Arsenic, barium, cadmium, chromium, copper, lead, mercury, selenium, silver and zinc are among the many contaminants that enter the environment through industrial, agricultural or other human activity, as well as through natural causes. Addressing this requires identifying the site, characterizing it in terms of the level of contamination and then cleaning, removing or isolating the affected areas. Determining the best course of action requires detailed and precise information on the contaminants that are present, which traditionally has been done in the lab. Recent advances in technology, however, enable accurate analysis in the field.