In order to assess the spatial and temporal patterns of the a-, b- and g-isomers of hexachlorocyclohexane (HCH) in the arctic biotic and abiotic environment, it is proposed that: (1) concentrations and ratios of HCH isomers be compared over time in air, water, seals, beluga, polar bears and seabirds to determine any shifts in isomeric ratios and how those shifts interrelate among the various media, and (2) concentrations and ratios of HCH isomers be compared spatially in the abiotic and biotic media and reasons for any patterns explored.