Is Chronic Traffic Noise Linked to Risk of Heart Attack, Heart Failure?

Evidence already demonstrates a possible connection between chronic exposure to traffic noise and atherosclerosis progression, but not such major cardiovascular events as acute myocardial infarction (AMI) and congestive heart failure (CHF), until now, with the recent report of study results in Environmental Health Perspectives.

The study authors found that the risk for both AMI and CHF incidence increased following chronic exposure to road traffic noise, according to the results seen among the approximately 1 million individuals aged 30 to 100 years comprising the study population and who lived in Toronto, Canada, between 2001 and 2005. None had a history of AMI or CHF at baseline, and follow-up continued until death, move out of Toronto, or end of follow-up on December 31, 2015. All were part of the Ontario Population Health and Environment Cohort.

Noise level was measured over a 24-hour period and overnight, then assigned to an area via its postal code. Traffic-related pollution (eg, ultrafine particles [UFPs; < 0.1 mcm diameter] and nitrogen dioxide) was also measured. Diagnoses of AMI and CHF were extracted from the Ontario Myocardial Infarction and Congestive Heart Failure databases and indicated with International Classification of Diseases, Tenth Edition codes.

Overall, the study population had 37,441 incidences of AMI and 95,138 of CHF, with each interquartile range change linked to a 7% to 8% greater risk of both incident AMI and CHF for 24-hour sound level and nighttime noise:

• 24-hour sound:
  • AMI: HR, 1.07 (95% CI, 1.06-1.08)
  • CHF: HR, 1:07 (95% CI, 1.06-1.09)
• Nighttime noise:
  • AMI: HR, 1.07 (95% CI, 1.05-1.08)
  • CHF: HR, 1.06 (95% CI, 1.05-1.07)

Additionally, compared with the lowest level of 24-hour sound (< 55 dBA), risk of incident AMI increased with each of the 3 higher levels of sound: 56-60, 61-65, and more than 65 dBA:

1. 56-60 dBA: HR, 1.07 (95% CI, 1.03-1.10)
2. 61-65 dBA: HR, 1.10 (95% CI, 1.06-1.13)
3. More than 65 dBA: HR, 1.12 (95% CI, 1.08-1.15)

Younger age was also shown, via stratified analysis, to possibly influence the link between 24-hour noise level and risk of incident CHF. Those younger than age 60 years had the greatest risk (HR, 1.18; 95% CI, 1.16-1.21) vs ages 60 to 74 years (HR, 1.07; 95% CI, 1.05-1.09) and > 75 years (HR, 1.01; 95% CI, 0.99-1.02; P < .001).

Long-term exposures to UFPs and nitrogen dioxide were also related to greater risk for AMI and CHF, following several sensitivity analyses, and those with adult-onset asthma were found to have a possible greater risk of developing AMI vs those without asthma (P = .202). The authors attribute this to the possibility that inflammation caused by asthma can contribute to developing coronary heart disease.

“In conclusion, our study showed positive associations between long-term residential exposure to road traffic noise and the incidence of AMI and CHF in Toronto, Canada, with nearly linear exposure–response relationships,” the authors noted.

Reference

Bai L, Shin S, Oiamo TH, et al. Exposure to road traffic noise and incidence of acute myocardial infarction and congestive heart failure: a population-based cohort study in Toronto, Canada. Environ Health Perspect. Published online August 12, 2020. doi:10.1289/EHP5809