Climate change and heat exposure to sugarcane harvesters in Costa Rica: Health and productivity outcomes

Background: Climate change is expected to increase temperatures worldwide particularly in the tropics, where already-hot conditions complicate labor-intensive jobs. According to the 2012 Climate Vulnerable Forum Monitor estimates for 2030, the most significant economic impact of climate change in Costa Rica will be due to effects of heat on work capacity and labor productivity. In Costa Rica, sugarcane production continues to increase in response to a demand for biofuels, and thousands of hectares of sugarcane are harvested by hand each year by a largely migrant labor force from Nicaragua. Empirical research is needed to document current heat stress exposure in sugarcane harvesters in order to 1) improve conditions for workers to prevent negative health effects of heat exposure and 2) prevent productivity loss. Methodology: A three year study sought to use quantitative and qualitative research to document the heat stress experienced by sugarcane harvesters. Interviews, non-participatory observation, symptom questionnaires, wet bulb globe temperature measurements, and calculations of metabolic load and limit values (using international standards) were used. Results: Harvesters are under heat stress for the majority of their shift and international standards would recommend working only 25% of each hour under the hottest conditions. Harvesters reported heat-related health symptoms more often than non-harvesters in the same company. The expected temperature increase even under the most conservative scenarios would negatively impact this already-challenging work setting.Conclusion: Immediate action is needed to decrease current heat exposure in an already vulnerable migrant working population and to prepare for expected climate change.