Key focus areas of the GEOHealth Hub include climate change and health as well as occupational health. The Heat Stress Study explores the relationship between these focus areas in Ethiopia. Climate models indicate that mean annual surface temperature in Ethiopia will increase by 3.5% to 8.5% (from 0.50C to 6 0C) by 2100 relative to a 1975 to 2005 baseline. Agricultural workers in commercial agriculture enterprises participate in strenuous tasks and experience an array of occupational risks and hazards. High humidity and extreme ambient temperatures coupled with heavy physical labor and low fluid consumption place agricultural workers at risk for heat strain and dehydration.14 As the number of hot days and heatwaves is expected to increase, agricultural workers will experience increased heat-related morbidity and mortality. These physiological impacts will, in turn, reduce worker productivity and, ultimately, aggregate economic output – yet the magnitude of such effects is unstudied in Africa. Heat stress and dehydration may figure into the emerging global epidemic of chronic kidney disease among workers, which has been shown to be growing rapidly in agricultural workers around the world – but again data on the link between heat stress and kidney function is almost nonexistent in Africa.
Cycle I (2016-2022)
In 2018 a pilot study was conducted in Ethiopia by researchers from Addis Ababa University, Ethiopia to assess the potential occupational health impacts of climate change among those working in the emergent floriculture industry. Using a cross-sectional study design (one time sampling), occupational heat stress was assessed in six greenhouses across three regions of the country with varying climatic and topographic settings (i.e., agro-ecologies). Heat exposure was measured using Wet Bulb Globe Temperature (WBGT) instruments during two seasons (warm and cool) and worker perceptions and possible health impacts of heat exposure were collected via interview-administered questionnaires. Research is scheduled to be underway in Kampala, Uganda in 2021 by the research team at Makerere University, Uganda.
Cycle II (2022-2026)
Building on the pilot study conducted in Cycle I, researchers from Addis Ababa University, Ethiopia will enroll 600 workers at commercial farms and track how heat stress affects worker-level productivity and in a subset of 50 workers kidney function will also be assessed. Research will be conducted across four large commercial farms selected based on their representation of different heat stress pressures, intensity of work, and gender balance of the workers. As in the pilot study, exposure to heat stress will be assessed using WGBT instruments (QuesTemp 34 WI, USA) placed in agricultural working environments to capture heat exposure during hotter (May) and cooler (November) seasons. Over the same time period as the temperature monitoring, researchers will collect information on the productivity of agricultural workers.
In addition, we are also hoping to assess biomarkers of kidney function in a subset of workers.
Researchers will analyze study data to better understand the impacts of climate change on the occupational health of agricultural workers as well as the economic impacts of heat stress on productivity. The two year Heat Stress Study will be initiated by Hub researchers at Addis Ababa University in 2023.