Love Canal and Its Mixed Legacy This week's Retro Report video looks at the story that began 35 years ago when toxic chemicals leaking from an old landfill thrust a upstate New York community called Love Canal into the national headlines. Here, the environmental writer Andrew C. Revkin looks at the mixed legacy. The galvanizing story was that of the frightened, outraged homeowners around Love Canal, an unfinished waterway in upstate New York that, in the industrial boom around World War II, became a chemical dump. That law has had a long and contentious history since, with its cost a continuing focus of the Government Accountability Office. Occidental Petroleum, which ended up with responsibility for the toxic site, reached settlements with 1,300 residents in 1983, New York State in 1994 and the Justice Department one year later. But now some families who bought homes nearby after the cleanup have gone to court, claiming harm from seeping pollutants. "New residents, attracted by promises of cleaned-up land and affordable homes, say in lawsuits that they are being sickened by the same buried chemicals from the disaster in the Niagara Falls neighborhood in the 1970s," the Associated Press reported this month. In the article, E.P.A. officials insist that the cleanup and containment of the pollution succeeded. A central question, for residents old and new, is whether the passage of time has bolstered or undermined initial health concerns related to the more than 80 chemicals buried at the site, including 11 that state officials at the time said were carcinogens. An initial burst of government and independent epidemiological investigations led to confused and sometimes contradictory results, with some finding significant health impacts but others seeing no pattern distinguishing the health of people who had lived there from residents of unaffected communities around Niagara County or New York State. A thorough study published by New York State in 2008 found some evidence of raised rates of birth defects but found that the overall cancer rate for residents was no different than that in the surrounding population. A persistent challenge in such studies is that ailments of greatest concern, like cancers, are rare enough that it is often impossible to detect a statistically significant indication of cause and effect amid the many other factors, like smoking, that can play a role. Another issue is that many cancers take decades to unfold. Dan Fagin, a longtime Newsday medical and environmental writer who wrote a recent extraordinary book on toxic sites and cancer, "Tom's River," noted in an email exchange that Love Canal had too many unknowns about exposure routes and doses and too few highly exposed people to settle questions of environmentally induced disease. "Like so much else in this fraught corner of science, Love Canal is a Rorschach test in which people see what they wish to see," he wrote. Believers see a manmade public health disaster linked through credible epidemiology to a range of health problems, especially developmental issues in children born of exposed mothers. They're right. Skeptics see a case of fear run amok amid initially overblown scientific claims, especially of high cancer rates and significant genetic damage, neither of which have held up very well under scrutiny. They're right, too. Campaigners who raised the alarm emphasize Love Canal as a symbol of the power of communities to defend themselves against corporate villainy. For more, read this news release from Gibbs's organization, the Center for Health, Environment and Justice, or this New York Times editorial in 2004. Meanwhile, for industry, it has become a case study showing how data - the lack of evidence of substantial health impacts around the waste site - don't always, or even often, rule the day when industrial pollution hits the news. A detailed history of the environmental campaign around Love Canal has been posted by the Boston University School of Public Health. The uncertainties do not diminish Love Canal's place in history, Mr. Fagin said. "I don't think Love Canal ever cracked the top 100 of the E.P.A.'s National Priorities List - there were (and still are) many sites where more people faced higher risks," he wrote. But America is still talking about Love Canal after more than 35 years because it was the first toxic waste site that was a truly national story, a testament to the relentlessness and organizing skills of Lois Gibbs and the Love Canal Homeowners Association, and to the importance of their legislative legacy, Superfund. This week's Retro Report is the 21st in a documentary series. The video project was started with a grant from Christopher Buck. Retro Report has a staff of 13 journalists and 10 contributors led by Kyra Darnton, a former "60 Minutes" producer. It is a nonprofit video news organization that aims to provide a thoughtful counterweight to today's 24/7 news cycle. The videos are typically 10 to 14 minutes long.