Exposure to hydrogen peroxide at TLV level does not induce lung function changes: a longitudinal study.

This study reports on longitudinal changes in lung function using spirometry of employees at a beverage processing plant, where exposure information (1995-2001) suggests that the threshold limit value (TLV)-Time Weighted Average (TWA) of 1 ppm was not likely exceeded. Changes over time in lung function (Forced Expiratory Volume of 1st second, FEV1; Forced Vital Capacity, FVC; and FEV1/FVC ratio; all expressed as percent of the predicted) were evaluated by using sparse lung function data obtained from 1993 to 2002 in 43 exposed and 31 unexposed workers. The longitudinal changes were assessed using multiple regression analysis where the dependent variable was the annual change of lung function indices and the independent variables were exposure and smoking habits. With regard to exposure, FVC increased, FEV1 was unchanged, and the FEV1/FVC ratio tended to decrease. The latter difference was not significant when FVC was used as a covariate. The FEV1 is significantly worse in smokers than in non-smokers. These data suggest that no lung function changes occur when the H2O2 levels were compliant to the exposure standard. Our findings support the current TLV-TWA of 1 ppm for H2O2.