AIRBORNE C-1-HALOCARBONS AND C2-HALOCARBONS AT 4 REPRESENTATIVE SITES IN EUROPE

Air concentrations of trichlorofluoromethane, trichloromethane, tetrachloromethane, 1,1,2-trichloro-1,2,2-trifluoroethane, 1,1,1-trichloroethane, trichloroethene and tetrachloroethene have been determined at four sites: a medium-sized (80,000 inhabitants), moderately industrialized city in southwest Germany, a mountain forest site in the northern Black Forest, a suburb south of Lisbon at the Atlantic coast of Portugal, and a truly remote oceanic site, the island of Madeira. As expected, there are large differences in the concentrations of those halocarbons which find wide technical applications and have relatively short atmospheric lifetimes; moderate or small differences are found for those with small anthropogenic sources-chloroform and tetrachloromethane. Chloroform tends to be higher at the marine sites, suggesting that it arises from natural sources.