Challenges in conducting epidemiological field studies evaluating associations between heat stress and renal health among workers in informal sectors: experiences from India.

Well-designed Environmental Epidemiological Studies (EES) play a crucial role in quantifying the influence of environmental exposures and their associated risks on health in the wider population. They provide critical research evidence for identifying and developing interventions to avert adverse health consequences from those exposures. However, uncertainty and variability inherent to any field based EES could hinder the nature and magnitude of association between an exposure and health outcome. This is particularly pronounced in resource limited settings and resource-tight research projects. The present study evaluated the association between occupational heat stress and renal health among informal work sectors in India which had some significant challenges. Informal workers exposed to chronic occupational heat stress had significantly higher adverse renal health outcomes than the unexposed workers. Our field challenges included gaining access and permissions to conduct the study, participant recalls bias and attrition, accurately estimating exposures, confounding from causes of both exposure and disease, and to a large extent tight-funding. Though opportunities are abundant, we must ensure field conditions are optimized to attain study objectives. A keen understanding and sensitivity towards the cultural and work settings is essential for successful project completion. Based on our experiences, we provide strategies to adopt to improve fieldwork and provide recommendations to help overcome the field challenges and achieve better results for future EES studies in developing country settings.