For most city dwellers, pigeons are just another speck in the hustle and bustle of urban life and are only truly noticed when they don’t move out of the way fast enough as you stride down the sidewalk. However, for environmental health scientist Rebecca Calisi from the University of California, Davis, pigeons are her primary focus and the basis of her research for potentially finding areas in cites with high level of contaminants dangerous to humans.
In the past, a few studies in Europe and Asia used pigeons as bioindicators of heavy metal contamination and Calisi took the lead to initiate the first study of this type in the U.S, and also tie the patterns to levels of lead in pigeon blood to those in children.
For people, sources of lead exposure include paint in old buildings and contaminated dust from soil, roads, and construction sites. Indoor paint probably doesn’t pose much of a risk to pigeons, but the birds may also be exposed to lead from rocks they swallow to help with digestion.
Calisi, along with a Barnard undergraduate, took blood samples from 825 pigeons from 13 neighborhoods in four of New York City’s five boroughs at the Wild Bird Fund, a wildlife rehabilitation center in New York City. “All of the birds were suspected of having lead poisoning, and had been brought to the facility because they were ill or behaving oddly.”
They found a correlation between pigeons’ blood lead levels and the rates of children with elevated lead in their blood. That is, the neighborhoods where pigeons tended to have the highest levels of lead – Soho, Greenwich Village, Lower Manhattan, the Lower East Side, and the Upper West Side in Manhattan – also had the highest rates of children with elevated lead levels according to city health department data.
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