. . . cancer-causing fumes There's a good reason why many people get headaches when they stand near tumble dryer vents. Prof. Anne Steinemann, a pollution expert at the University of Washington, led research that analyzed fumes emitted from clothes dryers drying clothes washed using scented detergents, with added scented dryer sheets. The researchers found more than 25 volatile organic compounds including 7 hazardous pollutants -- 2 of them, acetaldehyde and benzene, carcinogens. Steinemann pointed out that such toxins are health hazards not only for people living in homes where scented detergents and dryer sheets are used, but chemicals from these products get into public air and go down the drain into public waterways. Acetaldehyde is a toxic emission from automobiles. Steinemann and her group estimated that acetaldehyde emissions from the top five brands of scented laundry detergents would equal about 6% of automobile emissions in the Seattle area. Non-toxic laundry detergents are available from Seventh Generation. Steinemann, A. Chemical Emissions from Residential Dryer Vents During Use of Fragranced Laundry Products. Published online in Air Quality, Atmosphere and Health, August, 2011.