Environ. Sci. Technol. 1902, 16, 439-440
(4) Rees, T. F. In Lyon, W. S., Ed. “Radioelement Analysis
Quality Laboratory in Denver.
Progress and Problems”; Ann Arbor Science: Ann Arbor, MI, 1980; pp 199-206. (5) Bondietti, E. A.; Reynolds, S. A. In Ames, L. L., Ed. “Proceedings of Actinide-Sediments Reactions Working Meeting, Seattle, WA, February 10-11, 1976”, Report BNWL-2117, Battelle Northwest Laboratories, Richland, WA; pp 505-530. (6) Morris, D. A. “Hydrology of Waste Disposal-National Reactor Testing Station, Idaho, Annual Progress Report, 1962”,U.S. Geological Survey Open-File Report issued by U.S.Department of Energy as IDO-22044, April 1963.
Literature Cited (1) Cleveland, J. M.; Rees, T. F. Science (Washington, D.C.)
1981,212, 1506. (2) Robertson, J. B.; Schoen, R.; Barraclough, J. T. “The Influence of Liquid Waste Disposal on the Geochemistry of Water a t the National Reactor Testing Station, Idaho, 1952-70”;U.S. Geological Survey OpenrFile Report published by U.S.Department of Energy as IDO-22053, February 1974. (3) Barraclough, J. T.; Jensen, R. G. “Hydrologic Data for the Idaho National Engineering Laboratory Site, Idaho, 1971 to 1973”, U.S. Geological Survey Open-File Report published by U.S. Department of Energy as DO-22055, January 1976.
Received for review September 8,1981. Accepted February 25, 1982.
CORRESPONDENCE Comment on “Automobile Traffic and Lung Cancer. An Update on Blumer’s Report” SIR: The article by Polissar and Warren, in spite of extensive use of scientific survey language, did not really demonstrate any proofs for the claimed results, which appears to be in marked contrast to the Blumer study. To a considerable extent the different findings are attributable to the entirely different character of the survey areas used in the two studies. Being familiar with the conditions prevailing in both the Seattle and the Swiss locations (the latter happens to be the place where many decades ago I was born), I should like to point out that the study in the Swiss region took place at a location that is singularly suitable to studies of automotive exhausts and its consequencies. To understand this statement, it is necessary to describe the particular geographical and topographical features of the test area. The Swiss area under study was a stretch of highway in a narrow mountain valley, flanked on both sides by high mountains. The principal highway at the time of the survey was the only possible automotive communication between towns of that valley. All traffic had to use it. At the time of the survey rows of buildings on both sides of the highway were abutting that artery, with only 50 to 60 feet of space between the front walls of the structures on either side of the highway. Traffic at all other locations in that area was of strictly local character, with traffic of only a minute percentage of that of the main artery. It was a combination of circumstances that lent itself ideally to the kind of study Dr. Blumer et al. carried out; circumstances that would indeed be difficult to duplicate even in present-day Switzerland and practically impossible in US.cities, with their wider traffic arteries, less cluttered and wider spaced residential building patterns, and a much greater choice of routesinstead of the one main artery with no alternatives. Seattle, on the other hand, is entirely different. It is hilly and windy, and buildings generally are widely spaced, providing for no concentration of exhaust gases, with consequent entirely different results. It also does not 0013-936X/82/0916-0439$01.25/0
provide, as the Swiss community did, a sharp contrast between very heavily travelled roads and others with absolutely minimal or no automotive traffic at all. The small scope of the Swiss survey made it possible to obtain very detailed information on the length of time the various residents were exposed to exhaust gases. The Seattle report does not give that sort of information-at least not in the published excerpts. Because of the ideal natural configuration, the Swiss study can lay greater claim for demonstrating the differences between heavily travelled and lightly travelled locations, and its findings may indeed be more significant than those of the Seattle study. The Swiss town where Dr. Blumer et al. made their studies almost had the character of a laboratory situation, while Seattle was not favored by nature and traffic pattern with such ideal conditions. It would appear that the results of the Swiss survey can hardly be dismissed by a mere comparison with the results of the Seattle study. A detailed analysis of the basic conditions under which the Blumer study was made might easily explain the drastic difference between the findings at the two survey locations. Alphonse A. Kubly 777 Beach Road Sarasota, Florida 33581
SIR: Thank your for the opportunity to respond to Alphonse Kubly’s letter concerning our study ( I ) , which was an investigation of the findings of Blumer et al. (2,3). We would like to discuss Kubly’s main points in turn. First, we take Kubly’s comment on our use of “scientific survey language” as his concern that Blumer’s findings might be disregarded or discredited due to our study. Such should not be the case, When we read Blumer’s first paper (2) in translation, we felt that it was an excellent scientific study. We feel that our finding of an excess (but nonsignificant) risk for females partially supports Blumer’s results. The extent of reported risk is certainly different in the two studies, and it would be worthwhile finding out why this is so.
0 1982 American Chemical Society
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Kubly suggests that a radical difference between the physical settings in Switzerland and Seattle accounts for the difference in findings. In our original paper we also pointed out that the two locations may have dissimilar rates of automobile exhaust dilution. Kubly has amplified on the character of the Swiss town in his letter, and it is possible, as he suggests, that the Swiss results are due to an extreme type of setting. What is missing from both of the studies is an accurate measurement of exposure to automobile exhaust or fractions of it in the vicinity of the study subjects. Both studies used average daily traffic (ADT) as a surrogate for exposure. We would agree with Kubly that there is almost surely less exhaust dilution in the Swiss town than in Seattle. Another of Kubly’s points is that Seattle does not provide a sharp contrast between heavily travelled and less travelled roads. It is probably true that Seattle does not have many streets as quiet as some of those in the Swiss town. However, there was a wider range of exposures to traffic found among our study subjects than in the Swiss town. 74% of our 1330 subjects lived on streets with less than 2000 ADT, 16% lived on streets with 2000-15000 ADT, and 9% lived on streets with over 15000 ADT. The busy Swiss road carried 5000-6000 ADT, and the outer quarter of the town had, presumably, close to zero traffic. Kubly notes that Blumer was able to obtain very detailed information on the length of residence of the Swiss subjects. Indeed, our use of current residence to imply past exposure is a less powerful and less certain approach than use of length-of-residence data, which was available to Blumer. In our study only residence at diagnosis was available to us. We pointed out our lack of migration data and the potential importance of such data. If our subjects had been highly migratory, which is a possibility, then the imputed exposures could be in error. We have commented at length on the migration problem in environmental studies in another publication ( 4 ) . A point not discussed by Kubly is that excessive cancer deaths occurred for all sites combined in the Swiss study. The 75 cancer deaths along the busy road involved breast, uterus, ovaries, intestines, prostate, and other sites. It is unusual that an environmental insult has that general an effect. Would not the auto exhaust be expected to mimic the effects of smoking? Of the 75 cancer deaths along the busy road, only 11 were of the respiratory type. Is it possible that another mechanism-possibly stress-might play a role in the Swiss town? From Kubly’s description, the main road is an unpleasant place to live, and an unusual set of risk factors might be operating. By this time, the Swiss town has experienced an additional 11 years (1971-1981) of mortality that could be compared to the 12 years (1959-1970) reported on earlier. A replication study with very specific information on 9 variety of risk factors could possibly be carried out at this time. Other locations in the world may also have ideal settings for studying the effects of concentrated automobile exhaust. We thank A. A. Kubly and the editor for bringing some important points to our attention and providing us with the opportunity to comment on them. Literature Cited (1) Polissar, L.;Warner, H., Jr. Enuiron. Sci. Technol. 1981, 15, 713-714. ( 2 ) Blumer, W.; Jauman, T.; Reich, T. Schweiz. Rundsch. Med. (Praxis) 1972,61, 514-518. (3) Blumer, M.;Blumer, W.; Reich, T. Enuiron. Sci. Technol. 1977,11,1082-1084. 440
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(4) Polissar, L. Am. J . Epidemiol. 1980,111, 175-182.
Lincoln Polissar* Fred Hutchinson Cancer Research Center Program in Epidemiology and Biostatistics Seattle, Washington 98 104
Homer Warner, Jr. 1841 East 900 South Salt Lake City, Utah 84108
Comment on “Nature of Bonding between Metallic Ions and Algal Cell Walls” SIR The article by Crist and co-workers on the “Nature of Bonding between Metallic Ions and Algal Cell Walls” (Enuiron. Sci. Technol. 1981,15, 1212) raises some questions that we would like to address at this time. 1. The authors mention that the ZPC of algal cells is approximately at pH 3 (1). This is consistent with our observations of Chlorella. Electrophoretic mobility (EM) values decrease from pH 3 to pH 5. No further decrease is observed in EM with increases in pH to pH 9. Christ et al. observed significant proton dissociation at high pH values (Figure 1). This might suggest a higher ZPC than observed by other investigators. 2. The authors suggest that the response of intact cells and fragmented cells to cationic additions is similar. This is in contrast to our work. We have observed profound differences between active and inactive cells. Hydroxide titration curves (Figures 1 and 3) appear to exhibit a different response for intact and fragmented cells. Fragmented cells (Figure 3) have a low pH buffering capacity at pH 4 and a high buffering at pH 7, while intact cells (Figure 1) have a high buffering capacity at pH and a minimum buffering capacity at pH 7. These figures seem to contradict the authors contention that the ionic equilibria of intact and lysed cells is similar. 3. Our studies suggest that cell age and equilibration time are important when quantifying cationic adsorption/uptake by algal cells. Other studies have also reported similar results (2-4). The authors make no mention of equilibration times over which their cells were incubated. 4. Finally, we object to eq 2. Na+ + (ZnA) = (NaA) + Zn2+
(2)
An electroneutrality balance is a prerequisite to all aqueous transformations. We are at a loss to understand why it is not valid here. Literature C i t e d (1) Stumm, W.; Morgan, J. J. “Aquatic Chemistry”; WileyInterscience: New York, 1970;p 455. (2) Hassett, J. M.; Jennett, J. C.; Smith, J. E. Appl. Enuiron. Microbiol. 1981,41, 1097-1106. (3) Fujita, M; Hashizumie, K. Water Res. 1975,9, 889-894. (4) Button, K.S.Hostetter,H. P.J . Phycol. 1977,13,198-202.
Wllllam D. Schecher, James M. Haseett Charles T. Driscoll” Department of Civil Engineering Syracuse Unlversity Syracuse, New York 13210
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@ 1982 American Chemical Society
