• Posted November 15, 2023

Air Pollution Exposure Before Birth May Harm Reproductive Development: Study

Air pollution could be harming the development of children, reaching into the womb to alter their healthy growth, a new study reports.

Researchers say certain air pollutants appear to negatively alter a specific measure of prenatal exposure to hormones.

“These findings suggest air pollution may interfere with normal hormone activity during critical periods of prenatal and early infant development, and we suspect that disruption may have long-term consequences for reproductive health,” lead researcher Emily Barrett, a professor at Rutgers School of Public Health in New Jersey, said in a university news release.

In the study, researchers looked at data on the length between the genitals and the anus, also known as anogenital distance.

Alterations in anogenital distance might be related to hormone levels, semen quality, fertility and reproductive disorders, researchers said. In animal studies, anogenital distance is used to determine developmental toxicity of pollutants.

When anogenital distance is shorter in male offspring, it's a sign that toxic exposure is interfering with fetal testosterone production, Barrett said.

Barrett and her colleagues reviewed data from an ongoing study of pregnant women and their children in four U.S. cities: Minneapolis, San Francisco, Seattle and Rochester, N.Y.

As part of that study, anogenital distance was measured at birth in all children and at one year for boys, researchers said.

That data was compared with levels of nitrogen dioxide and fine particle pollution in the air of those cities.

Researchers identified a link between exposure to air pollution during key developmental windows and anogenital distance.

For example, higher particle pollution exposure during the end of the first trimester -- the so-called male programming window, when the male fetus typically receives a surge of hormones -- was associated with shorter anogenital length at birth.

Fine particle pollution also appeared to interfere with mini-puberty, a period in early infancy when hormone production is high.

The findings were published Nov. 15 in the journal Environmental Health Perspectives.

Such particle pollution is “like a trojan horse,” Barrett said, noting that particulate matter can carry known endocrine disruptors like the metals cadmium and lead.

“When these disruptors interfere with the body's hormones, the result could be lifelong impacts on our health, from cancer risks to impaired ability to conceive a child,” she said.

More information

The World Health Organization has more about children and air pollution.

SOURCE: Rutgers University, news release, Nov. 15, 2023