The Hopi Environmental Health Project (HEHP)- Measuring Concentrations of PM2.5 in Households on Hopi Lands

摘要

Despite an estimated 6.5 million people in the United States burning solid fuels for heating, respiratory health effects from indoor exposure to smoke and particulate matter (PM) have focused on populations in developing nations, and have been largely ignored in developed nations. The Hopi Tribe of Northern Arizona heavily relies on burning of coal and wood for heating and cooking during winter months. PM2.5 was measured in Hopi households for 24-hours during heating and non-heating seasons using real-time area monitors. Primary heating fuel type was recorded from questionnaires completed by primary respondents. Indoor mean concentrations of PM2.5 were assessed across seasons and household fuel types. Fifty-one households were sampled, 36 of which completed follow-up sampling during both heating and non-heating seasons. Across all households and seasons, mean (SD) concentrations of PM2.5 were 36.8 ug/m3 (175.3); 51.13 pg/m3 (218.7) during the heating season, and 18.6 pg/m3 (91.4) during the non-heating season. When considering fuel type, households burning wood and coal (n=17) had highest indoor PM2.5 concentrations (53.6 pg/m3 (136.0)) during the heating season. Homes using a combination of electricity, coal and wood (n=ll) during the heating season had an indoor concentration of 46.6 pg/m3 (155.7). During the heating season, concentrations were 4.16 times greater for coal and wood homes, 2.52 times greater in electric, coal and wood homes, and 2.03 times greater in homes burning coal, wood and natural gas, compared to the non-heating season. PM2.5 concentrations were elevated in coal and wood burning households. Although slight reductions were observed in homes that used a combination of electricity or natural gas with coal and wood, concentrations exceeded the USEPA ambient standard of 35 u.g/nr>3 and the WHO guideline of 25 u,g/m3. Occupants of these households may be overexposed to PM2.5 and at greater risk for developing respiratory and cardiovascular diseases.