"Environmental factors contribute to more than 25%of all diseases worldwide. In the United States, the yearly cost of just four childhood health problems linked to chemical exposures--lead poisoning, asthma, cancer, and developmental disabilities--is greater than $54 billion. Chemical exposures occur in homes, schools, workplaces, and throughout communities. Accidental releases, certain household products ,or hazardous sites are all possible causes of chemical exposures. Exposures that occur in the community may be difficult to identify and control. The Agency for Toxic Substances and Disease Registry (ATSDR) works to safeguard communities from chemical exposures. ATSDR investigates community exposures related to chemical sites and releases; works closely with federal, tribal, state, and local agencies to identify potential exposures; assesses associated health effects; and recommends actions to stop, prevent, or minimize these harmful effects. Many times, exposures occurred in the past and are difficult to evaluate. ATSDR scientists can estimate exposures based on previous similar situations (called modeling), test individuals in the area to determine whether exposures have occurred (bio-monitoring), and use cutting edge technology to understand these exposures. State of the art assessment methods-such as new sampling techniques and cancer modeling--help ATSDR evaluate the health effects of emerging contaminants such as perfluorochemicals".
Department of Health and Human Services: http://www.hhs.gov/