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patterns (with regions of both increasing and decreasing solubility) for decanol in sodium laurate solutions. In the present case, the varying concentration of both humic acid and toluene, it is possible that the toluene alters the cmc of the mixture. Detailed spectroscopic and colligative studies would be required to elucidate the mechanistic basis behind eq 1-2. Conclusions By use of the isopiestic apparatus of Sanemasa et al. (Id),precise measurements of toluene solubility as altered by humic acid have been obtained. Within the range 0-70 mg/L DOC, solubility increases of up to 8% of the intrinsic, zero organic solubility have been noted. By use of a partition coefficient model, these data show that toluene solubility by humic acid decreases (i.e., the partition coefficient decreases) with increasing humic acid concentration, in a manner similar to that reported for more hydrophobic pollutants. The results indicate that, while solubilization of toluene by DOC does occur, it may be of limited significance in affecting overall distribution of toluene in natural and engineered aquatic systems. It would be desirable to elucidate the mechanism of solubility and to determine the relative partition coefficients of various volatile pollutants. The present apparatus provides a means for obtaining high precision data for such coefficients, and futher studies on these areas are planned. Acknowledgments We thank H. E. Allen for his initial suggestion of this problem and P. V. Doskey for continued support and advice concerning analysis. Registry No. Toluene, 108-88-3; HzO, 7732-18-5.
Literature Cited (1) Diachenko, G. W. Ph.D. Thesis, University of Maryland, College Park, 1981. (2) Griffan, R. A.; Chian, E. S. K. “Attenuation of Water Soluble Polychlorinated Biphenyls By Earth Materials” 1980, EPA Report EPA-600/2-80-027.
(3) Mackay, D.; Shiu, W. Y.; Bobra, A.; Billington, J.; Chau, E.; Yeun, A.; Ng, C.; Szeto, F. “Volatilization of Organic Pollutants From Water” 1982, EPA Report EPA 600/382-019. (4) Carter, C. W. Ph.D. Thesis, Drexel University, Philadelphia, PA, 1982. (5) Perdue, E. M.; Wolfe, N. L. Enuiron. Sci. Technol. 1982, 16,847-852. (6) Carter, C. W.; Suffet, I. R. Enuiron. Sci. Technol. 1982,16, 735-740. (7) Roemelt, P. M.; Seitz, W. R. Environ. Sci. Technol. 1982, 16,613-616. (8) Landrum, P. F.; Nihart, S. R.; Eadle, B. J.; Gardner, W. S. Environ. Sci. Technol. 1984, 18, 187-192. (9) Means, J. C.; Wijayaratne, R. Science (Washington,D.C.) 1982,215,968-970. (10) Boehm, P. D.; Quinn,J. C. Geochim. Cosmochim.Acta 1973, 37, 2459-2477. (11) Matsuda, K.; Schnitzer, M. Bull. Environ. Contam. Toxicol. 1973,6, 200-204. (12) Pierce, R. H.; Olney, C. E.; Felbeck, G. T. Geochim. Cosmochim. Acta 1974, 38, 1061-1073. (13) Wershaw, R. L.; Purcar, P. J.; Goldberg, M. C. Environ. Sci. Technol. 1969, 3, 271-273. (14) Sanemasa, I.; Araki, M.; Deguchi, T.; Nagai, H. Bull. Chem. SOC.Jpn. 1982,53,1054-1062. (15) Kaplan, B. M. M. S. Thesis, Illinois Institute of Technology, Chicago, 1984. (16) Brownlee, K. A. “Statistical Theory and Methodology in Science and Engineering”; Wiley: New York, 1960. (17) Morrison, T. J.; Billet, F. J. Chem. SOC.1952,52,3819-3822. (18) Sutton, C.; Calder, J. A. J. Chem. Eng. Data 1975, 20, 320-322. (19) Perdue, E. M. In “Aquatic and Terrestrial Humic Materials”; Christman, R. F.; Gjessing, E. T. Eds.; Ann Arbor Science Publishers: Ann Arbor, MI, 1983; pp 441-460. (20) Chiou, C. T.; Freed, V. H.; Schmedding, D. W.; Kohnert, R. L. Environ. Sci. Technol. 1977, 11, 475-478. (21) Piret, E. L.; White, R. G.; Walther, H. C.; Mudden, A. J. Proc. R. Dublin SOC.1960, l A , 69-79. (22) Ekwall, P.; Mandell, L.; Fontell, K. Mol. Cryst. Liq. Cryst. 1969,8, 157-223.
Received for review September 7,1984. Accepted January 22, 1985.
CORRESPONDENCE Comment on “Comparlson of the Carcinogenic Risks from Fish vs. Groundwater Contamination by Organic Compounds” SIR: The accumulation of toxic chemicals by fish has long been recognized as a pervasive threat to piscivorous wildlife. Accordingly, the US.Fish and Wildlife Service has participated in the National Pesticide Monitoring Program (NPMP; now the National Contaminant Biomonitoring Program) since 1967 by periodically determining chemical residues in avian wildlife and in freshwater fish collected from national networks of stations. More recently, it has been recognized that chemical residues, especially residues of carcinogens,accumulated by food fishes
may also constitute a threat to the public health. The recent note by Connor (1)suggests that such concerns may be justified; however, we have reason to question Connor’s conclusions regarding the potential risks associated with contaminants in freshwater fish. In July, 1982, Connor wrote to our laboratory requesting recent information on contaminant residues in freshwater fish. He was sent copies of two articles that contained such information; both of these articles were correctly referenced under Literature Cited as ref 6 and 7 . On pp 140 and 151 of Schmitt et al. (2), and on p 22 of Schmitt et al. (3),it states, in essence, that NPMP data for residues in whole fish are representative of the contaminant levels to which piscivorous wildlife would be exposed but that the values reported are probably higher than concentrations in the edible tissues, to which humans would be exposed.
Not subject to US. Copyright. Published 1985 by the American Chemical Society
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Whole-fish samples include the viscera, which contains more lipid than does muscle tissue, as well as organs that concentrate organic contaminants. Connor was also advised of this in the cover letter that accompanied the material he requested. Inspection of Connor’s Figure 1 suggests that this caveat was ignored in calculating the risks associated with the consumption of freshwater fish; according to the figure legend, the bar labeled “FW” is based upon “average concentrations from 1979 freshwater fish survey for US.” The only sources cited for freshwater fish residues are our publications (2, 3). We sincerely hope that we have incorrectly interpreted Connor’s article-that he derived estimates of contaminant concentrations in the edible tissues of freshwater fish from FDA market surveys ( 4 ) or that our values for whole fish were adjusted before they were used, which cannot be determined on the basis of information in the published article. If we have misinterpreted, we extend our apologies and await clarification of the methods he used; however, if Connor used the 1979 NPMP information without applying some modification to derive his assessment, then freshwater anglers, commercial fishermen, and fishery managers throughout the United States await his revised estimates.
Literatwe Cited (1) Connor, M. S. Enuiron. Sci. Technol. 1984,18,628-631. (2) Schmitt, C. J.; Ludke, J. L.; Walsh, D. F. Pestic. Monit. J. 1981, 14, 136-206. (3) Schmitt, C. J.; Ribick, M. A.; Ludke, J. L.;May, T. W. U.S., Fish Wildl. Seru. Res. Publ. 1983, 152, 1-62. (4) “FY 79 Pesticides and Metals Program”; FDA 7305.007: Washington, DC, 1982.
Christopher J. Schmitt,” J. Larry Ludke US. Department of Interior Fish and Wildlife Service Columbia National Fisheries Research Laboratory Columbia, Missouri 65201
SIR: Schmitt and Ludke (1)were very kind in providing me access to their data. They very clearly indicated that their data were for whole fish. In fact, it was often necessary for me to transform between data for whole fish or fish liver concentrations to concentrations in the edible portion of the fish. The figure legend does cite the lengthier publication where this transformation is explained in more detail ( ( 2 )ref 13 in my original publication). In brief, I matched fish by age, lipid content, year, and location where information for both whole fish or edible concentration were available. I used the ratio of edible/ whole concentration (for these data, 0.3) to convert the data from Schmitt’s laboratory. Naturally, there can be a great deal of variation in this ratio so I used several independent methods to estimate human consumption of contaminants from fish. As I discussed in the explanatory paragraph for the figure, where the lengthier publication is again cited, the different methods are in general agreement.
Literature Cited (1) Schmitt, C. J.; Ludke, J. L. Enuiron. Sci. Technol., preceding paper in this issue. 646
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(2) Connor, M. S. “Management of Wastes in the Ocean”; Wiley: New York, in press.
Michael Stewart Connor Region 1 U.S. Environmental Protection Agency Boston, Massachusetts 02203
Comment on “Red Herrings in Acid Rain Research” SIR: Regarding the feature article by Havas et al. (11, I agree that it is time for all concerned to work together and not rely on questionable truisms. However, it seems that regulatory zealots with help from the popular media have been the leaders in espousing untested hypotheses as listed below: (1)Nitric acid in rain has the same effect as sulfuric acid. (2) Liming of lakes is only useful for research while further controls on NO, and SO, should be effected immediately. (3) Effects of alkaline emissions can be ignored. (4) Midwest SO,-NO, utility emissions are responsible for the acidity in Adirondack lakes while rain acidity is proportionate to such emissions. (5) Benefits derived from stringent SO, controls would outweigh their costs. (6) Acid rain causes severe damage to vegetation while benefits are negligible. The lack of validity of these hypotheses is discussed in a recent publication (2). Another unjustified hypothesis is that there are significant human health effects from acid precipitation. Because there is a dearth of evidence on adverse human health effects from acid precipitation, this is usually implied by statements such as used by Havas et al. (“Why must we tolerate decades of emissions, damage to the environment, and often human health before abatement measures are even considered?”). They fail to cite a single reference to support the health effect implication. Pollution control measures for SOz, NO,, particulate, etc. have been considered and effected for decades even though health effects at US. ambient levels remain unproven.
Literature Cited (1) Havas, M.; Hutchinson, T. C.; Likens, G. E. Enuiron. Sci. Technol. 1984,18, 176A-186A. (2) Innes, W. B. Chemtech 1984, 14, 440-447.
W. 6. Innes Purad Inc. 724 Kilbourne Dr. Upland, California 91786
SIR: Dr. Innes (I) is using the excuse of a rebuttal to our paper to introduce more red herrings into the literature. Little of what he has to say relates directly to our paper. The techniques used by Innes and others are classics. One technique is to alter the wording slightly so that the meaning changes substantially and then claim the
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0 1985 American Chemical Society
