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

Abstract 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

otorhinolaryngology and temporo-mandibular joint.

otorhinolaryngology and temporo-mandibular join

Exposure to Hydrogen Peroxide and Eye and Nose Symptoms Among Workers in a Beverage Processing Plant

Abstract OBJECTIVES: Two cross-sectional studies were undertaken on workers in a beverage processing plant to investigate the association between low H(2)O(2) exposure and symptoms of irritation (2005 study) and to investigate the effect of wearing respiratory protection (2006 study). METHODS: The study comprised 69 workers exposed to H(2)O(2) in sterile chambers and 65 unexposed controls. The exposure was assessed from measurements and work task information from employment records. The severity of work-related symptoms was evaluated using questionnaires. Data were analyzed by the Student's t-test, multiple linear regression and analysis of variance for repeated measures of symptoms. RESULTS: Symptoms of eye, nose and throat irritation were significantly (P < 0.001) more severe among exposed workers compared to controls. Exposure values were occasionally above American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value-time-weighted average (TLV-TWA) in the sterile chambers. The relationship between the severity of symptoms and the number of entrances in the chambers was significant (P < 0.0001) in 2005 but not in 2006, when respirators were used during work in the sterile chamber. No differences were found between exposed who entered a sterile chamber in 2005 but not in 2006 and exposed who entered a sterile chamber both in 2005 and 2006. This suggests that respirators provided an efficient protection and that the irritative effects of exposure to H(2)O(2) in 2005 did not disappear after 1 year. CONCLUSIONS: The source of risk was exposure in the sterile chamber, even though the time of exposure was generally only approximately 30 min. To ensure complete worker protection, there is a need for a short-term exposure limit for H(2)O(2) in addition to the existing ACGIH TLV-TWA value

N-3 fatty acids in patients with multiple cardiovascular risk factors

BACKGROUND: Trials have shown a beneficial effect of n-3 polyunsaturated fatty acids in patients with a previous myocardial infarction or heart failure. We evaluated the potential benefit of such therapy in patients with multiple cardiovascular risk factors or atherosclerotic vascular disease who had not had a myocardial infarction. METHODS: In this double-blind, placebo-controlled clinical trial, we enrolled a cohort of patients who were followed by a network of 860 general practitioners in Italy. Eligible patients were men and women with multiple cardiovascular risk factors or atherosclerotic vascular disease but not myocardial infarction. Patients were randomly assigned to n-3 fatty acids (1 g daily) or placebo (olive oil). The initially specified primary end point was the cumulative rate of death, nonfatal myocardial infarction, and nonfatal stroke. At 1 year, after the event rate was found to be lower than anticipated, the primary end point was revised as time to death from cardiovascular causes or admission to the hospital for cardiovascular causes. RESULTS: Of the 12,513 patients enrolled, 6244 were randomly assigned to n-3 fatty acids and 6269 to placebo. With a median of 5 years of follow-up, the primary end point occurred in 1478 of 12,505 patients included in the analysis (11.8%), of whom 733 of 6239 (11.7%) had received n-3 fatty acids and 745 of 6266 (11.9%) had received placebo (adjusted hazard ratio with n-3 fatty acids, 0.97; 95% confidence interval, 0.88 to 1.08; P=0.58). The same null results were observed for all the secondary end points. CONCLUSIONS: In a large general-practice cohort of patients with multiple cardiovascular risk factors, daily treatment with n-3 fatty acids did not reduce cardiovascular mortality and morbidity. Copyright © 2013 Massachusetts Medical Society