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As everyone appreciates, air is one of the essential components of life. It is a mixture of gases and small particles the composition of which is represented in the pie chart below.
The balance of these gases is affected by man's activities and it is when this balance is shifted or the air contains a substance which may be harmful to health or the environment that it is termed 'polluted'.
Many people think that air pollution is restricted to outdoor air but it can also be a problem indoors, both at home and at work, when ventilation is inadequate.
Common pollutants and their health effects
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POLLUTANT
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SOURCE
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EFFECT
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Benzene
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Motor vehicle exhausts and petrol evaporation
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Human carcinogen
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1-3 Butadiene
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Motor vehicle exhausts and chemical industrial processes.
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Human carcinogen
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Carbon Monoxide
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Incomplete combustion of organic materials (Carbon containing). Wood, coal, oil, gas. Outdoors: vehicle exhausts, heating appliances. Indoors: smoking, heaters (unvented).
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Reduces the oxygen-carrying capacity of the blood leading to headache, nausea, vomiting, eventually collapse and death.
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Lead
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Outdoors: motor vehicle exhausts. Indoors: may be present in water pipes and/or old paint.
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Cumulative effects on the nervous system that may impair children's intelligence and concentration.
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Nitrogen Dioxide
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Combustion of fossil fuels, road vehicles' power generation, industrial processes. Indoors: unvented gas cookers and other appliances.
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Throat and eye irritation (also involved in photochemical smog formation).
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Ozone
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Product of chemical reaction between other pollutants (Nitrogen Oxide and hydrocarbons in the presence of sunlight).
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Running eyes, throat irritation, breathing difficulties.
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PM10 (particles less than 10 micrometres in diameter)
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Combustion processes and natural sources such as dust, diesel and smoke.
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Small particles can penetrate deep into the lungs and cannot be expelled. They may cause irritation and/or carry with them toxic or carcinogenic substances.
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Sulphur Dioxide
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Domestic and industrial burning of coal.
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Irritation of the nerves in the nose, throat and airways. May also lead to constriction of the airways.
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Asbestos
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Building material, wall cladding, insulation, brake linings. Exposure usually indoors during building work and car maintenance.
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Scarring of the lungs and increased risk of lung, chest and abdominal cancer.
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Volatile Organic Compounds, e.g. Formaldehyde
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Paints, varnishes, glues and preservatives used in wood products. Foam insulation. Exposure indoors during decoration or construction.
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Breathing difficulties, eye and skin irritation, nausea and dizziness.
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Radon
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Rocks which contain naturally occurring radioactive material emit Radon gas.
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Increased risk of lung cancer.
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Cigarette smoke, Nicotine, tar, formaldehyde, oxides of nitrogen and Carbon Monoxide
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Smoking
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Eye, throat and lung irritation. Increased liability to respiratory illness. Increased risk of lung cancer. Non-smokers breathing in others' smoke are also at risk.
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Micro-organisms and allergens
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Biological contaminants, moulds, spores, viruses and bacteria
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Pneumonia-like respiratory illnesses, allergic reactions.
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Indoor Air Pollution
Indoor air pollution can only be controlled by the householder, but may be improved by increasing ventilation. However, if you are concerned about radon, asbestos or other building materials contact the Environmental Health Department.
Outdoor Air Pollution
Outdoor air pollution is being tackled by a number of agencies, under a range of legislation, briefly discussed in the pages of this website entitled Industrial Emissions and Air Quality Acts and Regulations.
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