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Benzene in Alaska: What does it mean to you?

Benzene in Alaska: What does it mean to you?. Mary Ellen Gordian, MD, MPH. Benzene is an Air Toxic. Common solvent found in gasoline; toxic in high concentrations In chronic exposures affects blood-cell production, causes diseases Aplastic anemia Myelodysplastic syndromeleukemias

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Benzene in Alaska: What does it mean to you?

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  1. Benzene in Alaska:What does it mean to you? Mary Ellen Gordian, MD, MPH

  2. Benzene is an Air Toxic • Common solvent found in gasoline; toxic in high concentrations • In chronic exposures affects blood-cell production, causes diseases • Aplastic anemia • Myelodysplastic syndromeleukemias • In low concentrations, it affects immune system by reducing CD4 cells

  3. Why is it here? • AK gasoline refined in AK • Crude contains as much as 7% benzene • AK gasoline contains 5% benzene • No market for benzene in AK • Not regulated under Clean Air Act • Currently no restriction on benzene in gasoline

  4. Benzene in Ambient Air

  5. Frequency Distribution of Benzene Concentrations Measured in Anchorage Homes (1995)

  6. CAA • Criteria pollutants in ambient air regulated • Lead, CO, ozone, SOx, NOx, particulates • Benzene is not a criteria pollutant! • No monitoring for benzene required

  7. Acute Effects of Benzene • Until recently, acute effects of benzene only known for high concentrations • Recent study of Chinese workers exposed to less than OSHA regulated concentration of benzene shows CD4 + lymphocytes reduced in dose-response manner to low-dose exposure to benzene

  8. ATSDRMinimal Risk Levels of Benzene Acute exposure - 9 ppb Intermediate exposure - 6 ppb Chronic exposure - 3 ppb

  9. Conversion Factors 1 ppb = 3.25 µg/m3 100 µg/m3 = 30.8 ppb

  10. What is the Indoor Air Health Study? • High risk homes identified through property-tax base • Owner occupied, high-risk households solicited to participate by direct mail • Householders asked to measure level of aromatic hydrocarbons in homes by exposing passive-vapor badges • Health surveys filled out for each family member

  11. Two-Year Study Now in Second Year • First year: testing methods • Adjustments made to questionnaires • Protocol established • Phase 2: collecting data from significant number of homes to determine whether indoor benzene is associated with respiratory health

  12. Other Research • Children ER visits for asthma from homes with higher indoor benzene levels than children with GI problems • Risk of asthma diagnosis increased in adults with higher exposure to aromatic hydrocarbons • Exposure to traffic increases risk of asthma diagnosis in children

  13. Distribution of Indoor Benzene in ppb 40 Frequency 30 20 10 Mean =3.32 Std. Dev. =3.627 N =79 0 0.00 5.00 10.00 15.00 20.00 parts per billion of benzene Preliminary Results Indoor Air Study

  14. 40 30 Cases 20 10 0 <1.5 ppb Low 1.5-to 4.0 ppb Medium >4.0 ppb High Categorizing Benzene Exposure

  15. Income vs Benzene Indoors

  16. Benzene vs. number of gasoline engines stored in the garage How many engines are stored in garage? 0 12 1 2 3 4 10 5 7 7 5 2. 0.0 low medium high range of benzene exposure Storing Gasoline Indoors

  17. Summary • Anchorage Indoor Air Health Study is underway • Determining health effects from low doses of benzene is important to the people of AK • Stay tuned. More to come!

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