Environmental Endocrine Disruptors and Human Sperm Chromosomal Abnormalities

Each year more than two million couples in the US who want to have children are infertile, and over two million conceptions are lost before the twentieth week of gestation. About 40% of cases of human infertility are due to male factors. Errors in chromosome segregation during meiosis result in structural aberrations and imbalances in chromosome number known as aneuploidy. There is emerging evidence that environmental chemicals can adversely affect spermatogenesis and the occurrence of chromosomal aberrations, possibly through mechanisms of endocrine hormone modulation.

This study is investigating novel relationships between sperm aneuploidy and common environmental exposures, specifically polychlorinated biphenyls (PCBs), DDT, organophosphates (OPs), and pyrethroids (PYRs). We have archived semen, serum, and urine samples from men who have attended a large hospital-based fertility clinic for fertility evaluation. Exposures to PCBs, DDT, OPs and PYRs have been well characterized in this population, and prior work from our group has found associations between organochlorines and inferior semen quality and contemporary use pesticides and DNA damage. The question remains as to whether these exposures impact sperm aneuploidy. We have validated an automated system that makes quantifying sperm aneuploidy in large sample sizes feasible so that the full complement of archived samples can be studied and novel relationships between sperm aneuploidy and common environmental exposures can be quantified.

Publications resulting from this research include the following: