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LETTERS Lead debate Dear Sir: The review by Stephen Budiansky concerning the effect of lead on man and his environment does a great disservice to science ( E S &T , March 1981, p. 243). Mr. Budiansky takes it upon himself to act as judge in this complex issue. I do not believe he is qualified to do so. Instead, it would be scientifically acceptable to present both sides of the issue and allow the reader to decide for himself. The title, “Lead: the debate goes on but not over science,” immediately prejudices the reader. Furthermore, the article is replete with similar statements in which the author makes judgments for which he is not qualified and which reflect his bias. The work of Dr. Needleman is certainly important in the area of lowlevel lead exposure, but other equally qualified scientists have conducted studies that have not shown an adverse effect of slightly higher blood lead levels. Scientists from the University of Cincinnati and EPA recently reviewed and evaluated clinical and animal studies that were designed to measure behavioral effects of moderate lead exposure. A total of 22 studies were reviewed. The authors stated, “There was no clear trend indicating that moderate lead exposure caused any abnormalities in behavioral development of children nor was there any compelling evidence which suggested that this was not the case.” The work of Dr. Patterson can be best described as controversial. There may be increases in lead on remote icecaps due to industrialization, and tuna may have low levels of lead which are increased through processing, but it is certainly by no means evident that humans are contaminated with large quantities of industrial lead. With the significant amounts of lead naturally present in soil, it should not be unexpected that plants grown in this soil would absorb some amount of this lead. Many studies show clearly that most of the lead in the normal human diet comes from that naturally present in the soil. It is misleading to suggest that studies by Drs. Needleman and Pat722
Environmental Science & Technology
terson comprise the final work in this area. Much research has been done and is still underway on lead. These studies have not stopped nor will they be halted by the suggestion of Mr. Budiansky that this is a political and not a scientific issue. Gary Ter Haar, Director Toxicology and Industrial Hygiene Department Ethyl Corp. Baton Rouge, La. 70801
Editor’s response Dr. Ter Haar rightly points out that other studies have come up with conclusions at odds with those of Drs. Patterson and Needleman. Yet he ignores the principal point of the story: Science is not decided by majority vote. The work of both Dr. Patterson and Dr. Needleman is of vastly superior quality to that of others. Dr. Patterson takes extreme precautions to prevent contamination of his samples; he has in fact shown time and time again that the conflicting results obtained by other workers were the direct result of sample contamination. In at least one instance, he did so by analyzing precisely the same sample that another group had; he found an error of six orders of magnitude in their reported results. It is unscientific to insist under these circumstances that the two differing results be given equal weight. Dr. Ter Haar’s statement that it is “by no means evident that humans are contaminated with industrial lead” ignores Dr. Patterson’s analysis of ancient Peruvian Indian bones, which showed prehistoric body-burdens of lead to be two to three orders of magnitude below present typical levels. Dr. Needleman’s epidemiological study controlled for a host of potentially confounding variables ignored by others. That other studies failed to find a link between low levels of lead and impaired health or intellectual performance does not mean there is no such link; it rather means that those studies were not sensitive enough to detect them. And this is not my conclusion; it is the conclusion of a panel of experts assembled by the Society of
Occupational and Environmental Health. Whether I am qualified to judge this complex issue is a matter for each reader to decide for himself. As for Dr. Ter Haar’s charge of bias on my part, I can only say that I came to the subject with an open mind and that, unlike Dr. Ter Haar, I have no vested interest in either side of the issue. Stephen Budiansky E S & T , Washington, D.C. 20036
Lead debate Dear Sir: While I would be the first to agree that there is a great deal of politics related to environmental questions concerning lead, I must strongly disagree with the view that the preponderence of scientific data support Mr. Budiansky’s position that man’s environment is heavily contaminated with lead and that this lead is having a detrimental effect on the health of children (ES&T, March 1981, p. 243). Budiansky’s predisposition on this matter is clear when one considers his unqualified acceptance of the studies and interpretations of Needleman and Patterson, supporting this view while stating that “the lead industry continues to cart around the results of studies that Needleman and others call poorly controlled and insensitive; these show no correlation between lead exposure and performance of children.” The fact is that the El Paso study (1) was not “insensitive.” In fact, in the evaluation of 22 epidemiological studies (2) which was mentioned, the following is stated regarding the El Paso study: “In many ways, this is one of the best thought out and most reasoned studies in the literature.’’ Of the five studies considered to be reasonably good, both the El Paso study and the Needleman study (3) were included. Interestingly, the only other study of those five to show adverse effects ( 4 ) has recently been repeated on the same group of children (continued on page 7 2 4 )
