Eyes and airways symptoms at low occupational exposure to toluene diisocyanate

In English Objectives Exposure to diisocyanates is a well known occupational hazard. The objective of this study was
to determine the possibility of an association between low exposure to toluene diisocyanate (TDI) (airborne
isocyanates and biomarkers of isocyanates in plasma and urine) and symptoms of the eyes and upper and lower
airways.
Methods Altogether 136 workers occupationally exposed to TDI and 118 unexposed employees were studied.
A physician compiled thorough medical and occupational histories and registered symptoms, total and workrelated,
of the eyes, nose, and lower airways. The exposure was assessed with personal air measurements and
with biomarkers of exposure in plasma and urine. The average exposure in the ambient air at the workplace of
the exposed participants was below 1 ppb.
Results Compared with the unexposed group, the exposed workers reported more total symptoms of the eyes
and lower airways, as well as nose bleeding. A similar pattern, with even higher odds ratios, was observed for
work-related symptoms. However, only eye symptoms proved to be significantly associated with the exposure,
notably with all of the exposure measures. The risk was more pronounced for exposure to 2,4-TDI than for
exposure to 2,6-TDI.
Conclusions Even very low exposure to TDI is related to negative health effects on exposed workers. Clear
dose–response relationships were observed between three different measures of exposure and symptoms of the
eyes.