A
Population-Based Cohort Study of Respiratory Disease
and Long-Term Exposure to Iron and Copper in Fine Particulate Air
Pollution and Their Combined Impact on Reactive Oxygen Species Generation
in Human Lungs
posted on 2021-03-05, 15:05authored byZilong Zhang, Scott Weichenthal, Jeffrey C. Kwong, Richard T. Burnett, Marianne Hatzopoulou, Michael Jerrett, Aaron van Donkelaar, Li Bai, Randall V. Martin, Ray Copes, Hong Lu, Pascale Lakey, Manabu Shiraiwa, Hong Chen
Metal
components in fine particulate matter (PM2.5)
from nontailpipe emissions may play an important role in underlying
the adverse respiratory effects of PM2.5. We investigated
the associations between long-term exposure to iron (Fe) and copper
(Cu) in PM2.5 and their combined impact on reactive oxygen
species (ROS) generation in human lungs, and the incidence of asthma,
chronic obstructive pulmonary disease (COPD), COPD mortality, pneumonia
mortality, and respiratory mortality. We conducted a population-based
cohort study of ∼0.8 million adults in Toronto, Canada. Land-use
regression models were used to estimate the concentrations of Fe,
Cu, and ROS. Outcomes were ascertained using validated health administrative
databases. We found positive associations between long-term exposure
to Fe, Cu, and ROS and the risks of all five respiratory outcomes.
The associations were more robust for COPD, pneumonia mortality, and
respiratory mortality than for asthma incidence and COPD mortality.
Stronger associations were observed for ROS than for either Fe or
Cu. In two-pollutant models, adjustment for nitrogen dioxide somewhat
attenuated the associations while adjustment for PM2.5 had
little influence. Long-term exposure to Fe and Cu in PM2.5 and estimated ROS concentration in lung fluid was associated with
increased incidence of respiratory diseases, suggesting the adverse
respiratory effects of nontailpipe emissions.