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Long-term Behavioral and Reproductive Consequences of Embryonic Exposure to Low-dose Toxicants
Published on: March 6, 2018
Y:X sperm ratio in boron-exposed men
Wendie A Robbins1, Fusheng Wei, David A Elashoff
1Center for Occupational and Environmental Health, University of California, Los Angeles, CA 90095-6919, USA. wrobbins@sonnet.ucla.edu
Journal of Andrology
|September 21, 2007
Summary
Environmental and workplace boron exposure is linked to a decrease in the Y:X sperm ratio, potentially explaining observed shifts in offspring sex ratios towards females in exposed populations.
Area of Science:
- Environmental Health
- Reproductive Toxicology
- Human Reproduction
Background:
- Epidemiologic studies suggest a link between elevated boron exposure and a shift in sex ratios at birth towards females.
- The paternal contribution to this phenomenon requires further investigation.
Purpose of the Study:
- To investigate the paternal origin of sex ratio shifts by examining the sperm Y:X chromosome ratio in men with varying boron exposure levels.
- To assess the relationship between environmental and occupational boron exposure and sperm Y:X ratio.
Main Methods:
- Assayed sperm Y:X ratio in 63 boron industry workers, 39 men in high environmental boron areas, and 44 controls using fluorescence in situ hybridization.
- Calculated total daily boron exposure from dietary intake and workplace air sampling.
- Measured internal boron dose in blood, urine, and semen.
Main Results:
- Total boron exposure strongly correlated with internal dose in blood, semen, and urine.
- Linear regression revealed a significant association between logged boron levels in biologic fluids and decreased sperm Y:X ratio.
- Boron workers exhibited a significantly lower sperm Y:X ratio compared to high environmental exposure and control groups.
Conclusions:
- Exogenous environmental and workplace boron exposures are associated with a reduction in the proportion of Y-bearing sperm.
- This finding provides a potential mechanism for the observed shifts in offspring sex ratios at birth in boron-exposed populations.
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