Economic Analysis of a Rest-Shade-Hydration-Sanitation Program at a Nicaraguan Sugar Mill

Background: Occupational heat stress mediated acute kidney injury (AKI) has been linked to the development of chronic kidney disease of non-traditional causes (CKDnt) in agriculture workers. Rest-shade-hydration-sanitation (RSH-S) programs are promising interventions for preventing CKDnt. An obstacle to the implementation of RSH-S programs is the concern that the reduced work time associated with these programs may reduce productivity and earnings. Objective: This study analyzes the economic impact of an RSH-S program implemented at a sugar mill in Nicaragua. Approach: Data were obtained from the sugar mill over a six-year, five-harvest period (Harvest 1: 2017-2018 through Harvest 5: 2021-2022). Data included health and productivity metrics and RSH-S program costs. During Harvest 1, existing heat mitigation strategies were in place but were not optimal. Thus, 2017 was considered the pre-RSH-S (baseline) period. Over subsequent harvests, progressively improved RSH-S programs were implemented. A cost-benefit analysis was conducted to estimate the return on investment of the RSH-S program. The analysis considered both fixed and variable costs associated with the program. Benefits were calculated based on productivity improvements and reductions in AKI cases. Findings: As soon as 2020, the costs of implementing the RSH-S program were offset by savings resulting from increased productivity and reduced cases of AKI. The RSH-S program yielded a positive return on investment from 2020 and onward. The average return on investment over the five-year period was 0.02 (or a return of $1.02 for every $1.00 invested), which takes into consideration the first two years of the intervention in which there was a negative return on investment. In 2022, every $1.00 invested in the RSH-S program saw a return of $1.60. Conclusions: Implementing an RSH-S program can provide both economic and health benefits, particularly in locations where climate change is increasing the already present risk and burden of occupational heat stress.