A Dose-Response Relationship in TDI Workers

Our plain-English summary of A Dose-Response Relationship in TDI Workers, by D.H. Wegman, L.D. Pagnotto, L.J. Fine, et al (1974).

The study

• Authors: D.H. Wegman, L.D. Pagnotto, L.J. Fine, J.M. Peters
• Published: Journal of Occupational Medicine:16(4)258-260, April (1974)
• Type of article: Journal article
• Our copy: from Johns-Manville's own medical library. The article is still under copyright, so we describe it here rather than post it.

In plain English

This article concerns toluene diisocyanate (TDI), a chemical used in making polyurethane foam, not asbestos. The authors tested all 111 first-shift production workers (78 men, 33 women) at a firm making polyurethane for mattresses and auto seat cushions. On a Monday in early November 1972, each worker's breathing was measured with a spirometer before work and again after eight hours on the job. Measured TDI exposures ranged from 0.002 ppm to 0.013 ppm, and workers were sorted into four exposure groups. In every group, the average change over the shift in FEV1 (the air blown out in one second) was a significant loss, including at 0.002 ppm. The losses appeared to grow with exposure. In a regression analysis, TDI exposure was the only significant predictor among the variables tested, which included age, height, smoking and duration of exposure. Workers who reported symptoms such as cough or phlegm showed larger drops, but none of these differences was statistically significant. The authors concluded that their data support a dose-response relationship between TDI exposure and acute respiratory effect.

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 field study of one workplace, with lung function measured before and after a single work shift and compared across workplace air-sampling exposure levels
• Who was studied: All 111 first-shift production workers (78 males, 33 females) at a firm using TDI to make polyurethane for mattresses and auto seat cushions. They were examined on a Monday after three days away from work, in early November 1972. The plant's location is not stated in the readable text.
• Exposure: Toluene diisocyanate (TDI). Air was sampled by the Marcali method and each worker was assigned the measured mean concentration for his or her job area. Exposures ranged from 0.002 to 0.013 ppm, and workers were grouped into four exposure groups.
• Main results:
  • For each of the four exposure groups, the mean change in FEV1 over the shift was significantly different from zero. The authors state that all groups, including those exposed to as little as 0.002 ppm TDI, showed acute loss of lung function.
  • The mean change in FEV1 across the four exposure groups suggested a dose-response relationship.
  • In a stepwise regression including age, height, years smoked, cigarettes smoked, duration of exposure in months and TDI dose, the magnitude of TDI exposure was a significant variable.
  • The text describes TDI exposure as the only significant variable in that regression.
  • Workers who reported each respiratory symptom (wheezing, breathlessness, cough, phlegm) showed a greater drop in FEV1 than those without it, but none of these differences was statistically significant.
  • Mean FEV1 loss showed no trend by age, years of cigarette smoking, duration of employment or smoking history.
• The authors' conclusion: The authors concluded that their data support a dose-response relationship between TDI exposure and acute respiratory effect.

Topics

Medical terms in this study, explained in our Lexicon: Dose-response relationship, FEV1.

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