Erin Ross Feb 21
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Pigeons may be proxies for pollution in people

Pigeons, surrounded by snow, cluster on dry ground around a New York City storm drain to stay warm
Pigeons of New York. Photo: Cem Ozdel / Anadolu Agency / Getty Images

Pigeons and people living in the same neighborhood are likely to have comparable rates of lead exposure, according to a study presented at the 2018 meeting of the American Association for the Advancement of Sciences in Austin, Texas.

Why it matters: The birds might one day serve as the metaphorical canary in a coal mine, alerting officials to pollution-caused illnesses before they occur in humans.

Pigeons have been used to look for the presence of environmental contaminants for some time. But until now, researchers didn’t know if their toxin levels correlated with those in humans in the same area.

What they did: Rebecca Calisi-Rodriguez, a biologist at the University of California, Davis, and undergraduate student Fayme Cai analyzed blood samples from 825 sick or injured birds brought to a wildlife rehabilitation center in New York between 2010-2015, and looked at the zip code they were found in. New York requires that young children be tested for lead exposure each year, so the scientists then cross-referenced public records of those results with those of the pigeons.

Why they did it: Although lead has been banned in the United States for decades, its residue can still be found in gasoline, pipes and paint that can be sources of dangerous levels of exposure. Researchers already knew that pigeons picked up environmental toxins, but until now no one knew if pollution in pigeons corresponded with pollution in people. Pigeons live their entire lives within a very small (about 2 kilometer) radius so if they test positive for toxins, they were probably exposed locally.

What they found: New York City neighborhoods with higher rates of high blood lead levels in children also had the highest rates of blood lead levels in pigeons. The association was strong, which means testing pigeons for pollutants could be a good proxy for testing people.

“Why test pigeons when you can test people?” is one of the most common questions Calisi-Rodriguez gets, especially since New York City requires mandatory lead checks for children.

  • Because pigeons live outside and eat off the ground, they might have greater exposure to environmental toxins than people. That means it could be easier to find those toxins in pigeon.
  • Other cities don’t have mandatory blood-lead level testing.
  • Drawing blood from humans (particularly children) can be traumatic for the patient.
  • Taking blood from humans in a region requires jumping through more hoops and possibly costs more than taking blood from pigeons.

What’s new? In a collaboration with Matthew Macmanes at the University of New Hampshire, Rodriguez-Calisi found that when pigeons are stressed (by being placed in a pillow case), different genes are activated in both male and female pigeons. Rodriguez-Calisi wonders if male and female pigeons (and possibly people) might respond to a chemical stressor, like lead, differently. Their initial study did not take the sex of pigeons into account but hope to in future work.

What’s next: Rodriguez-Calisi would also like to study populations of pigeons in other parts of the country to see if toxins vary in urban/rural areas and use the pigeons as indicators of other pollutants.

What's next for cancer immunotherapies

A researcher holds a plate used to grow T cells.
Photo: BSIP/UIG via Getty Images

Cancer immunotherapies that trigger a person's own immune system to recognize and attack cancer cells have logged some success in certain patients and with certain types of cancers. "But overall that is a minority of cancer patients," says Antoni Ribas from the University of California, Los Angeles.

Now, researchers are looking to leverage their understanding of what's working and what's not in patients receiving this class of drugs. (Science published a special section about cancer immunotherapy Thursday.)

The challenge: These are new avenues for research but they also spur serious concerns that must be addressed: unwanted and sometimes deadly side effects, unexplained lack of response by some cancers, and questions arising from combining multiple therapies and finding the optimal timing — which can make or break treatment.

The worst flu season in eight years

Note: Activity levels are based on outpatient visits in a state compared to the average number of visits that occur during weeks with little or no flu virus circulation; Data: Centers for Disease Control and Prevention; Chart: Chris Canipe/Axios

This year's flu season caught many experts off guard with both its sustained prevalence and its virulence. At its peak, there was a higher level of flu-like illnesses reported than any other year during the past eight years. Watch in the visual as it hits its peak around Week 18.

Why it matters: Public health officials try to capture this data when developing the next year's vaccines. And, of course, they want to find better ways to prevent severe flu seasons. There's a "Strategic Plan" to develop a universal vaccine to protect against a wider range of influenza viruses, Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, tells Axios.