AN INVESTIGATION OF CARDIOVASCULAR HEALTH OF WILDLAND FIREFIGHTERS AND IMPACT OF TEMPERATURE ON OCCUPATIONAL INJURIES AMONG WORKERS

Author

MD Zahid Hasan

Year of Award

2023

Document Type

Dissertation

Degree Type

Doctor of Philosophy (PhD)

Degree Name

Public Health

Department or School/College

School of Public and Community Health Sciences

Committee Chair

Curtis Noonan

Commitee Members

Erin Semmens, Erin Landguth, Tony Ward, Paul Smith

Publisher

University of Montana

Abstract

Cardiovascular events are the leading cause of on-the-job mortality among wildland firefighters (WFFs). Health screening programs play an important role in assuring the safety of workers in this arduous duty occupation. Some research has highlighted acute health effects in this worker population, but little is known about the impact of long-term, repeated exposures. To fill this gap, my dissertation investigated cardiovascular health status of wildland firefighters and explored the association of their work history (days assigned on fire) to the subclinical risks factors of cardiovascular health. My 1st study compared the subclinical risk factors of cardiovascular health of wildland firefighters to the US general population. This is a cross-sectional study which compared body mass index (BMI), total cholesterol, and blood pressure in 11051 WFFs aged 17 to 64 years using Department of the Interior Medical Screening Program (DOI MSP) clinical screening examinations between 2014 – 2018 to National Health and Nutrition Examination Survey (NHANES) of 2015-2016 cycle using adjusted logistic regression analyses. My 2nd study determined the association between the occupational history (lifetime operational period in days) of WFFs and subclinical measures of cardiovascular health. This cross-sectional study brings together WFF occupational history and medical screening records for Department of the Interior WFFs. We evaluated associations between the number of total days assigned on fire and three clinically measured cardiovascular indicators (body mass index (BMI), blood pressure, and total cholesterol). Our 1st study showed significantly higher odds of hypertension and prehypertension in WFFs (2.84 times more with 95% CI: 2.28; 3.53) than US general population. Our 2nd study showed high-risk categories of cholesterol is associated with work history (days assigned on fire) of WFFs. In addition to cardiovascular health of WFFs, the 3rd study of my dissertation explored the connection of temperature and occupational injuries. Workers may be particularly vulnerable to heat related injury and illness, such as heat exhaustion, heat stress, and heat stroke, which can cause sudden death due to cardiac arrest or permanent body injuries. Very little is known about the impact of temperature on injuries of workers in Montana and this study aims to address that. This is a time-stratified case-crossover study using worker compensation claims between 2007 and 2022, provided by the Montana Department of Labor and Industry. This study includes three occupational groups: construction workers, firefighters, and professional and technical workers. In addition to their combined analysis, we also perform analysis separately for each of these occupational group. We assessed the impact of temperature (extreme hot, hot, normal, cold, and extreme cold) on injuries of workers using conditional logistic regression in analyses adjusted for humidity, precipitation, wind direction, and wind speed. For construction workers and firefighters, extreme cold temperatures were associated with lower reporting (OR= 0.74; 95% CI: 0.64,0.85 and OR= 0.55; 95% CI: 0.33, 0.92 respectively) of workplace injury compared to the normal temperature in the temperature-injury model. In the adjusted model (adjusted for wind speed), we found that overall the odds of injury increase by 1.13 times (1.05-1.22) per unit (m/s) increase of wind speed. In this model, wind speed is only an important predictor of injury risk for construction workers and firefighters. The findings of these three studies suggest actions for protecting against cardiovascular disease among WFFs and will help intervention programs in Montana to reduce work related injuries among workers.

Recommended Citation

Hasan, MD Zahid, "AN INVESTIGATION OF CARDIOVASCULAR HEALTH OF WILDLAND FIREFIGHTERS AND IMPACT OF TEMPERATURE ON OCCUPATIONAL INJURIES AMONG WORKERS" (2023). Graduate Student Theses, Dissertations, & Professional Papers. 12228.
https://scholarworks.umt.edu/etd/12228