Chrysotile and rock wool fibers induce chromosome aberrations and DNA damage in V79 lung fibroblast cells

Abstract

According to global estimates, at least 107,000 people die each year from asbestos-related lung cancer, mesothelioma, and asbestosis resulting from occupational exposure. Chrysotile accounts for approximately 90% of asbestos used worldwide. Artificial substitutes can also be cytotoxic to the same degree as chrysotile. But only a few researchers focused on their genetic effects and mutagenicity information which is useful in evaluating the carcinogenicity of chemicals. In this study, chrysotile from Mangnai, Qinghai, China, and an artificial substitute, rock wool fiber were prepared as suspensions and were tested at concentrations of 50, 100, and 200 μg/ml in V79 lung fibroblasts. Chromosome aberrations were detected by micronucleus assay after exposure for 24 h, and DNA damage were estimated by single cell gel electrophoresis after exposure for 12, 24, or 48 h. According to the results, chrysotile and rock wool fibers caused micronuclei to form in a dose-dependent manner in V79 cells; olive tail moment values increased in a dose- and time-dependent manner. When V79 cells were exposed to a concentration of 200 μg/ml, the degree of DNA damage induced by chrysotile fibers was greater than rock wool fibers. Our study suggests that both chrysotile and rock wool fibers could induce chromosome aberrations and DNA damage. These materials are worthy of further study.

Occupational risk resulting from exposure to mineral wool when installing insulation in buildings

“…The main effect of mineral It is difficult to define precisely the boundary between the mixture in a solid form and the article, as with other substances and mixtures in the form of solids, but mineral wool producers usually treat these products as articles. Table 1 presents the obligations of producers marketing mineral wool, depending on the occurrence at the stage of the chemical substance, as a chemical mixture or an article, in the light of the REACH regulation [4] and the CLP regulation [5].…”

“…Recently, using a comet assay, Chinese researchers have shown that synthetic mineral fibers may be cytotoxic, although to a lesser extent than chrysotile asbestos [20]. Chinese studies have been evaluated by other scientists [21,22].…”

“…In addition, the biostability of mineral fibers in body fluids is less than the durability of asbestos fibers, and the crystal structure and durability of fibers are important factors affecting carcinogenic properties [3]. The lung half-life of mineral fibers with a length of >20 μm is <10 days [15,16], while insoluble amphibole fibers with IJOMEH 2020;33 6ic substance if it can be demonstrated that it meets 1 of the following 4 conditions [5]: -a short-term biopersistence test by inhalation has shown that fibers longer than 20 μm have a weighted half-life shorter than 10 days; or -a short-term biopersistence test by intratracheal instillation has shown that fibers longer than 20 μm have a weighted half-life shorter than 40 days; or -an appropriate intra-peritoneal test has shown no evidence of excess carcinogenicity; or -there have been no relevant pathogenicity or neoplastic changes in a suitable long-term inhalation test.…”

“…Note Q is based on biopersistence and toxicity studies, and Note R relates to the dimensions of fibers. Fibers meeting the conditions of Note Q are known as biosoluble [5]. According to Note Q, it is not required to classify mineral wool as a carcinogen-fibrosis.…”

“…Obligations of the producers of mineral wool depending on its recognition as a chemical substance, a chemical mixture or an article under the REACH and CLP regulations[4,5] …”