Joshua Lawson.
Joshua Lawson.

The puzzle of childhood asthma

According to the Lung Association, almost three million Canadians and more than 300 million people worldwide have asthma. Of those, roughly 100,000 Saskatchewan people are living with asthma, including 35,000 children.

"Asthma is one of the most common childhood conditions," said Joshua Lawson, epidemiologist with the Canadian Centre for Health and Safety in Agriculture (CCHSA) at the U of S. "It is estimated between 14 and 21 per cent of kids in Saskatchewan have the disease."

Several studies suggest farming or rural exposures are protective against asthma, the reasons for which are unknown. While one explanation may be the environment, including endotoxins, those same exposures may actually worsen asthma among those with the condition. Endotoxins, substances associated with the outer membrane of certain bacteria, are found in household dust—that is, basically every- where in the indoor environment.

"Given the puzzling nature of the relationship between some environmental exposures and asthma, it is important to investigate exposures other than endotoxin in order to help us understand the cause of the disease and identify agents which may trigger episodes," Lawson said.

In 2014, Lawson and his CCHSA team, including George Katselis, Donna Rennie and Shelley Kirychuk, were awarded a Saskatchewan Health Research Foundation (SHRF) Collaborative Innovation Development Grant co-funded by the Lung Association of Saskatchewan. The grant supports their work to identify constituents in dust and quantify their relationship with asthma, and assess personal monitoring as a way of collecting dust samples.

"Typically, studies rely on settled dust from carpets and mattresses to assess the role of endotoxin and childhood asthma," Lawson said. "But the difficulty with that is it may not account for the child's true exposure which can include other home or outdoor environments such as the farming environment and where children may be playing."

To get more accurate information, the team plans to outfit children for one week with a backpack device whose air intake sits at head level to better monitor the ambient air. This will give the researchers a better perspective of what the children are actually breathing and what they are exposed to as opposed to what is collected in settled dust.

The team's pilot study will be based on a recent cross-sectional survey of approximately 3,400 Grade 1 to 8 children in Saskatchewan who lived along an urban- rural gradient including children living in Regina, Prince Albert, and the rural area around Prince Albert.

"Even though kids living on farms or in rural areas may be less likely to have asthma compared to those living in urban areas, we still have a problem because, in Saskatchewan, 14 per cent of kids living in rural areas have asthma," Lawson said.

The new research methods will be used to further explore rural and farming exposures in relation to childhood asthma.

 

A version of this story originally appeared in Research for Health, published by the Saskatchewan Health Research Foundation.
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