Heavy metal pollution due to various sources such as from agro chemicals, ballast water, electronic waste, vehicle exhaust, industrial effluents, coal power plants, sludge wastes, medicinal chemicals, laboratory waste and domestic wastes are become a major threat to the environment. WHO has found there is a health risk due to long-range transboundary air pollutants containing heavy metals. Arsenic, Beryllium, radium, chromium and cadmium are well known carcinogens. Some of them(As and Cd) found in well waters (north central province of Sri Lanka, India, Korea, Chile and Bangladesh) or surface water bodies (Chile, Africa, China India and Bangladesh)which are in close proximity with agricultural lands or industrial zones or waste dumping areas (chemical or electronic). Several acute and chronic effects are being recorded. This book reviews heavy metals, sources, effects and remediation techniques in general.