Environmental measurements of total dust and fiber concentration in manufacturer and user of man-made mineral fibers

Our plain-English summary of Environmental measurements of total dust and fiber concentration in manufacturer and user of man-made mineral fibers, by J.H. Kim, H.S. Chang, K.Y. Kim, et al (Industrial Health, 1999).

The study

• Authors: J.H. Kim, H.S. Chang, K.Y. Kim, W.M. Park, Y.J. Lee, H.C. Choi, K.A. Kim, Y. Lim
• Journal: Industrial Health
• Published: 1999;37(3):322-8
• Cited by: 1 article, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Man-made mineral fibers (MMMF), most of which are referred to as man-made vitreous fibers (MMVF), are mostly amorphous silicates manufactured from glass, rock, or other minerals. Analysis for MMMF have been restricted largely to the measurement of total airborne mass concentrations, but more recently to the determination of airborne fiber levels by phase contrast optical microscopy. In Korea, many small factories are related with manufacturing and using MMMF without any special evaluation of environmental measurements. Though MMMF are known as the substitute of asbestos and their toxicity are regarded as very low, MMMF do not totally excluded from the respiratory and/or skin diseases now. Therefore, we evaluated the environments of many workplaces with total dust and fiber concentration. Most dust and fiber concentrations were below threshold limit value (TLV) at various industries and working processes. However, these data showed a slight relationship between total dust and fiber concentration.

In plain English

This study measured airborne dust and fibers at Korean workplaces that made or used man-made mineral fibers (MMMF), which the authors describe as substitutes for asbestos. Between March 1997 and February 1998, 116 workers at 20 workplaces wore personal air samplers. The workplaces were users and manufacturers of continuous filament glass fiber, one glass wool manufacturer, and rock wool workplaces. Fibers were counted under a phase contrast microscope and total dust was weighed. No workplace exceeded the ACGIH fiber limit of 1 fiber per cubic centimeter. No industry's average exceeded the Korean total dust limit of 10 mg/m3, but three men at continuous filament user plants and five men in rock wool work did. Rock wool workplaces had significantly higher total dust and fiber levels than the other industries. Fiber and total dust levels were only slightly correlated (r=0.398). Raw-material samples showed no asbestos contamination. The authors concluded that fiber exposure was low but that MMMF fibers should be measured in workplace monitoring. The tables of measured values were not included in the available text.

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 workplace air monitoring survey using personal air sampling of workers for fibers and total dust
• Who was studied: 116 workers at 20 workplaces across Korea, March 1997 to February 1998: continuous filament users (13 factories, 46 workers), continuous filament manufacturers (2 factories, 38 workers), glass wool manufacturer (1 factory, 12 workers), rock wool (4 factories, 20 workers)
• Exposure: Man-made mineral fibers: continuous filament glass fiber, glass wool and rock wool. Airborne fibers were counted by phase contrast microscopy (NIOSH 7400) and total dust was measured by weight. Bulk raw materials were checked for asbestos by polarized light microscopy.
• Main results:
  • No workplace exceeded the ACGIH threshold limit value of 1 fiber per cubic centimeter
  • No industry's average total dust exceeded the Korean limit of 10 mg/m3. Individually, three men at continuous filament user workplaces and five men in rock wool work exceeded it.
  • Rock wool industries had significantly higher airborne total dust than the other industries
  • By geometric mean fiber concentration, the rock wool industry was significantly higher than the industries using other MMMF (P<0.001)
  • Among continuous filament manufacturers, the sliver and mat processes had significantly higher fiber levels than other processes (P<0.05)
  • In glass wool manufacturing, molding had higher fiber levels than smelting and packing (P<0.05)
  • About 36-41% of total dust particles were 1-2 micrometers in size and 97-98% were under 10 micrometers
  • Fiber concentration and total dust concentration were only slightly correlated (r=0.398, P<0.05)
  • Bulk samples from all the industries showed no evidence of asbestos contamination
• The authors' conclusion: The authors concluded that, although fiber exposure levels were low in Korean industries making and using MMMF, it is desirable to measure MMMF fiber concentrations in workplace environmental monitoring
• Limitations the authors state:
  • Particle size was measured with a particle counting system only, so the results are not fully comparable with studies using electron microscopy

Topics

Medical terms in this study, explained in our Lexicon: Mineral Fiber, Vitreous, Silicate, Threshold Limit Value (TLV).

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