Natural-cause Mortality and Long-Term Exposure to Particle Components: An Analysis of 19 European Cohorts Within the Multi-Center ESCAPE Project

Environ Health Perspect. 2015 Jun;123(6):525-33. doi: 10.1289/ehp.1408095. Epub 2015 Feb 24.

Abstract

Background: Studies have shown associations between mortality and long-term exposure to particulate matter air pollution. Few cohort studies have estimated the effects of the elemental composition of particulate matter on mortality.

Objectives: Our aim was to study the association between natural-cause mortality and long-term exposure to elemental components of particulate matter.

Methods: Mortality and confounder data from 19 European cohort studies were used. Residential exposure to eight a priori-selected components of particulate matter (PM) was characterized following a strictly standardized protocol. Annual average concentrations of copper, iron, potassium, nickel, sulfur, silicon, vanadium, and zinc within PM size fractions ≤ 2.5 μm (PM2.5) and ≤ 10 μm (PM10) were estimated using land-use regression models. Cohort-specific statistical analyses of the associations between mortality and air pollution were conducted using Cox proportional hazards models using a common protocol followed by meta-analysis.

Results: The total study population consisted of 291,816 participants, of whom 25,466 died from a natural cause during follow-up (average time of follow-up, 14.3 years). Hazard ratios were positive for almost all elements and statistically significant for PM2.5 sulfur (1.14; 95% CI: 1.06, 1.23 per 200 ng/m3). In a two-pollutant model, the association with PM2.5 sulfur was robust to adjustment for PM2.5 mass, whereas the association with PM2.5 mass was reduced.

Conclusions: Long-term exposure to PM2.5 sulfur was associated with natural-cause mortality. This association was robust to adjustment for other pollutants and PM2.5.

Publication types

  • Meta-Analysis
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Air Pollutants / toxicity*
  • Environmental Exposure*
  • Europe
  • Humans
  • Particle Size
  • Particulate Matter / toxicity*
  • Proportional Hazards Models

Substances

  • Air Pollutants
  • Particulate Matter