Tuesday, December 16, 2008

Get the Lead Out, Evidence That OSHA's Lead Standard Lets Workers Get Sick

Occurrence of lead-related symptoms below the current occupational safety and health act allowable blood lead levels.

J Occup Environ Med - 01-MAY-2003; 45(5): 546-55
Rosenman KD; Sims A; Luo Z; Gardiner J

To determine the occurrence of symptoms of lead toxicity at levels below the current allowable Occupational Safety and Health Act blood lead level of 50 micrograms/dL, standardized telephone interviews were conducted of individuals reported to a statewide laboratory-based surveillance system. Four hundred and ninety-seven, or 75%, of the eligible participants were interviewed. Gastrointestinal, musculoskeletal, and nervous system symptoms increased with increasing blood lead levels. Nervous, gastrointestinal, and musculoskeletal symptoms all began to be increased in individuals with blood leads between 30-39 micrograms/dL and possibly at levels as low as 25-30 micrograms/dL for nervous system symptoms. The results of this study of increased symptoms are consistent with and provide added weight to previous results showing subclinical changes in the neurologic and renal systems and sperm counts at blood lead levels currently allowed by the Occupational Safety and Health Act.


BrooklynDodger(s) comments: The current level of concern for lead-in-blood in children, and by extension pregnant women, is 10 ug/100g. Little thought has been given to a level of concern in already born and grown up workers.

From the lead poisoning epidemics associated with tetraethyl lead and lead body solder, both auto industry outbreaks of the '20's and '30's, came the notion of controlling lead toxicity by monitoring body burden and removing workers from exposure. Hopefully something would have been done about the exposures, but mostly the response was yo-yo ing the employee.

The OSHA lead standard was promulgated in 1976, based on the science available a few years before. At that time, lead in blood of 80 ug/100g was the informal criterion for removal, although values up to 100 were observed. Most workers in lead industries has lead in blood over 40. OSHA dropped the removal trigger to 60 for a single test or a 3 test moving average of 50, with return permitted at 40. Levels of 40 were routinely observed in the general population not exposed occupationally.

Science had accumulated between 1975 and 1993, when the OSHA construction lead standard was promulgated. [Construction was omitted from 1910.1025; the extension of those protections to construction was required by legislation aimed at residential lead abatement.] Despite new data, the 60/50/40 regime was left in place.

This report from a state lead surveillance program reveals that symptoms of lead intoxication arise at 30 ug and maybe as low as 20 ug in adult workers.

The OSHA lead-in-air limit remains the strictest in the world. The Dodger(s) has(have) not surveyed medical removal levels for occupational exposures around the world.

But, the take home lesson is that one of OSHA's most protective chemical exposure standards permits exposures which cause frank symptoms among workers.

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