A new study has found that exposure to air pollution around the time of conception increases risk of birth defects.
It's a well known fact that air pollution is harmful to human reproduction, but the extent to which it harms fetuses continues to be explored by scientists. Many studies have linked air pollution to small and misshapen sperm, greater risk of premature birth, and lower birth weights. Now, a new study out of the University of Cincinnati College of Medicine, has linked air pollution to birth defects.
In a study called "Periconception Exposure to Air Pollution and Risk of Congenital Malformations," published in December 2016 in The Journal of Pediatrics, researchers examined data on birth defects for nearly 290,000 babies born in Ohio between 2009 and 2010. They compared this to air pollution measurements that were taken at the same time near the mothers' homes. Their focus was on fine particulate matter, also known as PM 2.5, which Reuters describes as "a mixture of solid particles and liquid droplets smaller than 2.5 micrometers in diameter that’s found in traffic exhaust and can include dust, dirt, soot, and smoke."
The scientists found that, when a mother is exposed to higher levels of PM 2.5 in the one month prior to and after conception, a fetus is more likely to have a birth defect, even after adjusting for other confounding factors. Previously it was known that the embryonic development stage is critical for proper fetal formation, but this study's month-by-month exposure risk assessment reveals that pollutants can accumulate in a mother prior to conception and still cause malformations.
The most common defects associated with air pollution are abdominal malformations and hypospadias, when the urethral opening is located on the underside of the penis or even the scrotum.
"When researchers looked at a subset of women who lived within 5 kilometers [3 mi] of a monitoring station, they found that for every 10 ug/m3 increase in PM 2.5 levels women experienced during the month after conception, their babies were 19 percent more [likely] to be born with birth defects."
At the time of the study, the Environmental Protection Agency's standard for PM levels was 15 ug/m3, but is currently 12 ug/m3.
Lead study author Dr. Emily DeFranco says, "Our study results support the importance of public health education and initiatives to minimize population exposure to airborne pollutants."
It could also be taken to support a move away from car dependency. Clearly these emissions-spewing vehicles will be the death of us, whether it's from the moment we're formed in utero to developing cancer later in life -- that is, if we're not killed in a crash, which is currently the leading cause of death for children in the U.S. between the ages of 1 and 18. Lloyd's daring suggestion to ban cars sounds wiser than ever.