Air Pollution

What is air pollution?

The European Environment Agency defines air pollution as "the presence of contaminant or pollutant substances in the air at a concentration that interferes with human health or welfare, or produces other harmful environmental effects."

The main source of air pollution is fossil fuel combustion, the central process for most electricity generation, heating systems and motor vehicles.

There are a vast range of air pollutants, which cause a variety of effects on the environment and health.

Air quality is key to the health of humans and ecosystems. Air pollution can lead to a variety of respiratory diseases, tuberculosis, bronchitis, heart and chest diseases, stomach disorders, and cancers. There is also growing understanding of the links between atmospheric problems such as local air pollution, acid rain, global climate change and stratospheric ozone depletion.

Air pollution is worst in Latin America and Asia. In cities such as Seoul and Mexico City, the air quality is so bad that some people wear facemasks to filter the air.

Background

Air pollution has historically been caused by industrialisation and the consequent proliferation in the use of 'fossil fuels' (and therefore sulphur dioxide emissions) in the industrial process.

In modern Britain, traffic is the major air polluter, with traffic fumes accounting for just over half of the total domestic nitrogen emissions. Petrol and diesel-engine motor vehicles emit a wide variety of pollutants, mainly carbon monoxide (CO), nitrogen oxides (NOx), volatile organic compounds (VOCs) and particulates (PM10), which have an increasing impact on urban air quality.

Pollution emissions are governed by the National Air Quality Standards, part of the 'National Air Quality Strategy' adopted by the Government in January 2000. The 2003 report sets health-based objectives for nine main pollutants: SO2, PM10, NO2, CO, Pb, benzene, 1,3-butadiene, O3 and PAHs. They also set objectives for SO2 and NOx for the protection of vegetation and ecosystems.

These Standards aim to meet the requirements of the EU Air Quality Framework Directive (1996/62/EC) and the subsequent 'daughter directive' (1999/30/EC), which set binding limits, to be met between 2001 and 2010, for nitrogen dioxide (and oxides of nitrogen), sulphur dioxide, particulate matter, and lead.

There are also international guidelines on environmental sustainability, principally the Rio Declaration 1992, resulting from the 'Earth Summit', and the 2002 declaration from the Johannesburg Sustainable Development Summit.


Controversies

Concerns about air pollution range from the very local - many rural and suburban councils cite the nuisance caused by bonfires as their principal air pollution problem - to the truly global. Pollution crosses national boundaries and international action, which is not always forthcoming, is required to address it. Moreover, evidence of climate change, caused by air pollution, suggests that pollution's effects may be irreversible and catastrophic.

Environmental concerns have only become mainstream in the developed world's political systems in the last 20 years or so, but many still claim that economic objectives are routinely given precedence over the environment. In the developing world, which is increasingly industrialising, the problem is becoming even more pressing.

Air pollution in the UK is cited as a contributing factor in a range of environmental and health problems, such as rising rates of childhood asthma, allergies and habitat loss, although its precise role is frequently vaguely defined.


Statistics

In urban areas in the UK in 2002, air pollution was recorded as moderate or higher on 20 days on average per site, compared with 25 days in 2001, and 59 days in 1993

In rural areas, the figure for 2002 was 30 days on average per site, compared with 34 in 2001. The number of days fluctuated between 21 days in 1987 and 50 days in 1990

The main causes of days of moderate or higher air pollution at urban sites are now ozone and fine particles (PM10). Sulphur dioxide used to be a significant contributor but has now fallen to relatively very low levels

66 per cent of all carcinogenic chemicals emitted into the air come from factories in the most deprived 10 per cent of communities in England

Between 1985 and 1994, SO2 emissions in Western, Central and Eastern Europe fell by 50 per cent in line with the Convention on Long Range Transboundary Air Pollution protocols. However, emissions in other regions, especially in parts of Asia, are a major and growing problem

Statistics 1 and 2: (Source - DEFRA 'Air quality headline indicator for sustainable development', 2002); Statistic 3: (Source: Friends of the Earth, 2003); Statistic 4: (Source: UN Environment Agency, 2003)

Quotes


"The state of the worlds' environment is still fragile. Conservation measures are far from satisfactory. At discussions on global finance and the economy, the environment is still treated as an unwelcome guest. High consumption lifestyles continue to tax the earth's natural life support systems. Research and development remains woefully under-funded, and neglects the problems of the poor. Developed countries in particular have not gone far enough in fulfilling the promises they made in Rio - either to protect their own environments or to help the developing world defeat poverty."

Kofi Annan, UN Secretary General, 'Towards a sustainable Future', 2002