A pregnant woman’s exposure to traffic pollution increases child’s asthma risk: UBC study

A pregnant woman’s exposure to traffic pollution increases the risk that her child will develop asthma, says a new study out of the School of Population and Public Health at the University of British Columbia.

The study culled data from administrative health databases and looked at 65,254 children born between 1999 and 2002 in the Greater Vancouver area. Researchers tracked the children for a decade and found that pregnant woman’s exposure to traffic pollution due to living close to highways during their pregnancy bear children who have a 25 per cent greater chance of developing asthma early in life.

Adjusting for birthweight, gestational period, household income, parity, breastfeeding at discharge, maternal age and education, the researchers found asthma risk during children’s pre-school years was increased by traffic pollution, particularly if the child is of low birthweight.

“Our study results highlight the danger of exposure to pollution while babies are still in the womb,” says lead author Hind Sbihi. “Air pollution from traffic sources increased the risk of developing asthma during early years before children reach school age, even in an urban area like Vancouver with relatively low levels of air pollution.”

In addition, the researchers found that a mother’s age is a risk factor.

“We also found that children born to older mothers were at higher risk of being impacted by air pollution exposure. This is particularly relevant in British Columbia, as the province has the highest proportion of mothers giving birth over the age of 35 years old in Canada,” said Sbihi.

In an editorial penned last July in the Canadian Medical Association Journal, Dr. Moneeza Walji warned that doctors were seeing increases in respiratory illnesses in children because of air pollution.

Another editorial in the same publication, written in 2008 by UBC’s Dr. Michael Brauer, said air pollution is the cause of more than 20,000 deaths in Canada, annually.

While many see Canada as relatively clean, Walji cautions that there are pockets of the country that could be in the danger zone.

“There is a lot of geographic variation when it comes to the improvement in air pollution,” Walji said. “There are some areas that have seen vast strides, and other places that are still striving from high pollution levels”

One area of the country that is dealing with the problem head on is New Brunswick. In a provincial initiative, air quality stats from 13 monitoring stations have been public since last summer. By going online, anyone can track levels of pollutants such as particulate matter, ozone, and carbon monoxide.

New Brunswick Lung Association president Barb Mackinnon says the previously unavailable information is already proving valuable.

“If we get a complaint, for example, from a member of the public who might have noticed an air pollutant in their particular area, we could have a look at that portal,” she says. “And if there is a monitor in the location where we get the complaint from, we could help that person interpret the data.”

The UBC study, “Perinatal air pollution exposure and development of asthma from birth to age 10 years”, was published in the European Respiratory Journal

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