A review on dust pollution levels in urban environment of Sri Lanka with special emphasis on heavy metals in dust

Dust containing Heavy Metals (HM) can accumulate in the soil, surface water bodies, and groundwater, disrupting ecosystems and posing significant human health risks through inhalation and consumption of those in water and food. The interpretation of the sources, distribution, and accumulation of HM in the urban dust in Sri Lanka, which has under tropical climatic conditions, would be useful for other developing countries with similar environments for developing and planning environmentally friendly, sustainable, sensitive, and healthy cities. Therefore, this paper provides a comprehensive risk assessment of HM in dust, raising awareness among urban policymakers about the requirement to reduce dust pollution and implement appropriate management strategies. Even though the potential sources are lower than in other megacities around the world, major cities of Sri Lanka are significantly polluted with dust containing several HM, implying that environmental conditions stimulate the accumulation and transformation of HM. Therefore, in addition to focusing on sources, the behaviour of heavy metals in different climatic conditions, as well as the geographic setting of cities and their countries, must be considered for the possible abundance of HM in the dust. Thus, additional research focusing on all aspects of the biogeochemical cycling of HM in urban environments is required in the future to meet the sustainable development goals of urban areas.