Scientific studies increasingly link air quality with newborn health

It’s easy to worry about what we do or don’t eat and drink, but we aren’t usually mindful of the tangy array of ingredients we sample every few seconds in the great big soup we call air. UBC researchers Elizabeth Nethery and Michael Brauer are challenging the notion that our air is safe to gulp—especially when it comes to pregnant women.

“Even in a city like Vancouver, which has relatively low levels of air pollution, we can see a difference between high and low exposures and in how much that has an influence on health and birth outcomes,” explains Nethery, a master’s of science candidate, in a well-lit laboratory at UBC’s Centre for Health and Environment Research. There, Nethery shows off the equipment she used in a recent study on the effects of air pollution on pregnant women. She presented the results earlier this fall at the International Conference on Environmental Epidemiology and Exposure in Paris.

Under a taped-up printout that reads “Having a smoking section in a restaurant is like having a pissing section in a swimming pool,” Nethery pulls out a complicated array of air pumps, particle filters, nitrogen-oxide monitors, and GPS trackers that are mounted on and carried in small backpacks. Over the past several months, she recruited 62 pregnant women to strap on the packs and keep a detailed journal of their whereabouts in the city for 48 hours at a time. She then tracked their exposure to particulate air pollution and nitrogen oxides, which are good measures of traffic emissions.

One of the participants, Adriana Molina, saw an advertisement for the study when she went into a lab for a routine blood test. Molina said she believes she has made at least a small contribution to the study of air pollution, a topic close to her heart.

“I’m from Mexico City. It’s a great city, but the big problem is the pollution,” Molina says.

Studies abound in scientific journals that claim links between in-utero exposure to traffic and industrial emissions and developmental health problems in heavily polluted urban centres such as Mexico City, Los Angeles, and some cities in the United Kingdom.

A January 2002 study published in the American Journal of Epidemiology and conducted through UCLA in 2001 determined that pregnant women who were exposed to high levels of ozone and carbon monoxide in the early stages of pregnancy were more likely than other women to give birth to babies with either cleft palates or defective heart valves. The Journal of Epidemiology and Community Health’s most-read on-line article of 2005, a study out of Birmingham, U.K., made a controversial correlation between childhood leukemia and pregnant women living near vehicle exhaust and sources of industrial combustion. That same year, a report out of the U.S. National Institute of Environmental Health Science found a link between air pollution and chromosomal damage in New York newborns.

Despite inevitable contention over the results of individual studies, the scientific community generally accepts that babies whose moms are exposed to high levels of air pollution are more likely to be born preterm or with a low birth weight than those whose mothers enjoy cleaner air. Low birth weights are associated with a higher risk of developmental problems, cardiac conditions, and diabetes.

Brauer, the director of UBC’s School of Occupational and Environmental Hygiene, is leading a large-scale study of birth outcomes in the Georgia Basin airshed. Even in the Lower Mainland, where the air quality is considered to be quite good, Brauer’s data confirm the effects of lowered air quality on birth weights.

“Our initial findings, which are in agreement with studies that have been done in L.A., is that [of all air-pollution sources in the region] traffic-related air pollution seems to be the strongest link,” Brauer reports.

Nethery and Brauer advise pregnant women to be aware of prolonged exposure to traffic emissions, wood smoke, and particulate matter: dust, dirt, and soot. Tobacco, air fresheners, cosmetics, pesticides, strong household cleaners, moulds, unvented gas appliances, and dust are among the potential indoor dangers, along with volatile organic compounds—the smelly components of new carpet and paints.

Nethery advises the rest of us to minimize air pollution in our communities by taking transit, walking, and avoiding driving.

It seems that Vancouver’s new anti-idling bylaw just got some new fuel.