Not everyone cheered when Dr. Richard Weisler arrived in Salisbury last month. Despite a recent national magazine spread celebrating his quest to find the root of cancer cases in his hometown, some of his toughest critics were residents of his old neighborhood.

Dr. Neil Patel, a lung specialist, buttonholed Weisler before a public meeting. Patel accused the Raleigh psychiatrist of spreading false fears about pollution and illness in his town.

"We do not need fear-mongering from you," said Patel, a resident of the Milford Hills neighborhood where Weisler's mother lived for 40 years. "When you go into any scientific study knowing what you want to prove, that's poor science."

Such jabs have hit Weisler for years, but he presses on. After his mother was diagnosed with lung cancer seven years ago, he suspected that a smelly industrial district nearby might have made her and others sick. At first, officials praised him for shining light on a potential hazard.

But after collecting data on the dead and ailing, Weisler started warning of local cancer clusters, even suspicious suicide rates. That won him fewer fans.

Linking disease to pollution is tricky, because so many factors could be to blame. Exposures to known health risks -- heredity, diet, smoking, age -- must either be ruled out or documented.

Still, evidence in Salisbury can appear tantalizing. The latest study, conducted by a federal agency petitioned by Weisler, found brain cancer and lymphoma in two Salisbury neighborhoods at rates five and six times higher than the rest of Rowan County.

For Weisler, that was proof enough of a hazard in Salisbury. Now he is urging the state to conduct more studies to understand how it happened and how to fix it.

"If you don't try to understand this, you don't learn how to prevent it in other places," said Weisler, who has filed a wrongful death lawsuit for his mother's estate against the owners of an asphalt plant situated near his mother's home.

But state and county health and environmental officials see no crisis. Individual health histories or random chance can explain elevated cancer rates, they say. Multiple environmental tests have convinced them that no risky levels of poisons are escaping the industrial spots near Milford Hills.

One-time allies wonder if Weisler's campaign is beginning to do more harm than good.

"It can become a negative when it creates undue fear," Mayor Susan Kluttz said.

Cancer hits home

Weisler started his Salisbury campaign after his ailing mother took him on a walk around the leafy Milford Hills neighborhood in 2000. Diagnosed with lung cancer at age 72, Rita Weisler had not smoked in more than 30 years, her son said.

The widowed owner of a successful beer distribution company pointed to house after house where neighbors had cancer. She suspected that a nearby liquid asphalt storage and distribution operation and an adjacent asphalt mixing outfit were to blame. One plant stores and distributes hot liquid asphalt, a derivative of crude oil. The second mixes liquid asphalt with sand and rocks to make paving materials.

Weisler, now 55, didn't buy his mother's suspicions at first. But as she grew too weak to walk, he started sorting her papers and found a letter from state regulators describing toxic air emissions at one asphalt plant, he said. Another time, on a day when the fumes were especially strong in Milford Hills, he saw a child's asthma flare. Later, he learned the state Department of Transportation had paid to unhook a neighbor from a contaminated well in 1993.

Weisler started digging deeper.

Research was not new to Weisler. He grew up expecting to join the family business, but a trip to Africa as a Tulane University student inspired him to be a doctor. In addition to treating patients, Weisler conducts studies with psychiatric drugs, brain imaging and genetics at his North Raleigh practice. He's on the adjunct faculty at UNC-Chapel Hill and Duke University; some Duke students now assist his Salisbury work.

Weisler dived into government records. He learned that a testing outpost the state operated for years at the asphalt mixing plant contaminated air and underground water with solvents. A former Exxon tank farm and a retail gas station not far away tainted water and soil, too.

Residents had long complained to the state Division of Air Quality about odors from the asphalt operations, particularly the storage and distribution outfit now run by Associated Asphalt. But no one had briefed people in Milford Hills or the nearby Meadowbrook neighborhood of the extent of nearby contamination.

"It was appalling," Weisler said.

Rowan County Health Director Leonard Wood remains grateful to Weisler for exposing it. That put more pressure on Associated Asphalt to install carbon filters on its tanks to help reduce odors in the neighborhoods, Wood said. Weisler's advocacy also helped lead to expanded state monitoring of emissions.

"He brought out concerns about how we in the public health field need to evaluate environmental concerns. He's done that well, probably more than people wanted to hear," Wood said.

But his theories about death and illness, Wood said, are far less convincing.

A seeming pattern

Cathy Gusa doesn't view Weisler as a fear-monger. Gusa grew up in Meadowbrook and knew Weisler when he was still Ricky, a very smart kid, Latin club member and tennis player at their Salisbury high school.

Her faith in him starts with marks on a map. Since 2000, Weisler has mapped the residences of the sick and the dead in Milford Hills and Meadowbrook. Different colored dots mark adult and child brain cancer cases, leukemia, pancreatic cancers, lung cancers and more.

A red dot on Forestdale Drive represents Cathy Gusa's late husband, Roy. After years living out of town, she and Roy moved to Meadowbrook in 1990 to be close to her mother. Five years later, Roy was diagnosed with a rare and lethal brain tumor called glioblastoma. A neighbor soon developed the same type of brain cancer.

Gusa is touched that someone is trying to understand what happened. "Until I talked with him, I never connected this to a source," said Gusa, who counts herself among dozens of residents in the neighborhoods who support Weisler's work.

And it's not only residents who want to know more. One author of the recent federal study, toxicologist Alden Henderson, said the results are compelling enough to warrant follow-up by state officials. But state public health officials are not convinced.

The increased disease rates detected by federal researchers focus on a population group that is too small to make broad generalizations, and cannot be definitively linked to the industries near the neighborhoods, they say. Air tests at nearby industrial sites found benzene levels comparable to other North Carolina cities and hydrogen sulfide at levels that could bother asthmatics. Both have been reduced.

Most residents in the neighborhoods have used city water for years. Rita Weisler made the switch in 1982, her son said. Those who don't are urged to get their wells tested.

"Just because a group of people has cancer doesn't mean there's one reason. Cancer is a complicated thing," said Dr. Doug Campbell, chief of the occupational and environmental epidemiology branch of the state's public health division.

Weisler's worries aren't confined to cancer, either. One Duke student conducting research with Weisler noticed a large number of suicides among the death certificates filed for people from Milford Hills and Meadowbrook. She and Weisler calculated that between 1994 and 2003, the suicide rate in the two neighborhoods was three times the statewide average.

Weisler thinks that hydrogen sulfide and other neurotoxins detected near the asphalt plants could be to blame. Animal studies show neurotoxins can alter levels of important brain chemicals, including some that affect mood. To test his theory, he and volunteers began researching suicide rates in Haywood County, where Weisler says emissions from a paper mill might be triggering a similar increased suicide rate.

"I don't see this as just about Salisbury," Weisler said.

But Campbell is skeptical. "Just finding suicides in an area doesn't mean special conditions cause them," he said.

The doctor hasn't published Salisbury data in an academic journal yet, but he carries posters describing his research to academic conferences. His campaign was the focus of a lengthy article in Oprah Winfrey's "O Magazine" earlier this year.

Weisler intends to stick with this, maybe even organize a volunteer team to conduct detailed health profiles of people who developed cancer in Milford Hills and Meadowbrook. Somewhere, there is an answer.

"I don't intend to go away," Weisler said.