The aim of this project is to compile information and create a computerized database of historical and present global lindane and endosulfan usage data as well as emission data for gamma-hexachlorocyclohexane (gamma-HCH) and endosulfan with 1 degree x 1 degree lat/long resolution. The objectives of this project are: A) to create global gridded g-HCH and endosulfan emission inventories; B) to study the linkage between global g-HCH and endosulfan use trends and g-HCH and endosulfan concentration trends in the Arctic; and C) to assist in comparing concentrations and ratios of different HCH isomers in the Arctic biotic and abiotic environments.