Impact of forest fires on regional air quality in Southeast Asia

Biomass burning, the burning of living and dead vegetation for land-clearing and land-use change, has been in practice in many tropical countries such as Brazil, Indonesia, Nigeria, and Mexico. Intense forest fires can also ignite subsurface organic soil components （e.g. peat）, which can continue to smolder long after the original surface fires are put out. Combustion of vegetation and peat has only recently been recognized as a major source of atmospheric pollution. The immediate effect of burning is the production and release of gases and particles into the atmosphere, in quantities that in some cases can be significant not only locally and regionally but also on a global scale. Vegetation fire emissions account for roughly half of the atmospheric constituents of hydrocarbon, carbon monoxide, nitrogen oxides, and precursors of tropospheric ozone and may be the second largest source of anthropogenic aerosols after the production of sulfates from SO2. As a result, there has been considerable interest in studying the contribution of forest fires to the production of air pollutants. In recent years, Southeast Asian countries have been affected repeatedly by episodes of smoke haze from forest fires in Indonesia. During 1997-1998, the region was again shrouded in a haze worsened by prolonged drought linked to the E1 Nino weather phenomenon. Satellite pictures confirmed that air pollutants, originating from fires covering an estimated 800000 hectares of southern Kalimantan, Sumatra, and Java, have been transported by southwesterly monsoon winds across neighbouring Malaysia and Singapore to as far as Thailand and the Philippines. The impact of these extensive fires on the health of the residents and ecology in the affected areas was substantial, costly, and possibly long lasting. Most of the research on the environmental aspects of biomass burning has been directed towards the tropics in Africa and America, specifically to the tropical rain forests of Brazil and to the savannas of Africa and South America.

Impact of forest fires on regional air quality in Southeast Asia