Metsovo lung was an epidemic of lung disease resulting from domestic exposure to

asbestos Asbestos () is a naturally occurring fibrous silicate mineral. There are six types, all of which are composed of long and thin fibrous crystals, each fibre being composed of many microscopic "fibrils" that can be released into the atmosphere b ...

in the village of

Metsovo Metsovo ( el, Μέτσοβο; rup, Aminciu) is a town in Epirus, in the mountains of Pindus in northern Greece, between Ioannina to the west and Meteora to the east. The largest centre of Aromanian (Vlach) life in Greece, Metsovo is a large re ...

in northwest Greece. Most of the inhabitants had previously been exposed to a

whitewash Whitewash, or calcimine, kalsomine, calsomine, or lime paint is a type of paint made from slaked lime ( calcium hydroxide, Ca(OH)2) or chalk calcium carbonate, (CaCO3), sometimes known as "whiting". Various other additives are sometimes used ...

derived from local soils containing

tremolite Tremolite is a member of the amphibole group of silicate minerals with composition: Ca2(Mg5.0-4.5Fe2+0.0-0.5)Si8O22(OH)2. Tremolite forms by metamorphism of sediments rich in dolomite and quartz. Tremolite forms a series with actinolite and ferro ...

asbestos. This caused an epidemic of

malignant mesothelioma Mesothelioma is a type of cancer that develops from the thin layer of tissue that covers many of the internal organs (known as the mesothelium). The most common area affected is the lining of the lungs and chest wall. Less commonly the lining ...

(MM) that reached an incidence 300 times that expected in populations not exposed to asbestos. This was accompanied by pleural

calcification Calcification is the accumulation of calcium salts in a body tissue. It normally occurs in the formation of bone, but calcium can be deposited abnormally in soft tissue,Miller, J. D. Cardiovascular calcification: Orbicular origins. ''Nature Mat ...

s (PCs) in almost half the adult population. Both conditions have declined significantly since the whitewash ceased to be used after 1985.

Locally high rate of PCs

In the early 1980s when the Medical School of

Ioannina Ioannina ( el, Ιωάννινα ' ), often called Yannena ( ' ) within Greece, is the capital and largest city of the Ioannina regional unit and of Epirus, an administrative region in north-western Greece. According to the 2011 census, the c ...

was established, a group of pneumonologists headed by S.H. Constantopoulos started encountering, almost on a daily basis, X-ray images with extensive PCs in inhabitants of Metsovo. The researchers were told that this was very common to Metsovites and was the result of old tuberculous

pleurisy Pleurisy, also known as pleuritis, is inflammation of the membranes that surround the lungs and line the chest cavity (pleurae). This can result in a sharp chest pain while breathing. Occasionally the pain may be a constant dull ache. Other sy ...

. However, since the picture was not even remotely similar to calcified pleurisy from previous tuberculosis, they began to investigate the precise frequency of PCs, whether their abnormal incidence was in fact confined to Metsovites, and their true cause. In a field study in Metsovo and other areas around Ioannina, it was confirmed that PCs were very common among Metsovites, around 50% of adult population, increasing to more than 80% in those above 70; and that they were seen only in Metsovo and three neighbouring villages.

Relation to asbestos

The relation to asbestos was identified when, a few months later, two consecutive patients appeared with massive

pleural effusion A pleural effusion is accumulation of excessive fluid in the pleural space, the potential space that surrounds each lung. Under normal conditions, pleural fluid is secreted by the parietal pleural capillaries at a rate of 0.6 millilitre per kilog ...

s that proved to be malignant mesothelioma. These were only the first of a series of mesotheliomas; seven in five years (1981–1985). This rate is roughly 300-times that expected in a non-asbestos exposed community. The combination of PCs and MM can only be attributed to asbestos exposure.Dennis J. Darcey and Tony Alleman. Occupational and environmental exposure to asbestos. In: Victor L. Roggli, Tim D. Oury and Thomas A. Sporn (Eds). Pathology of asbestos-associated diseases. 2nd edition, Springer Verlag 1992; p. 17-33 Transbronchial lung biopsies from Metsovites with extensive PCs were then obtained and sent to Mount Sinai Hospital in New York (doctors A. Langer and R. Nolan). Their analysis revealed long thin tremolite asbestos fibers in most biopsies in spite of their minuscule size.Langer AM, Nolan RP, Constantopoulos SH, Moutsopoulos HM. Association of Metsovo lung and pleural mesothelioma with exposure to tremolite-containing whitewash. Lancet i, 1987; April 25: 965-967Constantopoulos SH, Langer AM, Saratzis N, Nolan RP. Regional findings in Metsovo lung. Lancet ii, 1987; 452-453

Source of asbestos

The possibility of this exposure being occupational seemed very unlikely, as there are no asbestos mines or factories near Metsovo. The nearest such mine (active until 1990) is located near

Kozani Kozani ( el, Κοζάνη, ) is a city in northern Greece, capital of Kozani (regional unit), Kozani regional unit and of Western Macedonia. It is located in the western part of Macedonia (Greece), Macedonia, in the northern part of the Aliakmona ...

, a city 150 miles east of Metsovo. Guided by previous research by Izzetin Baris dealing with not-occupational (domestic) exposure of vast areas in

Anatolia Anatolia, tr, Anadolu Yarımadası), and the Anatolian plateau, also known as Asia Minor, is a large peninsula in Western Asia and the westernmost protrusion of the Asian continent. It constitutes the major part of modern-day Turkey. The re ...

(Turkey) from

erionite Erionite is a naturally occurring fibrous mineral that belongs to a group of minerals called zeolites. It usually is found in volcanic ash that has been altered by weathering and ground water. Erionite forms brittle, wool-like fibrous masses in t ...

and tremolite,Baris YI, Saracci R, Simonato L, Skidmore JW, Artvinli M. Malignant mesothelioma and radiological chest abnormalities in two villages in central Turkey. Lancet 1981; 1: 984-987Baris ΥΙ, Sahin AA, Ozesmi M, Kerse I, Ozen E, Kolacan B, Altinorrs M, Goktepeli A. An outbreak of pleural mesothelioma and chronic fibrosing pleurisy in the village of Karain/Urug in Anatolia. Thorax 1978; 33: 181-192 the researchers arranged a meeting with Metsovites where they were told that practically all households in Metsovo were using soil from nearby hills (white soil is ''louto'' in the local dialect) for whitewashing. The material was applied more often on walls around fireplaces, because this kept the walls white, unsoiled from the fire. This whitewash was used by everybody until 1940-1950 and gradually abandoned, so that in 1980 it was used by only 15% of the households and by 1985 it was completely abandoned.Constantopoulos SH, Saratzis NA, Goudevenos JA, Kontogiannis D, Karantanas A. Katsiotis P. Tremolite white-washing and pleural calcifications . Chest 1987; 92: 709-712 Samples of the whitewash were sent to Mount Sinai Hospital, and proved to contain fibers of tremolite asbestos identical to the material previously obtained from the lungs of Metsovites. ''Louto'' was obtained by digging soil from hills 5–10 km from Metsovo within the "

Pindos The Pindus (also Pindos or Pindhos; el, Πίνδος, Píndos; sq, Pindet; rup, Pindu) is a mountain range located in Northern Greece and Southern Albania. It is roughly 160 km (100 miles) long, with a maximum elevation of 2,637 metres ...

serpentine zone". It was shaped like a ball, crushed into powder, boiled and applied to the walls. Crushing the ball released more than 200 fibers/ml of air, when the accepted limits for occupational exposure are lower than one fiber/ml. There were minuscule fiber concentrations during the rest of the process, while no fibers were detected in the ambient atmosphere of Metsovo. There has never been any commercial use of the soil within the Pindos serpentine zone other than that mentioned (the asbestos mine in

was functioning until the early 1990s), but there have been several areas where soil had been used by small populations in the remote past for various domestic uses, as in Metsovo. In at least two of them there have been small "epidemics" of mesothelioma. The use of this soil has been abandoned for at least 50–60 years. Outside Greece and Turkey, similar use with similar results has been reported in other areas around the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

, but also as far as

New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign st ...

in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

.Constantopoulos SH. Environmental mesothelioma associated with tremolite asbestos: Lessons from the experiences of Turkey, Greece, Corsica, New Caledonia and Cyprus. Regulatory Toxicology and Pharmacology, 2008; 52: S110-S115

Projected course

Having found the most likely cause of PCs and mesotheliomas in Metsovo and the temporal course of its use, from 1940-1950 when it was used by all households until 1980-1985 when it was abandoned, it was possible to project the future course of this epidemic. First, other sources of asbestos exposure, after the abandonment of ''louto'', had to be excluded. Two clinical means of measuring exposure were used for this purpose. Both had been positive in practically all exposed Metsovites during the peak of ''louto'' use: chest

computed tomography A computed tomography scan (CT scan; formerly called computed axial tomography scan or CAT scan) is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers ...

(CT) and

bronchoalveolar lavage Bronchoalveolar lavage (BAL) (also known as bronchoalveolar washing) is a diagnostic method of the lower respiratory system in which a bronchoscope is passed through the mouth or nose into an appropriate airway in the lungs, with a measured amoun ...

(BAL).Constantopoulos SH, Dalavanga YA, Sakellariou K, Goudevenos J, Kotoulas OB. Lymphocytic alveolitis and pleural calcifications in non-occupational asbestos exposure. Protection against neoplasia? American Review of Respiratory Diseases, 1992; 146: 1565-1570 A study of Metsovites between the ages of 30 and 50 confirmed that ''louto'' was the only source of asbestos exposure in Metsovo, as none of the subjects examined had PCs or asbestos fibers.Gogali A, Ntzani E, Peristeri S, Tzarouchi L, Manda-Stachouli C, Vadivoulis Th, Dascalopoulos G, Tsampoulas K, Constantopoulos S, and Dalavanga Y. End of domestic asbestos exposure epidemic in Metsovo; N.W. Greece European Respiratory Society, Annual Congress 2012Gogali A, Ntzani E, Konstantinidis A, Peristeri S, Tzarouchi L, Manda-Stachouli C, Daskalopoulos G, Constantopoulos SH, Dalavanga YA. Assessment of an isolated environmental and domestic asbestos exposure in Metsovo NW Greece: evidence of containment (Submitted) Finally, after thirty years of research it was possible to examine the dynamics of the frequency of PCs among Metsovites between 1980-2010. As expected, their frequency was found to be decreasing and the age when PCs are first seen was increasing, In regard to mesothelioma, after the first study in the 1980s, two studies have shown that the incidence of mesothelioma is also dropping.Sakellariou K, Malamou-Mitsi V, Haritou A, Koumpaniou Ch, Stachouli C, Dimoliatis ID, Constantopoulos SH. Malignant pleural mesothelioma from non-occupational asbestos exposure in Metsovo (North West Greece); slow end of an epidemic? Εuropean Respiratory Journal, 1996; 9: 1206-1210Gogali A, Manda-Stachouli C, Ntzani EE, Matthaiou M, Konstantinidis AK, Zampira I, Koubaniou Ch, Dalavanga Y, Stefanou D, Constantopoulos SH and Daskalopoulos G. Malignant mesothelioma in Metsovo, Greece, from domestic use of asbestos: 30 years later. Εuropean Respiratory Journal,2012; 39: 1-2 However, the end of this epidemic cannot be predicted safely. Mesotheliomas appear usually 30–50 years after exposure but this can be prolonged, very rarely, to 70 years. Thus, since the use of ''louto'' stopped between 1980-1985, a decreasing incidence of mesothelioma may be expected until 2020-2030 and possibly 2040.Constantopoulos S. Metsovo lung. A detective story with a happy ending. PNEUMON Supplement 1, Vol 27, 2014

Notes

References

{{Reflist 1980s in Greece Asbestos disasters Mesothelioma Metsovo