A strong voice for environmental action in Louisiana's Cancer Alley

More than once, Subra says, she has been in a legal proceeding, sitting across from an oil company executive who dismisses her reports of widespread illness as "hysterical." She then receives a call from that executive at her home at night, anxiously detailing the rashes and breathing problems experienced by his own children.

"Did we do this?" they want to know. Subra quietly explains which chemicals might be to blame and what information to give the family's doctor.

One of Subra's worst-case scenarios is Mossville, which has the densest concentration of industrial facilities of any region in Louisiana.

Companies there manufacture vinyl chloride, which produces dioxin, a group of chemicals so nasty the federal government requires reporting on any dioxin release. The World Health Organization categorizes dioxins as hormone disrupters, carcinogenic and environmentally persistent — meaning the chemical accumulates in the food chain.

People in Mossville called Subra last year to find out what was making them so sick. Her testing showed that residents' blood dioxin levels were three times the national average.

She found dioxins in attic dust, in the dirt in residents' yards, in the fruits and vegetables and nuts in their gardens, in the fish they caught in local estuaries. She conducted tests and traced the chemical fingerprint back to a single industrial plant.

The state environmental quality agency came to Mossville to hold hearings — a company wanted a permit to build another plant. Subra presented her scientific evidence and local residents trooped forward, coughing and reporting their health problems.

"You name it, these people have got it," she said.

The agency granted the permit.