NEW YORK, July 19 (UPI) -- New research shows toxicity levels in urban pigeons are a good proxy for risk of lead poisoning in children.
When researchers compared the levels of lead in New York City pigeons with lead exposure measured in local children, the numbers revealed a strong geographic correspondence.
The study was carried out by Rebecca Calisi, now an assistant professor at the University of California, Davis, and undergraduate student Fayme Cai, while at Barnard College, Columbia University.
"Pigeons breathe the same air, walk the same sidewalks, and often eat the same food as we do," Calisi said in a news release. "What if we could use them to monitor possible dangers to our health in the environment, like lead pollution?"
Calisi and Cai measured lead levels in blood samples collected from 825 sick or injured pigeons treated at a local New York wild bird rehab center between 2011 and 2015. Each bird was identified with the zip code where it was found.
The researchers compared their findings with those of the New York City Department of Health and Mental Hygiene, which regularly screens children living in neighborhoods with a history of lead contamination.
The data sets revealed a high level of congruity. Calisi believes it's the first time lead levels in birds have been shown to correspond with those in humans.
"This is a powerful example of how we can use pigeons to monitor the location and prevalence of pollutants," Calisi said. "We can use these 'rats with wings' -- which are anything but -- to monitor dangers to human health."
Researchers published the results of their novel study this week in the journal Chemosphere.
The data collected by Calisi and Cai showed lead levels in pigeons spiked during summer months, just as public health researchers have found in children.
Scientists aren't sure exactly why this is -- or where exactly pigeons are being exposed to lead. Though lead has been banned in gasoline and paint for several decades, the toxic metal can still be found in layers of old paint in buildings in New York City.
It's possible construction sites release lead-laced soot and aerosols into the air, which pigeons ingest when swallowing gravel to aid digestion.
Because pigeons don't migrate and mostly remain within a few city blocks for most of their lives, they could be used to monitor other types of toxins in the environment.