Global hexachlorocyclohexane use trends and their impact on the arctic atmospheric environment

The relationship between the global technical HCH use trends and their impact on the arctic atmospheric environment has been studied. Two significant drops in global technical HCH usage were identified. In 1983, China banned the use of technical HCH. This represented the largest drop ever in global use rates. In 1990 India stopped technical HCH usage in agriculture and the former Soviet Union banned the use of technical HCH. Since 1990, India has been the biggest user of technical HCH in the world. Significant drops in atmospheric α-HCH in the arctic were observed between 1982 and 1983, and again between 1990 and 1992. The rapid response in atmospheric concentrations to usage is encouraging; however, since α-HCH concentrations in the arctic waters have remained relatively unchanged, the decline in atmospheric α-HCH has reversed the net direction of air-sea gas flux. The accumulated mass in oceans and large lakes may represent a new source of HCH to the arctic atmosphere.