Behind the wheel of her well-worn Chevy Impala on a recent morning, Subra navigates Highway 14 past oil refineries, natural gas transfer stations, bubbling waste ponds and oozing toxic dumps.
Exhausted towns huddle along the two-lane blacktop that skirts the Gulf Coast. They are known as "fenceline communities," because residents breathe whatever belches from the nearby smokestacks and drink what the companies release into the local water supply.
"My goodness, look at that," Subra said, pointing at a belching smokestack and reeling off a list of the chemicals wafting into a light blue sky.
Subra drives past a large, boxy facility surrounded by barbed wire, pointing out the Gulf South Research Institute where she worked for 14 years doing pharmaceutical and biotech testing for private businesses and the federal government.
Since then, she has worked as an EPA contractor as part of an emergency response team sent to toxic spills and other disasters to perform quick assessments. She's now helping the federal agency develop water toxicity tests for the regulation of hydraulic fracturing.
Subra has a business — commercial chemical analysis — that she neglects. The work that compels her is the pro bono help she has given to poor communities exposed to toxins.
"If it's an affluent community, you will have people with money who will speak out, who will have connections," Subra said. "The minority and the poor, for the most part, don't have a voice."
The energy industry, in particular, has frequently been across a corporate conference room from Subra. Tom Stewart, executive vice president of the Ohio Oil & Gas Assn., calls Subra "a ferocious advocate."
"She worries people on my side of the fence because she's very well-respected, and therefore she's effective," said Stewart, who has worked with Subra during reviews of state oil and gas regulations. "We don't always see eye to eye. However, I hold her in very high regard."
During the BP oil spill off the Louisiana coast, Subra joined with the Louisiana Environmental Action Network to prepare for oil reaching land. She recognized that high winds hitting the 68,000-square-mile slick were carrying the crude into the air. She warned of the potential danger from dispersants used to break up the slick and pushed for authorities not to burn off the oil when winds were blowing toward land.
After determining that dispersants contained neurotoxins, Subra demanded protective gear for the cleanup workers. Federal authorities and company officials had argued that the dispersants were safe and warned workers they would be fired if they wore the gear.
Subra prevailed. Eventually cleanup crews wore the protective coveralls, but even that couldn't fully protect them from the Gulf's toxicity.
"The husbands came in with it all over them and the wives washed their clothes," Subra said. "The husbands had symptoms and wives had symptoms: headaches, nausea, difficulty breathing, decreased lung function. Memory loss."
Mike Taylor worked for BP on its spill response and recalled a time he helped company lawyers prepare for a meeting with Subra.
"They thought highly of her, and they expected her to be a hard-nose," Taylor said.
He's up against Subra again, this time working as a contractor with Texas Brine, an oil and gas service company whose operations at nearby Bayou Corne created a massive sinkhole, leading to the evacuation of hundreds of residents last summer.
Taylor described many of the groups opposing the company as "anti-business" and "anarchists." But Subra, he said, "is the voice of reason. She understands the rules and regulations because she's helped formulate some of them."