Turkey National Mesothelioma Surveillance and Environmental Asbestos Exposure Control Program

Our plain-English summary of Turkey National Mesothelioma Surveillance and Environmental Asbestos Exposure Control Program, by S. Metintaş, H.F. Batırel, H. Bayram, et al (International Journal of Environmental Research and Public Health, 2017).

The study

• Authors: S. Metintaş, H.F. Batırel, H. Bayram, Ü. Yılmaz, M. Karadağ, G. Ak, M. Metintaş
• Journal: International Journal of Environmental Research and Public Health
• Published: 2017;14(11)
• Cited by: 26 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Malignant mesothelioma (MM) is an important health problem due to ongoing asbestos exposure. Environmental asbestos exposure leads to a high risk of MM in Turkey. The Turkish Mesothelioma Working Group and the Turkish Public Health Institute designed and performed the Turkey National Mesothelioma Surveillance and Environmental Asbestos Exposure Control Program (TUNMES-EAECP). The aim of this study was to analyze the results of the TUNMES-EAECP. Patients diagnosed with MM (code C45.0-C45.9) between 2008 and 2012 were identified. The "from case to the field" method was used to determine the villages with current or previous asbestos exposure. Special public health teams took soil samples from these villages, which were then examined using an X-ray diffractometer. Direct Standardized Average Annual Mesothelioma Incidence Rate (AMIR) and relative risk (RR) of MM were calculated. Finally, a projection on the incidence of MM between 2013 and 2033 was made. The number of confirmed MM cases was 5617 with a male to female ratio of 1.36. Mean age was 61.7 ± 13.4 (20-96) years. The median survival was eight (95% CI 7.6-8.4) months. Asbestos exposure continues in 379 villages, with 158,068 people still living in high risk areas. The standardized AMIR was 2.33/100,000 per year. The risk of MM was higher in males, in both sexes over the age of 40, in asbestos-containing provinces, and in those where the TUNMES was organized. Among the population with continuing asbestos exposure in rural areas, the number of MM cases between 2013 and 2033 was estimated as 2511. As such, the incidence of MM in Turkey is as high as in industrialized countries. Asbestos exposure in rural areas continues to be a serious problem in Turkey, which obviates the necessity for effective preventive measures.

In plain English

This national surveillance study identified 5617 malignant mesothelioma cases diagnosed from 2008 to 2012 in hospitals in 30 Turkish provinces. The authors sampled soil from house walls and roofs in villages where patients were born or lived. Of 1251 soil samples, 514 contained asbestos: chrysotile (70%), tremolite (20%) or mixed (10%). This placed ongoing exposure in 379 villages, home to 158,068 people. The standardized incidence rate for Turkey was 2.33 (95% CI 2.32 to 2.34) per 100,000 people per year. In villages with continuing exposure it was 79.00 (78.94 to 79.06). People from villages with asbestos in the soil had a risk ratio of 10.77 (95% CI 9.14 to 12.69) compared with those from villages without it. Most cases were pleural (95.1% in the authors' table), and median survival was 8 months (95% CI 7.6 to 8.4). The authors estimated 2511 new cases in these villages from 2013 to 2033 if this exposure was not abolished. They concluded that rural asbestos exposure remains a critical problem in Turkey. The researchers could not confirm the cases' histopathological diagnoses and collected no occupational exposure data.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: National surveillance study using hospital records of diagnosed mesothelioma cases, combined with soil sampling of villages linked to cases and a projection of future cases
• Who was studied: 5617 malignant mesothelioma cases (3241 men, 2376 women) diagnosed 2008–2012 in hospitals in 30 Turkish provinces covering 66.8% of the population. 3738 (66.5%) were born or had lived in rural areas. Soil samples came from 1018 villages.
• Exposure: Environmental asbestos in village soil used for whitewash, plaster, insulation, floors and roofs. Of 1251 soil samples analysed by X-ray diffraction, 514 contained chrysotile (70%), tremolite (20%) or mixed (10%) asbestos fibers.
• Main results:
  • Standardized mesothelioma incidence for all of Turkey: 2.33 (95% CI 2.32–2.34) per 100,000 per year overall; 2.88 (2.86–2.89) in men; 1.86 (1.85–1.87) in women
  • Population living in rural areas with continuing asbestos exposure. Crude incidence per 100,000 per year: 79.94 in men, 66.92 in women, 73.42 overall. Standardized incidence: 87.27 in men, 68.44 in women, 79.00 (78.94–79.06) overall.
  • Asbestos exposure was judged ongoing in 379 villages in 41 provinces with 158,068 inhabitants. The authors projected 2511 mesothelioma cases among these people for 2013 to 2033 if the exposure was not abolished.
  • Asbestos in the village soil versus none: rate 8.08 versus 0.75 per 100,000 per year, risk ratio 10.77 (95% CI 9.14–12.69)
  • Women versus men: risk ratio 0.80 (95% CI 0.76–0.84). Risk rose with age in both sexes compared with those under 40. Men 70 and over: risk ratio 23.67 (19.90–28.16). Women 70 and over: risk ratio 33.46 (29.71–37.68).
  • Provinces where the surveillance program was organized versus other provinces: risk ratio 3.78 (95% CI 3.34–4.28)
  • Elazig, Eskisehir and Diyarbakir were the highest-risk provinces, with risk ratios above eight
  • All cases: mean survival 11.4 months (95% CI 11.0–11.9), median survival 8 months (95% CI 7.6–8.4). 3495 of 5617 (62.2%) died during the study period.
  • Disease site per Table 1: pleural 5342 (95.1%), peritoneal 246 (4.4%), pericardial 29 (0.5%). Peritoneal cases were more likely to be women (p less than 0.001).
• The authors' conclusion: The authors concluded that asbestos exposure in rural areas remains a critical problem in Turkey. They also stated that occupational mesothelioma should now be expected as a problem.
• Limitations the authors state:
  • Cases came from hospital diagnostic records. The researchers could not confirm the histopathological diagnosis of the 5617 cases for this study. The authors note that such patients in Turkey are generally diagnosed by immunohistochemical staining.
  • Some villages with more cases than expected were not sampled, based on statements from regional administrators. Presence or absence of asbestos-contaminated soil could not be determined in those villages.
  • No data were collected on occupational exposure
  • How long villagers actually stayed in exposed villages was unknown, so individual cumulative exposure dose could not be determined

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma.

Medical terms in this study, explained in our Lexicon: Mesothelioma, Asbestos Exposure, Malignant Mesothelioma, Incidence, Relative Risk, Median Survival.

Related studies

• Environmental asbestos exposure in rural Turkey and risk of lung cancer — S. Metintas, M. Metintas, et al. (2012)
• Evaluation of the national health surveillance program of workers previously exposed to asbestos in Spain (2008) — M.G. Gómez, R. Castañeda, et al. (2012)
• Malignant mesothelioma due to non-occupational asbestos exposure from the Italian national surveillance system (ReNaM): epidemiology and public health issues — A. Marinaccio, A. Binazzi, et al. (2015)
• High-resolution computed tomography in cases with environmental exposure to asbestos in Turkey — F. Topçu, H. Bayram, et al. (2000)
• Programmed health surveillance and detection of emerging diseases in occupational health: contribution of the French national occupational disease surveillance and prevention network (RNV3P) — V. Bonneterre, L. Faisandier, et al. (2010)
• The assessment of the malignant mesothelioma cases and environmental asbestos exposure in Sivas province, Turkey — S. Berk, H. Yalcin, et al. (2014)

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