Asbestos and Mesothelioma
Asbestos counts ranged between 0.0244 - 0.1389 f/cc in the surrounding areas of the ORA-Egypt company in the 10th of Ramadan City, which has been shut down since 2004. Malignant pleural mesothelioma (MPM) is becoming an increasing problem in Egypt. MPM is related to the inhalation of asbestos fibres in low counts and is incurable when diagnosed. According to official registry data, most MPM cases were living close to asbestos production companies. Mesothelioma incidence was analyzed and studied in the available data during the period 1984-2005. Mesothelioma incidences increased from 159 cases during 1984 - 1999 to 733 cases during 2000 - 2005. The age of the patients ranged between 17 to 90 years with a mean age of 54 years.
The survival age varied between 6 to 15 months with median survival was approximately 1 year from diagnosis. Females represented ~39 % of the cases and males represented ~ 60% with male to female ratio of ~1.7.
Asbestos is a naturally occurring family of minerals formed by the combination of magnesium and silicon that have a strong fibrous and crystalline structure. Serpentine and amphibole are the main groups of asbestos. Serpentine includes only chrysotile, while amphibole contains amosite, actinolite, anthophyllite, crocidolite and tremolite (ATSDR, 2001). Chrysotile is the common asbestos type used and accounts for 95% of the world’s production (Smith and Wright, 1996). Asbestos has been recognized in Egypt for a long time as it was used by Egyptians for mummification (Abratt et al., 2004).
Industrialization utilizing asbestos started in Egypt in 1948 by Sigwart El-Maasara Company in south Cairo, after which 14 asbestos factories were presented by the year 2004 (Allen, 2006). Asbestos has been recognized as a health hazard in industrial workplaces (Selikoff and Lee, 1978) and inhalation of asbestos fibres can cause asbestosis, lung cancer, bronchogenic carcinoma and mesothelioma (Hughes, 2005).
Mesothelioma is a cancer arising from the mesothelial cells that line the pleural, pericardial and peritoneal surfaces (Carbone et al., 2002). Mesothelioma occurs in selected individuals among population groups, with known exposure to asbestos either in the workplace or in the community. Di Maria and Comba (2004) have reported that most persons exposed to asbestos inhalation do not develop mesothelioma, whereas others are affected by mesothelioma in the absence of association with previous occupational or environmental exposure to asbestos.
Malignant mesothelioma is a rare neoplasm that could be favored by a hereditary predisposing factor such as Ehlers-Danlos syndrome and Marfan’s syndrome (Bisconti et al., 2000). Genetic predisposition to mineral fibre carcinogenesis has led to an epidemic of mesothelioma in Turkey and some US families (Roushdy-Hammady et al., 2001; Dogan et al., 2006).
In the United States there are 2 500 cases and deaths per year of malignant mesothelioma which is often related to asbestos exposure (Carbone et al., 2007). Mesothelioma incidence rates are predicted to increase dramatically in developing countries due to poor regulation of asbestos mining and proliferation of industrial and household utilization of asbestos (Giaccone, 2002).
Mesothelioma continues to be a global problem due to ongoing exposure to fibres and as a legacy from past exposure to asbestos, even in countries where asbestos is currently banned or has been regulated-out of use for decades (McElvenny et al., 2005). Mesothelioma is an increasing problem in Egypt (Eldin and Mourad, 2003) and the incidence of mesothelioma is rising (Gaafar and Eldin, 2005). Epidemiological and environmental studies regarding exposure-response relationships between asbestos fibre counts and mesothelioma rates are lacking in Egypt. This review aims to present the current available data of airborne asbestos fibre counts and mesothelioma cases in the last 20 years in Egypt.
