A chief bank teller by trade, the diminutive grandmother of four says she can hold her own in a bar brawl. And I believe her, given some of the corporate and governmental clowns that she's been sparing with.

As the lead hound of a local watchdog group, Rossi has been imbibing bad air for nearly 15 years. In that time, she proudly admits, the local atmosphere has become less toxic. Though, she adds, it's mostly because she's bitched, howled and successfully sued Sunoco twice to demand that the oil refinery keep their poisons within legal limits.

I breathe easier because Joanne Rossi has been on the job. We all do. "Someone has to do it," says Rossi, who says she's had little help from official government sniffers.

And now Rossi can offer better evidence of malevolent odors than the say-so of her nose. Better even than the data gleaned from the buckets of air, which Community/Labor Refinery Tracking Committee volunteers have dutifully scooped up for analysis.

As a result of her group's most recent suit against Sunoco [News, "Refreshed Air," Jenna Portnoy, April 6, 2006], Rossi now owns the best nose in the nasty-air business. Known as a "hound," the Cerex UV Hound is a portable air sampler that uses UV light to detect individual chemicals in a bouquet of toxins.

Today, we're on her hound's maiden hunt, and as we pass the refinery, the graphs on Rossi's laptop leap up: butadiene, acrolein, ammonia, toluene — bad stuff all, though nothing beyond legal limits.

The hound itself is lying across the deck of our minivan. A yard long, it resembles a square bazooka. Every 30 seconds it sucks a sample through a long, black snout that's hanging out the window — which from the outside looks a bit like the schlong of a horse.

Other drivers stare at us, and cops do a double take, which only brings on fits of giggles from Rossi. She wants everyone to know that she and her pack are sniffing around.

And there are lots of toxins to snuff up. Southwest Philadelphia is a legendary toilet among pollution researchers. The Environmental Defense organization ranks the Sunoco refinery among the worst in the nation.

In addition to the refinery, auto body shops, dry cleaners, the trash-transfer station, the sewage plant and various junkyards are all part of South Philadelphia's 250 listed pollution sources. Rossi's crew has previously detected some seven known carcinogens (like benzene), 12 suspected cancer-causing agents (like MTBE), 16 respiratory irritants and 21 nervous-system toxins.

In her first lawsuit against Sunoco, in 1994, Rossi forced the oil company to upgrade their plant. But the poisons kept coming, she says, adding that the federal EPA's response only made matters worse.

In 2000, with her group on the verge of suing Sunoco again, the EPA asked Rossi to hold off while the agency worked out a national settlement to bring Sunoco's refineries into compliance. Rossi waited five years, while Sunoco racked up record profits. When she badgered the EPA for an update, she says the agency ignored her.

So in April 2005, Rossi unleashed another assault on Sunoco, alleging more than 1,000 violations. Sunoco settled in November, agreeing to upgrade their filtration equipment and to pay for Rossi's hound.

Now, says Rossi, she can suck up more local air pollution data than any city, state or federal agency in Pennsylvania. Rossi's hound can detect hundreds of compounds, while the city's Health Department monitors only five. Besides, adds Rossi, by the time the Health Department sends anyone out, the nasty gas is often long gone.

We drive to Ninth and Reed, where auto repair shops off gas into the neighborhood. "Look at the squiggles," says Rossi. "We've got something." What they find will be posted on their Web site by early October (www.pabucketbrigade.org/clrtc). For the first time, all the ingredients in South Philly's toxic brew will be recorded. "It's a pity we've got to police the polluters," says Rossi, "because the government won't."

I'm just grateful that someone is hounding them.

(bruce@schimmel.com)