Exposure
shortly after birth to ambient metals from fuel oil combustion and particles
from diesel emissions is associated with respiratory symptoms in young inner-city
children, according to a new study by researchers at the Columbia Center for
Children’s Environmental Health (CCCEH) at Columbia University’s Mailman School
of Public Health.
The
study is published in the December 1, 2009, issue of the American Thoracic
Society’s American Journal
of Respiratory and Critical Care Medicine.
“It
appears that exposure to ambient metals and diesel-exhaust particles in our air
may lead to several respiratory symptoms for young children living in urban
areas,” said senior investigator Rachel L. Miller, M.D., associate professor of
Medicine and Environmental Health Sciences (in Pediatrics) at New
York–Presbyterian Hospital/Columbia University Medical Center and co-deputy
director of CCCEH at the Mailman School of Public Health. “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.”
To
determine these effects, the researchers studied pollutant levels and
respiratory symptoms in a cohort of more than 600 New York City children from
Northern Manhattan and South Bronx between birth and two years of age. They
used monitoring data to gauge three-month average ambient air concentrations of
nickel, vanadium, elemental carbon and zinc as well as particulate matter.
After controlling for exposure to second-hand tobacco smoke, sex, ethnicity and
seasonal trends, they found that the airborne metals nickel and vanadium, whose
major source in New York City is residual oil combustion for heating, were risk
factors for wheezing in young children. Elemental carbon, an indicator of
diesel exhaust, was associated with increased frequency of coughing only during
cold and flu season months (September through April).
“These
findings increase our understanding of the effects of specific pollutants from
heating oil combustion and traffic on respiratory health in very young
children,” said Molini M. Patel, Ph.D., M.P.H., lead author and (previously) a
research scientist in the Division of Pulmonary, Allergy, and Critical Care
Medicine at Columbia College of Physicians and Surgeons and a CCCEH investigator.
“Our results are of concern especially because levels of nickel in our study
area, Northern Manhattan and the South Bronx, are among the highest in New York
City and in the U.S., as are the rates of pediatric asthma.”
These
findings contribute to a further understanding of how specific sources of air
pollution may impact child health.
Prior
research from the Columbia Center for Children’s Environmental Health showed
that exposure to multiple environmental pollutants may be associated with an
increase in risk for asthma symptoms among children. The researchers suggest
that improved regulatory action directed at specific pollution sources— such as
reducing residential boiler and emissions of airborne pollutants such as nickel
or elemental carbon— is needed to help protect young children living in urban
areas. A prospective follow-up of this birth cohort and measurement of
residential levels of metals and traffic-related particles will help determine
whether exposures to these pollutants are associated with increased respiratory
morbidity and development of asthma at later ages, according to the
researchers.
The
study was funded by the National Institutes of Environmental Health Sciences,
the U.S. Environmental Protection Agency, and several private foundations.
— News release courtesy of