toxic pollutants.
Factories and Industries:
Emission of harmful gases and chemicals into the air by the
increasing industrial activities. Manufacturing companies emit a
significant amount of carbon monoxide, hydrocarbons, organic
compounds, and chemicals into the air, lowering air quality.
Mining Activities:
Increasing emission of harmful substances through mining
activities. Dust and chemicals are released into the air throughout the
process, resulting in significant air pollution.
Domestic Resources:
Effects of domestic sources such as the use of chemical paints and
overuse of air conditioners. Household cleaning products and painting
supplies release hazardous chemicals into the air, polluting the
environment.
Pollution indicators
Organism/organisms or attributes of the community which can be
used to provide information on State of the environment and change
from normal conditions.
Organisms(microbes, plants, insects, bacteria etc)serving as indicators
of environmental pollution and giving Indications of the hazardous
substances or indication of the state of environmental pollution of
water, air, soil etc. by having ability to accumulate substances causing
pollution are called pollution indicators.
Indicator species:
An indicator species is any biological species that defines a
traitor characteristic of the environment. For example, a species may
indicate an environmental condition such as a disease outbreak,
pollution, species competition or climate change.
Pollution Indicators of Air
A plant is used to indicate air quality and locate sources of air
pollution utilizing known as air “Pollution Indicator Plant.” Indicator
plants containing a series of chambers, where the particulate matter and
chemicals have been removed by a series of filters. Bio-indicator plants
are very sensitive to a selected (toxic) chemical, they respond quickly
with typical visible foliar symptoms to the presence of medium-to-low
levels of the noxious agent; they are very cost-effective.The category of
plants as a indicator of air pollution are
1. Lichen (Parmelia Orthotrichum, Polytrichum)
2. Algae (Chlamydomonas, Chlorella, Chloro-coccum, Chlorosarcina).
3. Moss Tillandsia usneoides, Sphagnum, Bryum.
4. Herbs and grasses.
5. Tulsi.
6. Tobacco.
7. Lettuce plants.
1. Lichen (Parmelia):
For nearly 25 years that lichen growth and health can assess many air
pollutants and the value of these living organisms rather than man-made
instruments for assessing sulfur dioxide levels is that they are
inexpensive and give quick results. Lichens are especially useful in
forestry to assess where conifers should be planted since conifers are
affected by the same sulfur dioxide levels that cause lichen cover to
decline. The possibility of transplanting healthy lichens into areas
suspected of being polluted, and monitoring physiological parameters
such as respiration and photosynthesis, to give a rapid indication of
pollution level.
Lichens are grow in exposed places such as rocks or tree bark. Air
pollutants dissolved in rainwater,especially sulfur dioxide ,can damage
lichens, and prevent them from growing.This makes lichens natural
indicators of air pollution.
Lichens acting as bioindicator of heavy metals like (Pb, Cr, Cu, Cd, Ni
etc) caused due to pollution from motor vehicles activites on roadside
soils e.g Xanthoria candelaria,Xanthoria elegans etc.
2.Algae:
Aerial or sub-aerial algae would also be ideal as indicators of air pollution
because of ease of handling ,range of species specific sensitivity which is
greater than in higher plants and much quicker physiological responses to
air chemistry than occur in high plants .Many of the cortecolous,
lithophilous and epiphytic algae, liverworts, fern gametophytes are
ideally suited as air biological monitoring organisms. Using both
pollution tolerant and pollution sensitive species would be best for air
quality indication. Especially suitable as test organisms in the Air
Biomonitor are the microalgae found in both aerial and subaerial habitats
such as species of Chlamydomonas, Chlorella,
Chlorococcum,Gloeocystis,Pleurococcus,Chroococcus,
Nostoc,Oscillatoria.
3. Moss (Tillandsia):
Tillandsia usneoides is an indicator species to air pollution, that its
decline is directly related to raised levels of air pollution, and that the
most acidic pollutants are the most harmful. Air pollutants are absorbed
by Spanish moss. Tillandsia usneoides, commonly called Spanish moss,
is a relative of the pineapple (order Bromeliales, family Bromeliaceae,
genus Tillandsia (air plant), and species usneoides) (Spanish moss). In
fact, it is an epiphyte, a plant that gains all of its moisture and nutrients
from the air. The thin trichomes(scales) that cover the whole plant, these
trichomes play an important role in the absorption of moisture and
nutrients from the air. The trichome act as pump and draw moisture and
dissolved minerals into the plants through the stomata. This indicates that
whatever is present in the air including pollutants will be absorbed by the
plants.
MOSS
4. Herbs and grasses:
Changes in sensitive species of herbs and grasses occur much earlier than
in shrub and tree populations. Generally, the degree of ‘Crown die-back’
and death of trees is directly related to the level of SO2, NO2 HF and HCl
pollution of air.
5. Tulsi:
Tulsi is sensitive to pollution and a minor change in pollution level is also
been detected by this plant. Certain visual observations on the plant
supported our prediction that Tulsi can be used as effective bioindicator for
auto exhaust pollution. Tulsi act as bioindicator for determining the
increased level of nitrogen and sulphur status in atmosphere.
6.Tobacco
Biomonitoring of ozone with tobacco is miniaturized kit based on
tobacco seedlings (Nicotiana tabacum L.) cultivars Bel-W3 (O3-
supersensitive) and Bel-B (O3- resistant). The biomonitoring units
consisted of polystyrene tissue-culture plates with wells filled with
organic compost; each well held a 10-day-old tobacco seedling, raised in
a controlled environment.
7.Lettuce plants:
Lettuce plants as bioaccumulations of trace elements Homogeneous
adult lettuce plants, Lactuca sativa raised in a greenhouse were exposed
to ambient air in 15 dm3 containers at nine stations and regularly
provided with water until field capacity.
LETUCCE PLANT
.Pine bark trees and needle:
It acts as indicators of different degrees of heavy metal pollution (Urban,
Industrial, highway) concentrations e.g. lead (pb), zinc (Zn), nickel(Ni),
chromium (Cr) e.g. Turkish red pine (Pinusbrutia Ten.), Italian stone
pine (Pinus Pinea L.) etc
.
Spider webs
It acts as an efficient traps of air borne particulates and provide a useful
indicator for monitoring environmental pollutants because they are
unexpensive and easy to collect and are widespread in urban areas and
acts as best indicators Indicators of Heavy Metal Pollution e.g. (Pb, Zn,
Cu, Cd etc.) in Air e.g. Achaearanea tepidariorum,Araneus
ventricosus.
Pigeons:
Pigeons as an Indicator Species for monitoring Air Pollution. Heavy
metals like Zn, Pb causes DNA damage and traces of which is found in
kidney, lung, liver and blood of pigeons e.g. Wild pigeons.
