Toxic Metals Endanger Environment
Wide press coverage was accorded testimony by Dr. Henry A. Schroeder, Professor of Physiology at the Medical School, before the U.S. Senate Subcommittee on Environmental Pollution in late August. He warned that the health of Americans is being more seriously endangered by lead, cadmium, and other toxic metals in the environment than by the widely publicized threat from pesticides.
Dr. Schroeder said, “Man has been unwittingly exposing himself to increased amounts of trace metals in foods, water, and air since he first learned to use metals.” He told the Senators how man absorbs these in his system in three ways—directly through air and water and indirectly through metal absorption in the food chain.
“Lead from motor vehicle exhausts enters the environment in amounts of two pounds per capita a year,” he said. “Evidence of a biochemical abnormality in persons exposed to urban air concentrations of lead is beginning to appear. There is little doubt that, at the present rate of pollution, diseases due to lead toxicity will emerge within a few years.
“Cadmium pollution is a major fac- tor in high blood pressure, of which 23 million Americans suffer. Cardio-
vascular death rates are directly related to the amount of cadmium in drink- ing water. Cadmium is found in soft, acid water and gets into other water from water mains and pipes. It is used industrially to electroplate iron and steel for protection against corrosion.” Dr. Schroeder, who first began to study the role of trace elements in human systems 15 years ago, listed other trace elements which cause en- vironmental pollution. In order of im- portance after cadmium, they are lead, nickel carbonyl, beryllium, antimony, and mercury.
He suggested ways to curb this grow- ing environmental pollution problem. Lead, he said, can be virtually abolished from the air by eliminating alkyl lead additives to gasoline. Nickel carbonyl, he said, must be specifically treated to decompose it in smelter and refinery stacks and emissions from chimneys and diesel exhausts. Further, no nickel should be permitted in gasoline.
Beryliium and antimony in the air can be controlled by reducing particu- late emissions from coal smokes. Mer- cury in water can be kept to safe limits by regulating factory effluents and by finding less toxic fungicidal compounds for grains, paper, and paint, he said.
Dr. Schroeder also directed his com- ments to the food which man eats daily. “The hazard in some foods occurs not from contamination but from refine- ment. Most of the trace elements essen- tial for health are removed from pro- cessed foods. Unfortunately, they are not restored to the food. The residue of millfeeds which is rich in trace ele- ments is fed to domestic animals.”
Sen. Philip A. Hart (D-Mich.), sub- committee chairman, called Dr. Schroe- der “perhaps the acknowledged expert in the field of toxic metal physiology.” Director of the Dartmouth Medical School’s Trace Element Laboratory in Brattleboro, Vt., Dr. Schroeder could not appear in person, but his testimony was read into the official record.
