Persistent Organic Pollutants

The rapid growth in chemical and agrochemical industries during the last century have resulted in the environmental releases of a large number of new chemical compounds into the environment. According to the OECD, the daily use of chemicals includes about 70,000 mainly organic synthetic chemicals, and the number increases continuously (Schwarzenbach et al. 1993). Over the last decades, there has been an increasing focus on a subset of harmful organic chemicals, mostly of anthropogenic origin, that are commonly classified as Persistent Organic Pollutants (POPs). The group of intentionally produced chemicals discussed here include the polychlorinated biphenyls (PCBs) that were introduced in 1929, as well as γ-heaxchlorocyclohexane (γ-HCH) that has been produced as an insecticide since the 1940s. In addition, a number of potentially harmful organic chemicals are released as accidental and unwanted by-products from various industrial activities and combustion processes. This group includes the polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) as well as the polyaromatic hydrocarbons (PAHs). The POPs Protocol