Is long-term exposure to traffic pollution associated with mortality? A small-area study in London

Environ Pollut. 2016 Jan;208(Pt A):25-32. doi: 10.1016/j.envpol.2015.06.036. Epub 2015 Jul 7.


Long-term exposure to primary traffic pollutants may be harmful for health but few studies have investigated effects on mortality. We examined associations for six primary traffic pollutants with all-cause and cause-specific mortality in 2003-2010 at small-area level using linear and piecewise linear Poisson regression models. In linear models most pollutants showed negative or null association with all-cause, cardiovascular or respiratory mortality. In the piecewise models we observed positive associations in the lowest exposure range (e.g. relative risk (RR) for all-cause mortality 1.07 (95% credible interval (CI) = 1.00-1.15) per 0.15 μg/m(3) increase in exhaust related primary particulate matter ≤2.5 μm (PM2.5)) whereas associations in the highest exposure range were negative (corresponding RR 0.93, 95% CI: 0.91-0.96). Overall, there was only weak evidence of positive associations with mortality. That we found the strongest positive associations in the lowest exposure group may reflect residual confounding by unmeasured confounders that varies by exposure group.

Keywords: Epidemiology; Mortality; Small-area; Traffic pollution.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Air Pollutants / analysis
  • Air Pollutants / toxicity*
  • Environmental Exposure / analysis*
  • Female
  • Humans
  • Linear Models
  • London / epidemiology
  • Male
  • Middle Aged
  • Mortality*
  • Particulate Matter / analysis
  • Particulate Matter / toxicity
  • Poisson Distribution
  • Regression Analysis
  • Small-Area Analysis
  • Time Factors
  • Vehicle Emissions / analysis
  • Vehicle Emissions / toxicity*


  • Air Pollutants
  • Particulate Matter
  • Vehicle Emissions