Letters M Perfluorocarbon confusions Dear Editor: Your Government Watch report of January 1, 2001, “Proposed actions on fluorosurfactants” (Environ. Sci. Technol. 2001, 35 (1), 13A–15A) contains a serious error and omissions that may have misled your readers: Adverse effects of perfluorooctyl sulfonates (PFOS) have been observed only at high exposure levels and only in laboratory animal studies, where the No Observable Effect Levels for serum and liver are 47 and 72 µg/g, respectively. These levels are much higher than any human or wildlife exposure level, and based on the extensive data presently available, 3M believes that the low levels found in the general population and the environment are not associated with any adverse effects. The stated purpose of the Significant New Use Rule (SNUR) is to “provide EPA with the opportunity to evaluate an intended new use [of PFOS and specified related materials]
and associated activities and, if necessary, to prohibit or limit the activity before it occurs” (Fed. Regist. 2000, 65, 62,319). 3M’s voluntary phaseout of the manufacture of these compounds was announced in May 2000, and a detailed plan was provided to the EPA. This phaseout plan is not impacted by the SNUR Rule. MICHAEL A. SANTORO Director, Environmental, Health, Safety and Regulatory Affairs 3M Specialty Materials Markets 3M Center, Building 236-1B-10 St. Paul, MN 55144
Carbon trading? Dear Editor: With regard to your article on “Carbon trading” (Environ. Sci. Technol. 2000, 34 (7), 180A), first, the assertion of the Business Environmental Leadership Council (BELC), that most scientists view that, “enough is known about the science and envi-
ronmental impacts of climate change”, may be subject to doubt. Next, assuming that the practice of selling pollution production rights is correct, why doesn’t the same principle also apply to other individual interests, so that a citizen may, e.g., accumulate “credits” for his lawful conduct? Third, since only in a few cases it would make sense to purchase a factory’s dirty smoke, why should the right to produce that smoke be considered a tradable value? Unfortunately, the buyer of an emission permit may not always be the one who consumes the emission. The problem of greenhouse discharges is part of the general problem of the management of hazardous wastes. It is obvious that the excessive emission of a substance may only be compensated by cleanup processes. LAVRIA PROTOPAPADAKIS Agiou Georgiou 2 145 78 Ekali, Greece Phone: 00301-8131149
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