Chemical World This Week
The Top Stones concentration of lead in the air of central cities is not an 'Identifiable current threat" to the general population, a report by a National Research Council panel says 13 Science Ph.D.'s who received their degrees in 1970 found fewer jobs than did 1969 Ph.D.'s; this was particularly the case for chemistry Ph.D.'s 14 Scientists at Roswell Park Memorial Institute, Buffalo, N.Y., have developed human blood cell cultures stable enough to live forever 15 For the CPI, the 1970's have been dubbed "struggling," but the decade's success for chemicals depends on companies' pricing policies 24 Alcoholism is among the topranking health problems in the U.S. today. Although the "dipso" carries a social stigma, the condition is now more and more regarded as a disease 25 Many U.S. chemical companies are finding that it is increasingly valuable to have their stocks listed on foreign stock exchanges 39 Chemical companies are beginning to comment on Nixon's wageprice freeze, ask about controls that will follow end of freeze 44 New processes turn fly ash, coal-ash slag, copper tailings, and other industrial wastes into bricks for building 49
September 13, 1971
LEAD IN AIR NO THREAT Because hundreds of tons of lead used in automobile fuel additives and other products are spewed into the U.S. atmosphere daily, scientists and the public at large have become increasingly concerned about the potential health hazards of this air contaminant. But how serious a danger is it? According to a lengthy report issued last week by a National Research Council panel and prepared for the Environmental Protection Agency, the concentration of lead in the air of central cities is not an "identifiable current threat" to the general population. In the blood of the average city dweller, the lead concentration, the report says, is about half that necessary to cause biochemical changes in the body and about one fourth that at which the symptoms of lead poisoning begin to occur. Since airborne lead comes mainly from the combustion and dispersal of lead additives in gasoline, people exposed to unusually large amounts of automobile exhausts face a greater risk than does the average city dweller. In this high-risk group are traffic policemen, garage workers, and automobile mechanics. Also subject to such greater hazards are workers in leadusing industries. Even they, however, would have to develop much higher blood-lead concentrations than they actually do to show signs of lead poisoning, the report says. The NRC panel is more apprehenPolice, auto mechanics exposed to exj
sive about the threat to children. Children in inner cities have been found to have greater concentrations of lead in their blood than adults living in the same neighborhoods. In these children, the bloodlead levels are high enough to cause biochemical changes in their bodies, but not high enough to produce the symptoms of lead poisoning. The lead found in these children's blood may come not only from breathing polluted air but from swallowing dirt or street dust contaminated by previously airborne lead. In some children, the most serious hazard is in eating leadbased paints that have flaked off tenement walls. Mainly because of the large concentration of automobiles in cities, airborne lead is almost entirely an urban problem, the report points out. In the biggest U.S. cities, the air contains an average of about 20 times as much lead as does air in rural areas. However, because of the high degree of dispersal of automobile combustion products, the air's average lead content in most major American cities has not risen appreciably in the past 15 years, despite the marked increase in the use of cars. The report also notes that the concentration of lead in edible plants and animal food products has changed little, if at all, in recent decades. Thus, the amount of lead in people's diets has probably not changed much since 1940. usts face higher risk of health hazard
