2015 Progress Report: Improving Air Quality, Health and the Environment Through Household Energy Interventions in the Tibetan PlateauEPA Grant Number: R835422
Title: Improving Air Quality, Health and the Environment Through Household Energy Interventions in the Tibetan Plateau
Investigators: Baumgartner, Jill , Ezzati, Majid , Paradis, Gilles , Schauer, James J. , Wiedinmyer, Christine , Yang, Xudong
Institution: University of Minnesota , McGill University , National Center for Atmospheric Research , Tsinghua University , University of Wisconsin - Madison
EPA Project Officer: Keating, Terry
Project Period: September 1, 2013 through August 31, 2016 (Extended to August 31, 2018)
Project Period Covered by this Report: September 1, 2014 through August 31,2015
Project Amount: $1,489,361
RFA: Measurements and Modeling for Quantifying Air Quality and Climatic Impacts of Residential Biomass or Coal Combustion for Cooking, Heating, and Lighting (2012) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Global Climate Change , Tribal Environmental Health Research , Climate Change , Air
The overall objectives of this research are to develop tools to quantify the benefits of interventions for household use of solid fuels on air quality, climate change mitigation, and human health and to demonstrate these tools to a novel energy innovation program in the Tibetan Plateau. These goals will be achieved by integrating emissions and exposure measurements with a Chinese government sponsored solid fuel intervention program that addresses cookstoves, heating stoves, and residential fuel, and applying these measurements to regional climate models and a health intervention study to quantify health and climate mitigation benefits of the intervention. The study will demonstrate a framework to quantify the benefits of real world interventions and policies aimed at reducing household solid fuel emissions. The project will leverage an existing intervention program led by Tsinghua University to replace traditional fuels and stoves in 200 rural homes in the Tibetan Plateau. The project will integrate expertise of the project team members to quantify the reduction in emissions, exposures, and cardiovascular impacts of the intervention and to estimate the impact of larger-scale interventions on regional climate. The study results and their interpretation will be disseminated to policy makers and other relevant environmental and public health stakeholder groups.
The progress during this period focuses on the second (winter) season of baseline data collection of air pollution and health measurements, laboratory analysis of air pollution samples, and the analysis of these data. We completed the baseline winter season measurements of air pollution and health at our field site in the Tibetan Plateau, and thus completed the baseline (pre-intervention) evaluation. Specifically the following research tasks have been conducted: (1) In addition to existing trainees, we hired a postdoctoral fellow (NCAR), a PhD graduate student (UW-Madison) and two part-time graduate research assistants (McGill) to work on the project. All trainees had the opportunity to spend time at the field site in China and with collaborators in Beijing; (2) Continued to field test the improved biomass stove intervention in the Tibetan Plateau, followed by design changes at Tsinghua University; (3) Collected baseline environmental data (e.g., using traditional stoves/fuels) in winter, with initial summaries of the complete baseline results; (4) Analyzed summer air pollution samples including PM2.5 mass, black carbon, elemental carbon, organic carbon, NOx, and other gases along with initial summaries of results; (5) Collected socio-demographic, health, and biomarker data for study participants in winter (baseline), with initial summaries of baseline results; (6) Began developing the air quality models in the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem); (7) Held a 2-day research meeting in Beijing, which included participation from all project PIs and their trainees during December 2014 to discuss initial results and plan manuscripts. Details of research tasks are provided in the following section.
Hiring of trainees and research assistants
We additionally recruited and hired a postdoctoral fellow (NCAR), a Ph.D. student (UW-Madison) and two graduate research assistants (McGill University) to work on this study. The postdoctoral fellow at NCAR will work on air quality and climate modeling under the direction of Dr. Christine Wiedinmyer. The Ph.D. student at UW Madison is advised by Prof. Jamie Schauer and will work on laboratory analysis of the air pollution samples, including measurement of PM mass, black carbon, organic carbon and specific organic species. The research assistants at McGill are working with the PI (Prof. Jill Baumgartner) to assist with project logistics, supply ordering, and data cleaning.
Continued to field test the improved biomass stove intervention
We continued to field test the prototype stove intervention (a semi-gasifier stove that runs on processed biomass pellets) in homes located in the study region to evaluate its performance under “real-life” conditions and obtain feedback on user preferences. Feedback was then provided to the stove engineers at Tsinghua University so that adjustments could be made. In addition, the stove engineers traveled to the field site from Beijing to speak with villagers and directly observe stove use. During this report period, a number of adjustments were made to the stove design including the shift to a stand-alone stove with separate chimney, the integration of an automatic lighter and adjustable flame, and the addition of a water heater. In addition, the village biomass pellet factory was completed with the production equipment arriving in summer 2015. Test pellet production also started in summer 2015.
Participant follow-up for household and personal measurements of air pollution and health
Of the 204 participants in 203 homes enrolled in the study since its beginning, 173 participated in summer and winter measurements, 28 only in summer, and 3 only in winter. The decline in winter participation was due to death (N = 1), poor health (N =3), relocation to a nearby town to care for grandchildren (N = 17), and refusal (N= 7).
Preliminary results for personal exposure to air pollution
To match the summer baseline measurements, we measured their 48-h indoor concentrations and personal exposures to health- and climate-relevant air pollutants including PM2.5, CO, nitrogen oxide (NO), and nitrogen dioxide (NO2). Daily outdoor PM2.5 concentrations were also measured. A brief summary of these results are provided below.
Personal exposure to air pollution at baseline
Women's geometric mean (GM) 48-h exposure to PM2.5 was 80 μg/m3 (95% CI: 74, 87) in summer and twice as high; namely, 169 μg/m3 (95% CI: 150, 190), in winter. Women primarily cooking with electricity or LPG had lower GM exposure (83 μg/m3, 95% CI: 66, 104) than women primarily cooking with biomass (118 μg/m3, 95% CI: 109, 129). Women's GM exposure to CO was 1.2 ppm (95% CI: 0.9, 1.7; winter = 1.4 ppm, summer = 0.6 ppm). Personal CO and PM2.5 exposures were weakly correlated in the subsample of all women (r = 0.41, 95% CI: −0.02, 0.71) and 9 women living in homes without a tobacco smoker (r = 0.50; 95% CI: −0.31, 0.89), after removing an influential outlier.
Kitchen and ambient air pollution measurement at baseline
The 48-h GM indoor PM2.5 concentration in winter (252 μg/m3) was twice as high as in summer (101 μg/m3). Indoor 48-h CO concentrations ranged from 0.1–34.8 ppm and were also higher in winter than summer (1.3 ppm versus 0.8 ppm). Indoor CO and PM2.5 concentrations were moderately correlated (r = 0.60, 95% CI: 0.46, 0.72) with a stronger correlation in the summer (r = 0.85, 95% CI: 0.74, 0.91) compared with the winter (r = 0.58, 95% CI: 0.36, 0.74)
We observed higher indoor 48-h NO concentrations in winter than in summer (47.4 ppb versus 17.9 ppb; range: 7.6–120.5 ppb). Indoor 48-h NO2 concentrations ranged from 0–47.4 ppb and were higher in summer than in winter. Indoor measurement of NO and NO2 together allowed us to investigate the potential impacts of outdoor air pollution and chemistry on indoor air quality, which has not been previously investigated in these settings. Namely, our results suggest that conversion of NO to NO2 by ozone, even in rural settings, is important to consider. Future studies that measure NO2 or that consider multiple air pollution exposures from biomass and roadway traffic, which may be important for health, should consider measuring NO2, NO, and ozone.Mean outdoor 24-h time-weighted average PM2.5 concentrations were 28, 19, and 13 μg/m3 in June, July, and August, respectively. In winter, outdoor PM2.5 concentrations were 16, 25, and 15 μg/m3 in December, January, and February, respectively. Month-to-month variation in outdoor air pollution was greater than variation between summer and winter seasons.
Development of air quality models
We started the process of evaluating output from the Weather Research and Forecast model with Chemistry (WRF-Chem), a regional chemical transport model, against surface air-quality measurements across all of China, by region and by season. We are also evaluating several emissions scenarios that represent extreme cases of residential combustion mitigation, allowing for calculation of the fractional contribution to ambient PM2.5 from residential cooking and heating emission sources. Using a high-resolution regional simulation helps reduce uncertainties in assessing the contributions of different sources to exposure at provincial or city scales. This analysis is stand-alone but will also inform future energy scenario development.
Project team meeting in Beijing and continued communication between research groups
We held a 2-day full team in Beijing in December 2014 where the full team of researchers, including all study PIs and their trainees, presented their initial results and planned for subsequent manuscripts and reports. In addition to the in-person meeting, the full project team has bimonthly conference calls and we hold weekly calls among smaller groups of investigators. In addition, the project investigators (Baumgartner, Yang, Wiedinmyer, and their trainees) made regular visits to the project site to observe field operations and inform key decisions about data collection related to air quality and climate modeling.
Now that the two seasons of baseline measurements are complete, our priority is to process and analyze these data and then the publish results. In Project Year 3, we anticipate publishing peer-reviewed articles that focus on energy package development and testing as well as analysis of baseline air pollution exposures and kitchen/ambient concentrations and related health impacts in the Tibetan Plateau, modeling of emissions and air quality from cooking and heating and its climate/health impacts in China, and cross-sectional evaluation of the relationship between air pollution exposures and cardiovascular markers. In addition to continuing our full team conference calls and weekly smaller group calls, we plan to hold a 2-day team meeting in Beijing in winter 2015 that will include presentations and discussions with all study investigators, trainees, and field staff members. In addition, we will continue to data collection in the Tibetan Plateau during the post-stove intervention phase of the study.