Occurrence of Occupational Injuries and Within Day Changes in Wet Bulb Temperature Among Sugarcane Harvesters

ABSTRACT

Objective

Climate change has implications for human health worldwide, with workers in outdoor occupations in low- to middle-income countries shouldering the burden of increasing average temperatures and more frequent extreme heat days. An overlooked aspect of the human health impact is the relationship between heat exposure and increased risk of occupational injury. In this study, we examined the association between occupational injury occurrence and changes in outdoor temperatures through the workday among a cohort of Guatemalan sugarcane harvesters.

Methods

Occupational injuries recorded for the 2014/2015 to 2017/2018 harvest seasons were collected from a large agribusiness employing male sugarcane harvesters in Southwest Guatemala. Wet Bulb Globe Temperature (WBGT) for the same period was collected from the El Balsamo weather station. We used a logistic mixed effects model to examine the association between injury occurrence and (1) the average WBGT during the hour injury was recorded, (2) the average WBGT during the hour prior to the injury being recorded, and (3) the change in the hourly average WBGT prior to the injury being recorded.

Results

There were 155 injuries recorded during the study period. Injuries were recorded most often between 14:00 and 16:00 (n = 62, 40%) followed by 8:00 and 10:00 (n = 56, 36%). There were significant differences in the average hourly WBGT and the hour in which injuries were recorded (p-value <.001). There were no observable associations between average hourly WBGT (OR: 1.00, 95%CI: 0.94, 1.05; p-value: 0.87), lagged average hourly WBGT (OR: 1.01, 95%CI: 0.97, 1.05; p-value: 0.71), or change in average hourly WBGT (OR: 0.96, 95%CI: 0.89, 1.04; p-value: 0.35) and recorded occupational injury.

Conclusions

This is the first study that has examined how changes in WBGT throughout the day are related to occupational injury among agricultural workers. Although this study did not demonstrate an association, there is a need for future research to examine how various measurements of WBGT exposure are related to occupational injury in agricultural worker populations.

KEYWORDS:

• Occupational injury
• heat exposure
• climate change

Disclosure statement

The University of Colorado and Pantaleon have a Memorandum of Understanding. Pantaleon provided the University of Colorado investigators with de-identified data, all of which were collected by the company for business purposes prior to the analysis. The funder had no role in data analysis or data interpretation. The University of Colorado employed appropriate research methods in keeping with academic freedom, based conclusions on critical analysis of the evidence, and reported findings fully and objectively. The terms of this arrangement were reviewed and approved by the University of Colorado in accordance with its conflict of interest policies.

Additional information

Funding

Work was supported by Training Grant T42 OH00929 funded by the Centers for Disease Control and Prevention. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the Centers for Disease Control and Prevention or the Department of Health and Human Services.