The smoke from wildfires can have harmful effects on human health, especially for children, seniors, and the chronically ill.

"A new study says firefighters who toiled in the wreckage of the World Trade Center in 2001 were 19 percent more likely to develop cancer than those who were not there, the strongest evidence to date of a possible link between work at ground zero and cancer."

"Bird flu was in decline -- but health officials warned Monday that it appears to be on the rise again. The United Nations' Food and Agriculture Organization (FAO) "urged heightened readiness and surveillance against a possible major resurgence" of the virus, which has crossed over from birds to infect 565 people and kill 331 of them since its appearance in 2003."

"When it comes to the safety of dyeing food, the one true shade is gray.

Artificial colorings have been around for decades, and for just about as long, people have questioned whether tinted food is a good idea. In the 1800s, when merchants colored their products with outright poisons, critics had a pretty good case. Today’s safety questions, though, aren’t nearly so black and white — and neither are the answers.

"Five of the 57 ingredients in dispersants approved by the U.S. Environmental Protection Agency for use on oil spills are linked to cancer, finds a new research report based on data obtained through a Freedom of Information Act request by environmental groups on the Gulf of Mexico."

"Hundreds of Native American children attend schools that haven’t properly disposed of hazardous waste, haven’t contained asbestos in heating systems, and whose water systems exceed the maximum allowable level for arsenic in tap water – conditions barred under federal environmental laws."

"Nearly 1,600 children age 5 and younger live close enough to an airport in Brevard County to be at risk from leaded gasoline used by small piston planes and helicopters."

Bottled water companies seem to be actively marketing their products to minority groups. Latinos and African Americans spend a higher portion of their income on bottled water than whites do, and surveys say this is because they view tap water as risky. There is evidence that public drinking water systems in minority communities are either lacking or less safe.

"The federal Conservative party has sent a threatening email to the widow of an asbestos victim in the latest chapter of Canada's debate over the hazardous mineral."

"Millions of Americans have been ingesting them for years—perchlorate, hexavalent chromium, volatile organic compounds—not because they’re safe, but because they are among 6,000 toxins the EPA has not gotten around to regulating in municipal drinking water systems.

But after a change in administrations and a scathing review by the General Accounting Office, the EPA has begun to develop regulations to remove these chemicals from tap and bottled water—and industry has begun efforts to delay or prevent their implementation."