AMHERST, Mass. – An environmental and reproductive epidemiologist from the University of Massachusetts Amherst has won a three-year career development award from the National Institutes of Health (NIH) to examine the impact of ambient environmental factors on male fertility.
The $435,000 grant from the NIH’s National Institute of Environmental Health Sciences will allow Carrie Nobles, an assistant professor in the School of Public Health and Health Sciences, to advance knowledge in this “area of very understudied research. It will focus on impacts associated with ambient air pollution, such as traffic and power plant emissions; and ambient temperature, both hot and cold.
“We’ve really overlooked preconception men’s health,” Nobles says. “Over the past few decades we have seen a decline in sperm quality and it is feared that some of this is due to environmental exposures.”
Her research aims to identify the risks associated with ambient exposures to male fertility and to identify future research directions that may lead to medical and behavioral interventions for males prior to fertility treatment. About 12% of couples in the United States seek treatment for infertility. Male subfertility is a factor in about half of couples, and the cause is usually unknown.
“There has actually been a large body of research on air pollution and sperm quality, mostly in countries with very high levels of air pollution,” says Nobles. “And this research suggests that exposure to air pollution can lead to poorer sperm quality.”
In the United States and other countries with low to moderate air pollution, little research has focused on the potential impact on sperm quality. In addition to air pollution, Nobles will examine ambient temperature during sensitive windows of spermatogenesis and its relationship to sperm quality.
His study will use data from the Folic Acid and Zinc Supplementation Trial (FAZST), drawing on four replicate semen samples from more than 2,300 participants.
The nobles will also examine epigenetic factors that may be involved in male fertility, with a particular focus on the impact of exposure to air pollution on sperm DNA methylation.
She will assess the impact of male partners’ exposure to air pollution and ambient temperature during spermatogenesis on the likelihood of pregnancy during infertility treatment.
The results could help identify the best times for couples to schedule in vitro fertilization (IVF), an expensive procedure. “If, for example, a high temperature turns out to be a big problem and can reduce the likelihood of pregnancy in this cycle, then couples may want to try different times of the year,” says Nobles.
Nobles will be mentored primarily by former UMass Amherst environmental epigeneticist Richard Pilsner, now a professor, and Robert Sokol, MD, chair of molecular obstetrics and gynecology and director of molecular genetics and infertility at CS Mott Center for Human Growth and Development at Wayne State University School of Medicine. Other members of his mentoring team are University of California, Berkeley causal inference expert Laura Balzer, formerly of UMass Amherst, and University of Maryland associate professor Timothy Canty, whose l expertise includes air quality modeling.