Tracking an Outbreak of Lead Poisoning to a Surprising Source

It started in 1994 with alarming levels of lead showing up in some Monterey County kids. Lead robs the body of iron and calcium—nutrients crucial to child development. The poisoning triggers progressive neurological damage, and as lead levels rise, a child’s IQ plummets.

Looking for the source, Celeste Hall, a public health nurse in the coastal town of Seaside, noticed that most of the affected kids’ families came from Oaxaca—part of a wave of migration to Monterey County that began in the 1970s. Some health officials started thinking that Mexican immigrants were arriving in California already contaminated with lead. But Hall and Seaside clinic physician Eric Sanford thought not, since many of the poisoned kids were born here, not in Mexico. They suspected the poison trail was less direct—and considerably more complicated. How right they were.

The threat was still a disturbing puzzle when UCSF epidemiologist Margaret Handley joined the hunt in 2000. Handley ‘86, MPH ‘90, Ph.D. ‘00, had cut her teeth on problems like this. As an undergrad in environmental studies, she investigated state reports of chemical exposure, and later zeroed in on lead’s impact upon the reproductive health of battery plant workers. Keep reading