LETTERS Lead-acid battery emissions Dear Editor: The recent comparison of ozone reduction and lead discharges from battery-powered vehicles by Lester B. Lave et al. (Sept. 1996, pp. 402A-407A) uses a curious mix of outdated and current information. The authors assert that lead emissions from the use of lead-acid batteries in electric vehicles may result in "adverse impacts that are substantially larger than the modest air quality benefits that will result." We would like to point out some data that may be useful in future analyses of this type. Air emissions from secondary lead smelting (i.e., battery recycling) are likely to be lower than reported by Lave et al. For the two largest companies that operate secondary lead recyclers nationwide, air emissions at their California smelters have dropped from one-half to one order of magnitude from 1991 to 1993 (Kimbrough, D. E., Environ. Set. Technol. .195, 29, 2217-21)) While Lave et al. implied that low air emissions are unique to California, Toxics Release Inventory data for secondary lead recyclers nationwide show a downward trend in air emission factors of 100- to 1000-fold from 1987 to 1992 (Steele N L C thesis University of California LosAngeles 1995) Lave et al. also suggest that increased recycling of electric vehicle batteries will cause California's smelters to exceed regulatory limits on air emissions. This is not inevitable. For example, one of the recyclers has responded to this possibility by exploring the building of a lead electrowinning pilot facility. Electrowinning of lead, should it prove feasible, would have virtually no air emissions and may increase the efficiency of lead-acid battery recycling. Thus, technological improvements in lead recycling IT13V b e spurred by the introduction of electric vehicles with lead-acid batteries Solid waste is implied to be as
great a health threat as air emissions. Substantial amounts of low lead concentration solid waste are generated by recycling, but far less than would be generated were leadacid batteries not recycled. Approximately 5% of lead-acid batteries are not recycled annually; one cannot assume these are landfilled. Batteries may last longer than expected and thus still be in service, be abandoned in junked cars, or stored indefinitely in garages. In addition, it is highly unlikely that large lead-acid battery packs would not be recycled, as it is more likely that the consumer would have the job of replacement done at an auto repair facility
It is not inevitable that increased recycling of electric vehicle batteries will cause lead smelters to exceed air emissions limits. As for weathering of solid waste, lead-contaminated wastes that are classified as toxic are managed by treatment to reduce lead solubility and by disposal to stringently regulated hazardous waste landfills. Furthermore, studies indicate that leadcontaminated wastes in landfills degrade and migrate downward extremely slowly, on the order of thousands of years (Rathje, W. L. et al. American Antiquity 1992 57 43747). Thus, hazards from lead in solid waste 9X6 overstated An additional issue that should be addressed concerns where potential increases in lead emissions will occur. According to Lave et al., the people who live in New York and California will benefit from reduced ozone, nitrous oxides, and carbon monoxide. Although not mentioned in the study, they should also benefit from reduced particulate matter as a
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result of gas-to-particle conversions and reduced toxic emissions. However, if increased lead emissions do occur, they will most likely not occur in California or New York. A direct comparison of costs and benefits must account for the regions to which those costs and benefits will accrue. NANCY L. C. STEELE Altadena, G4 91001 DAVID E. KIMBROUGH Castaic Lake Water Agency Saugus, CA 91350 Authors' response Steele and Kimbrough assert that "For the two largest companies that operate secondary lead recyclers nationwide, air emissions at their California smelters have dropped from one-half to one order of magnitude from 1991 to 1993." Data quality is a major problem for environmental emissions from lead smelting, battery manufacture, and battery recvcling. Steele and Kimbrough rely on data that is not publicly available. Readers can decide for themselves how much confidence to place in data where it is not possible sess its quality or representativeness Publicly available data tend to contradict this confidential data. According to Toxics Release Inventory data for GNB, Inc. (Vernon, Calif.), release of lead compounds to the air increased from 3400 lb/year in 1991 to 6700 lb/year in 1994; release to the environment on site increased from 3400 lb/year in 1991 to 6700 lb/year in 1994; and total lead releases and transfers on site and off site increased from 719 422 lb to 816 930 lb over the same period. Lead releases also increased at Quemetco Inc (City of Industry Calif) from 1991 to 1994 Neither facility reports any emissions for lead only lead compounds Steele and Kimbrough comment that "Toxics Release Inventory data for secondary lead recyclers nationwide show a downward trend in air emissions factors of 100- to 1000fold from 1987 to 1992." Their state-
