Abstract
Objective: To evaluate the effect of low to moderate occupational lead exposure on thyroid function we conducted a cross-sectional study of 151 male lead smelter workers. Methods: Parameters of thyroid function were assessed in relation to both subacute and cumulative lead exposure over a 10-year employment period. Blood lead levels, obtained from plant surveillance records, were used to establish four ordinal levels of current and cumulative exposure (< 15, 15-24, 25-39, and ≥ 40 μg/dl). Results: Mean values for the lowest as compared with the highest current exposure group were similar for thyroxine (T4: 6.8 versus 6.1 μg/dl), estimated free thyroxine (EFT4: 1.6 ng/dl in both groups), and thyroid-stimulating hormone (TSH: 1.8 versus 1.7 mIU/l); there was no evidence of a significant trend for diminished thyroid function associated with increasing current lead exposure. Similarly, no significant difference was observed for T4, EFT4, or TSH in relation to the 10-year cumulative exposure or for adjusted analyses controlling for potential confounders, including age and alcohol use. Conclusion: In contrast to studies observing thyroid dysfunction in the setting of high lead exposure and related clinical poisoning, our findings weigh against a significant physiologic effect on thyroid function at lower levels (< 60 μg/dl) of occupational lead exposure.
Original language | English (US) |
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Pages (from-to) | 453-458 |
Number of pages | 6 |
Journal | International Archives of Occupational and Environmental Health |
Volume | 71 |
Issue number | 7 |
DOIs | |
State | Published - Oct 1 1998 |
Keywords
- Lead
- Lead poisoning
- Pituitary gland
- Thyroid diseases
- Thyroid hormones