Semen quality of men employed at a lead smelter.
OBJECTIVE
To evaluate the effects of recent and long term occupational lead exposure on indicators of male reproductive health.


METHODS
In a cross sectional study of male employees of a lead smelter (n = 2469), blood samples were obtained from 152 workers including 119 who also provided semen samples. Semen analysis and serum concentrations of testosterone, follicle stimulating hormone, and luteinising hormone were used as indicators of reproductive health. Semen and hormone variables were examined in relation to measures of current and long term body lead burden estimated from current blood lead concentrations and historical blood lead monitoring data.


RESULTS
For current blood lead concentration groups of < 15, 15-24, 25-39, > 40 micrograms/dl, the geometric mean sperm concentrations were, respectively, 79.1, 56.5, 62.7, and 44.4 million cells/ml and geometric mean total sperm counts were 186, 153, 137, and 89 million cells (P for trend 0.04). Compared with workers with blood lead concentrations less than 15 micrograms/dl, workers with current blood lead concentrations of 40 micrograms/dl or more had an increased risk of below normal sperm concentration (odds ratio (OR) 8.2, 95% confidence interval (95% CI) 1.2-57.9) and total sperm count (OR 2.6, 95% CI 0.4-15.7), based on World Health Organisation standards. Independent of current lead exposure, sperm concentration, total sperm count, and total motile sperm count were inversely related to measures of long term lead exposure. No association was found between lead exposure and measures of sperm motility, sperm morphology, or serum concentrations of reproductive hormones.


CONCLUSIONS
Blood lead concentrations below the currently accepted worker protection criteria seem to adversely affect spermatogenesis.
Alexander
B H
BH
Department of Epidemiology, University of Washington, Seattle 98195, USA.
Checkoway
H
H
van Netten
C
C
Muller
C H
CH
Ewers
T G
TG
Kaufman
J D
JD
Mueller
B A
BA
Vaughan
T L
TL
Faustman
E M
EM
D000328:Adult; D003430:Cross-Sectional Studies; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007854:Lead / Q000009:adverse effects* / Q000097:blood; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008669:Metallurgy; D016273:Occupational Exposure / Q000009:adverse effects*; D012661:Semen / Q000187:drug effects*; D013076:Sperm Count / Q000187:drug effects*; D013081:Sperm Motility / Q000187:drug effects; D013094:Spermatozoa / Q000166:cytology / Q000187:drug effects; D013739:Testosterone / Q000097:blood
D007854:Lead; D013739:Testosterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone