Air Pollution

Air pollution is the contamination of air due to the presence of substances

in the atmosphere that are harmful to the health of humans and other living
beings, or cause damage to the climate or to materials.[1] There are many
different types of air pollutants, such as gases (including ammonia, carbon
monoxide, sulfur dioxide, nitrous oxides, methane, carbon dioxide and
chlorofluorocarbons), particulates (both organic and inorganic), and
biological molecules. Air pollution can cause diseases, allergies, and even
death to humans; it can also cause harm to other living organisms such as
animals and food crops, and may damage the natural environment (for
example, climate change, ozone depletion or habitat degradation) or built
environment (for example, acid rain). Air pollution can be caused by both
human activities and natural phenomena.

Air pollution is a significant risk factor for a number of pollution-related

diseases, including respiratory infections, heart disease, COPD, stroke and
lung cancer. Growing evidence suggests that air pollution exposure may be
associated with reduced IQ scores, impaired cognition, increased risk for
psychiatric disorders such as depression and detrimental perinatal health.
The human health effects of poor air quality are far reaching, but principally
affect the body's respiratory system and the cardiovascular system.
Individual reactions to air pollutants depend on the type of pollutant a
person is exposed to, the degree of exposure, and the individual's health
status and genetics.

Outdoor air pollution attributable to fossil fuel use alone causes ~3.61
million deaths annually, making it one of the top contributors to human
death,[5][12] with anthropogenic ozone and PM2.5 causing ~2.1 million.
Overall, air pollution causes the deaths of around 7 million people
worldwide each year, or a global mean loss of life expectancy (LLE) of 2.9
years,[15] and is the world's largest single environmental health risk, which
has not shown significant progress since at least 2015. Indoor air pollution
and poor urban air quality are listed as two of the world's worst toxic
pollution problems in the 2008 Blacksmith Institute World's Worst Polluted
Places report.[ The scope of the air pollution crisis is large: 90% of the
world's population breathes dirty air to some degree. Although the health
consequences are extensive, the way the problem is handled is considered
largely haphazard or neglected.

1
Productivity losses and degraded quality of life caused by air pollution are
estimated to cost the world economy $5 trillion per year but, along with
health and mortality impacts, are an externality to the contemporary
economic system and most human activity, albeit sometimes being
moderately regulated and monitored. Various pollution control technologies
and strategies are available to reduce air pollution.Several international and
national legislation and regulation have been developed to limit the
negative effects of air pollution.] Local rules, when properly executed, have
resulted in significant advances in public health. Some of these efforts have
been successful at the international level, such as the Montreal Protocol,
which reduced the release of harmful ozone depleting chemicals, and the
1985 Helsinki Protocol, which reduced sulphur emissions,while others,
such as international action on climate change, have been less successful.

Sources Of Air Pollution

Anthropogenic (human-made) sources

Controlled burning of a field outside of Statesboro, Georgia, in preparation for spring

planting

2
 Smoking of fish over an open fire in Ghana, 2018

These are mostly related to the burning of fuel.

 Stationary sources include:

o fossil-fuel power plants and biomass power plants both have smoke
stacks (see for example environmental impact of the coal industry)
 Oil and gas sites that have methane leaks
o burning of traditional biomass such as wood, crop waste and dung. (In
developing and poor countries, traditional biomass burning is the major
source of air pollutants.It is also the main source of particulate pollution in
many developed areas including the UK & New South Wales. Its
pollutants include PAHs.)
o manufacturing facilities (factories)
 a 2014 study found that in China equipment-, machinery-, and
devices-manufacturing and construction sectors contributed more
than 50% of air pollutant emissions.This high emission is due to
high emission intensity and high emission factors in its industrial
structure.[50]
o waste incineration (incinerators as well as open and uncontrolled fires of
mismanaged waste, making up about a fourth of municipal solid terrestrial
waste)
o furnaces and other types of fuel-burning heating devices
 Mobile sources include motor vehicles, trains (particularly diesel locomotives and
DMUs), marine vessels and aircraft as well as rockets and re-entry of
components and debris. The air pollution externality of cars enters the air from
the exhaust gas and car tires (including micro plastics). Vehicles were reported to
be "producing about one-third of all U.S. air pollution" and are a major driver of
climate change.

3
  Agriculture and forest management strategies using controlled burns. Practices
like slash-and-burn in forests like the Amazon cause large air pollution with the
deforestation. Controlled or prescribed burning is a practice used in forest
management, agriculture, prairie restoration, and greenhouse gas reduction.
Foresters can use controlled fire as a tool because fire is a natural feature of both
forest and grassland ecology. Controlled burning encourages the sprouting of
some desirable forest trees, resulting in a forest renewal.

There are also sources from processes other than combustion:

 Fumes from paint, hair spray, varnish, aerosol sprays and other solvents. These
can be substantial; emissions from these sources was estimated to account for
almost half of pollution from volatile organic compounds in the Los Angeles basin
in the 2010s.
 Waste deposition in landfills produces methane.
 Nuclear weapons, toxic gases, germ warfare, and rocketry are examples of
military resources.
 Agricultural emissions and emissions from meat production or livestock
contribute substantially to air pollution
o Fertilized farmland may be a major source of nitrogen oxides.

Natural sources

Dust storm approaching Stratford, Texas in 1935

 Dust from natural sources, usually large areas of land with little
vegetation or no vegetation
 Methane, emitted by the digestion of food by animals, for example
cattle

4
  Radon gas from radioactive decay within the Earth's crust. Radon is a
colorless, odorless, naturally occurring, radioactive noble gas that is
formed from the decay of radium. It is considered to be a health
hazard. Radon gas from natural sources can accumulate in buildings,
especially in confined areas such as the basement and it is the
second most frequent cause of lung cancer, after cigarette smoking.
 Smoke and carbon monoxide from wildfires. During periods of active
wildfires, smoke from uncontrolled biomass combustion can make up
almost 75% of all air pollution by concentration.
 Vegetation, in some regions, emits environmentally significant
amounts of volatile organic compounds (VOCs) on warmer days.
These VOCs react with primary anthropogenic pollutants –
specifically, NOx, SO2, and anthropogenic organic carbon
compounds – to produce a seasonal haze of secondary pollutants.
Black gum, poplar, oak and willow are some examples of vegetation
that can produce abundant VOCs. The VOC production from these
species result in ozone levels up to eight times higher than the low-
impact tree species.
 Volcanic activity, which produces sulfur, chlorine, and ash
particulates

Emission factors

Beijing air in 2005 after rain (left) and a smoggy day (right)

Air pollutant emission factors are reported representative values that aim to
link the quantity of a pollutant released into the ambient air to an activity

5
connected with that pollutant's release. The weight of the pollutant divided
by a unit weight, volume, distance, or time of the activity generating the
pollutant is how these factors are commonly stated (e.g., kilogrammes of
particulate emitted per tonne of coal burned). These criteria make
estimating emissions from diverse sources of pollution easier. Most of the
time, these components are just averages of all available data of
acceptable quality, and they are thought to be typical of long-term
averages.

There are 12 compounds in the list of persistent organic pollutants. Dioxins

and furans are two of them and intentionally created by combustion of
organics, like open burning of plastics. These compounds are also
endocrine disruptors and can mutate the human genes.

E-waste processing in Agbogbloshie, Ghana using open-burning of electronics to

access valuable metals like copper. Open burning of plastics is common in many
parts of the world without the capacity for processing. Especially without proper
protections, heavy metals and other contaminates can seep into the soil, and
create water pollution and air pollution.

The United States Environmental Protection Agency has published a

compilation of air pollutant emission factors for a wide range of industrial
sources The United Kingdom, Australia, Canada and many other countries
have published similar compilations, as well as the European Environment
Agency

6
 Group Names Roll No
Azhari Adem
Azahir Adem
Mielat Tsegay
Azamit Beyene
Rimon Michael
Simon Teshome
Noah Iseyas
Adonay
Betiel Negasi