Examining Agricultural Workplace Micro and Macroclimate Data Using Decision Tree Analysis to Determine Heat Illness Risk

Details

• Personal Author:
  Hertzberg V ; Mac VVT ; McCauley LA
• Description:
  With ambient temperatures projected to increase by 0.1 degrees C per decade over the next 2 decades, heat-vulnerable populations including the poor, the elderly, military personnel, first responders, and outdoor workers will be at heightened risk for heat-related illness (HRI). Farmworkers represent a category of outside workers susceptible to HRI. In fact agricultural workers experience heat-related deaths at an annual rate that is 20 times that of the U.S. civilian workforce. Beyond experiencing adverse environmental conditions at their workplace, agricultural workers experience a high level of vulnerability due to socioeconomic disparities including decreased access to healthcare, separation from their families, low income, crowded housing often in poor condition, and little control over their work environments. While the threats of HRI in this population are well-recognized there have been few studies that actually capture the heat conditions of the worksite, nor have researchers assessed the validity to which environmental monitoring station reflect the temperatures at the worksite. Researchers encounter common methodological and design issues in conducting field studies to assess occupational heat hazards in agricultural work including barriers to farmworker recruitment due to the migratory nature of their work, population enumeration, and employee fear of a loss of confidentiality and an employer knowing they are participating in a research study. While some farm owners are willing to cooperate with researchers in supporting investigations, many are not. Many farmworkers are not employees of large agricultural operations, but instead work for small independent contractors. Exclusive reliance on industry-supported research studies may block the inclusion of many vulnerable workers, leading to biased findings. Despite the development of comprehensive biomonitoring protocols for HRI, work site-based environmental monitoring presents a variety of challenges including accurate and efficient use of weather assessment equipment, access to the worksite in some agricultural communities, and variation among numerous worksites. The Girasoles Study is a project assessing agricultural workers in multiple communities in the state of Florida to characterize HRI and to examine the factors that predispose an individual to be particularly vulnerable to HRI. The design of Girasoles was based upon the Farmworker Vulnerability to Heat Hazards Framework. The hazard component of the framework (environmental heat) was captured from local monitoring stations of the Florida Automated Weather Network (FAWN) that generate publicly available weather information. The validity of data from monitoring stations in accurately capturing heat exposure is problematic. The actual microclimate in a workplace can deviate significantly from the general climate of a district because direct solar radiation and wind speed play important roles in heat stress experienced by outdoor workers. In an attempt to measure bias in using general climate data generated by the FAWN system, we used an iButton (Maxim Integrated Products, Inc., San Jose, California), a small personal temperature logger attached to participants' clothing, to measure microclimate conditions at individual worksites, recording ambient temperature and humidity. The iButton technology can be worn inside or outside clothing, does not interrupt the flow of work, and is not affected by moisture. Beyond the need for accurate worksite environment assessment for research studies, there is a great need to provide outdoor workers with accessible and informative heat-risk measures. To our knowledge, there is no inexpensive wearable device to provide workers with real time temperature readings of their environment. While the iButton technology captures the temperature in the workplace, it does not have a mechanism to provide the information directly to the worker. Instead, the data are downloaded after a shift to capture retrospectively, the temperatures of the work environment. A readily accessible resource that stratifies levels of heat risk is the heat index (HI) which is reported by the National Weather Service (NWS) from calculations generated from regional weather data, and broadcast on local weather station channels. Heat index is calculated from ambient air temperature, commonly referred to as temperature, and relative humidity, commonly referred to as humidity. Therefore, the aims of this study were two-fold: (1) To determine if regional weather data is associated with direct worksite monitoring of environmental conditions; and (2) To utilize regional weather data to build a useful model for predicting worksite environmental conditions for agricultural workers. Description provided by NIOSH
• Subjects:
  • Agriculture
  • Emigration and Immigration
  • Hot Temperature
  • Occupational Health
  • Safety
• Keywords:
  • Agriculture
  • Agricultural workers
  • Agricultural industry
  • Hot environments
  • Heat exposure
  • Body fluid balance
  • Immigrant workers
  • Seasonal workers
  • Body temperature
  • Author Keywords: agricultural
  More +
• ISSN:
  1076-2752
• Document Type:
  Text
• Funding:
  Grant ; Cooperative Agreement
• Genre:
  Journal Article
• Place as Subject:
  Florida ; Georgia ; OSHA Region 4
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  107-114
• Volume:
  61
• Issue:
  2
• NIOSHTIC Number:
  nn:20053417
• Citation:
  J Occup Environ Med 2019 Feb; 61(2):107-114
• Contact Point Address:
  Valerie Vi Thien Mac, PhD, RN, Nell Hodgson School of Nursing, Emory University, 1520 Clifton Road, Room 370, Atlanta, GA 30322
• Email:
  valerie.mac@emory.edu
• Federal Fiscal Year:
  2019
• NORA Priority Area:
  Agriculture, Forestry and Fishing
• Performing Organization:
  Emory University, Atlanta
• Peer Reviewed:
  True
• Start Date:
  20140901
• Source Full Name:
  Journal of Occupational and Environmental Medicine
• End Date:
  20180831
• Download URL:
  https://stacks.cdc.gov/view/cdc/216173/cdc_216173_DS1.pdf
• File Type:
  [PDF - 676.52 KB]
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:d8dce206fec6ba5030015e81f3174cf74e6f588c955c9b8504d5e2ca07047616823ebc3113ce6d4660d6757d8a3ac22feb35f92fe3065fcdb02e908615d82c3e