Evaluation of potential gastrointestinal carcinogenicity associated with the ingestion of asbestos

Mechanisms of action of mineral fibres in a placental syncytiotrophoblast model: An in vitro toxicology study

Asbestos has been widely used due to its unique characteristics. It is known that exposure to asbestos causes serious damage to health but one species, chrysolite, is still used because it is considered less toxic and not biopersistent in some countries. The aim of our study was to investigate if cellular process underlying the proliferation, differentiation and cell death of placental tissues could be modify in presence of asbestos fibres (50 μg/ml final concentration), long chrysolite fibres (CHR-L) and short chrysolite fibres (CHR-S), using BeWo cell line, an in vitro model that mimics the syncytiotrophoblast (STB), the outer layer of placental villi. Our data demonstrated that none of the fibres analysed alter syncytiotrophoblast formation but all of them induce ROS formation and reduced cell proliferation. Moreover, we showed that only CHR-L fibre induced was able to induce irreversible DNA alterations that carried cells to apoptosis. In fact, BeWo cells exposed to CHR-L fibre showed a significant increase in cleaved CASP3 protein, a marker of apoptosis. These data suggest that CHR-L may induce death of the placental villi leading to impaired placental development. The impairment of placental development is the basis of many gestational pathologies such as preeclampsia and intrauterine growth retardation. Since these pathologies are very dangerous for foetal and maternal life, we suggest to the gynaecologists to carefully evaluate the area of maternal residence, the working environment, the food used, and the materials used daily to avoid contact with these fibres as much as possible.

Attributable Fraction of Cancer Related to Occupational Exposure in Italy

BACKGROUND

Exposure to occupational carcinogens is an important and avoidable cause of cancer. We aimed to provide an evidence-based estimate of the burden of occupation-related cancers in Italy.

METHODS

The attributable fraction (AF) was calculated based on the counterfactual scenario of no occupational exposure to carcinogens. We included exposures classified as IARC group 1 and with reliable evidence of exposure in Italy. Relative risk estimates for selected cancers and prevalences of exposure were derived from large-scale studies. Except for mesothelioma, a 15-20-year latency period between exposure and cancer was considered. The data on cancer incidence in 2020 and mortality in 2017 in Italy were obtained from the Italian Association of Cancer Registries.

RESULTS

The most prevalent exposures were UV radiation (5.8%), diesel exhaust (4.3%), wood dust (2.3%) and silica dust (2.1%). Mesothelioma had the largest AF to occupational carcinogens (86.6%), followed by sinonasal cancer (11.8%) and lung cancer (3.8%). We estimated that 0.9% of cancer cases (N~3500) and 1.6% of cancer deaths (N~2800) were attributable to occupational carcinogens in Italy. Of these, about 60% were attributable to asbestos, 17.5% to diesel exhaust, followed by chromium and silica dust (7% and 5%).

CONCLUSIONS

Our estimates provide up-to-date quantification of the low, but persistent, burden of occupational cancers in Italy.

Management of Asbestos Containing Materials: A Detailed LCA Comparison of Different Scenarios Comprising First Time Asbestos Characterization Factor Proposal

This work addresses the complex issue of asbestos containing materials (ACMs) management, by focusing on the scenario of six municipalities comprised in the Reggio Emilia province of Emilia Romagna Italian region. Particularly, the life cycle assessment (LCA) methodology was applied in order to assess in a quantitative and reliable manner the human toxicity as well as the ecotoxicity impacts associated with all of the different phases of ACMs management. The latter comprises mapping of ACMs, creation of a risk map for defining priority of intervention, encapsulation and removal of ACMs, as well as the as obtained asbestos containing waste (ACW) end of life. Particularly, a thermal inertisation treatment performed in a continuous industrial furnace was considered as the innovative end of life scenario to be compared with what actually was provided by the legislation of many countries worldwide, that is, the disposal of ACW in a controlled landfill for hazardous wastes. A characterization factor for asbestos fibers released both in outdoor air and in occupational setting was proposed for the first time and included in the USEtox 2.0 impact assessment method. This allowed us to reliably and quantitatively highlight that inertisation treatments should be the preferred solutions to be adopted by local and national authorities, especially if the obtained inert material finds application as secondary raw materials, thus contributing to a decrease in the environmental damage (limited to its toxicological contributions) to be associated with asbestos management.