Pigeons Track Lead Dangers
A much maligned feathered city-dweller may deserve a second look, according to researchers who say pigeons could be the key to tracking lead exposure in children.
A new study, published this week in the journal Chemosphere, looks at lead levels in pigeons in urban neighborhoods and compares them with blood lead levels in children in the same area, as reported by public health entities. The study finds a correlation between lead levels in the birds and the children.
The study was carried out by Rebecca Calisi, formerly at Columbia’s Barnard College, who is now a professor in the Department of Neurobiology, Physiology and Behavior at the University of California, Davis. She worked with Barnard undergrad Fayme Cai on the research.
Neighborhood and Season
Calisi and Cai’s research centers on two main factors related to lead exposure. One is locale, and another is season—lead levels in children tend to rise in summer, and the new study found the same phenomenon in pigeons.
Calisi and Cai found that neighborhoods that had a higher rate of children with elevated lead levels correlated with neighborhoods where pigeons had higher recorded lead levels.
Neighborhood to neighborhood, Calisi and Cai found that those neighborhoods (mostly in Manhattan) that had a higher rate of children with elevated lead levels correlated with neighborhoods where pigeons had higher recorded lead levels.
Pigeons, according to previous research, are believed to generally spend their lives within a radius of about 2 kilometers, a trait that makes localized studies tenable.
The researchers say they studied blood lead levels in 825 “visibly ill or abnormally behaving pigeons” in New York City over a five-year period, from 2010 to 2015. They used data provided by New York’s Wild Bird Fund, a group that collects and rehabilitates sick and injured wild birds in the city.
|By Darwin Bell – CC BY-SA 2.0, via Flickr
Old lead paint in buildings that are deteriorating or being demolished can lead to higher lead levels in the soil and groundwater.
Pigeons have been studied in relation to heavy-metals contamination in the past, the study’s authors say, but this research is thought to be the first correlating lead levels in pigeons and humans.
The new study notes that there are a number of factors that could contribute to high blood lead levels, in birds and humans. A correlation between heavy traffic and higher lead levels has been found; old lead paint in buildings that are deteriorating or being demolished can also lead to higher lead levels in the soil and groundwater.
Lead in paint was banned in the United States in 1978; lead as an additive in gasoline was phased out starting in the 1970s, and completely banned in 1996.
Birds for Good
The researchers hope that their data can help devise new ways of tracking and responding to lead contamination in urban areas—for the childrens’ sake, even if the birds themselves remain unpopular.
“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.”