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GEO-3: GLOBAL ENVIRONMENT OUTLOOK  
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Urban air pollution

Air pollution is common, particularly in developing country cities, due to the growing number of motor vehicles and increasing industrial activity. In countries such as India, Indonesia, Nepal, Malaysia and Thailand vehicles with two-stroke engines, such as motorcycles and three-wheel taxis, comprise more than one-half of all motor traffic and pollute heavily. Poor maintenance of vehicles, poor fuel quality and poor road conditions also contribute. The burning of biomass such as firewood and agricultural wastes is a further source of air pollution in many poor areas (World Bank 2000).

Motor vehicles cause serious environmental problems in developed countries as well. In Australia and New Zealand, there is a high dependence on private motor vehicles which leads not only to the need to clear land for roads but also to increasing emissions of carbon dioxide, lead, zinc and copper (Hughes and Pugsley 1998, MoE New Zealand 1997).

A range of policy measures and technologies including catalytic converters, unleaded fuel and alternative fuels such as compressed natural gas are being introduced to improve the quality of urban air. New coal-fired power plants in many Asian countries now use electrostatic precipitators which can reduce emissions of particulates by more than 99 per cent. Subsidies are provided for the use of renewable technologies such as wind turbines and solar photovoltaics. In China, the city of Beijing has implemented 68 atmospheric pollution prevention measures which are resulting in significant reductions in SO2, NO2 and SPM levels (SEPA 1999).

Urbanization level (%): Asia and the Pacific
Urban populations (millions) by sub-region: Asia and the Pacific

Graph and map show high level of urbanization in Australia and New Zealand compared with other subregions. Urbanization is proceeding fast in all other subregions except Central Asia

Source: compiled from United Nations Population Division 2001