Chlorine: New Facts, New Recommendations

In October 1992, the International Joint Commission (IJC) suggested that the U.S. and Canadian governments begin phasing out persistent toxic chemicals, including chlorine. IJC is a federally-appointed board, established in 1909 to advise the U.S. and Canadian governments on treaties and laws for preserving water quality along their mutual border. Many other organizations and individual authors have recommended against releasing chlorinated organic compounds into the environment. The balance of opinion among scientists seems to be that a ban on chlorinated organics would be justified, while a ban on chlorine or inorganic chlorine compounds would not. A summary of positions taken by various organizations on this question is on p. 59 of the Jan. 22 Science News, as a sidebar in an article by Janet Raloff called "That Feminine Touch" (p. 56-59). This is the second of a two-part series, the first of which was called "The Gender Benders" and appeared in Science News for January 8, on p. 24-27.

The U.S. Environmental Protection Agency, together with Environment Canada, announced at the end of 1993 that they opposed total elimination of chlorine and chlorine compounds as industrial feedstocks. This was welcome news not only to the paper industry, most of which uses chlorine compounds to bleach pulp, but also to American cities, which disinfect with chlorine 98% of the water Americans drink, and to people whose health is maintained with prescription drugs, about 85% of which are produced with the aid of chlorine.

New information about the effect of organochlorines on early sexual development, especially in men, continues to come to light. (This information is summarized in the above article by Janet Raloff.) Partial or complete reversal of a male fetus's gender may be brought about if it is exposed to too much estro-gen or to chemicals (notably organochlorines and nonylphe-nols) that either mimic the action of estrogen or block the production of androgen. Females are not seriously affected, because feminine development is the "default pathway."

Since the organochlorines concentrate in fat tissues and do not get excreted, they accumulate in the body, producing a cumulative effect over the years. So exposure to, say, ten "hormonal toxicants" at undetectable levels, at different times, may have the same effect as one or more sizable doses. These compounds also turn up at great distances from the point of production. Many observers have found them at all levels of the Arctic food chain.

The use of chlorine in the chemical industry is described in "Is This the End for Chlorine?" by S. Cooper and D. Adams, in Eur. Chem. News v. 59 #1576, 5 July 1993, suppl. Chemscope Environment Review, pp. 8-9 (1994 Paper & Board Abstracts Abstr. 649). Pesticides, solvents, polyvinyl chloride (PVC), refrigerants and bleaching agents all contain chlorine. The paper industry has reduced its use of chlorine, but the PVC industry has not. As chemical alternatives to chlorine exist, the abstract says, "it can only be a matter of time before this harmful chemical substance is phased out completely."

The decreasing production of dioxin as a byproduct in pulp bleaching with chlorine is described in "Dioxin: An Industry Success Story," by Josephine S. Cooper, in the October 1993 Tappi Journal. Only a tenth as much dioxin was discharged from pulp mills (in pulp, effluent and sludge) in 1992 as in 1988. Ms. Cooper is Vice President, Environmental and Regulatory Affairs, American Forest and Paper Association.