MedWire News: Exposure to ambient metals contained in pollution from heating oil combustion and traffic in early life is associated with an increased risk for respiratory symptoms in young children, study results show.
The findings, published in the American Journal of Respiratory and Critical Care Medicine, show that specific sources of air pollution can negatively affect children’s respiratory health and could have important public health implications, say Rachel Miller (Columbia University, New York, USA) and team.
The researchers studied data on 687 inner-city children born in New York between 1998 and 2006.
Parental questionnaires were used to gather information on respiratory symptoms in the children every 3 months until the age of 2 years.
Every 3 months, data from pollution monitoring stations situated in the study area were used to assess the children’s average exposure to metal constituents of ambient fine particulate matter (PM2.5), including nickel (Ni), vanadium (V), and zinc (Zn), as well as elemental carbon (EC).
After accounting for gender, exposure to environmental tobacco smoke, season of the year, and other factors, the researchers found that a 0.014 µg/m3 increase in 3-month average interquartile range (IQR) concentrations of ambient Ni was associated with a significant 28% increased risk for wheeze.
An IQR increase of 0.003 µg/m3 in 3-month average concentrations of V was associated with a 10% increased risk for wheeze, but the significance of this association fell significantly after adjustment for confounding factors.
Exposure to increased levels of EC, an indicator of diesel exhaust concentrations, was associated with an increased risk for cough, but only during the cold and flu season (September through April).
However, total PM2.5 levels were not associated with wheeze or cough, the researchers note.
They conclude: “These results suggest that exposure to ambient metals and EC from heating oil and/or traffic at levels characteristic of urban environments may be associated with respiratory symptoms among very young children.”
Miller added: “The effects of exposure to airborne metals had not been studied previously in children so young, and these findings could have important public health implications for members of inner-city communities in New York City and elsewhere.”
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