Global Pollution of the Oceans with Chlorinated Hydrocarbons

Abstract

The chemical industry produces, from chlorine, simple volatile chlorinated hydrocarbons with 1–2 carbon atoms, to a certain extent also chlorine-fluorine compounds. The largest amounts are divided among dichlorethane (EDC, H₃C-CHCl₂; around 20 million t produced world-wide in 1973), cancerogenous vinylchloride(H₂C=CHCl; 10 million t), solvents used in industry, and byproducts which are not intentionally released, but do, however, turn up in the environment, for example in the water and sediment of the Bay of Liverpool (Pearson and McConnell 1975). Practically the entire production of many compounds reaches the environment, for example the solvent trichlorethylene (ClHC=CCl₂; approximately 1 million t produced world-wide in 1973), the degreasing solvent trichlorethane (CH₃-CCl₃; 0.5 million t), the compounds perchlorethylene (Cl₂C=CCl₂; 1 million t) and carbontetrachloride (CCl₄; 1 million t) used in the textile dry-cleaning, and chlorofluoro-hydrocarbons of various compounds used as a propellant gas in spray cans and as a coolant (freon, frigene; 1 million t). These substances are almost resistant to microorganisms. In the atmosphere, however, photo-oxydation into hydrochloric acid takes place under the influence of ultraviolet rays. Hydrolysis can be observed in the hydrosphere. The half-life values are in the area of months.