Many chemicals can, when properly used, significantly contribute to the improvement of our quality of life, health and well-being. But other chemicals are highly hazardous and can negatively affect our health and environment when improperly managed.10 chemicals or groups of chemicals of major public health concern are: Air pollution Arsenic Asbestos Benzene Cadmium Dioxin and dioxin-like substances Inadequate or excess fluoride Lead Mercury Highly hazardous pesticides Ref :