Traffic-related air pollution and prostate cancer risk: a case-control study in Montreal, Canada

Occup Environ Med. 2013 Jul;70(7):511-8. doi: 10.1136/oemed-2012-101211. Epub 2013 Mar 26.

Abstract

Objectives: There is a paucity of information on environmental risk factors for prostate cancer. We conducted a case-control study in Montreal to estimate associations with exposure to ground-level nitrogen dioxide (NO2), a marker for traffic-related air pollution.

Methods: Cases were 803 men with incident prostate cancer, ≤75 years of age, and diagnosed across all French hospitals in Montreal. Concurrently, 969 controls were drawn from electoral lists of French-speaking individuals residing in the same electoral districts as the cases and frequency-matched by age. Concentrations of NO2 were measured across Montreal in 2005-2006. We developed a land use regression model to predict concentrations of NO2 across Montreal for 2006. These estimates were back-extrapolated to 1996. Estimates were linked to residential addresses at the time of diagnosis or interview. Unconditional logistic regression was used, adjusting for potential confounding variables.

Results: For each increase of 5 parts per billion of NO2, as estimated from the original land use regression model in 2006, the OR5ppb adjusted for personal factors was 1.44 (95% CI 1.21 to 1.73). Adding in contextual factors attenuated the OR5ppb to 1.27 (95% CI 1.03 to 1.58). One method for back-extrapolating concentrations of NO2 to 1996 (about 10 years before the index date) gave the following OR5ppb: 1.41 (95% CI 1.24 to 1.62) when personal factors were included, and 1.30 (95% CI 1.11 to 1.52) when contextual factors were added.

Conclusions: Exposure to ambient concentrations of NO2 at the current address was associated with an increased risk of prostate cancer. This novel finding requires replication.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Air Pollution / adverse effects*
  • Air Pollution / analysis
  • Case-Control Studies
  • Environmental Exposure / adverse effects*
  • Environmental Exposure / analysis
  • Humans
  • Logistic Models
  • Male
  • Middle Aged
  • Nitrogen Dioxide / analysis
  • Nitrogen Dioxide / toxicity*
  • Prostatic Neoplasms / chemically induced*
  • Prostatic Neoplasms / epidemiology
  • Quebec / epidemiology
  • Risk Factors
  • Vehicle Emissions / toxicity*

Substances

  • Vehicle Emissions
  • Nitrogen Dioxide