About

Darby Jack, PhD, is a Professor of Environmental Health Sciences at Columbia University Irving Medical Center. His research focuses on environmental health risks in developing countries, the health impacts of climate change, and the role of the urban environment in shaping health. He has a particular emphasis on the health effects of exposure to indoor air pollution from biomass fuels. Dr. Jack has contributed to developing a Columbia-wide biomass working group supported by the Center for Environmental Health in Northern Manhattan, which coordinates interdisciplinary research on this topic. His work includes efforts to measure the health benefits of clean cookstoves in Ghana and collaborations with exposure scientists in New York to estimate the effects of air pollution exposures on people who commute by bicycle. He holds a BA from Williams College and a PhD from Harvard University.

Research topics

• Business
• Waste management
• Demography
• Environmental economics
• Biology
• Geography
• Medicine
• Economics
• Pediatrics
• Engineering
• Natural resource economics

Selected publications

• Food Security Outlook for Eastern Africa by 2050: Climate Change Impacts and Population-Driven Demand Gaps

  Current Environmental Health Reports · 2026-02-21 · 1 citations

  articleOpen accessSenior author

  This review examines the future of food availability in Ethiopia, Kenya, and Uganda in the context of rapid population growth and accelerating climate change. It aims to assess the implications of projected climate-induced yield declines and demographic trends for food security by 2050, with a focus on cereal demand and supply under IPCC RCP 4.5 and 8.5 scenarios. Projections indicate that regional temperatures will rise by 1.8–3.0 °C by mid-century, leading to cereal yield reductions ranging from 13% to 22%. Uganda is projected to face the largest yield losses, while Ethiopia is expected to warm most rapidly. Concurrently, population growth will dramatically increase food demand, with Ethiopia, Kenya, and Uganda reaching populations of 230, 93, and 109 million, respectively, by 2050. Cereal requirements will grow to 50.6 million tons for Ethiopia, and 23 million tons each for Kenya and Uganda. Despite modest assumptions of 1.5% annual productivity gains, projected cereal deficits remain high—21% in Ethiopia, 71% in Kenya, and 60% in Uganda. Without urgent and transformative action, the region is likely to face deepening food insecurity, rising malnutrition, and increased dependence on food imports. Strategic investments in climate-resilient agriculture—including drought-tolerant crop varieties, improved water management, early warning systems, and diversified livelihoods—are essential. Coupling these with nutrition-sensitive interventions and regional cooperation can enhance food system resilience and safeguard vulnerable populations against mounting climate and demographic pressures.

  PublisherOA PDFDOI

• Personal fine particulate matter (PM2.5) exposure level and associated factors among pregnant women in rural Butajira, Ethiopia: a longitudinal study

  BMC Public Health · 2026-05-07

  articleOpen access

  Fine particulate matter (PM₂.₅) exposure remains a major global public health concern, especially in low-resource countries where biomass fuels are commonly used for household energy. In these environments, extended indoor cooking and poor ventilation increase pregnant women’s vulnerability to PM₂.₅ exposure. However, no study in Ethiopia has directly measured personal PM2.5 exposure among pregnant women. Therefore, this study aimed to assess personal PM₂.₅ exposure level and associated factors among pregnant women residing in rural Butajira, Ethiopia. A community-based longitudinal cohort study with repeated measures was conducted between March and June 2025 among 328 pregnant women. Personal exposure to PM₂.₅ was measured at averagely 20, 30, and 36 weeks of gestation using Atmotube Pro air quality monitors. Structured questionnaires were used to collect socio-demographic, household, and cooking-related characteristics. Mean group differences were tested using one-way ANOVA and independent t-tests. A linear mixed-effects regression model with robust SEs was used to identify factors influencing personal PM2.5 exposure. Variables with p < 0.20 in bivariable analysis entered to multivariable model, and the estimated regression coefficients and their 95% confidence intervals were exponentiated to express results as multiplicative effects on PM₂.₅ exposure. A total of 328 pregnant women contributed 923 repeated PM2.5 measurements. The mean personal PM₂.₅ exposure was 237.4 µg/m³ (SD ± 17.6) at 20 weeks, 233.8 µg/m³ (SD ± 15.7) at 30 weeks, and 256.6 µg/m³ (SD ± 13.1) at 36 weeks of pregnancy, with overall mean exposure of 242.3 µg/m³ (SD ± 15.6). Highland residents, women spent more than five hours a day in cooking, and women who lived in homes with thatched roofs were attributed to higher exposures. Using crop and animal residue, age of women, being housewife, farmer partner, living in highland area, low wealth index, and partner negligence were predictors of personal PM2.5 exposure. Personal PM₂.₅ exposure levels among pregnant women were 16-fold higher than the guideline values recommended by the World Health Organization. Living in highland area, using crop and animal residue as fuel source, and partner negligence were factors for personal PM2.5 exposure. Reducing maternal exposure may be achieved through encouraging clean cooking technologies, enhancing ventilation, and incorporating males in energy decision-making.

  PublisherDOI

• Beyond access: clean energy use in low-income and middle-income countries

  The Lancet Global Health · 2026-03-17 · 4 citations

  articleOpen access

  Access to clean energy-here defined as electricity, liquefied petroleum gas, biogas, and ethanol-has increased substantially in low-income and middle-income countries over the past three decades.However, millions still lack reliable and affordable access to electricity and clean cooking fuels.This Series paper explores the drivers of clean energy adoption, assesses tools for tracking progress, and examines persistent barriers-including high costs, unreliable supply, and insufficient availability.Simplistic metrics, such as Sustainable Development Goal 7's binary indicators (eg, whether an individual has an electricity connection or not), risk overstating the health and equity impacts of energy transitions by overlooking fuel stacking, dynamic consumption patterns, and the gendered burden of polluting fuels.Drawing from historical trends and national policies, we show how targeted subsidies, robust supply chains, and coordinated investments have spurred increased clean fuel use.Meaningful gains require moving beyond technical fixes to inclusive, evidence-based strategies that address inequities, ensure affordability and reliability, and deliver lasting health benefits. Key messages Clean energy is central to global health, yet billions depend on polluting fuels Economic constraints are the primary determinants of fuel choices and therefore health outcomes Current metrics for clean energy access exaggerate progress and obscure health risks Targeted subsidies, robust supply chains, and coordinated investments have driven progress More rigorous causal evaluations of clean energy policy's health and climate impact are needed Streamlined, transparent funding is essential to meet health and climate goals www.

  PublisherOA PDFDOI

• The Impact of New York City's Open Streets Program on Local Traffic

  SSRN Electronic Journal · 2025-01-01

  preprintOpen access
  PublisherDOI

• Household Air Pollution Exposures Over Pregnancy and Maternal Blood Pressure Trajectories through 8 Years Postpartum: Evidence from the Ghana Randomized Air Pollution and Health Study (GRAPHS)

  medRxiv · 2025-01-18 · 1 citations

  preprintOpen access

  Background: Household air pollution is a major contributor to cardiovascular disease burden in women in Sub-Saharan Africa. However, little is known about exposures during pregnancy or the effect of clean cooking interventions on postpartum blood pressure trajectories. Methods: The Ghana Randomized Air Pollution and Health Study (GRAPHS) randomized 1414 non-smoking women in the first and second trimesters to liquefied petroleum gas (LPG) or improved biomass stoves - vs control (traditional three-stone open fire). Personal exposure to carbon monoxide was measured at four prenatal timepoints and three times over the first postpartum year. Participants were prospectively followed with annual resting BP measurements at 2, 4, 5, 6, 7, and 8 years postpartum. We employed linear mixed effects models to determine effect of GRAPHS interventions on postpartum BP, and to examine associations between prenatal and postnatal CO and postpartum BP. Results: LPG intervention was associated with 3.54mmHg (95% CI -5.55, -1.53) lower change in systolic BP from enrolment through 8 years postpartum, and 2.27mmHg (95% CI -3.61, -0.93) lower change in diastolic BP from enrolment through 8 years postpartum, as compared to control. In exposure-response analysis, average prenatal CO was positively associated with change in systolic BP from enrolment (β=0.71mmHg, 95% CI 0.08, 1.30, per doubling of CO). Conclusions: LPG cookstove intervention initiated in early pregnancy and maintained through the first postpartum year was associated with lower systolic and diastolic BP trajectories through 8 years postpartum. These findings support the need to integrate clean cooking solutions into existing antenatal care packages.

  PublisherOA PDFDOI

• Beyond Access: Clean Energy use in Low-and Middle-Income Countries

  SSRN Electronic Journal · 2025-01-01

  preprintOpen access
  PublisherDOI

• Household air pollution exposures over pregnancy and maternal blood pressure trajectories through 8 years postpartum: Evidence from the Ghana Randomized Air Pollution and Health Study (GRAPHS)

  Environmental Research · 2025-10-19 · 1 citations

  articleOpen access
  PublisherOA PDFDOI

• Early life cookstove interventions and children's blood pressure: Evidence from the Ghana randomized air pollution and health study

  Environmental Research · 2025-09-30 · 1 citations

  articleOpen access
  PublisherOA PDFDOI

• An exploratory analysis of miRNAs measured in placental tissue and their associations with prenatal exposure to household air pollution

  Current Zoology · 2025-12-30

  articleOpen access

  Abstract Household air pollution (HAP) has been associated with adverse pregnancy and birth outcomes, but the underlying mechanisms remain unclear. Pollutants can cross the placenta, potentially causing dysregulation of the crucial organ. Placental microRNAs (miRNAs) may serve as biomarkers of placental health, but studies of prenatal air pollutant exposure and placental miRNAs using non-targeted approaches have been scarce. We leveraged personal air monitoring data from mothers enrolled in the Ghana Randomized Air Pollution and Health Study to estimate prenatal exposure levels to carbon monoxide (CO) and particulate matter &amp;lt;2.5 µm (PM2.5). Placental tissue small RNA was sequenced and aligned to miRbase v22. We used sparse principal components analyses (sPCAs) to identify candidate placental miRNAs associated with prenatal CO (N = 133) and PM2.5 (N = 85) exposure. Associations between candidate miRNAs and prenatal exposures were assessed using linear regressions. We identified four placental miRNAs upregulated with prenatal CO exposure (miR-128–3p, miR-423–3p, miR-671–3p, and miR-744–5p) and five downregulated miRNAs (miR-29b-3p, miR-30e-5p, miR-101–3p, miR-130a-3p, and miR-376b-3p) at P &amp;lt; 0.1. Among female infants only, five miRNAs were downregulated (miR-101–3p, miR-130a-3p, miR-19b-3p, miR-106b-5p, and miR-301a-3p) and one upregulated (miR-22–3) with CO exposure (P &amp;lt; 0.1). We did not identify any associations between placental miRNAs and prenatal PM2.5 exposure. Our results support associations of prenatal CO exposure with differential expressions of critical placental miRNAs that have been implicated in placental disorders by previous studies. This is the first study to examine associations of these exposures with placental miRNAs using a non-candidate approach and lays the groundwork for targeted studies of placental miRNAs associated with prenatal HAP exposure.

  PublisherDOI

• Beyond air pollution: a national assessment of cooking-related burns in Ghana

  Injury Prevention · 2024-08-06 · 3 citations

  articleOpen access

  INTRODUCTION: Household energy transitions have the potential to reduce the burden of several health outcomes but have narrowly focused on those mediated by reduced exposure to air pollution, despite concerns about the burden of injury outcomes. Here, we aimed to describe the country-level incidence of severe cooking-related burns in Ghana and identify household-level risk factors for adults and children. METHODS: We conducted a national household energy use survey including 7389 households across 370 enumeration areas in Ghana in 2020. In each household, a pretested version of the Clean Cooking Alliance Burns Surveillance Module was administered to the primary cook. We computed incidence rates of severe cooking-related burns and conducted bivariate logistic regression to identify potential risk factors. RESULTS: We documented 129 severe cooking-related burns that had occurred in the previous year. The incidence rate (95% CI) of cooking-related burns among working-age females was 17 (13 to 21) per 1000 person-years or 8.5 times higher than that of working-age males. Among adults, the odds of experiencing a cooking-related burn were 2.29 (95% CI 1.02 to 5.14) and 2.40 (95% CI 1.04 to 5.55) times higher among primary wood and charcoal users respectively compared with primary liquified petroleum gas users. No child burns were documented in households where liquified petroleum gas was primarily used. CONCLUSION: Using a nationally representative sample, we found that solid fuel use doubled the odds of cooking-related burns compared with liquified petroleum gas. Ghana's efforts to expand access to liquified petroleum gas should focus on safe use.

  PublisherOA PDFDOI

Recent grants

• Child Lung Development Following a Cookstove Intervention: Evidence from GRAPHS

  NIH · $5.6M · 2017–2028

• Understanding adoption of clean cookstoves

  NIH · $2.5M · 2014–2021

• Circulating microRNAs in extracellular vesicles, household air pollution and lung development in Ghana

  NIH · $375k · 2018–2021

• Potential Inhaled Dose of Particulates, Biking and Cardiovascular Indicators

  NIH · $498k · 2015–2017

Frequent coauthors

• Kwaku Poku Asante

  Ghana Health Service

  115 shared

• Steven N. Chillrud

  Columbia University

  95 shared

• Patrick L. Kinney

  Boston University

  82 shared

• Mohammed Mujtaba

  Kintampo Health Research Centre

  76 shared

• Seyram Kaali

  Kintampo Health Research Centre

  73 shared

• Kenneth Ayuurebobi Ae-Ngibise

  Ghana Health Service

  61 shared

• Seth Owusu‐Agyei

  University of Health and Allied Sciences

  57 shared

• Ashlinn Quinn

  54 shared

Education

• PhD, Harvard Kennedy School

  Harvard University

  2007