Environmental exposure to asbestos in eastern Turkey

Environmental exposure to asbestos in eastern Turkey

H. Canan Hosanoglu

ASBESTOS is a naturally occurring mineral that is chemically and physically distinct; its use in industry is common. People who are occupationally or environmentally exposed to asbestos may develop pleural and pulmonary diseases. (1) Among individuals with certified occupational exposures to asbestos in the United States, 20% die of pneumoconiosis. (2) Few, if any, reports have documented occupational exposure to asbestos in Turkey, but several studies have detailed an increased prevalence of benign and malignant pleural diseases resulting from environmental asbestos exposure. Asbestos deposits–mostly tremolite and chrysotile–are found in some rural areas of central and southeast Anatolia. (3-8)

Malatya is a city in the eastern part of Turkey; environmental asbestos exposures and asbestos-related diseases have not been investigated previously in this region. Since pleura] plaques with calcifications were commonly found among people admitted to the hospital in Guzelyurt, we undertook an investigation to determine the presence of environmental asbestos and the prevalence of asbestos-related diseases among its inhabitants.

Materials and Method

Geographical area and subjects. Guzelyurt is a town in Hekimhan with 4,870 inhabitants. Hekimhan is the largest district of Malatya, a city in eastern Turkey (Fig. 1). About 1/4 of the Guzelyurt inhabitants (1,200/4,870) were selected as potential participants; 920 subjects (449 males and 471 females [1/5 of the population]) actually participated. This study was conducted under the auspices of the Ministry of Health of the Turkish Republic and the Inonu University Presidency. The purpose of the study was explained to all participants, each of whom volunteered to participate fully.

[FIGURE 1 OMITTED]

Photofluorograms. One photofluorogram of each subject was performed and read sequentially by 2 pulmonologists and 1 radiologist; each was unaware of the others’ evaluations. If 2 of the 3 readers agreed on the presence of an abnormality, the subject was identified as a case. Subjects with a blunted costophrenic angle were assigned to the group if they also had pleural plaques or diffuse pleural thickening.

Patients with symptoms and highly affected photofluorograms were investigated thoroughly (n = 16) with chest radiographs and thorax computed tomographies (CTs). Case records from patients who were admitted to the hospital in Guzelyurt with pleural and pulmonary malignancies were analyzed separately.

Sample analyses. Mineral analyses were conducted on samples of soil obtained from local river beds, white soil, and stucco from the walls of houses in Guzelyurt. At least 2 samples (i.e., approximately 100-gm each) were obtained from the white soil or from the house walls. The impurities in the samples were removed by the sedimentation method. After sedimentation, the dried powders from the samples were ground with an agate mortar and pestle, which prepared them for x-ray diffractometer (XRD) analysis. The XRD analyses were completed, using 30-kV and 10-mA power, with Cu[K.sub.[alpha]] radiation (Rigaku RadB system, Sevenoaks [Kent, United Kingdom]). The XRD analyses were performed with a Rigaku RadB (Japan) powder-diffraction system for which Cu[K.sub.[alpha]] ([lambda] = 1.54046 [Angstrom]) radiation, a nickel filter, 10-mA power, and 2 gm of powders were used in each experiment. The dried powders were also investigated for the presence of asbestos fibers via scanning electron microscopy (SEM) (JEOL 6400 [Japan]) at different magnifications (x500, x1,000, and x2,000).

Statistical analyses. Statistical analyses included calculation of the prevalence of asbestos-related disorders and the incidence of pleural and pulmonary malignancies among the inhabitants of Guzelyurt. We compared the age- and gender-stratified nominal data obtained from study participants with chi-square tests (SPSS Ver. 7.5; SPSS, Inc. [Chicago, Illinois]).

Results

The samples taken from the river beds, white soil sources, and stucco from the walls of some houses in Guzelyurt revealed the presence of asbestos. XRD analyses of the samples identified tremolite and chrysotile asbestos fibers (Fig. 2). SEM analyses also revealed the presence of serpentine and amphibole asbestos types (Fig. 3).

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Participants’ ages ranged from 6 to 85 yr (mean [[bar]x] = 27 yr, standard deviation [SD] = [+ or -] 20 yr). The rate of participation was lowest among inhabitants who were [greater than or equal to] 70 yr of age. Overall, participants were younger than the general population of Guzelyurt (Table 1).

The results of the photofluorograms, by age and gender, are shown in Table 2. The numbers of individuals who had asbestos-related abnormalities seen by 1,2, or 3 readers are shown in Table 3. We used the criteria that 2 or more readers had to identify an abnormality for a subject to be classified as a case; on that basis, 85 cases had asbestos-related radiological findings (i.e., 9.2% of the total sample). When we examined only those cases who were 20+ yr of age, that figure increased to 20.0%.

Pleural plaques with calcifications (Table 1) were the most common asbestos-related finding (n = 48 cases [5.2%]). All patients, except for 1, who had calcified pleural plaques were at least 30 yr of age. Subjects who were at least 50 yr of age demonstrated calcified plaques more frequently than did subjects who were < 50 yr of age (p = 0.006). Thirty-five cases had radiological changes related to causes other than asbestos exposure (Table 4).

The prevalence of asbestos-related radiological findings increased with age, to 64.0% (16/25) among subjects at least 70 yr of age (Table 5). We found no statistical difference in the proportion of asbestos-related disorders between males and females. The radiological findings are listed in Table 6. Most asbestos-related changes were bilateral, and mediastinal involvement was common.

The 16 patients who had symptoms and highly affected photofluorograms ranged in age from 44 yr to 79 yr ([bar]x = 61 yr, SD = 10 yr). Their primary symptoms were dyspnea and chest pain. Chest radiographs and thorax CTs revealed 1 patient with exudative pleural effusion. Cytological examination of pleural fluid and biopsy results did not reveal a specific diagnosis; we considered the effusion to result from asbestos exposure. None of the patients needed bronchoscopic evaluation and none were diagnosed with a malignancy. The chest xray and thorax CT of 1 of the patients are shown in Figure 4.

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Our 3-yr retrospective hospital record review of patients from Guzelyurt revealed 1 patient who was diagnosed and treated with a pleural malignancy and 4 patients who were diagnosed and treated with pulmonary malignancies. Of the 5 patients, 2 were female and 3 were smokers. The incidence of malignant pleural mesothelioma was 6.8 per 100,000 inhabitants of Guzelyurt; the incidence was 27.4 per 100,000 for lung cancer. The total incidence of pulmonary and pleural malignancies was 34.2 per 100,000 inhabitants.

Discussion

In this study, we demonstrated asbestos in the environmental samples taken from various settings in Guzelyurt. The asbestos types found in the soil were chrysotile and tremolite, findings that were similar to types reported in other studies conducted in many locations in Anatolia. (3-8) We also identified serpentine and amphibole types in our current study. The routes of exposure to asbestos in this region are likely similar to those reported in other studies from Turkey. Men dig the raw material in the mountains and transport it to their homes where women apply it to the house walls as whitewash. This procedure is repeated annually. Villagers also use asbestos-containing talc as a substitute for baby powder, and stucco is used on roofs for insulation and preventing water leaks. (3-5)

Householders in Guzelyurt are exposed chronically to asbestos dust, and this may be the reason why some individuals have early onset and, in some cases, extensive lesions. Not all of the inhabitants in Guzelyurt use stucco and whitewash in their houses, but all 16 inhabitants with massive pleural plaques claimed to have used asbestos-containing soil as a whitewash sometime in the past.

Our results showed that asbestos-related disorders increase with age. Duration of asbestos exposure, and amount and type of asbestos fibers, play a role in the development of asbestos-related disorders. (9-13) Low-level exposures from work-related, household, and environmental sources may induce pleural plaques. Higher exposure levels may be required for diffuse pleural thickening. Circumscribed pleural plaques and diffuse pleural thickening develop slowly with a latency period of approximately 15 yr. (14) This fact may explain why almost all cases who had pleural plaques exceeded 30 yr of age. Another explanation may be that as economic circumstances in Turkey continue to improve, younger subjects substitute new alternatives for asbestos-contaminated whitewash in their homes. The latter may explain why the prevalence of asbestos-related disorders was 64.0% in patients [greater than or equal to] 70 yr of age, but the prevalence was only 24.6% for individuals 50-59 yr of age.

Malignant pleural mesothelioma can occur with a low rate of asbestos exposure and a minimum latency of 10 yr from the first exposure. Only 1 yr of heavy exposure or 5-10 yr of moderate exposure may increase lung cancer risk by 2-fold or more. (12,15) In 1994, the overall incidence of pulmonary and pleural malignancy was reported as 5.9 per 100,000 by the Health Ministry of Turkey. We calculated an incidence of pulmonary and pleural malignancy of 34.2 per 100,000 inhabitants in Guzelyurt–an increase approximately 6 times that for the entire nation.

Previous studies from rural parts of central and southeastern Anatolia revealed pleural calcifications, diffuse pleural thickening, mesothelioma and lung malignancies related to asbestos exposure–but relatively few asbestosis cases were noted. (4-8) Asbestos-related pleural abnormalities are divided into (1) pleural plaques mainly involving parietal pleura, and (2) diffuse pleural thickening involving mainly the visceral pleura. (12) Pleural plaques seen in chest x-rays are mostly calcified. Non-calcified plaques are not visualized radiographically until the fibrous tissue is sufficiently thick. (16) Other disorders include benign asbestos-related pleural effusion, blunted costophrenic angle, crow’s feet, or rounded atelectasis. Pleural plaques with calcifications were the most commonly seen radiological finding in Guzelyurt. The prevalence of asbestos-related pleural abnormalities was 7.3% (n = 67) in our study; t .9% (n = 18) had dig fuse infiltrative changes. Asbestosis is associated with relatively high doses of asbestos exposure for a protracted period of time, usually from occupational exposures to fibers in inhaled air. Asbestosis is not usually related to environmental exposures.

Environmental asbestos presents a major public health problem in the rural parts of central and southeastern Anatolia. This study demonstrated that soil contaminated with asbestos is the likely cause of asbestos-related disorders in Guzelyurt. Thousands of Turkish inhabitants are exposed to environmental asbestos without being aware of its hazards. A health education program is needed that explains the dangers of asbestos exposure and warns about the use of asbestos-containing soils for whitewash. Even if cultural practices were changed and all persons were moved out of asbestos-contaminated areas immediately, the protracted latency for developing asbestos-related diseases means that health problems from prior exposures are likely to be seen for at least 3 to 4 decades.

This project was supported in part by a grant from the Inonu University Research Foundation.

Submitted for publication October 13, 2001; revised; accepted for publication May 29, 2002.

Requests for reprints should be sent to Dr. H. Canan Hasanoglu, Koru Mahallesi Kocatepe Sitesi, 5. Blok No. 8 Cayyolu, 06530, Ankara, Turkey.

E-mail: hhasanoglu@hotmail.com

Table 1.–Age Distribution of the Population and Study

Subjects Who Resided in Guzelyurt

Population Subjects

Age (yr) n % n %

0-4 497 10.2 — —

5-19 1,438 29.5 495 53.8

20-29 795 16.3 95 10.3

30-39 522 10.7 108 11.7

40-49 408 8.4 54 5.9

50-59 435 8.9 57 6.2

60-69 477 9.8 86 9.3

[greater than or equal to] 70 298 6.1 25 2.7

Total 4,870 920

Table 2.–Asbestos-Related Abnormalities Identified from

Photofluorographs of Subjects, by Age Group and Sex

Pleura

Pleural

plaques

Age Cases Diffuse

(yr) (n) Sex thickening C N Effusion

5-19 495 M 0 0 0 0

F 0 1 0 0

20-29 95 M 0 0 0 0

F 0 0 1 0

30-39 108 M 0 0 0 0

F 0 0 1 0

40-49 54 M 1 4 0 0

F 2 3 0 0

50-59 57 M 0 6 0 0

F 1 5 0 0

60-69 86 M 2 13 0 1

F 3 3 0 0

[greater than

or equal to] 70 25 M 1 5 0 0

F 1 8 0 0

Total 11 48 2 1

Pleura

Lung

Age Cases Blunted Interstitial

(yr) (n) Sex CA fibrosis Total

5-19 495 M 0 0 0

F 0 0 1

20-29 95 M 0 0 0

F 0 0 1

30-39 108 M 0 4 4

F 1 1 3

40-49 54 M 1 2 8

F 0 2 7

50-59 57 M 0 2 8

F 0 0 6

60-69 86 M 2 3 21

F 1 3 10

[greater than

or equal to] 70 25 M 0 0 6

F 0 1 10

Total 5 18 85

Notes: n = number of cases, M = male, F = female, C = calcified, N =

noncalcified, and CA = costophrenic angle.

Table 3.–Asbestos-Related Abnormalities Identified from

Photofluorographs of Subjects, by Number of Independent

Readers

No. of independent

readers

Radiological abnormality 1 2 3

Pleura

Diffuse thickening 9 2 9

Pleural plaques

N 2 1 1

C 8 9 39

Effusion 1 0 1

Blunted CA 5 1 4

Lung

Interstitial fibrosis 12 10 8

Notes: N = noncalcified, C = calcified, and CA= costophrenic

angle.

Table 4.–Disorders among Cases Whose Photofluorograms Showed

Abnormalities Unrelated to Asbestos Exposure

TB Mediastinal

Age (yr) Sex sequela Cardiomegaly enlargement

5-19 M 0 0 3

F 2 0 1

20-29 M 0 0 0

F 0 0 0

30-39 M 1 0 0

F 1 0 0

40-49 M 0 0 0

F 0 0 0

50-59 M 0 1 0

F 1 5 1

60-69 M 6 2 0

F 1 3 1

[greater than or

equal to] 70 M 0 1 0

F 1 0 0

Total 13 12 6

Hydatid

Age (yr) Nodule cyst Cavitation Total

5-19 0 0 0 3

0 1 0 4

20-29 1 0 0 1

0 0 0 0

30-39 0 0 0 1

0 0 0 1

40-49 1 0 0 1

0 0 0 0

50-59 0 0 0 1

0 0 0 7

60-69 0 0 0 8

0 0 1 6

[greater than or

equal to] 70 0 0 0 1

0 0 0 1

Total 2 1 1 35

Notes: M = male, F = female, and TB = tuberculosis.

Table 5.–Numbers and Proportions of Asbestos-Related Disorders, by Age

and Sex

No. of

cases with

No. of asbestos-

cases related

Age (yr) Sex surveyed disorders Percentage

5-19 M 234 0 0.00

F 261 1 0.20

20-29 M 49 0 0.00

F 46 1 1.05

30-39 M 52 4 7.69

F 56 3 5.36

40-49 M 37 8 21.05

F 17 7 41.18

50-59 M 20 8 40.00

F 37 6 16.22

60-69 M 45 21 46.67

F 41 10 24.39

[less than or

equal to] 70 M 13 6 46.15

F 12 10 83.33

Total 920 85

Percentage

Age (yr) of age

5-19 0.20

20-29 1.05

30-39 6.48

40-49 27.78

50-59 24.56

60-69 36.05

[less than or

equal to] 70 64.00

Total 9.24

Notes: M = male, and F = female.

Table 6.–Localization of Asbestos-Related Disorders

Localization

Disorder Bilateral Right Left

Diffuse pleural thickening

Costal 11 0 2

Basal 10 0 3

Mediastinal 10 0 0

Pleural plaques

Costal 37 2 4

Basal 36 2 5

Mediastinal 36 0 1

Pleural effusion 0 0 1

Blunted CA 0 2 3

Interstitial fibrosis 10 5 3

Note: CA = costophrenic angle.

References

(1.) Fraser RS, Pare JAP, Fraser RG, et al. Pleuropulmonary disease caused by inhalation of inorganic dust (pneumoconiosis). In: Fraser RS (Ed). Synopsis of Diseases of the Chest, 2nd ed. Philadelphia, PA: W. B. Saunders Co., 1994; pp 705-39.

(2.) Rosenberg DM. Asbestos-related disorders: a realistic perspective. Chest 1997; 111(5):1424-26.

(3.) Baris YI. Asbestos and Erionite Related Chest Diseases. Ankara, Turkey: Semih Ofset Mat Ltd Co, 1987; pp 3-67.

(4.) Selcuk ZT, Coplu L, Emri S, et al. Malignant pleural mesothelioma due to environmental mineral fiber exposure in Turkey: analysis of 135 cases. Chest 1992; 102(3):790-96.

(5.) Yazicioglu S, Oktem K, Ilcayto N, et al. Association between malignant tumors of the lungs and pleura. Chest 1973; 73(1):52-57.

(6.) Baris YI, Artvinli M, Sahin AA. Environmental mesothelioma in Turkey. Ann NY Acad Sci 1979; 330:423-33.

(7.) Yazicioglu S. Pleural calcification associated with exposure to chrysotile asbestos in southeast Turkey. Chest 1976; 70(1):43-48.

(8.) Coplu L, Dumortier P, Demir AU, et al. An epidemiological study in an Anatolian village in Turkey environmentally exposed to tremolite asbestos. J Environ Pathol Toxicol Oncol 1996; 15():177-82.

(9.) Mossman BT, Churg A. Mechanisms in the pathogenesis of asbestosis and silicosis. Am J Respir Crit Care Med 1998; 157(5 Part 1):1666-80.

(10.) Churg A. Deposition and clearance of chrysotile asbestos. Ann Occup Hyg 1994; 38(4):625-33, 424-25.

(11.) Churg A, Wright JL. Persistence of natural mineral fibers in human lungs: an overview. Environ Health Perspect 1994; 102 (suppl 5):229-33.

(12.) Tossavainen A. Asbestos, asbestosis and cancer: the Helsinki criteria for diagnosis and attribution. Scand J Work Environ Health 1997; 23(4):311-16.

(13.) Morgan A, Evans JC, Holmes A. Deposition and clearance of inhaled fibrous minerals in the rat: studies using radioactive tracer techniques. In: Walton WH (Ed). Inhaled Particles. Oxford, U.K.: Pergamon Press, 1977; pp 259-74.

(14.) Schwartz DA. New developments in asbestos-induced pleural diseases. Chest 1991 ; 99(1):191-98.

(15.) Boutin C, Schlesser M, Frenay C, et al. Malignant pleural mesothelioma. Eur Respir J 1998; 12(4):972-81.

(16.) Mcloud TC. Conventional radiography in the diagnosis of asbestos-related disease. Radiol Clin North Am 1992; 30(6): 1177-89.

H. CANAN HASANOGLU

MUNIRE GOKIRMAK

Inonu University

Turgut Ozal Medical Center

Department of Pulmonary Diseases Malatya, Turkey

TAMER BAYSAL

Inonu University

Turgut Ozal Medical Center

Department of Radiology Malatya, Turkey

ZEKI YILDIRIM

Inonu University

Turgut Ozal Medical Center

Department of Pulmonary Diseases Malatya, Turkey

NURHAN KOKSAL

Sutcu Imam University

Faculty of Medicine

Department of Pulmonary Diseases K. Maras, Turkey

YUNUS ONAL

Inonu University

Faculty of Engineering

Department of Chemical Engineering Malatya, Turkey

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