High risk of malignant mesothelioma and pleural plaques in subjects born close to ophiolites.
BACKGROUND
Ophiolites, a special sequence of geologic rock units, are known sources of naturally occurring asbestos. The aim of this study was to test whether the occurrence of malignant mesothelioma (MM) or pleural plaques (PPs) in the province of Sivas, Turkey, is determined by the proximity of the patient's birthplace to ophiolites and, if so, to establish the magnitude of the risk.


METHODS
The birthplaces of patients with MM or PPs (cases) and patients with prostate or breast cancer (control subjects), diagnosed between 2000 and 2010 and identified through a mandatory cancer registry or from hospital records (PPs), were located on a geologic map, and the nearest distance to ophiolites was measured. The relation of MM or PPs with distance to ophiolites was analyzed by logistic regression. Samples of soil and house plaster were determined by x-ray diffraction.


RESULTS
Patients with MM (n = 100) or PPs (n = 133) were born significantly nearer to ophiolites (median distance, 4.5 km for men, 0 km for women) than were patients with prostate cancer (n = 161) or breast cancer (n = 139) (median distance, 20 km for both). ORs were 1.6 (men) ( P < .001) and 2.0 (women) ( P < .001) for every 5-km decrease in the distance of birthplace to ophiolites for MM, compared with prostate and breast cancer, respectively.


CONCLUSIONS
In this area without substantial industrial asbestos use, there is an association between the occurrence of mesothelioma (and of PPs) and the proximity of the subject's birthplace to ophiolites.
Department of Pulmonology, Sivas Numune Hospital, Sivas, Turkey. Electronic address: drmehmetbayram@yahoo.com.
Mehmet
M
Bayram
Department of Thoracic Surgery, Sivas Numune Hospital, Sivas, Turkey.
Isa
I
Dongel
Department of Pulmonology, Yedikule Teaching Hospital for Pulmonology and Thoracic Surgery, Istanbul, Turkey.
Nur Dilek
ND
Bakan
Department of Geological Engineering, Cumhuriyet University, Sivas, Turkey.
Hüseyin
H
Yalççn
Department of Pathology, Sivas Numune Hospital, Sivas, Turkey.
Ruhiye
R
Cevit
Chest Department, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium.
Pascal
P
Dumortier
Occupational and Environmental Medicine, Unit of Lung Toxicology, Katholieke Universiteit Leuven, Leuven, Belgium.
Benoit
B
Nemery
D000328:Adult; D000368:Aged; D001194:Asbestos / Q000009:adverse effects* / Q000032:analysis; D002273:Carcinogens / Q000032:analysis; D016022:Case-Control Studies; D004781:Environmental Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D005260:Female; D005843:Geography / Q000706:statistics & numerical data; D006798:Housing; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D008654:Mesothelioma / Q000453:epidemiology / Q000209:etiology*; D000086002:Mesothelioma, Malignant; D008875:Middle Aged; D010995:Pleural Diseases / Q000453:epidemiology / Q000209:etiology; D010997:Pleural Neoplasms / Q000453:epidemiology / Q000209:etiology*; D012111:Residence Characteristics; D012307:Risk Factors; D012987:Soil / Q000032:analysis; D014421:Turkey / Q000453:epidemiology; D014961:X-Ray Diffraction
D002273:Carcinogens; D012987:Soil; D001194:Asbestos