Eye and airway symptoms in low occupational exposure to toluene diisocyanate.
OBJECTIVE
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 work-related, 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.
Littorin
Margareta
M
Department of Occupational and Environmental Medicine, University Hospital, Lund, Sweden. margareta.littorin@med.lu.se
Axmon
Anna
A
Broberg
Karin
K
Sennbro
Carl-Johan
CJ
Tinnerberg
Håkan
H
D000328:Adult; D000395:Air Pollutants, Occupational / Q000009:adverse effects; D015415:Biomarkers; D003430:Cross-Sectional Studies; D004306:Dose-Response Relationship, Immunologic; D005128:Eye Diseases / Q000139:chemically induced* / Q000276:immunology / Q000503:physiopathology; D005260:Female; D006801:Humans; D017953:Isocyanates; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D012141:Respiratory Tract Infections / Q000139:chemically induced* / Q000276:immunology / Q000503:physiopathology; D013548:Sweden; D014051:Toluene 2,4-Diisocyanate / Q000009:adverse effects* / Q000097:blood / Q000302:isolation & purification / Q000652:urine
D000395:Air Pollutants, Occupational; D015415:Biomarkers; D017953:Isocyanates; D014051:Toluene 2,4-Diisocyanate