Objective: The aim of this study was to describe a study of medical monitoring methods and lessons learned in detecting health outcomes in U.S. plants producing toluene diisocyanate (TDI). Methods: A multidisciplinary team implemented a medical and environmental monitoring program in three TDI plants. Results: Of 269 eligible workers, 197 (73%) participated and 42 (21%) met symptom and/or lung function criteria that would trigger evaluation for possible asthma over 5 years of data collection. Subsequent evaluation was delayed for most, and a web-based data collection system improved timeliness. Conclusion: Medical monitoring of TDI workers identified workers triggering further assessment per study protocol. Systems and/or personnel to ensure rapid follow-up are needed to highlight when triggering events represent potential cases of asthma needing further evaluation. Implementation of a research protocol requires resources and oversight beyond an occupational health program.

Objective: This study examines asthma risk in facilities producing toluene diisocyanate (TDI). Methods: A total of 197 workers were monitored from 2007 to 2012. TDI air concentrations were used to estimate exposures. Results: The incidence of cases consistent with TDI-induced asthma was 0.009 per person-years (seven cases) or consistent with TDI-induced asthma or asthma indeterminate regarding work-relatedness was 0.012 (nine cases). Increased risk of cases consistent with TDI asthma was observed for cumulative (odds ratio [OR] = 2.08, 95% confidence interval [CI] 1.07 to 4.05) per logarithm parts per billion-years and peak TDI exposures (OR = 1.18, 95% CI 1.06 to 1.32) (logarithm parts per billion). There was a weak association with cumulative and peak exposures for decline of short-term forced expiratory volume in one second (FEV1). Asthma symptoms were associated with workers noticing an odor of TDI (OR 6.02; 95% CI 1.36 to 26.68). Conclusions: There is evidence that cumulative and peak exposures are associated with TDI-induced asthma.

OBJECTIVE:The aim of this study was to investigate lung function among toluene diisocyanate (TDI) production workers.METHODS:One hundred ninety-seven U.S workers performed spirometry from 2006 through 2012. Results were compared within the study cohort and with U.S. population measures. A mixed-effects model assessed factors affecting repeated forced expiratory volume in 1 second (FEV1) measurements.RESULTS:The cohort's mean FEV1 and forced vital capacity (FVC) percent reference values, although greater than 90%, were significantly lower and the prevalence of abnormal spirometry (predominantly restrictive pattern) was significantly higher than in the U.S.POPULATION:Differences in lung function among workers with higher cumulative TDI exposure were in the direction of an exposure effect, but not significant.CONCLUSION:We found little evidence of an adverse effect of TDI exposure on longitudinal spirometry in these workers. The association between TDI exposure and the increasing prevalence of a restrictive pattern needs further exploration.

Authors: E. Bray, RN; and P.R. Conner, MD Presenting Author: Eileen Bray, RN; Occupational Care Management Nurse; BASF Corporation; Mt. Olive, NJ

Communication to workers of epidemiology study results is gaining increasing emphasis because of the need to notify study subjects and the responsibility to warn workers of potential workplace hazards. Industry has a unique responsibility in this regard both for ethical reasons and for gains in improving workers' knowledge of workplace hazards. We describe our recent efforts to notify 9648 workers potentially interested in the results of an epidemiology study that found increased rates for cancer. We found that both study and nonstudy subjects were equally interested the findings. We conclude that most workers view the notification as evidence of the company's commitment to maintain a safe workplace, and are pleased that the company undertook the study and reported the results to them. Unfavorable comments comprised less than 1% of the responses.

Epidemiologic studies on dioxin, specifically 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), have not consistently found an increased cancer risk. This study examines mortality rates for 754 employees at a chemical plant after an accident in 1949 in which 122 workers developed chloracne from high exposure to TCDD. We also examined exposure to 4-aminobiphenyl, a potential bladder carcinogen. Although the numbers are small, and confounding factors cannot be ruled out, workers exposed to 4-aminobiphenyl who developed chloracne from the accident had increased mortality rates from soft tissue sarcoma, bladder cancer, and respiratory cancer. All soft tissue sarcomas occurred among workers with potential 4-aminobiphenyl exposure, whereas no soft tissue sarcomas occurred among workers with TCDD exposure alone. In these workers, exposure to TCDD alone at levels great enough to cause chloracne was not associated with increased cancer rates.