Asbestos has been well documented to be a carcinogen and co-carcinogen associated with the induction of mesothelioma, lung cancers and other benign lung diseases [1, 2]. 'Asbestos' is a generic term for a group of six naturally occurring fibrous silicate minerals. It is grouped into two major classes: Serpentine, which contains a magnesium silicate called chrysotile and Amphibole, which includes crocidolite, amosite, anthophyllite, actinolite and tremolite . Asbestos has been used in more than 3,000 products because of its high tensile strength, relative resistance to acid and temperature, varying textures and degrees of flexibility. It does not evaporate, dissolve, burn, or undergo significant reactions with other chemicals, which make asbestos non-biodegradable and environmentally cumulative. Over 95% of the total commercial asbestos use all over the world is chrysotile asbestos . Chrysotile has the morphology of being curly and pliable . Size, geometry, chemical composition and surface charge of various asbestos types play an important role in interactions with cells that lead to cell injury and disease [6, 7]. Respiratory impairment, bronchial asthma, chronic bronchitis was noticed in asbestos cement factory workers . However, in the case of chrysotile asbestos, its positive surface charge is more important than its morphology in rendering a toxic and lytic potential . The iron content in chrysotile, primarily present as a surface contaminant  is low (~1–6%), but has to be considered in its toxicity.
Asbestos fibres in the environment can result from mining, milling and weathering of asbestos-bearing rocks, and from the manufacture, wear, and disposal of asbestos-containing products . Because of the widespread use of asbestos, its fibres are ubiquitous in the environment. Indoor air can become contaminated with fibres released from building materials, especially if they are damaged or crumbling. Common sources of asbestos in homes are ceilings, pipe insulation, boiler coverings, wallboard, floor, ceiling tiles, sheets, pipes and jointings, etc. Asbestos-cement products, e.g. roof tiles, contain as much as 11–12% of chrysotile asbestos. As a result of continuing exposure to the weather and to acid rain, the surface of asbestos-cement products becomes corroded and weathered. Cement particles, asbestos fibres and agglomerates of particles and fibres are therefore released from the surface and may be dispersed in air and water in large amounts .
The toxicity of asbestos is characterized by a number of processes, among which the production of reactive oxygen and reactive nitrogen species (ROS and RNS) are thought to be the most important ones. Highly reactive oxygen species such as the hydroxyl radical can be produced through Fenton-type reaction catalysed by iron impurities present on the surface. ROS/RNS are also produced in the lungs by the chronic inflammatory reaction produced by the prolonged phagocytic activity of macrophages against the bio-persistent fibres . ROS/RNS can cause various types of DNA damages. The most extensively studied are lesion of 8-oxodeoxyguanosine (8-oxodGuo) or the corresponding base (8-oxoGua). These altered nucleotides can be detected in the DNA of cell lines of human or animal origin after treatment with asbestos fibres [13, 14].
Smailyte et al.  analyzed the cancer risk in Lithuanian cement producing workers and found that exposure to cement dust may increase lung and bladder cancer. He further reported a dose related risk for stomach cancer. Fatima et al.  have reported chromosomal abnormalities in asbestos cement factory workers. Rahman et al.  found chromosomal aberrations, sister chromatid exchanges and micronuclei formation in the blood lymphocytes of asbestos cement factory workers in comparison to their controls. Dušinská et al.  investigated chromosomal and DNA damage in former asbestos cement plant workers. As discussed above chrysotile is the most commercially exploited variety of asbestos and mostly used as asbestos-cement for building material. There are not many studies that assess the cyto- and genotoxicity of asbestos cement in vitro using cell lines. In the present study, we have investigated if asbestos-cement causes similar effects in cellular systems regarding cytotoxicity and genotoxicity than chrysotile asbestos. The micronucleus assay was applied to test the genotoxic effects of asbestos cement in V79-cells (Chinese hamster lung cells), an established cell culture model. Application of kinetochore analysis, radical measurements and iron chelator experiments gave more informations about the mechanistic background, which seems to be based on the formation of free radicals.