Testing the effectiveness of household fuel conservation strategies: Policy implications for increasing the affordability of exclusive clean cooking.

BACKGROUND: Exclusive clean fuel use is essential for realizing health and other benefits but is often unaffordable. Decreasing household-level fuel needs could make exclusive clean fuel use more affordable, but there is a lack of knowledge on the amount of fuel savings that could be achieved through fuel conservation behaviors relevant to rural settings in low- and middle-income countries. METHODS: Within a trial in Peru, we trained a random half of intervention participants, who had previously received a liquefied petroleum gas (LPG) stove and were purchasing their own fuel, on fuel conservation strategies. We measured the amount of fuel and mega joules (MJ) of energy consumed by all participants, including control participants who were receiving free fuel from the trial. We administered surveys on fuel conservation behaviors and assigned a score based on the number of behaviors performed. RESULTS: Intervention participants with the training had a slightly higher conservation score than those without (7.2 vs. 6.6 points; p = 0.07). Across all participants, average daily energy consumption decreased by 9.5 MJ for each 1-point increase in conservation score (p < 0.001). Among households who used exclusively LPG (n = 99), each 1-point increase in conservation score was associated with a 0.04 kg decrease in LPG consumption per household per day (p = 0.03). Using pressure cookers and heating water in the sun decreased energy use, while using clay pots and forgetting to close stove knobs increased energy use. CONCLUSION: Our findings suggest that a household could save 1.16 kg of LPG per month for each additional fuel conservation behavior, for a maximum potential savings of 8.1 kg per month. Fuel conservation messaging could be integrated into national household energy policies to increase the affordability of exclusive clean fuel use, and subsequently achieve the environmental and health benefits that could accompany such a transition.

Effects of a household air pollution intervention using liquefied petroleum gas stoves, continuous fuel distribution and behavioural messaging on dietary and sodium intake of adult women in Puno, Peru: a randomised controlled trial.

OBJECTIVE: Household air pollution (HAP) is a widespread environmental exposure worldwide. While several cleaner fuel interventions have been implemented to reduce personal exposures to HAP, it is unclear if cooking with cleaner fuels also affects the choice of meals and dietary intake. DESIGN: Individually randomised, open-label controlled trial of a HAP intervention. We aimed to determine the effect of a HAP intervention on dietary and Na intake. Intervention participants received a liquefied petroleum gas (LPG) stove, continuous fuel delivery and behavioural messaging during 1 year whereas control participants continued with usual cooking practices that involved the use of biomass-burning stoves. Dietary outcomes included energy, energy-adjusted macronutrients and Na intake at baseline, 6 months and 12 months post-randomisation using 24-h dietary recalls and 24-h urine. We used t-tests to estimate differences between arms in the post-randomisation period. SETTING: Rural settings in Puno, Peru. PARTICIPANTS: One hundred women aged 25-64 years. RESULTS: At baseline, control and intervention participants were similar in age (47·4 v. 49·5 years) and had similar daily energy (8894·3 kJ v. 8295·5 kJ), carbohydrate (370·8 g v. 373·3 g) and Na intake (4·9 g v. 4·8 g). One year after randomisation, we did not find differences in average energy intake (9292·4 kJ v. 8788·3 kJ; P = 0·22) or Na intake (4·5 g v. 4·6 g; P = 0·79) between control and intervention participants. CONCLUSIONS: Our HAP intervention consisting of an LPG stove, continuous fuel distribution and behavioural messaging did not affect dietary and Na intake in rural Peru.

Household Air Pollution Concentrations after Liquefied Petroleum Gas Interventions in Rural Peru: Findings from a One-Year Randomized Controlled Trial Followed by a One-Year Pragmatic Crossover Trial.

BACKGROUND: Household air pollution (HAP) from biomass fuel combustion remains a leading environmental risk factor for morbidity worldwide. OBJECTIVE: Measure the effect of liquefied petroleum gas (LPG) interventions on HAP exposures in Puno, Peru. METHODS: We conducted a 1-y randomized controlled trial followed by a 1-y pragmatic crossover trial in 180 women age 25-64 y. During the first year, intervention participants received a free LPG stove, continuous fuel delivery, and regular behavioral messaging, whereas controls continued their biomass cooking practices. During the second year, control participants received a free LPG stove, regular behavioral messaging, and vouchers to obtain LPG tanks from a nearby distributor, whereas fuel distribution stopped for intervention participants. We collected 48-h kitchen area concentrations and personal exposures to fine particulate matter (PM) with aerodynamic diameter ≤2.5µm (PM2.5), black carbon (BC), and carbon monoxide (CO) at baseline and 3-, 6-, 12-, 18-, and 24-months post randomization. RESULTS: Baseline mean [±standard deviation (SD)] PM2.5 (kitchen area concentrations 1,220±1,010 vs. 1,190±880 µg/m3; personal exposure 126±214 vs. 104±100 µg/m3), CO (kitchen 53±49 vs. 50±41 ppm; personal 7±8 vs. 7±8 ppm), and BC (kitchen 180±120 vs. 210±150 µg/m3; personal 19±16 vs. 21±22 µg/m3) were similar between control and intervention participants. Intervention participants had consistently lower mean (±SD) concentrations at the 12-month visit for kitchen (41±59 µg/m3, 3±6 µg/m3, and 8±13 ppm) and personal exposures (26±34 µg/m3, 2±3 µg/m3, and 3±4 ppm) to PM2.5, BC, and CO when compared to controls during the first year. In the second year, we observed comparable HAP reductions among controls after the voucher-based intervention for LPG fuel was implemented (24-month visit PM2.5, BC, and CO kitchen mean concentrations of 34±74 µg/m3, 3±5 µg/m3, and 6±6 ppm and personal exposures of 17±15 µg/m3, 2±2 µg/m3, and 3±4 ppm, respectively), and average reductions were present among intervention participants even after free fuel distribution stopped (24-month visit PM2.5, BC, and CO kitchen mean concentrations of 561±1,251 µg/m3, 82±124 µg/m3, and 23±28 ppm and personal exposures of 35±38 µg/m3, 6±6 µg/m3, and 4±5 ppm, respectively). DISCUSSION: Both home delivery and voucher-based provision of free LPG over a 1-y period, in combination with provision of a free LPG stove and longitudinal behavioral messaging, reduced HAP to levels below 24-h World Health Organization air quality guidelines. Moreover, the effects of the intervention on HAP persisted for a year after fuel delivery stopped. Such strategies could be applied in LPG programs to reduce HAP and potentially improve health. https://doi.org/10.1289/EHP10054.

Effects of a Household Air Pollution Intervention with Liquefied Petroleum Gas on Cardiopulmonary Outcomes in Peru. A Randomized Controlled Trial.

Rationale: Approximately 40% of people worldwide are exposed to household air pollution (HAP) from the burning of biomass fuels. Previous efforts to document health benefits of HAP mitigation have been stymied by an inability to lower emissions to target levels. Objectives: We sought to determine if a household air pollution intervention with liquefied petroleum gas (LPG) improved cardiopulmonary health outcomes in adult women living in a resource-poor setting in Peru. Methods: We conducted a randomized controlled field trial in 180 women aged 25-64 years living in rural Puno, Peru. Intervention women received an LPG stove, continuous fuel delivery for 1 year, education, and behavioral messaging, whereas control women were asked to continue their usual cooking practices. We assessed for stove use adherence using temperature loggers installed in both LPG and biomass stoves of intervention households. Measurements and Main Results: We measured blood pressure, peak expiratory flow (PEF), and respiratory symptoms using the St. George's Respiratory Questionnaire at baseline and at 3-4 visits after randomization. Intervention women used their LPG stove exclusively for 98% of days. We did not find differences in average postrandomization systolic blood pressure (intervention - control 0.7 mm Hg; 95% confidence interval, -2.1 to 3.4), diastolic blood pressure (0.3 mm Hg; -1.5 to 2.0), prebronchodilator peak expiratory flow/height2 (0.14 L/s/m2; -0.02 to 0.29), postbronchodilator peak expiratory flow/height2 (0.11 L/s/m2; -0.05 to 0.27), or St. George's Respiratory Questionnaire total score (-1.4; -3.9 to 1.2) over 1 year in intention-to-treat analysis. There were no reported harms related to the intervention. Conclusions: We did not find evidence of a difference in blood pressure, lung function, or respiratory symptoms during the year-long intervention with LPG. Clinical trial registered with www.clinicaltrials.gov (NCT02994680).

Nitrogen dioxide exposures from LPG stoves in a cleaner-cooking intervention trial.

BACKGROUND: Liquefied petroleum gas (LPG) stoves have been promoted in low- and middle-income countries (LMICs) as a clean energy alternative to biomass burning cookstoves. OBJECTIVE: We sought to characterize kitchen area concentrations and personal exposures to nitrogen dioxide (NO2) within a randomized controlled trial in the Peruvian Andes. The intervention included the provision of an LPG stove and continuous fuel distribution with behavioral messaging to maximize compliance. METHODS: We measured 48-hour kitchen area NO2 concentrations at high temporal resolution in homes of 50 intervention participants and 50 control participants longitudinally within a biomass-to-LPG intervention trial. We also collected 48-hour mean personal exposures to NO2 among a subsample of 16 intervention and 9 control participants. We monitored LPG and biomass stove use continuously throughout the trial. RESULTS: In 367 post-intervention 24-hour kitchen area samples of 96 participants' homes, geometric mean (GM) highest hourly NO2 concentration was 138 ppb (geometric standard deviation [GSD] 2.1) in the LPG intervention group and 450 ppb (GSD 3.1) in the biomass control group. Post-intervention 24-hour mean NO2 concentrations were a GM of 43 ppb (GSD 1.7) in the intervention group and 77 ppb (GSD 2.0) in the control group. Kitchen area NO2 concentrations exceeded the WHO indoor hourly guideline an average of 1.3 h per day among LPG intervention participants. GM 48-hour personal exposure to NO2 was 5 ppb (GSD 2.4) among 35 48-hour samples of 16 participants in the intervention group and 16 ppb (GSD 2.3) among 21 samples of 9 participants in the control group. DISCUSSION: In a biomass-to-LPG intervention trial in Peru, kitchen area NO2 concentrations were substantially lower within the LPG intervention group compared to the biomass-using control group. However, within the LPG intervention group, 69% of 24-hour kitchen area samples exceeded WHO indoor annual guidelines and 47% of samples exceeded WHO indoor hourly guidelines. Forty-eight-hour NO2 personal exposure was below WHO indoor annual guidelines for most participants in the LPG intervention group, and we did not measure personal exposure at high temporal resolution to assess exposure to cooking-related indoor concentration peaks. Further research is warranted to understand the potential health risks of LPG-related NO2 emissions and inform current campaigns which promote LPG as a clean-cooking option.

Exploring the impact of a liquefied petroleum gas intervention on time use in rural Peru: A mixed methods study on perceptions, use, and implications of time savings.

BACKGROUND: Efforts to promote clean cooking through adoption of clean-burning fuels such as liquefied petroleum gas (LPG) are often based on the idea that near-exclusive use of LPG could lead to health improvements. However, benefits beyond health, such as time savings, could be more tangible and meaningful to LPG users. OBJECTIVES: This study investigated the effect of an LPG intervention on time spent cooking and collecting fuel, using objective measures of stove temperatures combined with self-reports under conditions of near-exclusive LPG use. We also investigated the perceived value of any time savings and potential economic and quality of life implications. METHODS: We analyzed data from the Cardiopulmonary outcomes and Household Air Pollution trial in Puno, Peru, a randomized controlled trial with 180 participants assessing exposure and health impacts of an LPG stove, fuel, and behavioral intervention. Surveys conducted with 90 intervention women receiving free LPG and 90 control women cooking primarily with biomass assessed time spent cooking and collecting biomass fuel and use of time savings. Cooking time was objectively measured with temperature sensors on all stoves. Qualitative interviews explored perceptions and use of time savings in more depth. RESULTS: Intervention women spent 3.2 fewer hours cooking and 1.9 fewer hours collecting fuel per week compared to control women, but cooked on average 1.0 more meals per day. Participants perceived time saved from LPG positively, reporting more time for household chores, leisure activities, and activities with income-generating potential such as caring for animals and working in fields. DISCUSSION: This paper suggests that the benefits of LPG extend beyond health and the environment. LPG use could also lead to economic and quality of life gains, through increased time for work, rest, and consumption of hot meals, and reduced arduous biomass fuel collection.

Effects of a liquefied petroleum gas stove intervention on pollutant exposure and adult cardiopulmonary outcomes (CHAP): study protocol for a randomized controlled trial.

BACKGROUND: Biomass fuel smoke is a leading risk factor for the burden of disease worldwide. International campaigns are promoting the widespread adoption of liquefied petroleum gas (LPG) in resource-limited settings. However, it is unclear if the introduction and use of LPG stoves, in settings where biomass fuels are used daily, reduces pollution concentration exposure, improves health outcomes, or how cultural and social barriers influence the exclusive adoption of LPG stoves. METHODS: We will conduct a randomized controlled, field intervention trial of LPG stoves and fuel distribution in rural Puno, Peru, in which we will enroll 180 female participants aged 25-64 years and follow them for 2 years. After enrollment, we will collect information on sociodemographic characteristics, household characteristics, and cooking practices. During the first year of the study, LPG stoves and fuel tanks will be delivered to the homes of 90 intervention participants. During the second year, participants in the intervention arm will keep their LPG stoves, but the gas supply will stop. Control participants will receive LPG stoves and vouchers to obtain free fuel from distributors at the beginning of the second year, but gas will not be delivered. Starting at baseline, we will collect longitudinal measurements of respiratory symptoms, pulmonary function, blood pressure, endothelial function, carotid artery intima-media thickness, 24-h dietary recalls, exhaled carbon monoxide, quality-of-life indicators, and stove-use behaviors. Environmental exposure assessments will occur six times over the 2-year follow-up period, consisting of 48-h personal exposure and kitchen concentration measurements of fine particulate matter and carbon monoxide, and 48-h kitchen concentrations of nitrogen dioxide for a subset of 100 participants. DISCUSSION: Findings from this study will allow us to better understand behavioral patterns, environmental exposures, and cardiovascular and pulmonary outcomes resulting from the adoption of LPG stoves. If this trial indicates that LPG stoves are a feasible and effective way to reduce household air pollution and improve health, it will provide important information to support widespread adoption of LPG fuel as a strategy to reduce the global burden of disease. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT02994680 , Cardiopulmonary Outcomes and Household Air Pollution (CHAP) Trial. Registered on 28 November 2016.