Anthropogenic emissions of trichloromethane (chloroform, CHCl3) and chlorodifluoromethane (HCFC-22): Reactive Chlorine Emissions Inventory

Anthropogenic emissions of trichloromethane (CHCl3, chloroform) in 1990 hav e been estimated with a variety of methods specific to the source category. The largest source category for CHCl3 was found to be pulp and paper manuf acturing, responsible for an estimated 30 +/- 8 Gg yr(-1) reactive chlorine in the form of CHCl3. Water treatment of various types was estimated to co ntribute another 19 +/- 12 Gg. Manufacturing facilities of products other t han pulp or paper and other relatively minor sources were estimated to emit an additional 13 +/- 5 Gg yr(-1), for a total of 62 +/- 25 Gg yr(-1) react ive chlorine in the form of CHCl3. The global flux of chlorodifluoromethane (HCFC-22) is well characterized from industrial and regulatory data to hav e been 195 Gg in 1990, equivalent to 80 +/- 0.6 Gg yr(-1) as active chlorin e. The fluxes of reactive chlorine from CHCl3 and HCFC-22, distributed glob ally in a 1 degrees latitude times 1 degrees longitude grid, revealed areas highest in emissions.