The effects of cool roofs on health, environmental, and economic outcomes in rural Africa: study protocol for a community-based cluster randomized controlled trial

BACKGROUND

High ambient air temperatures in Africa pose significant health and behavioral challenges in populations with limited access to cooling adaptations. The built environment can exacerbate heat exposure, making passive home cooling adaptations a potential method for protecting occupants against indoor heat exposure.

METHODS

We are conducting a 2-year community-based stratified cluster randomized controlled trial (cRCT) implementing sunlight-reflecting roof coatings, known as "cool roofs," as a climate change adaptation intervention for passive indoor home cooling. Our primary research objective is to investigate the effects of cool roofs on health, indoor climate, economic, and behavioral outcomes in rural Burkina Faso. This cRCT is nested in the Nouna Health and Demographic Surveillance System (HDSS), a population-based dynamic cohort study of all people living in a geographically contiguous area covering 59 villages, 14305 households and 28610 individuals. We recruited 1200 participants, one woman and one man, each in 600 households in 25 villages in the Nouna HDSS. We stratified our sample by (i) village and (ii) two prevalent roof types in this area of Burkina Faso: mud brick and tin. We randomized the same number of people (12) and homes (6) in each stratum 1:1 to receiving vs. not receiving the cool roof. We are collecting outcome data on one primary endpoint - heart rate, (a measure of heat stress) and 22 secondary outcomes encompassing indoor climate parameters, blood pressure, body temperature, heat-related outcomes, blood glucose, sleep, cognition, mental health, health facility utilization, economic and productivity outcomes, mosquito count, life satisfaction, gender-based violence, and food consumption. We followed all participants for 2 years, conducting monthly home visits to collect objective and subjective outcomes. Approximately 12% of participants (n = 152) used smartwatches to continuously measure endpoints including heart rate, sleep and activity.

DISCUSSION

Our study demonstrates the potential of large-scale cRCTs to evaluate novel climate change adaptation interventions and provide evidence supporting investments in heat resilience in sub-Saharan Africa. By conducting this research, we will contribute to better policies and interventions to help climate-vulnerable populations ward off the detrimental effects of extreme indoor heat on health.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS) DRKS00023207. Registered on April 19, 2021.

Synthetic Chemical Trade as a Potential Driver of Global Health Disparities and Data Gaps on Synthetic Chemicals in Vulnerable Populations

PURPOSE OF REVIEW

Most research on toxic exposures in vulnerable populations focuses on air pollution. Synthetic chemical production, however, is a multi-billion-dollar industry that lacks appropriate international regulation to protect those exposed to toxic chemicals. This paper aims to describe the country-level import and export of key groups of synthetic chemicals using data from the United Nations Comtrade Database and provide a narrative review of the evidence from January 2018 to August 2019 on exposure to, health effects of, and interventions to reduce synthetic chemicals in vulnerable populations around the world.

RECENT FINDINGS

Generally, a small number of high-income countries export the majority of synthetic chemicals, while most low-income countries import more chemicals than they export, which may contribute to higher levels of synthetic chemicals in those settings. However, few studies have quantified exposures to synthetic chemicals in low- and middle-income countries, the health effects of such exposures, or interventions to mitigate exposures. Synthetic chemicals continue to enter markets despite our limited knowledge of their effects on human health, particularly in the most vulnerable populations. We need more research to understand the health impacts of these pervasive exposures.