Global technical hexachlorocyclohexane usage and its contamination consequences in the environment: from 1948 to 1997

Global technical 1,2,3,4,5,6-hexachlorocyclohexane HCH. usage data are surveyed from 1948 to 1997. In order to fill both temporal and spatial gaps of the usage data, registration status and the residue concentration of this insecticide in various environmental compartments are considered. A linkage between the accumulated use-density over arable land and the contamination in the environment in each country has been studied. Six levels are classified for both use-density and contamination. By assuming the use-density should be at the same level as the contamination for each country, a spatial interpolation for usage data is made for those countries with residue concentration data but no usage data. Similarly, a spatial interpolation for contamination level is made for those countries with usage data but no residue concentration data. This hypothesis is also applied to judge the accuracy of usage data for those countries where these two sets of data are not in the same level. The total global technical HCH usage between 1948 and 1997 has been estimated to be approximately 10 million t. Historical maximum contamination levels as well as 1990 contamination levels are also presented for each country based on the published sources and an estimation from the use-density. The results show that, China, Japan, and India were most polluted countries by this pesticide during different period of time, and India was still the highest contaminated country in 1990, and most likely, the most polluted area by technical HCH today.