Photo: AZPM Nitric acid breaks down or "digests" toenails so scientists can analyze their chemical composition.

In Miranda Loh’s lab, toenails are telling stories. They arrive in little brown envelopes almost every week, sometimes in batches of three or four, sometimes by themselves.

And together, they’re piecing together a puzzle that could affect the health of more than a million Arizonans.

Loh, an assistant professor of environmental health sciences at the University of Arizona Mel and Enid Zuckerman College of Public Health, is trying to measure Arizonans’ exposure to arsenic over time.

Read the full story, "Arsenic and Old Toenails," by Gisela Telis, Arizona Public Media, May 10, 2012.