It seems like pigeons are more than some annoying birds with a rat-like behavior. Based on the latest study, they can tell us if cities have reached a critical point of air pollution.
A team of scientists has collected blood samples from hundreds of injured and sick pigeons in New York City from 2010 to 2015 to establish if there is any connection between these birds and environmental issues.
At the end of the study, they came to the conclusion that all these pigeons had high lead levels during summer months. Worse, these findings were also linked to lead levels found in blood samples taken from children.
In other words, these birds and children experienced the same consequences due to air pollution. It means that if these birds get sick, kids are more likely to get sick as well.
According to Rebecca Calisi, lead author of the study and assistant professor of neurobiology, physiology, and behavior at the University of California, pigeons live in the same environment as we do and they usually eat the same food as us.
This connection between humans and these birds helped Calisi and her colleague from Columbia University, New York City, to come up with the idea that pigeons can be used to monitor air pollution in cities.
The U.S. Centers for Disease Control and Prevention stressed that high lead levels could result in severe consequences for children such as the inability to pay attention, and lower IQ levels.
But no one knows where these high lead levels originate from because there are already decades since gasoline is lead-free. Scientists said that only some houses still have a lead paint, but that is not enough to cause such health disorders in pigeons.
The only viable explanation is that construction sites and roads are the places where lead exposure is higher meaning that it can be easier inhaled. Researchers speculate that pigeons might have high lead levels in their blood due to the fact that they sometimes ingest roadside gravel to improve their digestion process.
Also, children might carry lead on their shoes all the way home. Some European cities already use pigeons to monitor air pollution originating from fire retardants, pesticides, and heavy metals. It is worth mentioning that pigeons are used to detect cancer tumors in mammograms as well.