ISES-ISEE 2018 CIEHR Presentations

The Hopi Environmental Health Project is funded through the Center for Indigenous Environmental Health Research (CIEHR) at the University of Arizona. When introducing the project to the community, the Tribal Chairman stressed the importance of involving Hopi youth in projects that engender an interest in scientific careers. We conducted two "Student Science" projects during 2017-18 through the Hopi Junior/Senior High School. The projects were conducted in four science classes, and involved students in media specific exposure assessment activities related to radon and arsenic exposure. Prior to initiating the school project, a letter was sent home to parents describing the radon (or arsenic) evaluation and stressing that this was a school science project. During the first class meeting, a 15-minute introductory description of radon (or As) was provided by UA students and faculty. Following the presentation, aid was provided for accurate completion of collection forms (radon or water). Bill-caps were offered to students as incentives. Students took the sampling materials (a sorbent air sampler or water test tubes) home and collected samples. Deidentified samples were returned to school with the collection forms and analyzed at a commercial/university laboratory. Data were returned from the designated lab to the ESC. The ESC prepared individual reports for students and placed them in sealed, addressed envelops for distribution to the "Student Scientists." The concept of confidentiality was discussed. The ESC consolidated data from the four classes and each student received a data sheet containing all deidentified results for evaluation and reported duration or consumption values for each individual. Analysis involved graphing the data, determining the percent of the group exceeding the analyte standard, and calculating individual and group mean exposures. Evaluation of the outreach indicated that most students enjoyed the project and learned the fundamental concepts.

Water quality data from Native American lands in Northern Arizona is limited. The effect of long-term exposure to arsenic in drinking water may influence the development of later onset cancers and pulmonary diseases and are of concern to the Hopi Tribe. Methods: Since December of 2017, tap water and urine samples have been collected from 18 households on Hopi lands. Tap water and urine samples were evaluated for speciated arsenic concentrations by ICP-MS. Results: Of the 18 households surveyed, 50% report that their main source of water ingestion is a combination of both tap water and bottled water. Preliminary data indicate that arsenic concentrations in the tap drinking water range from 2.84 to 21.32 mg/L, with a median concentration of 14.69 mg/L. Based on these data, we performed a preliminary quantitative risk assessment on the relative risk of lung and bladder cancer from exposure to arsenic in tap water. The analysis indicated the risk of males for lung and bladder cancers to be 8.27 and 3.71 in 106, respectively in assuming consumption of tap water exclusively. The analysis also indicated the risk of females for lung and bladder cancers to be 6.48 and 1.02 in 106, respectively in assuming consumption of tap water exclusively. These preliminary results exceed the EPA's acceptable carcinogenic risk limit of 1 in 106. These are only preliminary results.

Indoor air quality (IAQ) is essential for optimum health. To assess indoor air one needs to examine sources natural and human-caused emissions in buildings. Radon is one indicator used to indicate building quality. The sources of indoor radon comes primarily from soils. In closed spaces, we find higher concentration of radon, due to lack of ventilation. It worth mention that Hopi homes lack basements. Methods: Time-integrated continuous radon monitor (Sun Nuclear) was placed in nineteen homes for a 24-hour sampling period on Hopi lands during the winter season. Results: Indoor Radon concentrations varied from 0-9.5 pCi/L during the winter months. The mean concentration of radon among all houses is 1.983Ci/L. Diurnal radon concentrations are elevated between 10 p.m to 8 a.m. and decline during the day (9 a.m. and 8 p.m.). Four (21%) of the homes had daily average values that exceeded action levels of Environmental Protection Agency (EPA) of 4.0 pCi/L. Discussion: There is a pattern in diurnal radon concentration associated with household ventilation patterns. During the night-time, we assume closed windows and doors leading to an accumulation of indoor radon. During the day time, ventilation reduces indoor radon levels. Homes with elevated radon concentrations suggest poor ventilation and possibly housing quality. Conclusion: The hourly results provide options in determining the type of radon reduction plans that might be recommended to families to reduce indoor radon exposure. Future analysis will include house types and location within Hopi lands.

Household reliance on biomass and solid fuels has resulted in an estimated 4.3 million pre-mature annual deaths globally. Despite the prevalent use in developing nations, recent studies suggest that low-income rural populations of the United States, and other affluent countries, may experience similar exposures to HAPs due to incomplete combustion of fuels indoors. Methods: Indoor 24-hour PM2.5 concentration was measured during 2 winter heating seasons (2017 & 2018) and 1 summer non-heating season (2017) using real-time area monitors (pDR-1500) set at 1-minute logging intervals. Average 24-hour indoor PM2.5 concentration was compared across household primary heating fuel type during heating and non-heating seasons. Results: To date, 26 homes have been sampled during the heating season, of which 11 have complete follow-up data during the non-heating season. Indoor mean (SD) PM2.5 concentration in all households was 30.0 μg/m3 (120.8), and was 40.3 μg/m3 (145.8) during heating seasons and 9.9 μg/m3 (30.1) during the non-heating season. Coal-wood burning homes had indoor PM2.5 concentration of 57.9 μg/m3 (185.8) during heating (n=9) and 8.4 μg/m3 (19.3) during non-heating season (n=6). During the burning season, electrically heated (5.3 μg/m3 (5.8)) and electric-natural gas heated (9.9 μg/m3 (9.4)) homes had the lowest 24-hour concentration compared to homes that burned a combination of wood, coal & electricity (42.1 μg/m3 (156.8)), and coal, wood & natural gas (49.3 μg/m3 (111.3)) for heating. Discussion: Households that primarily burn wood and coal for heat had elevated indoor PM2.5 concentrations compared to homes heated with other fuel types. Even in homes using a combination of natural gas and electricity with wood and coal, indoor levels exceeded the EPA 24-hour ambient standard of 35 μg/m3. This project will continue to monitor indoor air quality and recruit households on the Hopi Lands