Airborne Particulate Matter and Associated Heavy Metals: A Review

Unplanned urbanization, industrial enhancement, and tremendous increase in motor vehicle traffic lead to exponential rise in pollution. Air pollutants, such as nitrogen oxides (NOx), sulfur dioxide (SO2), carbon monoxide (CO), particulate matter (PM 2.5 and PM 10), volatile organic compounds (VOCs), ozone (O-3), and heavy metals are found at a high concentration in the atmosphere. Particulate matter with 10 mu m or less in diameter (PM10) is known to have adverse effects on human health and the environment. Particle pollution is known to have many environmental effects from poor visibility to more serious consequences such as acid rain, which pollutes soil and water. Heavy metal determination in ambient air is an important area for environmental researchers because of their toxicity to human beings. Some heavy metals (hexavalent chromium (Cr), arsenic (As), cadmium (Cd) and nickel (Ni)) have been listed as carcinogens. Furthermore, heavy metals in the atmosphere can accumulate in various plants and animals and enter humans through the food chain. Heavy metals have toxic effects when they are involved in biochemical reactions in living organisms. The Government of India has proposed National Clean Air Programme (NCAP)-a powerful step in acknowledging and resolving the problem of deteriorating ambient air quality. This study reports the major sources of particulate matter and heavy metals in the atmosphere, their effects and control for sustainable environment.