Ghana Randomized Air Pollution and Health Study (GRAPHS)
January 10, 2025 | Completed Project | Reading time: 8 min
Introduction
The Kintampo Health Research Centre (KHRC) conducted this large study to test whether using clean cookstoves could reduce harmful health effects caused by household air pollution. The study sought to investigate how air pollution from cooking with wood, charcoal, and other biomass fuels affect the health of pregnant women and their babies.
Principal Investigators
Dr. Kwaku Poku Asante, Dr. Seth Owusu-Agyei.
Co-investigators
Drs. Patrick Kinney, Darby Jack, Robin Whyatt, Dr. Blair Wylie, Dr. Xinhua Liu, Dr. Alexander Manu, Mrs. Charlotte Tawiah, Mr. Kenneth Ae-Ngibise, and Mr. Charles Zandoh.
Background
In 2019, air pollution caused an estimated 6.7 million premature deaths.1 Household air pollution (HAP) from incomplete combustion of solid fuels (wood, dung, crop residue and charcoal) in inefficient home cookstoves in low-income and middle-income countries (LMICs) accounts for about one-third of this mortality burden, and in some areas is also an important source of ambient air pollution.
Systematic reviews have found associations between HAP exposure and morbidity and mortality across the life course, including reductions in birth weight2 and increased risk for early childhood acute lower respiratory illnesses (ALRI), the leading killer of children under 5 years of age.3 In Ghana, approximately 11 000 deaths and 467 000 disability adjusted life years annually are attributed to HAP exposure. Half of the world's population relies on biomass - wood, coal, crop residue) for cooking/ heating. Women & children are disproportionately exposed.
Objectives of the Study
The goal of this trial is to test the effectiveness of commercially available, low-cost improved cook stoves in improving infant health outcomes from birth through twelve months of age.
Methodology
This study was a cluster-randomized controlled trial conducted in 35 communities within the Kintampo Health and Demographic Surveillance System (KHDSS) area. Communities were matched based on socio-economic status (SES) and served as the units of randomization. A total of 1,415 participants, all of whom were the primary cooks in their families, were identified during their pregnancies (before the third trimester) through community surveillance by residence field workers (RFWs). These communities were randomly assigned to either an early intervention or a late intervention group.
The trial included two cookstove intervention groups and one control group. Participants in all groups were provided with mosquito bed nets and health insurance. Those in the LPG intervention group received a two-burner LPG cookstove, two 14.5 kg LPG cylinders, and monthly LPG refills at no cost for the duration of the study. Additional LPG was provided as needed, ensuring continuous access to clean cooking fuel. Participants in the control group did not receive any cookstove intervention.
To measure the participants’ exposure to harmful pollutants, the study monitored carbon monoxide (CO) levels and fine particulate matter (PM2.5) in their environments. CO exposure was assessed using Lascar EL-USB-CO sensors, while PM2.5 was measured with microPEM monitors. CO monitoring began at enrollment, before the intervention cookstoves were distributed, and continued three weeks after the cookstoves were introduced. Additional measurements were taken twice more during the remaining months of pregnancy. After childbirth, CO exposure monitoring was conducted for both mothers and their children at 1, 3, and 9 months postpartum. PM2.5 measurements were conducted for a subset of participants during the second CO monitoring session (three weeks after enrollment) and again when the child reached three months of age.
This design provided a detailed understanding of how the intervention cookstoves affected air quality and exposure to pollutants, both during pregnancy and in the early months of the child’s life.
Expected Outcomes
The introduction of improved cookstoves before the third trimester of pregnancy is expected to result in a significant increase in the average birth weight of newborns. Also, starting the use of improved cookstoves during this period is anticipated to significantly reduce the incidence of severe pneumonia, as assessed by physicians, in infants during their first 12 months of life.
Key Findings: What Do These Findings Mean?
This study tested whether using cleaner stoves and fuels could reduce air pollution in homes and improve children’s health. Pregnant women were divided into three groups: one group received liquefied petroleum gas (LPG) stoves with free monthly fuel deliveries, another received improved biomass stoves, and the third group acted as a control.
The results showed no clear health benefits from either of the interventions when considering all participants together, although women in the LPG group did experience lower personal exposure to air pollution. These findings suggest that using clean cookstoves alone may not be enough to fully address the health risks associated with polluted household air.
To significantly improve health, policies in low- and middle-income countries need to tackle all sources of air pollution, not just cooking. This means ensuring access to clean and affordable energy for all households while also addressing pollution from other sources like traffic, waste burning, and industrial emissions.
Collaborating institutions
Mailman School of Public Health, Columbia University, New York, NY, USA.
Kintampo Health Research Centre, Ghana Health Service, Brong Ahafo Region, Kintampo, Ghana.
Division of Maternal-Fetal Medicine, Vincent Department
of Obstetrics and Gynecology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
Funders
National Institute of Health of USA
Thrasher Research Fund
Global Alliance for Clean Cookstoves.
Study Duration : 5 Years
Start Date : February 2012
End Date : June 2016
Conclusion
While clean cookstoves can help reduce household air pollution, more comprehensive solutions are needed to tackle the broader issue of air pollution and its impact on health in low-income countries like Ghana. The GRAPHS study highlighted the importance of addressing all sources of air pollution, not just household cooking, to improve public health. This includes pollution from traffic, waste burning, and other sources. Investigators of this study also stressed the need for more studies to understand how household air pollution affects lung growth, especially in unborn babies.