Health survey of former workers in a Norwegian coke plant: Part. 1. Estimation of historical exposures

Our plain-English summary of Health survey of former workers in a Norwegian coke plant: Part. 1. Estimation of historical exposures, by P.R. Romundstad, A. Rønneberg, H.L. Leira, et al (Occupational and Environmental Medicine, 1998).

The study

• Authors: P.R. Romundstad, A. Rønneberg, H.L. Leira, T. Bye
• Journal: Occupational and Environmental Medicine
• Published: 1998;55(9):616-21
• Cited by: 8 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Objective: To estimate historical exposure levels at a coke plant for all agents considered to be of importance for epidemiological studies of mortality and cancer incidence.

Methods: Time weighted average exposure (8 h TWA) was estimated based on personal measurements for polycyclic aromatic hydrocarbons (PAHs) and carbonaceous particulates. Exposure to quartz was estimated relative to the concentration of carbonaceous particulates. These estimates were adjusted for the use of airstream helmets. Exposure to other agents were estimated qualitatively (asbestos, benzene, and arsenic) or semi-quantitatively (carbon monoxide (CO) and heat) based on measurements and other indicators of exposure.

Results: Exposure to PAHs was highest for those who worked at the top of the ovens (300 micrograms/m3) in the period from 1970-6. The estimated PAH exposure was reduced to an average of 65 micrograms/m3 after the introduction of exposure control measures in 1976. The estimates for carbonaceous particulates ranged from 1 to 16 mg/m3, with the highest exposure for workers at the top of the ovens and at the coke screening station.

Conclusions: The exposure of greatest concern in this study is to PAHs, but exposures to carbonaceous particulates and CO may also be of importance. The major limitations of this study are the lack of personal measurements before 1975 and the total lack of measurements for some of the exposed categories of workers. Despite these limitations, we think that this assessment reflects the actual exposures for most of the former employees. The assessment thus provides a reasonable tool for the subsequent epidemiological study and for future epidemiological follow up studies at the coke plant.

In plain English

This study estimated past workplace exposures at a Norwegian coke plant that operated from 1964 to 1988, for a later study of cancer and deaths among former workers. The authors used plant records, earlier measurements, questionnaires from 628 of 824 former workers employed over a year and alive in 1993, and 515 interviews. Polycyclic aromatic hydrocarbons (PAHs) were highest for workers on top of the ovens in 1970 to 1976. Twelve measurements from 1976 averaged 300 µg/m3, the figure used for that period. After control measures and airstream helmets, the 1977 to 1988 estimate was 65 µg/m3. Carbonaceous dust estimates ranged from 1 to 16 mg/m3. Asbestos was judged from reported time in direct contact with it. Bricklayers averaged 2.5 hours a week (mainly chrysotile), and maintenance staff and gas cracking station workers reported half an hour to one hour weekly. The authors concluded that PAHs were of greatest concern, though carbonaceous dust and carbon monoxide may also matter. Their stated limitations included a lack of measurements before 1975 (though some dust sampling from 1970 to 1975 is listed), none for maintenance workers, and no representative asbestos measurements.

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: Historical exposure assessment (job exposure matrix) for a planned epidemiological study of cancer incidence and mortality
• Who was studied: Former workers of a Norwegian coke plant operated from 1964 to 1988. Of 824 workers with more than 1 year of total employment who were alive in 1993, 628 answered a questionnaire and 515 were interviewed.
• Exposure: PAHs, asbestos, carbonaceous particulates, quartz, arsenic, benzene, carbon monoxide and heat at a coke plant
• Main results:
  • PAH exposure was highest for top oven workers in the period 1970 to 1976
  • For top oven workers, 12 personal PAH measurements taken in 1976 had an arithmetic mean of 300 µg/m3 (SD 254; 95% CI 139 to 461)
  • The job exposure matrix assigned top oven workers a PAH estimate of 300 µg/m3 for 1971 to 1976
  • For top oven workers, the job exposure matrix estimate for PAHs for 1977 to 1988 was 65 µg/m3, after control measures introduced in 1976 and adjustment for airstream helmets
  • Helmet use was estimated to reduce PAH exposure by 50% for top oven workers and 33% for side oven workers
  • Carbonaceous particulate estimates ranged from 1 to 16 mg/m3, highest for top oven and coke screening workers
  • Measurement data for carbonaceous particulates comprised 124 personal samples from 1974 to 1987 and 200 area samples from 1970 to 1975
  • Quartz exposure for workers with the highest carbonaceous particulate exposure was estimated at about 240 µg/m3
  • Asbestos exposure was assessed from the time workers reported working in direct contact with the material
  • Bricklayers were exposed to asbestos (mainly chrysotile) for an average of 2.5 hours a week and were classified as exposed
  • Maintenance personnel and gas cracking station workers reported a mean asbestos exposure of half an hour to one hour weekly and were also classified as exposed
  • Categories classified as exposed to carbon monoxide had an estimated 8 h TWA exposure of between 10 and 30 ppm
  • The workers with the highest arsenic exposure (arsenic mixing in the sulphur cleaning department) had an estimated 8 h TWA of about 5 µg/m3
  • Benzene exposure in exposed categories after 1970 was suggested to be between 0.1 and 3 ppm
• The authors' conclusion: The authors concluded that PAHs were the exposure of greatest concern, and that carbonaceous particulates and carbon monoxide may also be of importance
• Limitations the authors state:
  • The authors cite a lack of measurements before 1975 and no measurements at all for some exposed categories (maintenance workers); the article's measurement table nonetheless lists some carbonaceous particulate sampling from 1970 to 1975
  • No representative measurements for carbon monoxide, arsenic, benzene and asbestos
  • No measures of PAH uptake through the skin
  • Oven exposure estimates before 1971 are particularly uncertain because no sampling was done during the side filling period
  • Carbon monoxide and benzene sampling was probably less representative because there were few samples and the reasons for sampling were uncertain

Related studies

• Mortality and incidence of cancer among oil exposed workers in a Norwegian cable manufacturing company. Part I. Exposure conditions 1920-79 — A. Rønneberg, K. Skyberg (1988)
• Relationship of mortality, occupation, and pulmonary diffusing capacity to pleural thickening in the First National Health and Nutrition Examination Survey — D.P. Loomis, G.W. Collman, et al. (1989)
• Estimates of historical exposures by phase contrast and transmission electron microscopy in North Carolina USA asbestos textile plants — J.M. Dement, D. Myers, et al. (2009)
• A survey of acute and chronic disease associated with Yersinia enterocolitica infection. A Norwegian 10-year follow-up study on 458 hospitalized patients — A. Saebø, J. Lassen (1991)
• A radiographic survey of public school building maintenance and custodial employees — H.A. Anderson, L.P. Hanrahan, et al. (1992)
• Comment on "Mesothelioma from asbestos exposures: Epidemiologic patterns and impact in the United States" by R A Lemen, Journal of Toxicology and Environmental Health, Part B 2016;19:250-265 — C. Magnani, D. Mirabelli, et al. (2017)

Browse more research in Occupational and Environmental Medicine, or return to medical research.