Traffic pollution tied to low-birth-weight risk

Traffic-related air pollution has been linked with adverse birth outcomes, in particular low birth weight, for some time, but confounding with noise pollution has been an issue in determining true causal association.

A new study from Imperial College, London has suggested that concentrations of traffic pollutants, especially particulate matter, but not noise (as an independent variable), are associated with low birth weight or being ‘small for gestational age’. Both exhaust and non-exhaust PM2.5 may be implicated, with consistent evidence that the exhaust component in particular is associated with the effect. An increase in PM2.5 of 2.2 µg m-3 (the interquartile range in the study) may lead to a 2-6% increased chance of low birth weight.

Although on an individual level factors such as smoking have much greater effect, on a population level the impact may still be significant as there is often little pregnant women can do to reduce exposure. Commentary on the paper suggests wide-ranging action led by policy makers to reduce ambient pollutant concentrations is the best means of tackling the problem.

For the full commentary from Reuters and link to the abstract click here