AIR POLLUTION-1966 WEDNESDAY, JUNE 15, 1966 UNITED STATES SENATE, SUBCOMMITTEE ON AIR AND WATER POLLUTION The subcommittee met at 9:55 a.m., pursuant to recess, in room 4200, Senate Office Building, Senator Edmund S. Muskie (chairman of the subcommittee) presiding. Present: Senators Muskie and Boggs. Also present: Senator Cooper. Senator MUSKIE. The committee will be in order. Our first witness this morning, and I again wish to express my appreciation for his courtesy and cooperation in going over to today from yesterday, Dr. Clair C. Patterson from the California Institute of Technology. Dr. Patterson, it is a pleasure to welcome you this morning. STATEMENT OF DR. CLAIR C. PATTERSON, PH. D., CALIFORNIA INSTITUTE OF TECHNOLOGY Dr. PATTERSON. Good morning, Mr. Chairman. It is a pleasure to have you invite me here to speak. I have been nudged by some of your staff to write out the presentation which I have managed to do rather early in the morning in my hotel room. It is not in very good shape. I only have one or two copies. If it is all right with you, I will read from this statement. Will it be all right? Senator MUSKIE. Yes. Dr. PATTERSON. It will take perhaps 15 minutes. Geochemical studies of lead cycles in the oceans and the atmosphere of the earth show that the chemical precipitation of dissolved lead on the bottom of the seas amounts to about 10 thousand tons of lead per year, as compared to some millions of tons of lead per year which is produced by industry. It has been observed that lead now enters the seas via rivers in amounts that exceed natural values, values that we infer existed during prehistoric times, by about an order of magnitude. It is no myth that there are only about 100,000 tons of lead in the upper mixed layers of all of the oceans of the entire earth which may be compared to industrial rates of production of millions of tons of lead, and of the storage of lead in various forms which amount to tens of millions of tons in our human environment of cities and towns. It is clear from these figures that the industrial production and utilization of lead today far exceeds the natural rates of flow of lead 311 in geochemical cycles of the oceans and the atmosphere. The surfaces of the open ocean appear to be polluted with lead mined by man. Analysis of lead in preserved snow layers near the North Pole show that the atmosphere has become progressively more polluted with lead to a maximum today. Because of this extensive pollution, typical lead levels observed in our environment may be grossly higher than natural lead levels. It is important therefore to carefully distinguish between the typical levels of lead in our environment and those natural levels which refer to the levels of lead in body and environment which prevailed during the creation and the evolution of our physiological responses to lead. It is reasonable therefore to set aside typical observations of lead and to consider what the natural values might be by geochemical means. We can consider, for example, the abundance of certain trace elements in the earth which are similar to lead, and infer a level of lead from these values. Such elements as germanium, tin, thallium, mercury, bismuth, when considered in our environment suggest that the natural amount of lead in a 70 kilogram man should be of the order of 1 to 10 milligrams. When we consider the abundance of the alkaline earth series, calcium, strontium, barium and its relationship to lead in soil, plants, man's diet, and in man himself, we infer that the natural amount of lead in a 70 kilogram man should be about 2 milligrams. Using this natural value for the body burden of man, we can estimate that the natural concentration of lead in food should be approximately 0.01 p.p.m., 0.0005 microgram per cubic meter in air, 0.0005 p.p.m. in natural waters, and a natural concentration of lead in blood of 0.002 p.p.m. How do these values compare with typical ones observed in America today? The average body burden of lead in Americans is estimated to be about 200 mg. of lead, the average concentration of lead in food is about 0.2 p.p.m. The average concentration of lead in blood is about 0.2 p.p.m., and the average concentration of lead in city atmosphere is about 1 microgram of lead per cubic meter. What are the consequences of this discrepancy between inferred natural values of lead and observed typical values? There is clear and strong suggestion that the average resident of the United States is being subjected to severe chronic lead insult. It is possible that deleterious effects to the health of large numbers of people are being caused by these high levels of exposure. An important consideration in this matter involves not just a possible increase in mortality but the possibility that the course of human events could be perturbed by this toxic metal since the function of the central nervous system in humans may be affected. I feel an obligation to go beyond the presentation of these geochemical observations and ideas on this lead problem because the posture of the U.S. Public Health Service, the California State Department of Public Health and the teaching faculties in occupational medicine and environmental health engineering has been to defend and promote ideas that may be dangerous to the health of all Americans. I have chosen to present five points which are important to the views of a physical scientist on these matters. Point 1. At no time have persons in the above organizations distinguished explicitly and clearly between typical and natural concen trations of lead in the food and bodies of Americans. On the contrary, they have implied in various reports and publications that typical values are natural and therefore safe and harmless. Since some occupational medical people and lead industrialists have quoted such documents in refuting any suggestions of danger, it is important that these organizations clarify their stand on whether concentrations of about 0.2 p.p.m. of Pb, which now exist in the food and blood of most Americans, are typical or natural. If these values are natural, the reasons for believing this should be given. If they are not, then natural level should be given, with justifying reasons. If natural levels are unknown, then reasons should be given for regarding present levels as safe with respect to subacute but severe exposure. Point 2. These organizations profess to guard public health and control dangerous exposure, yet their activities seem to be based upon a philosophy of control at the dispersal end of the chain of production and utilization of lead which is economically expedient, and which is inadequate, breaks down and fails in the face of massive, overwhelming production. No attempts have been made to conduct material balance studies of lead production and utilization or to evaluate lead contamination of food chains. To point out these inadequacies and to emphasize the need for consideration of ways to control the production of toxic substances rather than their improper dispersal, the responsible bodies mentioned above should be asked by you to justify their actions and to clarify their stands on the following issues: (a) The maximum permissible level of Pb in apples set by the U.S. Department of Agriculture is 7 p.p.m. If lead were to be added to the food of humans to the extent of 7 p.p.m. they would die of classical lead poisoning. No attempt has been made to regulate the quantity of apples or apple products that may be ingested. No attempt has been made to investigate the total production of lead arsenate nor the faction of it dispersed into foodstuffs. (b) A U.S. Public Health Service advisory committee seriously considered in 1959 whether increasing the concentrations of lead tetraethyl from 3 to 4 ml. per gallon of gasoline would increase the hazard to public health from air pollution, and decided that it would not. Yet, nowhere in the report was it explicitly and clearly stated that this issue was pointless, and that instead, the total rate of burning of tetraethyl in a given area was the important issue. No mention was made of how controls of the latter might be implemented, nor was any attempt made to evaluate the extent to which lead tetraethyl had polluted the air since its manufacture in the twenties. By its approval of an increase of lead tetraethyl concentration in gasoline under the charge given to the committee, it was implied that no hazard from lead tetraethyl at present was involved. The committee then seemed to absolve itself of this responsibility by expressing dissatisfaction with the situation and recommended that a proper verdict could be reached by asking lead industries to work together with the Public Health Service to investigate and decide whether lead industries had indeed committed any sins. (c) It has been observed that levels of 3 micrograms of Pb per cubic meter in the atmosphere induce excretion of abnormal amounts of coproporphyrin III in children which suggests that the destructive disruption of certain blood-forming mechanisms has occurred at these levels of exposure. These concentrations of lead exist, on the average, in the Los Angeles Basin. It has also been observed that concentrations of 30 micrograms of lead per cubic meter exist near freeways in California. Upon breathing 15M3 of air per day with an absorption of 40 percent of the lead in it, about 180 micrograms of Pb per day would be calculated to enter the blood per day at these levels of exposure. I am talking about people living in apartments adjacent to California freeways. In experiments with several humans, it was observed that Pb entering the blood at the rate of 160 micrograms of Pb per day would lead to classical lead poisoning within 4 years, while a rate of about 240 micrograms of Pb per day would lead to lead poisoning within 8 months. These data again suggest that it may be dangerous for persons, especially children, to live near freeways for periods as long as decades, yet the California State Department of Public Health and the U.S. Department of Public Health Service have issued a report in 1965 after jointly considering these matters with representatives from lead industries for 5 years, which states that present levels of lead exposure are insignificant with respect to the threat of lead poisoning. Point 3. These organizations deny that the levels of lead exposures and absorption have increased in millions of Americans during the last few decades as the result of the use of lead tetraethyl. The basis for this view has been given qualitatively, without comparisons of figures, that lead levels in the bodies of Americans today are not higher than those measured in the early thirties. The methods of analysis and the subjects studied were not the same in the two instances. During this same period, measured concentrations of lead in sea water by different investigators have decreased from 5 micrograms of Pb per liter to 0.05 micrograms of Pb per liter yet no physical scientist would accept this as evidence that the concentrations of lead in sea water have decreased with time. Actually, the concentration of lead pollution in preserved layers of snow has been shown to increase with time to a maximum today. It can be shown from material balance considerations and from isotopic tracers that nearly all the lead in the atmospheres of American cities originates today from lead tetraethyl, and that 30 years ago lead concentrations in these areas should have been about a hundred times less. It can also be shown from considerations of concentrations of lead in food, air, and water, the amounts ingested, and the efficiencies of absorption, that lead in city air contributes a third to two-thirds of the lead absorbed into the blood leading to an expectation of blood lead differences between city dwellers and rural residents resulting from different exposure to lead tetraethyl pollution. These expectations are borne out by observations that urban dwellers who don't smoke have on the average 0.15 to 0.17 part per million of Pb in blood while rural inhabitants have only 0.11 part per million Pb in blood. This is a large, significant, and measurable difference which must be ascribed to lead alklys and which must have occurred during the last 30 years. These organizations should be asked to show how they decided that lead alkyls have not polluted the atmosphere of cities by several orders of magnitude, and how they decided that the elevation of blood lead levels of city dwellers cannot be attributed to lead alkyls. Point 4. These organizations believe that the danger to public health by lead exists in the form of classical lead poisoning which in turn is founded on the concept of a threshold for morphological damage. Symptoms traditionally ascribed to lead poisoning may apply only to a minor manifestation of a disease which may now exist in major segments of the American population now exposed to abnormally high levels of lead. An organism is expected to exhibit a broad range of variable response to different levels of exposure to a toxic substance which would include degrees of detrimental interference with cell metabolism, some of which would be difficult to recognize but nevertheless would be significant. Since these organizations deny that any other form of lead poisoning exists, they should be required to set forth the biochemical mechanisms which predict and explain the effects on cell metabolisms and tissue functions throughout the human body at all levels of lead exposure which justify their public statements that present levels of lead exposure are harmless and safe. Point 5. It is clear, from the history of development of the lead pollution problem in the United States that responsible and regulatory persons and organizations concerned in this matter have failed to distinguish between a scientific activity and the utilization of observations for a material purpose. A scientist considers his data objectively because he has no material purpose. To him, science is an activity of the mind-the formulation of ideas concerning observations, the seeking of new observations, the revision of ideas it is an inherently dynamic process of formulation and revision. It is not static and there are no facts. The utilization of observations for material purposes is not science. It is engineering; it is the defense and promotion of industrial activity; it is the guarding of public health. This utilization is not done objectively. It is done subjectively. My activity in defending public health here in these statements is not science, just as the activities of the lead industries in defending their continued production and sale of lead products is not science. In some of the points discussed above, we have both used the very same observations to justify different views because our purposes are different. It is not just a mistake for public health agencies to cooperate and collaborate with industries in investigating and deciding whether public health is endangered-it is a direct abrogation and violation of the duties and responsibilities of those public health organizations. In the past, these bodies have acted as though their own activities and those of lead industries in health matters were science, and they could be considered objectively in that sense. Whether the best interests of public health have been served by having public health agencies work jointly with representatives of 64-886-66-21 |