Published in The Lancet, the paper pointed the finger at fine particles of soot and dust, emissions of which are also stirring a health scare in parts of Asia, especially China.
Scientists led by Rob Beelen of Utrecht University in the Netherlands looked at 22 previously-published studies that monitored the health of 367,000 people in 13 countries in western Europe.
The individuals, recruited in the 1990s, were followed for nearly 14 years.
During the time of the study, 29,000 people died, according to the data.
Beelen's team went around to all the study areas to get readings of traffic pollution between 2008 and 2011.
They used these as a basis for calculating the long-term exposure of local residents to two kinds of particulate matter and to two kinds of gas emissions.
They took into account factors such as smoking habits, socio-economic status, physical activity, body-mass index and education that can skew the results.
buy singulair online buy singulair online no prescription
The biggest source of concern was PM2.5, meaning par