Australië en Nieuw Caledonia: natuurlijke asbestvindplaatsen in kaart
21-02-2007Binnenkort worden in Australië en op het Franse pacific eiland Nieuw Caledonia de natuurlijke asbestvindplaatsen in kaart gebracht. Onlangs meldde een onderzoek dat mesothelioom op het eiland Nieuw Caledonia 10 x vaker voorkomt dan in Frankrijk. Bekend is dat asbest in nikkelmijnen voorkomt, maar niet waar precies en in welke concentratie. Australië had vroeger asbestmijnen. In 2005 liet een Amerikaans onderzoek zien dat naarmate mensen dichter bij een natuurlijke asbestvindplaats wonen het risico op longvlieskanker (pleuraal mesothelioom) groter is. Bron: Hobart Mercury, 16 januari 2007. Baumann F. et al. (2007). Pleural mesothelioma in New Caledonia: An acute environmental concern. Cancer Detect Prev. 2007.31(1):70-6.
Baumann F, Rougier Y, Ambrosi JP, Robineau BP (2007). Pleural mesothelioma in New Caledonia: An acute environmental concern. Cancer Detect Prev. 2007.31(1):70-6.
Abstract
Background: In 1991, a relationship was established between excess cases of pleural cancer in New Caledonia and a traditional lime, called “Po”, to cover houses. Our study aimed to determine whether the Po is the only cause of mesothelioma in New Caledonia.
Methods: Eligible cases were pleural tumor diagnosed between 1984 and 2002 with histological diagnosis of mesothelioma. For each case, two controls were selected from the cancer registry. Cases and controls were compared for the ethnic groups and the places of residence. To identify environmental risk factors, we used first a qualitative analysis comparing villages with and without mesothelioma cases, then a linear regression including Po, mining activity and serpentinite in surface soil.
Results: Sixty-eight cases were included: 37 men and 31 women. Melanesians had the highest risk (OR=16.18. 95% CI=[5.68. 49.64]) and 30% of the cases lived in Houailou (OR=119). Mining activity and Po were not significant risk factors. The existence of a significant relationship between soil containing serpentinite and mesothelioma was demonstrated (p=0.017). The sex ratio close to 1 and the number of young cases are consistent with environmental exposure.
Conclusion: Po did not explain all cases. only serpentinite in the soil was identified as a significant risk factor. A research project has been initiated in the area around Houailou, with the objective of constructing a model taking into account: exposure to the Po, exposure to airborne pollution by asbestos fibres at the place of residence, and occupational exposure. Epidemiological and geological investigations are underway