Monkeys Are Canaries in Lead Mine

In a study in the American Journal of Physical Anthropology, researchers showed that macaques that live side by side with humans in Nepal show elevated lead levels in their bodies. The human population is thus probably also being exposed to unsafe lead. Cynthia Graber reports

Illustration of a Bohr atom model spinning around the words Science Quickly with various science and medicine related icons around the text

Join Our Community of Science Lovers!

You’ve heard about the canary in the coal mine. And frogs as signals of environmental degradation. The latest animal to serve as a harbinger of toxic exposures to humans may be: monkeys. That’s according to research in the American Journal of Physical Anthropology.

Macaques live in close quarters with people in parts of Nepal. So scientists thought that the monkeys might be “sentinels” for human lead exposure. Lead can have multiple deleterious health effects, from impairing neurological development to kidney, liver, and circulatory and respiratory problems.

The research team wanted to avoid stressing the animals, so they took a few strands of hair from individuals living around a temple in Katmandu. It’s in a densely populated area that contains old lead batteries, flaking lead-based paint, and lead-contaminated soil, a by-product of leaded gas. Lead levels varied in the macaques, but the highest concentrations were in the young—like human children, young macaques tend to pick up objects and stick them in their mouths.


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


Scientists say they’ll next try to nail down whether macaque lead levels are indeed predictive of lead poisoning in humans. The hope is that monitoring macaque lead can improve conditions for humans and monkeys alike.

—Cynthia Graber

[The above text is an exact transcript of this podcast.]

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American

Subscribe