**3. Asbestos-related diseases**

**1. Introduction**

160 Occupational Health

factors.

It is becoming evident that both environmental and genetic factors may influence the development of many diseases [1–7]. It is therefore important to consider gene-environment interactions when studying diseases related to exposure to different hazards and lifestyle

Environmental and lifestyle factors have been investigated in many epidemiological studies using self-reported information obtained by questionnaires, interviews, records or measurements of exposure. However, very few epidemiological studies included the information on genetic risk factors. Similarly, many studies investigating genetic factors obtained little information on environmental factors and lifestyle. Genetic predisposition can be presumed from family history, from phenotypic characteristics (e.g. metabolic capacity) or, most impor-

The research into gene-environment interactions requires the information on both environmental/lifestyle and genetic factors [7, 8]. Primary candidates for gene-environment interaction studies have been mostly genes coding for xenobiotic-metabolising enzymes [3]. Genetic variability in these genes may lead to interindividual differences in the capacity for xenobiotic metabolism, thus modifying an individual's susceptibility to the development of disease [3].

The approach to the analysis of gene-environment interactions is presented using the example of our study into asbestosis, which is one of the most frequent asbestos-related diseases. According to the model of causation, asbestos exposure, genetic factors and possibly also unknown causes have a crucial role in the occurrence of asbestosis [9]. Although asbestosrelated diseases are among the most extensively studied occupational diseases, and the causal relationship between asbestos exposure and asbestosis has been well proved [10–14], relatively little has been known about the genetic factors that might modify an individual's susceptibility

Asbestos is a commercial name for a group of fibrous silicates with certain toxic properties, such as the ability to produce inflammation, fibrous scarring and cancer [18–20]. Based on their physical and chemical structures, asbestos fibres can be classified into two major groups:

Occupational exposure to asbestos occurs in asbestos mining, production and milling of asbestos fibres; in asbestos cement industry; in construction; in machine and insulation product industry; in ship building or repair; in car industry; in production of brakes and clutches; in car, bus, lorry, railway carriage and aeroplane repair; in asphalt mixing; in disposal of asbestos waste and materials; in brickworks; in textile industry and in other industries and activities

tantly, from an analysis of deoxyribonucleic acid (DNA) sequence [8].

to the development of this disease [6, 15–17].

**2. Asbestos exposure**

[20, 22, 26–28].

chrysotile and amphiboles [20–25].

Asbestos exposure has been associated with the development of asbestosis; pleural diseases, such as pleural plaques, diffuse pleural thickening and pleural effusion and several types of cancer: lung cancer, diffuse malignant mesothelioma of the pleura and peritoneum, cancer of the larynx, cancer of the ovary as well as the cancers of the buccal mucosa, the pharynx, the gastrointestinal tract and the kidney [11, 12, 16, 25, 29–41].
