Occupational exposures during routine activities in coal-fueled power plants

Our plain-English summary of Occupational exposures during routine activities in coal-fueled power plants, by M.J. Bird, D.L. MacIntosh, P.L. Williams (Journal of Occupational and Environmental Hygiene, 2004).

The study

• Authors: M.J. Bird, D.L. MacIntosh, P.L. Williams
• Journal: Journal of Occupational and Environmental Hygiene
• Published: 2004;1(6):403-13
• Cited by: 10 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Limited information is available on occupational exposures during routine, nonoutage work activities in coal-fueled power plants. This study evaluated occupational exposures to the principal contaminants in the facilities, including respirable dust (coal dust), arsenic, noise, asbestos, and heat stress. The data were collected over a 3-month period, during the summer of 2001, in 5 facilities that were chosen to be representative of the coal-fueled power plants of a large southeastern power-generating company. Each of the facilities was divided into 5 similar exposure groups based on previous exposure assessments and job tasks performed. From 4 of the 5 facilities, 392 air samples and 302 noise samples were collected with approximately 50 respirable coal dust, 32 arsenic, 15 asbestos, and 70 noise samples from each of the 4 plants. One of the previously surveyed facilities was also evaluated for heat stress, and 1 additional coal-fueled power plant was surveyed for a total of 20 personal heat stress samples. Personal monitors and area WBGT monitors were used. Of the nearly 400 air samples collected, only 1 exceeded the allowable occupational exposure value. For the noise samples, 55 (approximately 18%) were equal to or greater than the Occupational Safety and Health Administration (OSHA) 8-hour hearing conservation program level of 85 dBA, and 12 (approximately 4%) were equal to or greater than the OSHA 8-hour permissible exposure level of 90 dBA. Heat stress monitoring at the facilities indicates that 26% of the 1-hour TWAs were exceeded for one or all of the recommended heat stress limits. The data also concluded that some work sites were above the heat stress ceiling values recommended by the National Institute for Occupational Safety and Health (NIOSH). Four of the 20 employees personally monitored exceeded the recommended limits for heart rate or body core temperature. This suggests there is a potential for heat strain if signs and symptoms are ignored. Recommendations are made to better control the heat stress exposure.

In plain English

This study measured workplace exposures during routine, non-outage work at coal-fueled power plants of a large southeastern US power company. Randomly chosen workers in five job-based groups wore samplers during their shifts. At four plants, the authors also placed area asbestos samplers near asbestos-containing materials such as removed turbine shells and asbestos piping. The article does not name the fiber types. Of 61 area asbestos samples, 12 were above the detection limit of 0.003 fibers per cubic centimeter (f/cc). These ranged from 0.003 to 0.007 f/cc, below the OSHA limit of 0.1 f/cc. All 128 arsenic samples were below detection, and 1 of 203 respirable coal dust samples exceeded the OSHA limit. Of 302 noise samples, 55 reached at least 85 dBA and 12 at least 90 dBA. Of 20 mechanics monitored for heat, 4 exceeded recommended heart-rate or body-temperature limits. The authors concluded that asbestos, arsenic and coal dust exposures during routine work were expected to be low. They noted that unusual maintenance tasks not done routinely should be evaluated separately.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Cross-sectional occupational exposure survey (industrial hygiene sampling) using personal and area monitoring
• Who was studied: Workers at five coal-fueled power plants of a large southeastern US power-generating company, grouped into five similar exposure groups (Electricians, Fossil fuel services, Instruments and controls, Mechanics, Operations). Air and noise sampling took place at four plants. Heat stress was measured at two plants on 20 mechanics. The article dates the work to summer 2001.
• Exposure: Respirable coal dust, silica (in bulk coal), inorganic arsenic, noise and heat stress. Asbestos was measured by area samples placed near asbestos-containing materials workers might encounter. Analysis was by NIOSH method 7400; fiber types are not identified.
• Main results:
  • Asbestos (area samples, four plants): 12 of 61 samples were above the detection limit of 0.003 f/cc.
  • The detected asbestos values ranged from 0.003 to 0.007 f/cc, below the OSHA PEL of 0.1 f/cc.
  • Respirable coal dust: 4 of 203 samples were above the detection limit. One sample, from the Instrument and Control group at Plant 4 (5.3 mg/m3), exceeded the OSHA PEL of 2.4 mg/m3.
  • Inorganic arsenic: all 128 samples were below the limit of detection and below the OSHA PEL of 10 micrograms per cubic meter.
  • Noise: of 302 samples, 55 (about 18%) were at or above 85 dBA. 12 (about 4%) were at or above the 90 dBA OSHA PEL.
  • Heat stress: 4 of 20 personally monitored employees (20%) exceeded recommended heart rates or body temperatures.
• The authors' conclusion: The authors concluded that asbestos, inorganic arsenic and coal dust exposures under normal routine activities are expected to be low. They added that non-routine maintenance activities should be evaluated individually, and that asbestos maintenance plans should be kept up so exposures stay low.
• Limitations the authors state:
  • Unusual maintenance activities, such as bag house clean-outs, may cause elevated arsenic exposures not captured by this survey.
  • The personal heat stress monitors used have known shortcomings.
  • Heat stress evaluations made no adjustments for clothing or body weight.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Power plants and utilities.

Medical terms in this study, explained in our Lexicon: Occupational Exposure, OSHA, NIOSH.

Related studies

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• Malignant mesothelioma in thermoelectric power plant workers in Italy — P. Crosignani, F. Forastiere, et al. (1995)
• Asbestos related health hazards among power plant workers — Y. Lerman, A. Finkelstein, et al. (1990)
• Mortality among workers in the geothermal power plants at Larderello, Italy — E. Pira, M. Turbiglio, et al. (1999)
• Extrapulmonary neoplasms among asbestos-exposed power plant workers — I.G. Ron, H. Ron, et al. (1999)

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