Greece: Whitewash over asbestos

The local residents of Metsovo northwestern Greece have unwittingly brought fame to their small town by following the traditional practice of whitewashing their homes. The whitewash they used was made from local soil called luto which was crushed, boiled and applied to the walls. However, even though exposure was brief, at most three times a year, it had serious detrimental health effects. The soil was contaminated with tremolite, a type of asbestos, and large amounts of fibres were released and inhaled, leading to a high prevalence of disease.

Almost half of the town's population developed pleural calcifications (PCs) around the lungs and a very high proportion (about 300 times that expected from the general population) succumbed to malignant pleural mesothelioma (MPM), a deadly cancer. For MPM, death usually follows within one year of diagnosis. The condition was named Metsovo lung and it was later discovered in other areas of Greece in which asbestos-containing soil was converted into household whitewash.

The use of luto has now been phased out and the incidence of PCs and MPM has declined over the last 20 years. However, the link between the development of PCs and MPM remains intriguing. It appears that sufferers who developed PCs were less likely to contract MPM, suggesting that they confer some kind of protection. This link has been investigated by a 10-person team from the Universities of Ioannina in Greece and Siena in Italy and the data have been published in the Journal of Proteome Research, with senior author Luca Bini from Siena.

The team collected bronchoalveolar lavage fluid (BAL) from residents of Metsovo with and without PCs, as well as samples from control subjects living in a different area. All Metsovites had used luto for decades. The fluids were subjected to proteomics analysis to try and identify proteins that were involved in the reaction to fibre exposure in both disease states: MPM with and without PCs.

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