Mortality and incidence of cancer among oil exposed workers in a Norwegian cable manufacturing company. Part I. Exposure conditions 1920-79

Our plain-English summary of Mortality and incidence of cancer among oil exposed workers in a Norwegian cable manufacturing company. Part I. Exposure conditions 1920-79, by A. Rønneberg, K. Skyberg (British Journal of Industrial Medicine, 1988).

The study

• Authors: A. Rønneberg, K. Skyberg
• Journal: British Journal of Industrial Medicine
• Published: 1988;45(9):589-94
• Cited by: 11 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Heavy high viscosity oils, transformer oils, and very light low viscosity oils have been used in a Norwegian company in the impregnation, sheathing, and installation of paper insulated cables. The aim of the present study was to determine exposures to oils and other chemicals at these workplaces from 1920 to 1979. Oil mist was sampled on glass fibre or membrane filters and analysed by infrared spectroscopy. Oil vapour concentrations were measured with a direct reading total hydrocarbon analyser with a flame ionisation detector. The results suggested average oil mist levels of 0.5-4 mg/m3 and oil vapour levels within 10-100 mg/m3. Definitive exposure to asbestos occurred in sheathing until the late 1950s, whereas only minor exposure to asbestos took place in installation and impregnation.

In plain English

This article, Part I of a two-part study, assessed past exposures at a Norwegian cable company's Oslo plant. The authors aimed to determine exposures to mineral oils and other chemicals in impregnation, sheathing and installation from 1920 to 1979. They used company history and air measurements, mostly from 1980 onward; oil mist samples reflected conditions described as typical of the 1960s and 1970s. Eight-hour average oil mist levels on glass fibre filters were 0.2 mg/m3 in impregnation and 0.3 mg/m3 in sheathing. Membrane filters consistently gave higher results than glass fibre filters. The authors estimated average oil mist levels of 0.5-4 mg/m3 and oil vapour levels of 10-100 mg/m3. Asbestos powder of unknown type was used less than one hour a week on one sheathing press until 1958. Pipe insulation in impregnation contained chrysotile and amosite. Installation workers used asbestos tape and board less than an hour a week. The authors concluded that definitive asbestos exposure occurred in sheathing until the late 1950s, with only minor exposure in installation and impregnation. They said the oil mist results should be read as high estimates of high viscosity oil mist levels.

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: Industrial hygiene exposure assessment combining historical information with workplace air measurements of oil mist and oil vapour
• Who was studied: Workplaces for impregnation, sheathing and installation of paper insulated cables at a Norwegian cable company's plant in Oslo, covering 1920-79. Most measurements were made in the 1980s, with one in 1979. The linked mortality and cancer results appear in a separate paper (Part 2).
• Exposure: Mineral oils (high viscosity oils, transformer oils, low viscosity oils) and kerosene. Asbestos: powder of unknown type in sheathing until 1958, chrysotile and amosite pipe insulation in impregnation, and asbestos tape and board in installation.
• Main results:
  • Oil mist samples taken in 1980-2 were collected under work conditions typical of the 1960s and 1970s.
  • Eight-hour time weighted average oil mist levels on glass fibre filters were 0.2 mg/m3 in the impregnation area and 0.3 mg/m3 in the sheathing area.
  • Simultaneous sampling gave consistently lower oil mist results with glass fibre filters than with membrane filters.
  • Total oil levels during cable installation were 17 mg/m3 (range 4-48) and 32 mg/m3 (range 12-60) in two unventilated jointing houses. A jointing house with fresh air supply had 13 mg/m3 (range 8-52), and ventilated halls had 5 mg/m3 (range 1-40).
  • A single short-term hydrocarbon vapour measurement during cleaning of hot impregnation equipment with kerosene in 1979 showed 2000-4000 mg/m3.
  • The authors estimated that cable splicers were exposed to time weighted average oil levels within 10-50 mg/m3.
  • Asbestos powder of unknown type was mixed with water and used less than one hour every week until 1958 on one sheathing press. In installation, woven asbestos tape and asbestos board were used for less than one hour a week.
• The authors' conclusion: The authors concluded that average oil mist levels were about 0.5-4 mg/m3 and oil vapour levels 10-100 mg/m3. They also concluded that definitive asbestos exposure occurred in sheathing until the late 1950s, with only minor asbestos exposure in installation and impregnation.
• Limitations the authors state:
  • Oil mist results must be interpreted as high estimates of high viscosity oil mist levels. One reason given is that condensation of low viscosity oil vapours cannot be ruled out.
  • Estimates of extractable material in the filters were based on very few blank filters. Some samples were quantified by assuming the standard curve stayed linear below the most dilute standard.
  • Results from the direct reading total hydrocarbon analyser had poor precision.
  • No total oil measurement was performed in impregnation or sheathing.

Topics

Medical terms in this study, explained in our Lexicon: Infrared Spectroscopy (IR).

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• Incidence of cancer among Norwegian boiler welders — T.E. Danielsen, S. Langård, et al. (1996)
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• Incidence of cancer among welders and other workers in a Norwegian shipyard — A. Melkild, S. Langård, et al. (1989)

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