FRANK MIRER, PhD, CIH, is a professor in the CUNY School of Public Health in New York. He can be reached at (212) 396-7782 or Editor’s note: Frank Mirer’s Synergist contributions previously appeared in our Insight section. This month marks Mirer’s first appearance in the Columns section. His “Risky Business” column will continue to focus on regulations, public policy, and the science of industrial hygiene.
Getting the Lead Out Catching Up to New Science
Lead exemplifies the advance of authoritative conclusions about workplace hazards, especially potency, against the backdrop of no advance in regulatory protections. For lead, the advances in interpretation come from population studies rather than the pre-1975 occupational studies that are the basis of the OSHA regulation. The OSHA lead-in-air (LIA) limit, 50 µg/m3, is intended to limit employees’ body burden of lead, as indicated by lead in blood (LIB), to less than 50 µg/dl (100 grams of blood). The standard was promulgated in 1978, and was constrained by feasibility of engineering controls in the most difficult industry sector, smelters, as well as the health data of the time. The 2012 authoritative review by the National Toxicology Program notes “sufficient” evidence for decreased glomerular filtration rate; the association of maternal lead-blood levels with reduced fetal growth at < 5 µg/dl in adults; and increased blood pressure, risk of hypertension, and incidence of essential tremor at <10 µg/dl. (This exhaustive collection of data, which was subjected to extensive peer review, noted other effects with “limited” evidence.) The issue for IHs should be adjusting the LIA limit to the more protective LIB criteria. HISTORY Lead came up on the OSHA regulatory agenda during the golden age of rulemaking in 1978. The Steelworkers led the hearings for the labor movement. I testified before OSHA on behalf of the United Auto Workers in April 1977, and organized panels of union leaders and rank-and-file workers to testify as well. The Teamsters were also very important. When the lead standard was issued, industry filed a lawsuit against OSHA. In 1980 the DC Court of Appeals upheld the standard, finding it feasible in industries with the highest exposures (smelters, battery plants). The Court also upheld the revolutionary medical removal protection-multiple physician review (MRP-MPR) provisions. With the change in presidential administration in 1981, the Reagan OSHA joined industry in appealing against the standard, but this was rejected by the courts. The 1978 lead standard omitted construction. In response to a union lawsuit, OSHA agreed to move forward in construction but failed to act until Congress passed the Housing and Community Development Act of 1992 requiring a construction lead standard. The standard specified detailed work practices. The adverse effects of lead on reproduction and development, noted in the OSHA record, also spawned a surge in “fetal protection” policies, in which managements recently forced by the Equal Employment Opportunity Commission to hire women into well-paying blue collar jobs attempted to “protect” women from lead by terminating them, while leaving men to be exposed despite evidence for adverse developmental results from paternal exposure. In April 1975, Bunker Hill Smelter in Idaho required women workers who wanted to retain higher-paying jobs to be sterilized. The fetal protection issue spawned multiple lawsuits, finally resolved in 1991 when the Supreme Court reversed lower courts and ruled fetal protection policies illegal in UAW v. Johnson Controls.
Editor's note: California followed suit in September, announcing its intention to list glyphosate as a carcinogen under Proposition 65.
Opposition to the use of Agent Orange in Vietnam was part of my motivation to move from chemistry to toxicology, and the insecticide parathion was part of my post-doctoral project. And I claim expertise (or at least experience) in this process by serving on two IARC working groups, and on National Toxicology Program (NTP) peer review groups for bioassay reports, the criteria for evaluating those bioassay reports, and the Report on Carcinogens (ROC).
- Frank Mirer
IARC Monographs Volumes 112 and 113 address insecticides and herbicides. They classify lindane as known to be carcinogenic to humans (Group 1); DDT, malathion, and diazinphos as probably carcinogenic (Group 2A); and 2,4-D, tetrachlorvinphos and parathion as possibly carcinogenic (Group 2B). Although few IHs work in agriculture, we are likely to get questions about pesticide use in homes and, regarding glyphosate, on our lawns.
- Frank Mirer