Lung cancer xray

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).

[FIGURES 2-3 OMITTED]

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.

[FIGURE 4 OMITTED]

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.