A study in mice suggests that high levels of ozone in the air may impair a woman's ability to conceive a baby. Ozone is an air pollutant that is known to affect the heart and lungs, but had not been seen to affect fertility before.
This research is in its early stages, and it is not known if this finding will be seen in further studies. Findings in animal research do not always translate to similar findings in people.
A research team led by Patricia Silveyra, Ph.D., assistant professor in the Pennsylvania State University College of Medicine found that mice that were exposed to ozone for a short period of time had decreased levels of progesterone, an important hormone involved in ovulation and pregnancy. They had been studying the effects of ozone on lung inflammation in mice when they noted the change in progesterone levels, and then decided to examine this finding on progesterone further.
They exposed female mice to 2 parts per million (ppm) of ozone for 3 hours on the day the mice were expected to ovulate. This amount of ozone would be the equivalent of a person breathing high levels of ozone. Not only did levels of progesterone decrease by 75%, the number of eggs the mice ovulated was reduced by 30%.
Based on these findings, if this reduction is the same in people, women in large cities could possibly experience fertility issues when ozone levels are very high, which often happened in summer. In summer, strong sunlight and heat combine with pollution from industrial emissions, car exhaust, and gasoline vapors to form ozone. Groups considered most vulnerable during high-pollution days currently include children, the elderly, and people with asthma.
This research was presented at the American Society for Investigative Pathology Annual Meeting in Boston last week.
