In both developed and rapidly industrialising countries, the
major historic air pollution problem has typically
been high levels of smoke and sulphur dioixide arising
from the combustion of sulphur-containing fossil fuels
such as coal for domestic and industrial purpose. The major
threat to clean air is now posed by traffic
emissions. Petrol and diesel-engined motor vehicles emit a
wide variety of pollutants, principally carbon
monoxide (CO), oxides of nitrogen (NOx), volatile
organic compounds (VOCs) and particulates (PM10), which
have an increasing impact on urban air quality. In addition,
photochemical reactions resulting from the
action of sunlight on nitrogen dioxide (NO2) and VOCs from
vehicles leads to the formation of ozone, a
secondary long-range pollutant, which impacts in rural areas often
far from the original emission site. Acid
rain is another long-range pollutant influenced by vehicle NOx emissions.
In all except worst-case
situations, industrial and domestic pollutant sources, together with their impact on air quality, tend to be steady-state or improving over time. However, traffic pollution problems are worsening world-wide. Below is an introduction to the principal pollutants produced by industrial, domestic and traffic sources: Click here for a glossary of terms used in air pollution. To find out more about air pollution visit the Enviropedia  |
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Lead and Heavy Metals |
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 Since the introduction of unleaded petrol in the UK there has been a significant reduction in urban lead levels. In recent years industry, in particular secondary non-ferrous metal smelters, have become the most significant contributors to emissions of lead. The highest concentrations of lead and heavy metals are now therefore found around these installations in industrial areas. Even small amounts of lead can be harmful, especially to infants and young children. In addition, lead taken in by the mother can interfere with the health of the unborn child. Exposure has also been linked to impaired mental function, visual-motor performance and neurological damage in children, and memory and attention span. |
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Click other pollutant below to view more: |
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