Turning up the volume on the health impacts of noise
The constant drone of traffic noise wafting through your windows at night may be more than a minor annoyance. It may be bad for your health.
Research by Ryerson health geographer Tor Oiamo has found that ongoing noise exposure, particularly to chronic traffic noise, can be more than an irritation. It can add audible stress to your life, causing negative impacts such as sleep disruption and even contributing to developing health issues such as high blood pressure or diabetes.
Working with Toronto Public Health after a city noise bylaw review triggered a request to study the health effects of noise, professor Oiamo measured the noise levels in more than 200 locations throughout the city. He was also able to model noise exposure using traffic volumes, which can be used to accurately predict noise levels. Through a retroactive study, professor Oiamo and his partners accessed more than one million health-related surveys taken by Toronto residents through 15 years to analyze health impacts and long-term noise exposure. While the new noise bylaw was approved by city council in 2019, professor Oiamo and his collaborators are still producing papers with the findings.
One recent paper professor Oiamo co-authored was published in the Journal of the American Heart Association (external link, opens in new window) and showed ongoing exposure to road traffic noise was associated with elevated risks in developing diabetes mellitus and hypertension in long-term residents of Toronto between the ages of 35 and 100. Another recent paper he co-authored, published in Environmental Health Perspectives (external link, opens in new window) , showed the link chronic exposure to road traffic noise has to increased risks of acute heart attacks and congestive heart failure in Toronto residents between the ages of 30 and 100.
“The study that we did really showed that things like traffic noise in particular are having the broadest, most significant impacts because they affect so many people across the entire city,” said professor Oiamo. Professor Oiamo’s studies, as well as other studies conducted around the world, have shown a strong link between traffic noise and coronary heart disease, a health impact which he says is “by far the most strongly supported level there is.”
About 93 per cent of people living in Toronto are exposed to constant noise levels of 45 decibels, he added, but that is really the “baseline hum” of the city. Not much is known about the health impacts of the most common sources of noise complaints, such as a loud concert, leaf blowers or construction, which tend to be one-offs or temporary. But researchers do know traffic noise has an impact, and the (PDF file) results from the Toronto Public Health study (external link, opens in new window) have led the city to commit to developing a noise action plan with potential reduction goals in the decibel levels that people are exposed to. While a reduction to zero would be impossible, professor Oiamo says exposure to about 50 to 55 decibels is when health risks increase. That decibel level usually means people have to raise their voices during conversations to be heard over the noise.
“Any goal is a good goal,” he said of noise reduction targets.
His review of the data also addressed the connection between socio-economic factors and noise exposure. Using Canadian census tract data, he found the lowest income census tract areas were 10 times as likely to have at least 50 per cent of its residents exposed to higher risks from noise exposure than the highest income areas. “We know that socio-economic characteristics can affect a lot of health outcomes,” he said.
Professor Oiamo continues to examine the Toronto data. He is also working on other noise exposure research projects, such as developing noise exposure estimates for other cities in Canada with the Canadian Urban Environmental Health Research Consortium (external link, opens in new window) , which has researchers across the country working to measure environmental exposures such as air pollution, climate change and more.
Funding and support for this research have been provided by Toronto Public Health, the City of Toronto and the Canadian Institutes of Health Research.