Carlos F. Gould is a 2021-2023 Stanford Earth Postdoctoral Fellow. Carlos is working to understand the drivers of unequal health risks and under what circumstances environmental health interventions and policies can improve health and well-being. His research has combined epidemiology, exposure science, and survey data collection to enhance our understanding of how to reduce household air pollution by promoting the use of clean cooking technologies. Carlos holds a PhD in Environmental Health Sciences from Columbia University and a BA in Environmental Studies from Yale University.
Honors & Awards
Stanford Earth Postdoctoral Fellow, Stanford University (2021-2023)
Predoctoral Fellowship to Promote Diversity in Health-Related Research (F31), National Institutes of Health (2020-2021)
Award for Exemplary Doctoral Teaching Fellow in Environmental Health Sciences, Columbia University EHS (2019)
Initiative for Maximizing Student Development Predoctoral Fellowship, National Institutes of Health (2016-2018)
Marshall Burke, Postdoctoral Faculty Sponsor
Prenatal household air pollutant exposure is associated with reduced size and gestational age at birth among a cohort of Ghanaian infants
2021; 155: 106659
Low birth weight and prematurity are important risk factors for death and disability, and may be affected by prenatal exposure to household air pollution (HAP).We investigate associations between maternal exposure to carbon monoxide (CO) during pregnancy and birth outcomes (birth weight, birth length, head circumference, gestational age, low birth weight, small for gestational age, and preterm birth) among 1288 live-born infants in the Ghana Randomized Air Pollution and Health Study (GRAPHS). We evaluate whether evidence of malaria during pregnancy, as determined by placental histopathology, modifies these associations.We observed effects of CO on birth weight, birth length, and gestational age that were modified by placental malarial status. Among infants from pregnancies without evidence of placental malaria, each 1 ppm increase in CO was associated with reduced birth weight (-53.4 g [95% CI: -84.8, -21.9 g]), birth length (-0.3 cm [-0.6, -0.1 cm]), gestational age (-1.0 days [-1.8, -0.2 days]), and weight-for-age Z score (-0.08 standard deviations [-0.16, -0.01 standard deviations]). These associations were not observed in pregnancies with evidence of placental malaria. Each 1 ppm increase in maternal exposure to CO was associated with elevated odds of low birth weight (LBW, OR 1.14 [0.97, 1.33]) and small for gestational age (SGA, OR 1.14 [0.98, 1.32]) among all infants.Even modest reductions in exposure to HAP among pregnant women could yield substantial public health benefits, underscoring a need for interventions to effectively reduce exposure. Adverse associations with HAP were discernible only among those without evidence of placental malaria, a key driver of impaired fetal growth in this malaria-endemic area.
View details for DOI 10.1016/j.envint.2021.106659
View details for Web of Science ID 000679253400001
View details for PubMedID 34134048
A cluster randomised trial of cookstove interventions to improve infant health in Ghana.
BMJ global health
2021; 6 (8)
INTRODUCTION: Household air pollution from solid fuel combustion for cooking and heating is a leading cause of childhood morbidity and mortality worldwide. We hypothesised that clean cooking interventions delivered during pregnancy would improve child health.METHODS: We conducted a cluster randomised trial in rural Ghana to test whether providing pregnant women liquefied petroleum gas (LPG) cookstoves or improved biomass cookstoves would reduce personal carbon monoxide and fine particulate pollution exposure, increase birth weight and reduce physician-assessed severe pneumonia in the first 12 months of life, compared with control participants who continued to cook with traditional stoves. Primary analyses were intention-to-treat. The trial was registered with ClinicalTrials.gov and follow-up is complete.RESULTS: Enrolment began on 14 April 2014, and ended on 20 August 2015. We enrolled 1414 pregnant women; 361 in the LPG arm, 527 in the improved biomass cookstove arm and 526 controls. We saw no improvement in birth weight (the difference in mean birth weight for LPG arm births was 29 g lighter (95% CI -113 to 56, p=0.51) and for improved biomass arm births was 9 g heavier (95% CI -64 to 82, p=0.81), compared with control newborns) nor severe child pneumonia (the rate ratio for pneumonia in the LPG arm was 0.98 (95% CI 0.58 to 1.70; p=0.95) and for the improved biomass arm was 1.21 (95% CI 0.78 to 1.90; p=0.52), compared with the control arm). Air pollution exposures in the LPG arm remained above WHO health-based targets (LPG median particulate matter less than 2.5 microns in diameter (PM2.5) 45 g/m; IQR 32-65 vs control median PM2.5 67 g/m, IQR 46-97).CONCLUSIONS: Neither prenatally-introduced LPG nor improved biomass cookstoves improved birth weight or reduced severe pneumonia risk in the first 12 months of life. We hypothesise that this is due to lower-than-expected exposure reductions in the intervention arms.TRIAL REGISTRATION NUMBER: NCT01335490.
View details for DOI 10.1136/bmjgh-2021-005599
View details for PubMedID 34452940
Firewood, forests, and fringe populations: Exploring the inequitable socioeconomic dimensions of Liquified Petroleum Gas (LPG) adoption in India
ENERGY RESEARCH & SOCIAL SCIENCE
Liquified petroleum gas (LPG) is an important clean fuel alternative for households that rely on burning biomass for daily cooking needs. In India, Pradhan Mantri Ujjwala Yojana (PMUY) has provided poor households with LPG connections since 2016. We investigate cooking fuel use in households to determine the impact of the policy in the Central Indian Highlands Landscape (CIHL). The CIHL has a large population of marginalized social groups, including Indigenous, Scheduled Tribe, Schedule Caste, and Other Backward Caste people. We utilize survey data from 4,994 households within 500 villages living in forested regions collected in 2018 and a satellite-derived measure of forest availability to investigate the household and ecological determinants of LPG adoption and the timing of this adoption (pre- or post-2016). In addition, we document patterns of firewood collection and evaluate the extent to which households acquiring LPG change these activities. The probability of cooking with LPG was lowest for marginalized social groups. We observe that households recently adopting LPG, likely through PMUY, are poorer, more socially marginalized, less educated, and have more forest available nearby than their early-adopter counterparts. While 90% of LPG-using households continue to use firewood, households that have owned LPG for more years report spending less time collecting firewood, indicating a waning reliance on firewood over time. Policies targeting communities with marginalized social groups living near forests can further accelerate LPG adoption and displace firewood use. Despite overall growth in LPG use, disparities in access to clean cooking fuels remain between socioeconomic groups in India.
View details for DOI 10.1016/j.erss.2021.102012
View details for Web of Science ID 000647782500012
View details for PubMedID 33959474
View details for PubMedCentralID PMC8095680
The effect of clean cooking interventions on mother and child personal exposure to air pollution: results from the Ghana Randomized Air Pollution and Health Study (GRAPHS)
JOURNAL OF EXPOSURE SCIENCE AND ENVIRONMENTAL EPIDEMIOLOGY
2021; 31 (4): 683-698
Clean cooking interventions to reduce air pollution exposure from burning biomass for daily cooking and heating needs have the potential to reduce a large burden of disease globally.The objective of this study is to evaluate the air pollution exposure impacts of a fan-assisted efficient biomass-burning cookstove and a liquefied petroleum gas (LPG) stove intervention in rural Ghana.We randomized 1414 households in rural Ghana with pregnant mothers into a control arm (N = 526) or one of two clean cooking intervention arms: a fan-assisted efficient biomass-burning cookstove (N = 527) or an LPG stove and cylinder refills as needed (N = 361). We monitored personal maternal carbon monoxide (CO) at baseline and six times after intervention and fine particulate matter (PM2.5) exposure twice after intervention. Children received three CO exposure monitoring sessions.We obtained 5655 48-h maternal CO exposure estimates and 1903 for children, as well as 1379 maternal PM2.5 exposure estimates. Median baseline CO exposures in the control, improved biomass, and LPG arms were 1.17, 1.17, and 1.30 ppm, respectively. Based on a differences-in-differences approach, the LPG arm showed a 47% reduction (95% confidence interval: 34-57%) in mean 48-h CO exposure compared to the control arm. Mean maternal PM2.5 exposure in the LPG arm was 32% lower than the control arm during the post-intervention period (52 ± 29 vs. 77 ± 44 μg/m3). The biomass stove did not meaningfully reduce CO or PM2.5 exposure.We show that LPG interventions lowered air pollution exposure significantly compared to three-stone fires. However, post-intervention exposures still exceeded health-relevant targets.In a large controlled trial of cleaner cooking interventions, an LPG stove and fuel intervention reduced air pollution exposure in a vulnerable population in a low-resource setting.
View details for DOI 10.1038/s41370-021-00309-5
View details for Web of Science ID 000624370600001
View details for PubMedID 33654272
View details for PubMedCentralID PMC8273075
- Jointly modeling the adoption and use of clean cooking fuels in rural India ENVIRONMENTAL RESEARCH COMMUNICATIONS 2020; 2 (8)
- Sustained LPG use requires progress on broader development outcomes NATURE ENERGY 2020; 5 (6): 430-431
Long-standing LPG subsidies, cooking fuel stacking, and personal exposure to air pollution in rural and peri-urban Ecuador
JOURNAL OF EXPOSURE SCIENCE AND ENVIRONMENTAL EPIDEMIOLOGY
2020; 30 (4): 707-720
Ecuador presents a unique case study for evaluating personal air pollution exposure in a middle-income country where a clean cooking fuel has been available at low cost for several decades. We measured personal PM2.5 exposure, stove use, and participant location during a 48-h monitoring period for 157 rural and peri-urban households in coastal and Andean Ecuador. While nearly all households owned a liquefied petroleum gas (LPG) stove and used it as their primary cooking fuel, one-quarter of households utilized firewood as a secondary fuel and 10% used induction stoves secondary to LPG. Stove use monitoring demonstrated clear within- and across-meal fuel stacking patterns. Firewood-owning participants had higher distributions of 48-h and 10-min PM2.5 exposure as compared with primary LPG and induction stove users, and this effect became more pronounced with firewood use during monitoring.Accounting for within-subject clustering, contemporaneous firewood stove use was associated with 101 μg/m3 higher 10-min PM2.5 exposure (95% CI: 94-108 μg/m3). LPG and induction cooking events were largely not associated with contemporaneous PM2.5 exposure. Our results suggest that firewood use is associated with average and short-term personal air pollution exposure above the WHO interim-I guideline, even when LPG is the primary cooking fuel.
View details for DOI 10.1038/s41370-020-0231-5
View details for Web of Science ID 000533035400002
View details for PubMedID 32415299
View details for PubMedCentralID PMC7316622
The drivers of sustained use of liquified petroleum gas in India
2020; 5 (6): 450-457
Ninety-five per cent of Indian households now have access to liquified petroleum gas (LPG), with 80 million acquiring it under the Pradhan Mantri Ujjwala Yojana (PMUY) since 2016. Still, having a connection is not enough to eliminate household air pollution. Studying panel data from rural households in six major states from 2014-2015 and 2018, we assess the determinants of cooking energy transition from solid fuels to LPG. We find that PMUY beneficiaries have much lower odds of using LPG as the primary or exclusive fuel compared with general customers, irrespective of their economic status. Village-level penetration of LPG as a primary fuel and the years of LPG use positively influence its sustained use, while ease of access to freely available biomass and reliance on uncertain and irregular income sources hinder LPG use. The findings highlight the need to interlace cooking fuel policies with rural development, to enable a complete transition towards cleaner cooking fuels.
View details for DOI 10.1038/s41560-020-0596-7
View details for Web of Science ID 000529011400001
View details for PubMedID 32719732
View details for PubMedCentralID PMC7384753
The role of education and attitudes in cooking fuel choice: Evidence from two states in India
ENERGY FOR SUSTAINABLE DEVELOPMENT
2020; 54: 36-50
Widespread adoption of clean cooking fuels is a necessary step toward reducing household air pollution and improving population health. Here we use large-scale surveys (10,000 households) from two Indian states, Kerala and Rajasthan, to examine how education and attitudes toward cooking associate with the adoption of liquefied petroleum gas (LPG), India's most popular clean cooking fuel. We report three main results. First, education is a strong predictor of LPG adoption. Second, perceptions that LPG is good and affordable and progressive health-related perceptions are associated with LPG ownership. Third, and surprisingly, education does not predict positive attitudes toward clean cooking fuels. These results suggest that education leads to LPG adoption, but not through attitudinal changes. Further research should examine the mediators of the observed robust education-adoption association.
View details for DOI 10.1016/j.esd.2019.09.003
View details for Web of Science ID 000507929900004
View details for PubMedID 32669760
View details for PubMedCentralID PMC7363404
Household fuel mixes in peri-urban and rural Ecuador: Explaining the context of LPG, patterns of continued firewood use, and the challenges of induction cooking
Nationwide transitions from cooking with solid fuels to clean fuels promise substantial health, climate, and environmental benefits. For decades, Ecuador has invested heavily in consumption subsidies for liquified petroleum gas (LPG), a leading clean fuel. With the goal of understanding household energy use in a context where LPG is ubiquitous and cheap, we administered 808 household surveys in peri-urban and rural communities in Coastal and Andean Ecuadorian provinces. We assess cooking fuel patterns after long-term LPG access and the reach of induction stoves promoted through a recent government program. Nearly all participants reported using LPG for more than a decade and frequent, convenient access to highly subsidized LPG. Nonetheless, half of rural households and 20% of peri-urban households rely on firewood to meet specific household energy needs, like space heating or heating water for bathing. Induction was rare and many induction owners reported zero use because the required equipment had never been installed by electricity companies, their stove had broken, or due to fears of high electricity costs. Our discussion is instructive for other countries because of Ecuador's long-standing clean fuel policies, robust LPG market and standardized cylinder recirculation model, and promotion of induction stoves.
View details for DOI 10.1016/j.enpol.2019.111053
View details for Web of Science ID 000505104100020
View details for PubMedID 32675905
View details for PubMedCentralID PMC7365656
The Gendered Nature of Liquefied Petroleum Gas Stove Adoption and Use in Rural India
JOURNAL OF DEVELOPMENT STUDIES
Clean cooking fuels promise substantial health benefits for rural households, but almost three billion people continue to rely on traditional biomass for their cooking needs. We explore the role of gender in the adoption of LPG, a clean cooking fuel, in rural India. Given that women are responsible for most households' cooking needs, we propose that gender inequality is an obstacle to LPG adoption because men may fail to appreciate the full benefits of clean cooking fuels. Using data for 8,563 households from the ACCESS survey, we demonstrate that households where women participant in decison-making are more likely to adopt LPG for cooking than households in which a man is the sole decision-maker. We extend our analytic framework to evaluate the relationship between household characteristics and LPG and firewood use. Access and cylinder costs were both negatively associated with LPG use and while LPG adoption reduced firewood use, fuel stacking remains the norm in study households. This study has implications for future policy designs to increase LPG adoption and use to obtain the multiple benefits of cleaner cooking.
View details for DOI 10.1080/00220388.2019.1657571
View details for Web of Science ID 000486182700001
View details for PubMedID 32508360
View details for PubMedCentralID PMC7274193
LPG as a clean cooking fuel: Adoption, use, and impact in rural India
2018; 122: 395-408
Liquefied petroleum gas (LPG) is by far the most popular clean cooking fuel in rural India, but how rural households use it remains poorly understood. Using the 2014-2015 ACCESS survey with over 8,500 households from six energy-poor Indian states, we offer a broad but detailed survey of LPG use in rural India. We find that (i) fuel costs are a critical obstacle to widespread adoption, (ii) fuel stacking is the prevailing norm as few households stop using firewood when adopting LPG, and (iii) both users and non-users have highly positive views of LPG as a convenient and clean cooking fuel. These findings show that expanding LPG use offers great promise in rural India, but affordability prevents a complete transition from traditional biomass to clean cooking fuels.
View details for DOI 10.1016/j.enpol.2018.07.042
View details for Web of Science ID 000447576700037
View details for PubMedID 32581420
View details for PubMedCentralID PMC7314235
Government policy, clean fuel access, and persistent fuel stacking in Ecuador
ENERGY FOR SUSTAINABLE DEVELOPMENT
2018; 46: 111-122
After more than three decades of access to low-cost liquefied petroleum gas (LPG) financed by large direct government subsidies, more than 90% of Ecuadorian households cook primarily with LPG. Due to the large fiscal burden of the LPG subsidy, increases in electricity from hydropower, and other sociopolitical factors, the Government of Ecuador launched a major induction stove program (PEC) to reduce the demand for LPG. We assess the effects of the LPG subsidies and PEC using government records, interviews, academic literature, newspaper reports, household surveys, and focus groups. Household surveys, conducted in rural, northern Ecuadorian households (n=383), characterized cooking patterns and fuel access. Focus groups (n=6) were carried out with a subset of surveyed households to better characterize survey findings. The LPG subsidy was developed as part of broad social support reforms in the early 1970s, without specific aims to reduce the health impacts of household air pollution from woodfuel or provide economic benefits as part of the transition to a clean cooking fuel. Nonetheless, the subsidy has resulted in nearly all Ecuadorian households cooking primarily with LPG. PEC has generated the sale of 740,000 induction stoves since its inception in 2014, short of the goal of 3.5 million. Among the rural households surveyed, LPG use, acceptance, and satisfaction was high, however, more than three-quarters of those surveyed reported weekly woodfuel use. Induction stove ownership (17%) and use as a primary cooking fuel (1%) was low among the rural households surveyed; furthermore, households owning induction stoves reported very low satisfaction with the stoves. Here we show that nationally-representative surveys reporting only "primary cooking fuef" use may underestimate solid fuel use as a supplemental household cooking energy, particularly in rural areas where fuel availability issues play a stronger role in decisions about what fuels to use.
View details for DOI 10.1016/j.esd.2018.05.009
View details for Web of Science ID 000440968400012
View details for PubMedID 30294142
View details for PubMedCentralID PMC6173323
- Prevalent degradation and patterns of use, maintenance, repair, and access to post-acquisition services for biomass stoves in Peru ENERGY FOR SUSTAINABLE DEVELOPMENT 2018; 45: 79-87
Soot and the city: Evaluating the impacts of Clean Heat policies on indoor/outdoor air quality in New York City apartments
2018; 13 (6): e0199783
New York City has had a long history of implementing local policies to reduce air pollution. Enacted as a part of PlaNYC, the Clean Heat policies aim to lower wintertime ambient air pollution by phasing out dirty No. 6 heating fuel oil and transitioning to comparatively cleaner No. 4, No. 2, or natural gas. This study evaluates the impacts of policies on ambient air pollution and, given that people spend the majority of their time inside, importantly, indoor air pollution. Using a natural experiment, we evaluate the effects of the policies by measuring average two-week levels of indoor and outdoor black carbon (BC) and fine particulate matter (PM2.5) in 48 upper Manhattan apartments in successive winter heating seasons before and after mandated fuel transition. We failed to observe systematic improvements in indoor BC and PM2.5 concentrations in follow-up. However, outdoor levels of PM2.5 did improve, with statistical differences observed among buildings converting to the cleanest fuels. Non-statistical improvements were observed for outdoor BC. However, when accounting for meteorological differences, apartment characteristics, and behavioral patterns that may have influenced air pollution measurements, these differences were not significant. The study results have important policy and equity implications considering the differential improvements in air quality by conversion to No. 4 oil as compared to the cleaner No. 2 oil and natural gas.
View details for DOI 10.1371/journal.pone.0199783
View details for Web of Science ID 000436645400067
View details for PubMedID 29953529
View details for PubMedCentralID PMC6023219
Association of exercise-induced wheeze and other asthma symptoms with emergency department visits and hospitalizations in a large cohort of urban adolescents
2018; 135: 42-50
Exercise-induced wheeze (EIW) has been found to be associated with asthma-related urgent care in school-aged children. Despite asthma's high prevalence and morbidity among adolescents, this association has not been examined in adolescents. We tested the association of EIW and other asthma symptoms to asthma-related ED visits and hospitalizations in urban adolescents with probable asthma. We hypothesized that EIW would be associated with urgent care.In this cross-sectional study 30,467 high school students (mean age = 16.0) from 49 NYC schools completed two brief validated measures, one assessing probable asthma and the other the frequency of six asthma symptoms over the past year. Adolescents also reported if in the past year they had an asthma-related ED visit or hospitalization. Analyses presented here included students with probable asthma (n = 9149). Using logistic regression, we modeled each asthma symptom as a function of ED visits and hospitalizations adjusting for sex, age, race/ethnicity and asthma severity. Multivariable models included all symptoms to account for the potential interaction between symptoms.Among adolescents with probable asthma, EIW was associated with ED visits and hospitalizations. In multivariable models wheeze without a cold, chest tightness, night wakening, but not EIW, were significantly associated with both ED visits and hospitalizations.Unlike findings with younger children, EIW does not appear to be associated with ED visits and hospitalizations among urban adolescents with probable asthma. Instead, symptoms, such as chest tightness and night wakening, appear to be important at identifying adolescents at risk for asthma-related urgent care.
View details for DOI 10.1016/j.rmed.2018.01.005
View details for Web of Science ID 000425287400008
View details for PubMedID 29414452
View details for PubMedCentralID PMC5806151