Impacts of biomass burning and regional haze on the pH of rainwater in Brunei Darussalam

A number of reports have suggested that biomass burning in the tropics may have an acidifying effect on precipitation with consequent effects on tropical ecosystems. Although SE Asia has been repeatedly affected by severe haze caused by tropical forest fires, the impacts on rainwater acidity and chemistry have not yet been reported. In the present communiction we report, for the first time, the impacts of fires and haze on rainwater pH in SE Asia during the past three haze episodes. The analysis of rainwater in Brunei Darussalam during severe haze episodes in Borneo in 1994, 1997, and 1998 failed to reveal any significant impacts on rainwater acidity or wet deposition of hydrogen ions.