The Association Between Dimethylacetamide Exposure and Liver Toxicity:A Large Retrospective Analysis in Workers From Four European Factories

Objective: This study examines the association between 8-h time weighted N, N-dimethylacetamide (DMAc) air exposure and potential hepatocellular injury in a retrospective study among fibre-production workers in four European factories. Methods and Results: Twenty-nine (1.5%) of 1844 alanine aminotransferase (ALT) observations had liver values two times above normal; 0.2% three times above normal and 0.05% five times above normal. Two (0.1%) observations were indicative of hepatocellular injury. Logistic regression analyses showed an odds ratio for elevated ALT of 0.88 per 1 ppm (P trend = 0.39). Linear random effects regression analyses showed a decrease of one international unit (IU/L) ALT per 1 ppm increase of DMAc exposure (P = 0.002). Conclusions: This study found no association between DMAc exposure and hepatoxicity amongst European workers. The prevalence of elevated liver values was lower compared to the general population without occupational exposure

An evaluation of concentrations of styrene-7,8-oxide in rats and humans resulting from exposure to styrene or styrene-7,8-oxide and potential genotoxicity.

There is potential for oral exposure of humans to styrene (ST) such as from migration of residual levels in polystyrene food containers. After absorption, ST is metabolised to styrene-7,8-oxide (SO), an alkylating epoxide. Hence, a comparison of blood burdens of SO resulting from oral exposures to ST was made with SO burdens possibly warranting genotoxic concern. A validated physiological toxicokinetic model was used for the assessment. Model calculations predicted for exposures to ST that maximum concentrations of SO in venous blood of rats and humans should not exceed 0.33 mg/ml and 0.036μg/ml, respectively, because of saturation of the SO formation from ST. The daily area under the concentration-time curve of SO in venous blood (AUCSO) was directly proportional to the dose of ST (mg/kg body weight; BW), independent of the exposure route (inhalation or oral exposure). In resting humans, the daily AUCSO was about half that in rats at the same amount of ST/kg BW (calculated up to 100mg ST/kg BW in humans). Taking into account the results of cytogenetic studies in ST-exposed rats, it was deduced that no genotoxic effects of SO are to be expected in ST-exposed humans, at least up to a daily amount of 100mg ST/kg BW, which is equivalent to 100 times the amount originating from the Overall Migration Limit for ST migrating from food contact plastics in the EU. Therefore, no potential genotoxic concern is predicted for ST uptake from food packaging, based on the reported combined measured and modelled data

The Association Between Dimethylacetamide Exposure and Liver Toxicity: A Large Retrospective Analysis in Workers From Four European Factories

Objective: This study examines the association between 8-h time weighted N, N-dimethylacetamide (DMAc) air exposure and potential hepatocellular injury in a retrospective study among fibre-production workers in four European factories. Methods and Results: Twenty-nine (1.5%) of 1844 alanine aminotransferase (ALT) observations had liver values two times above normal; 0.2% three times above normal and 0.05% five times above normal. Two (0.1%) observations were indicative of hepatocellular injury. Logistic regression analyses showed an odds ratio for elevated ALT of 0.88 per 1 ppm (P trend = 0.39). Linear random effects regression analyses showed a decrease of one international unit (IU/L) ALT per 1 ppm increase of DMAc exposure (P = 0.002). Conclusions: This study found no association between DMAc exposure and hepatoxicity amongst European workers. The prevalence of elevated liver values was lower compared to the general population without occupational exposure