Commonly, we treat air pollution as a separate entity to water pollution. However, air pollutants can end up in water bodies such as river and lakes thus contaminating our drinking water source.

Not only do these pollutants can affect the water bodies nearby their source, they also could be carried away by winds, clouds and rains thus polluting water bodies at regions far away from the source area. It is even more of a problem when the contaminated air is carried across the globe to pollute pristine environments such as gazetted water catchment areas.

There are multiple sources of air pollution which include both anthropogenic and natural sources. Examples of anthropogenic sources are burning of fossil fuels, industrial and agricultural chemical release and solid waste incineration. Forest fire and volcanic activities are examples of natural processes which contribute to air pollution. Common air pollutants which also lead to water pollution are NOX, SOX, and heavy metals such as mercury.

There are a number of ways in which these air pollutants can be deposited into the water bodies. Direct deposition of air pollutants into the water bodies happens when the air pollutants fall onto the surface of the water bodies by means of rainwater and dust or simply due to gravity. Another way is when the land deposited with the air pollutants is being washed away into the water bodies. Some of the adverse effects of these air pollutants when they end up in water are uncontrolled algal blooms, contaminated fish and unsafe drinking water.

Mathini Arveena Ravee
Forum Air Malaysia