Associations between heat exposure, vigilance, and balance performance in summer tree fruit harvesters

June T Spector; Jennifer Krenz; Miriam Calkins; Dawn Ryan; Jose Carmona; Mengjie Pan; Anna Zemke; Paul D Sampson

doi:10.1016/j.apergo.2017.09.002

Associations between heat exposure, vigilance, and balance performance in summer tree fruit harvesters

Appl Ergon. 2018 Feb:67:1-8. doi: 10.1016/j.apergo.2017.09.002. Epub 2017 Sep 15.

Authors

June T Spector¹, Jennifer Krenz², Miriam Calkins³, Dawn Ryan⁴, Jose Carmona⁵, Mengjie Pan⁶, Anna Zemke⁷, Paul D Sampson⁸

Affiliations

¹ Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA; Department of Medicine, University of Washington, Seattle, WA, USA. Electronic address: spectj@u.washington.edu.
² Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA. Electronic address: jkrenz@u.washington.edu.
³ Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA. Electronic address: miriac@u.washington.edu.
⁴ Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA. Electronic address: dmryan@u.washngton.edu.
⁵ Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA. Electronic address: carmonaj@u.washington.edu.
⁶ Department of Statistics, University of Washington, Seattle, WA, USA. Electronic address: mpan1@u.washington.edu.
⁷ College of Medicine, The Ohio State University, Columbus, OH, USA. Electronic address: Anna.Zemke@osumc.edu.
⁸ Department of Statistics, University of Washington, Seattle, WA, USA. Electronic address: pds@u.washington.edu.

Abstract

Background: We sought to evaluate potential mediators of the relationship between heat exposure and traumatic injuries in outdoor agricultural workers.

Methods: Linear mixed models were used to estimate associations between maximum work-shift Wet Bulb Globe Temperature (WBGT_max) and post-shift vigilance (reaction time) and postural sway (total path length) in a cross-sectional sample of 46 Washington State tree fruit harvesters in August-September 2015.

Results: The mean (SD) WBGT_max was 27.4 (3.2)°C in August and 21.2 (2.0)°C in September. The mean pre-work-shift participant urine specific gravity indicated minimal dehydration. Twenty-four percent of participants exhibited possible excessive sleepiness. There was no association between WBGT_max and post-shift reaction time or total path length.

Conclusions: Heat exposure was not associated with impaired vigilance or balance in this study, in which the overall mean (SD) WBGT_max was 25.9 (4.2)°C. However, the study identified opportunities to ensure adequate pre-work-shift hydration and to optimize sleep and work-shift timing in order to reduce occupational injury and heat-related illness risk.

Keywords: Heat exposure; Postural sway; Psychomotor vigilance.

Publication types

Evaluation Study

MeSH terms

Adult
Agriculture / methods*
Cross-Sectional Studies
Dehydration
Female
Fruit
Heat Stress Disorders / etiology*
Hot Temperature / adverse effects*
Humans
Linear Models
Male
Middle Aged
Occupational Exposure / adverse effects*
Occupational Injuries / etiology*
Postural Balance
Reaction Time
Seasons
Sleep
Trees
Washington
Work Schedule Tolerance / physiology

Abstract

Publication types

MeSH terms

Grants and funding