Short-Term Exposure to Nitrogen Dioxide May Up Mortality Risk

FRIDAY, March 26, 2021 (HealthDay News) — Short-term exposure to nitrogen dioxide (NO₂) is associated with an increased risk for total, cardiovascular, and respiratory mortality, according to a study published online March 24 in The BMJ.

Xia Meng, Ph.D., from Fudan University in Shanghai, and colleagues examined the short-term associations between NO₂ and total, cardiovascular, and respiratory mortality in 398 cities from 22 low- to high-income countries/regions.

The researchers observed increases of 0.46, 0.37, and 0.47 percent in total, cardiovascular, and respiratory mortality, respectively, in association with a 10 µg/m³ increase in NO₂ concentration on lag 1 day (previous day) on average. After adjustment for copollutants (particulate matter with aerodynamic diameter ≤10 µm or ≤2.5 µm, ozone, sulfur dioxide, and carbon monoxide), these associations remained robust. For all three causes, the pooled concentration-response curves were almost linear, with no discernable thresholds. Across the 398 cities, the proportion of deaths attributable to NO₂ concentration above the counterfactual zero level was 1.23 percent.

“The concentration-response curves were linear without discernible thresholds, suggesting a need to revise and tighten the current air quality guidelines of NO₂ for greater public health benefit, and to consider a regulation limit for daily mean NO₂ concentration,” the authors write. “These findings contribute to a better understanding of how to optimize public health actions and strategies to mitigate air pollution.”

Abstract/Full Text