Exposure, lung function, and symptoms in car painters exposed to hexamethylendiisocyanate and biuret modified hexamethylendiisocyanate

Individuals who paint cars often complain to doctors about respiratory problems. Car painters are exposed to isocyanates, especially hexamethylendiisocyanate (HDI), and biuret modified HDI (HDI-BT). The mean exposure to HDI-BT was 115 micrograms/m3 in the air (range 10-385 micrograms/m3), which exceeds the time-weighted Swedish threshold level of 90 micrograms/m3. Exposure to HDI was about 1.0 microgram/m3 with brief peaks. This study investigated the effect of HDI and HDI-BT on lung function and included two control groups: (1) car platers, exposed to the same solvents and grinding dust as car painters, but not to isocyanates, and (2) car mechanics (controls), not exposed to the mentioned agents. Car painters and car platers were compared to car mechanics on Monday before work. Acute effects of car painting were tested by comparing the lung function values on Monday morning with those on Friday afternoon. Pulmonary function was evaluated by means of spirometry and a single breath nitrogen washout. Spirometry in painters and platers did not differ from that in controls, i.e., car mechanics. Closing volume in relation to vital capacity (CV%) was increased in car painters, suggestive of a "small airways disease" on Monday before work and tended to increase during a work week. Car platers did not differ from controls.