Children born in Sarnia are at a higher risk of developing asthma than kids born in other southwestern Ontario cities, according to a new London-based study.
Researchers from Lawson Health Research Institute and Western University followed 114,427 children born in Sarnia, London, and Windsor for ten years.
“It’s known that cities in Southwestern Ontario have varied levels of air pollution because of differences in industry and traffic," said researcher Dr. Dhenuka Radhakrishnan. “We wanted to see if children born in three cities had a different risk of developing asthma due to the differing air pollution levels in the three regions, even though the people living in these cities are otherwise comparable in many ways.”
What researchers found was that children born between 1993 and 2009 in Sarnia, where there are several chemical and petroleum refineries, were more likely to develop asthma in the first few years of life than their counterparts in London and Windsor. By the age of 10, nearly 24 per cent of children in Sarnia who participated in the study were diagnosed with asthma, compared to 21 per cent in Windsor and 17 per cent in London.
The findings were most apparent in the first two years of life, but continued beyond the age of six.
Researchers did account for other asthma associated risk factors in the study, such as sex, socioeconomic status and urban versus rural setting.
Asthma is the most common chronic disease among Canadian children and is the leading cause of emergency room visits and hospital stays for young kids.
"Reassuringly, we found the asthma risk for children has reduced in more recent years as pollution levels have also decreased,” said Radhakrishnan.
Researchers also found evidence that exposure to air pollution during pregnancy can influence whether a child gets asthma.
“We need to carefully examine how reducing air pollution exposures within a geographic area translates to reductions in asthma development. Understanding the amount of air pollution that a mother and infant are exposed to, and how this impacts their personal risk, could enable regions to target safer levels for their residents,” said Lawson Associate Scientist Dr. Salimah Shariff.
The study was published in the Canadian Medical Association Journal Open on Tuesday, one day before World Asthma Day.