2017 Progress Report: Improving Air Quality, Health and the Environment Through Household Energy Interventions in the Tibetan Plateau

EPA 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, 2016 through August 31,2017
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

Objective:

The overall objective of this research is 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. This goal 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 and 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.

Progress Summary:

The progress during this period focuses on the final set of post-intervention measurements of stove use, air pollution, and health; continued laboratory analysis of air pollution; laboratory analysis biological samples; and the analysis and publication of data resulting from this study. Specifically the following research tasks have been conducted: (1) collected the final round of post-intervention environmental and health data in winter; (2) continued laboratory analysis of air pollution samples for PM2.5, black carbon, elemental carbon, and organic carbon species; (3) analyzed biological samples of buccal cells for telomere length and dried blood spot samples for metabolic profile analysis; (4) continued the development of air quality models; (5) integrate pre- and post-intervention data to assess the air pollution and health impacts of the stove intervention; (6) held investigator research meetings in Montreal, Wisconsin, and Colorado which included participation from groups of project PIs and their trainees to discuss ongoing and planned analyses and manuscripts.

Results and preliminary findings

In this section, we present the main results from our longitudinal assessment of government-sponsored household energy intervention package in rural China. The study included repeated seasonal baseline and post-intervention measurements. We gathered a uniquely rich dataset for over 200 rural Chinese women in 12 villages, half of which were randomly assigned to receive the energy package, and collected individual data on arterial stiffness, central hemodynamics and blood pressure, household stove use and exposures to air pollution, and key covariates on up to 5 visits over 3 years. These data allowed us to investigate the impacts of the energy intervention package on air pollution and cardiovascular outcomes in women who received the energy package compared with those who did not.

Our longitudinal study was subject to participant loss to follow-up (n=42 women, 20%), reasons for which included temporary relocation to care for grandchildren (n=20), refusal (n=18), illness (n=3), and death (n=1). Baseline cardiovascular outcomes and their risk factors were generally balanced between (i) intervention versus control women and (ii) women who participated post-intervention versus those lost to follow-up. Systolic blood pressure (BP) differed between intervention and control women (p<0.05), though these differences were later controlled for in the statistical analysis.

We observed decreases in BP for all women enrolled in the study. Control women had greater mean decreases in brachial systolic (-4·1 mmHg, 95% credible interval (95%CIe) -7·4, -0·9) and diastolic BP (-2·0 mmHg, 95%CIe -3·6, -0·5) compared with intervention women (systolic: -2·7, 95%CIe -5·0, -0·4; diastolic: -0·3, 95%CIe -1·4, 0·8), with similar findings for central BP and arterial stiffness, though the differences were not statistically significant.

Average exposures to PM2.5 and black carbon also decreased among intervention women from pre- to post-intervention (PM: summer: -33% mg/m3 [95% confidence interval (CI) -48%, -18%]; winter: -14% mg/m3 [95%CI -34%, +4%]; black carbon: summer; -57% mg/m3 [95% CI -76%, -38%] winter: -61% mg/m3 [95% CI -80%, -41%]). However similar, and in some cases larger, average decreases in PM2.5 exposures and its major chemical components were also observed for the control group. Also, despite observed reductions in PM2.5 exposures after intervention, levels were still magnitudes higher than the World Health Organization’s interim air quality target for the intervention group (summer mean: 60.7 mg/m3; winter mean: 152.9 mg/m3).

Added value of these results: Our study is the first to evaluate the longitudinal air pollution and cardiovascular impacts of a household energy package intervention. It is important contribution to the household energy literature which is largely comprised of highly-controlled randomized trials and small-scale evaluations of single stove technologies, many of which have demonstrated poor emissions and thermal efficiency performances prior to study. We conducted detailed 48-h measurements of personal exposure in both the winter and summer season. We also measured a comprehensive set of cardiovascular outcomes that are strong predictors of future cardiovascular disease including blood pressure, central hemodynamics, and arterial stiffness. In the statistical models, we controlled for a range of important confounders (e.g., ambient temperature, socioeconomic status, secondhand smoking, dietary sodium intake, physical activity) which were absent from most previous studies of household energy and cardiovascular risk.

Implications of all the evidence: Air pollution contributes to an estimated 900,000 yearly premature cardiovascular deaths in China, highlighting the need to identify effective interventions that reduce air pollution and its cardiovascular burden. In our prospective study of a multipurpose semi-gasifier stove and biomass fuel intervention, blood pressure and central hemodynamics improved among women who received the intervention, however similar or larger improvements were observed among control women, many of whom transitioned to gas stoves during the study. Our results suggest that policies promoting these interventions should be considered with caution, particularly in regions where transitions to modern fuels like gas are underway.

Future Activities:

Data collection for this study is complete. We anticipate publishing peer-reviewed articles that focus on the post-intervention analysis of air pollution exposures, biological samples, and related health impacts. Larger-scale chemical and biological analysis of air pollution samples will happen alongside the epidemiologic studies to provide additional insights into the toxicity of PM. We also plan to continue modeling of emissions and air quality from cooking and heating and its climate/health impacts in China. We will continue knowledge translation through various outlets including presentations at conferences and scientific and policy meetings as well as media interviews.


Journal Articles on this Report : 4 Displayed | Download in RIS Format

Other project views: All 33 publications 10 publications in selected types All 10 journal articles
Type Citation Project Document Sources
Journal Article Carter E, Shan M, Zhong Y, Ding W, Zhang Y, Baumgartner J, Yang X. Development of renewable, densified biomass for household energy in China. Energy for Sustainable Development 2018;46:42-52. R835422 (2017)
  • Full-text: ScienceDirect-Full Text HTML
    Exit
  • Abstract: ScienceDirect-Abstract
    Exit
  • Other: ScienceDirect-Full Text PDF
    Exit
  • Journal Article Lai AM, Carter E, Shan M, Ni K, Clark S, Ezzati M, Wiedinmyer C, Yang X, Baumgartner J, Schauer JJ. Chemical composition and source apportionment of ambient, household, and personal exposures to PM2.5 in communities using biomass stoves in rural China. Science of the Total Environment 2019;646:309-319. R835422 (2017)
  • Abstract from PubMed
  • Full-text: ScienceDirect-Full Text HTML
    Exit
  • Abstract: ScienceDirect-Abstract
    Exit
  • Other: ScienceDirect-Full Text PDF
    Exit
  • Journal Article Secrest MH, Schauer JJ, Carter EM, Baumgartner J. Particulate matter chemical component concentrations and sources in settings of household solid fuel use. Indoor Air 2017;27(6):1052-1066. R835422 (2017)
  • Abstract from PubMed
  • Abstract: Wiley-Abstract
    Exit
  • Journal Article Shan M, Carter E, Baumgartner J, Deng M, Clark S, Schauer JJ, Ezzati M, Li J, Fu Y, Yang X. A user-centered, iterative engineering approach for advanced biomass cookstove design and development. Environmental Research Letters 2017;12(9):095009. R835422 (2017)
  • Full-text: IOP Science-Full Text HTML
    Exit
  • Abstract: IOP Science-Abstract
    Exit
  • Other: IOP Science-Full Text PDF
    Exit
  • Supplemental Keywords:

    China, cookstoves, blood pressure

    Progress and Final Reports:

    Original Abstract
  • 2014 Progress Report
  • 2015 Progress Report
  • 2016 Progress Report
  • Final