• Health Effects of Indoor-Air Benzene in Anchorage Residences: A Study of Indoor-Air Quality in Houses with Attached Garages

      Gordian, Mary Ellen; Frazier, Rosyland; Hill, Alexandra; Schreiner, Irma; Siver, Darla; Stewart, Alistair; Morris, Steve (Institute of Social and Economic Research, University of Alaska Anchorage, 2009-06)
      Benzene is a known carcinogen. It affects white blood cells; it causes leukemia and aplastic anemia. It may also affect the immune system which is dependent on white blood cells.1 It has been removed from all household products, but it is still present in gasoline. Alaskan gasoline is particularly high in benzene (>5%). Gasoline refined in Alaska has high concentrations of benzene and other the aromatic compounds as much as 50% aromatics by volume. Leaving the aromatics in the gasoline helps cars start in the cold, but it also puts high concentrations of benzene in both the ambient and indoor air. We already knew from previous work done in Alaska by Bernard Goldstein in Valdez2 and the Anchorage Department of Health and Human Services in Anchorage3 that people were exposed to high ambient levels of benzene in the winter, and that there were high indoor benzene concentrations in homes with attached garages if the garage was used to store gasoline or gasoline powered engines. Benzene does not bioaccumulate in the body as dioxin or some pesticides do. But are its effects cumulative? Does a little dose of benzene everyday have the same effect as a large dose over less time? Benzene reduces CD4 cells in a dose-response manner at workplace concentrations less than 1 ppm (OSHA 8-hour exposure limit) in workers.4 People who live in homes with high benzene concentrations may be exposed 24 hours a day, seven days a week. There have been no studies of health effects of such environmental exposure to benzene. This study was done to determine three things: 1. What percentage of Anchorage homes with attached garages had high levels of indoor benzene? 2. Were the high levels of indoor benzene affecting the health of the residents? 3. Were residents more likely to develop asthma in homes with high levels of indoor benzene?
    • Report on the Benzene Study of 2008-2009

      Gordian, Mary Ellen (Institute of Social and Economic Research, University of Alaska Anchorage, 2010-05-25)
      The purpose of this study was to determine whether reducing the amount of benzene in gasoline, which is scheduled to take place in 2011, will effect a change in indoor air benzene levels in Anchorage, Alaska. This is an interim report that discusses the first phase of a two-phase study. The first phase measured benzene levels in homes and garages every month for over one year. Due to the lack of chemical markets, the gasoline refined in Alaska contains 5% or more of benzene. Over the past two decades, volatile organic compounds (VOCs) measured in Anchorage, Alaska, have had higher concentrations in both indoor and ambient air than most other cities in the United States. Previous studies in Anchorage have shown that attached garages are a significant source of benzene and other VOCs in the living space of homes. In 2007-2008 we conducted a randomized study of houses with attached garages in Anchorage, Alaska, to determine whether there were associated respiratory health risks. We asked the resident owners of these houses to measure the benzene, toluene, ethyl benzene, and xylenes (BTEX) in their homes for one week using a passive vapor monitor badge. The results of that study showed that 47% of the houses had indoor-air benzene levels that—if they were maintained throughout the year—would exceed the minimal risk levels for inhalation set by the Agency for Toxic Substances and Disease Registry (ATSDR). Sixteen percent of the houses exceeded the acute risk. The results also showed that the BTEX measured in the indoor air came from gasoline fumes. We conducted this second study to determine whether levels found on a single, weekly measurement adequately represented the actual annual exposure in that house. We also wanted to see what the ratio was between levels in the garage and levels in the house since most of the exposure was thought to be coming into the house from the garage. We were also interested in any seasonal variation in the exposure to indoor benzene concentrations. This study would give us that sense of seasonal variability to be able to approximate long-term exposure and to guide future study. We were getting baseline data that could demonstrate the effect of the reduction in benzene in gasoline on the indoor air quality in Anchorage. It is expected that the level of benzene in gasoline will be reduced starting as soon as next year.