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Clinical & Medical Case Reports

Case Report Volume 3 Issue 3

Prevalence of chronic obstructive pulmonary disease and correlation with occupational exposure in milos milos island

Eleni Bania,1 Ilias Apostolopoulos,2 Zampeta Kiritsi,2 Ioanna Ninou,2 Viorelis Drougias,1 Stergios Giotas,1 Dimitris Maroulis,3 Ilias Zoidakis,3 Konstantinos Gourgoulianis1

1Department of Pneumonology, University of Thessaly, Greece
2General Practitioner, Director of Milos Health Center, Greece
3Physical therapist, Angelini Pharma Hellas, Greece

Correspondence: Eleni Bania, Pneumonologist, PhD Candidate of Medical School, University of Thessaly, Clinic, Lampsa 15–Girokomeio, Greece, Tel 0030 6958008644

Received: November 04, 2015 | Published: December 3, 2015

Citation: Bania E, Apostolopoulos l, Kiritsi Z, et al. Prevalence of chronic obstructive pulmonary disease and correlation with occupational exposure in milos milos Island in Greece. MOJ Clin Med Case Rep. 2015;3(3):239-242. DOI: 10.15406/mojcr.2015.03.00068

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Abstract

Aims: Evaluation of general health level of residents of Milosisl and through respiratory functional testing, bone density measurement in correlation with occupational and environmental exposure.

Case: Study protocol consisted of only one visit during which nativity, demographic characteristics, risk factors, occupational exposure, comorbidities and current medication were recorded and FEV1, FVC, FEV1/FVC, SatO2% and T–score were measured. The participants were over 35years of age. For the description of the qualitative variables, absolute (number of observations) and relative frequencies (percentages) were used.

Results: 181 residents fulfilled the inclusion criteria of the study. 5,5% of the participants suffered from COPD, while 22.1% of the study population was exposed to perlite or other mineral dust. According to our analysis it is shown that COPD and occupational exposure to mineral dust are not correlated. Osteoporosis and osteopenia were recorded in 10.5% of the cases. Other co–morbidities recorded were hypothyroidism and eye disorders.

Conclusion: The prevalence of the patients with COPD (5,5%) is lower than the rates established in previous studies for the general population. The majority of the study population (77.9%) was not exposed to perlite, bentonite, caoline or asbestos. The exposure degree of the population probably plays a crucial role in the impact of mineral dust on its general health level.

Keywords: COPD, perlite, osteoporosis, milos island, bentonite, caoline, asbestos chronic obstructive, FVC, pulmonary disease, FEV, threshold limit value

Abbreviations

COPD, chronic obstructive pulmonary disease; EU, European union; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; GOLD, global initiative for chronic obstructive lung disease; TLV, threshold limit value; TWA, time weighted average

Introduction

The adverse effect of mineral dust on general health level of the population has been widely studied lately. The research interest has been mainly focused on the respiratory function of coal miners and workers exposed to silica and asbestos containing dust1–3 because a significant increase in COPD independent of smoking has been observed.4–5 Among the materials considered hazardous for workers’ health are perlite, bentonite and caoline.6 Perlite is an amorphous volcanic glass that has relatively high water content. It is mainly used as a soil conditioner, packaging material, construction insulator, agriculture substrate and as a filter aid. Perlite is regarded as a generally safe material, and the threshold limit value for perlite is 5mg/m.7,8 Bentonite is a clay mineral, which contents silica in percentages which range from1–20%. Up to date, several studies9–11 have shown that exposure especially occupational–to silica, may be associated mainly with lung and kidney malignancies in workers. Researchers found that bentonite particles may induce cytotoxicity and oxidative stress, as well as genotoxicity in human lymphoblast B cells.12,13 The use of bentonite is widely spread in chemical, pharmaceutical, cosmetic and food industry, engineering, agriculture and mining. Humans are exposed to bentonite through occupational and environmental pathways, mostly by the respiratory tract and dermal contact.

The island of Milos belongs to the Cycladic island complex and is located 140km southeast of Attiki. It is a product of volcanic activity with more than 100mining sites located in the island, 25 of which are active perlite and bentonite mines.14 Milos is the largest bentonite and perlite production and processing center in the European Union, with an excavation rate of about 1,000,000 tons bentonite and 500,000 tons perlite per year. Based on the above we conducted an epidemiological study in order to evaluate the general health level of Milos’ residents through respiratory functional testing, bone density measurement in correlation with occupational and environmental exposure.

Case

This is an on–interventional epidemiological study of three days duration that took place in Milos Island on July 2013. It was conducted by a research team in collaboration with Milos Health Center. The study population consisted of 181 permanent residents of either gender, aged over 35years. All of the participants gave informed written consent. Study protocol consisted of only one visit during which nativity, demographic characteristics, risk factors, occupational exposure, comorbidities and current medication were recorded and FEV1, FVC, FEV1/FVC, SatO2% and T–score were measured.

Inclusion criteria

  1. Male or female patients>35years, permanent residents of Milos Island.
  2. Available data: Patient’s history
  3. Patients who have provided written informed consent for their participation in the present research.

Exclusion criteria

  1. Patients who refuse to provide written informed consent
  2. Patients who participate in clinical trial with study drug.

COPD classification by severity was based on revised GOLD 2014 guidelines.15 According to bone density measurement, patients with T–score≤–2.5 were defined as suffering from osteoporosis, while patientswithT–score–2.5<T–score<–1 were defined as suffering from osteopenia.16 For the description of the qualitative variables, absolute (number of observations) and relative frequencies (percentages) were used. The level of statistical significance was set atp<0.05.

Results

181 permanent residents of Milos participated voluntarily in the study. 5.5% of the study population suffered from COPD (10/181). According to respiratory functional testing, 3 patients suffered from moderate COPD (50%≤FEV1<80%) and only 1 from severe COPD (30%≤FEV1<50%). Moreover, the majority of the residents (77.9%–146/181) did not report any exposure to perlite, bentonite, caoline or asbestos etc. Population distribution by COPD and exposure to mineral dust can be seen in Table 1. According to our analysis it is shown that COPD and occupational exposure to mineral dust are not correlated (p–value=0.536>0.05). 10.5% of the participants suffered from osteoporosis (19/181). Population distribution by bone density measurement can be seen in Figure 1. According to our analysis it is shown that COPD and metabolic bone disease (osteoporosis–osteopenia) are not correlated (p–value=0.052>0.05) 23 participants suffered from a thyroid disorder (12.71%) by hypothyroidism in most of the cases (Figure 2) while only 6.1% (11/181) of the study population reported an eye disorder.

Figure 1 Metabolic bone disease.

Figure 2 Thyroid disorders.

Distribution of COPD⃰ and exposure to minerals

COPD⃰

Exposure to Minerals

Yes

No

Total

Yes

3

37

40

No

7

134

141

Total

10

171

181

Table 1 Distribution of COPD ⃰ and exposure to minerals

*Chronic obstructive pulmonary disease

Discussion

Although relevant bibliographic references are limited, there is evidence that prolonged occupational and environmental exposure to “nuisance” mineral dusts may have an adverse effect upon general health level and especially the respiratory function of the population However, according to our study, the percentage of permanent residents of Milos that suffered from COPD was 5.5%, although 22.1% of the population reported some exposure to perlite, bentonite, caoline or asbestos etc. It is worth noticing that the estimated prevalence of COPD in Milos’ permanent population is lower than the rates established for the general population. In a study17 published in 2004 by Tzanakis and co. the COPD prevalence by community setting was as follows: Athens, 6%; other urban areas, 10.1%; semiurban areas, 8.5%; and rural areas, 9.1%. There could be a possible selection bias due to the time period and seasonal variations, especially regarding COPD exacerbations. This is due to the fact that COPD exacerbations (which are related to symptoms deterioration) are more frequent during the winter season,18 a fact that could sensitize more COPD patients to participate to the study. Nevertheless, the percentage of the population suffering from COPD shown in our study seems to be in accordance with the respective rates in EU.19–22

The absence of correlation between COPD presence and exposure to mineral dust shown in our study comes in opposition to recent study23 published in 2013 by Sampatakis and co. Demonstrating that permanent residents of Milos island exposed to perlite and bentonite mining dust, indicate an increased risk of developing diseases of the respiratory system, such as pneumonia, chronic obstructive pulmonary disease and allergic rhinitis. Internationally, there are only two recent studies examining the effect of perlite dust on the health of exposed workers available. In the first study24 the authors reached to the conclusion that although 12–year perlite exposure did not lead to decreased spirometric indices, there was a significant decrease in diffusion capacity of the lungs, which indicates a possible small airway obstruction. In the second study,25 24 industrial workers in Taiwan that were exposed accidentally to large quantities of perlite dust were followed for 6 months. During this period the symptoms observed among the workers were cough, eye irritation, shortness of breath and throat irritation. Moreover, three of them developed signs of Reactive Airway Dysfunction Syndrome (RADS)26 and performed a Forced Expiratory Volume in one second (FEV1) less than 80%. Both studies were conducted in working places. In the first one, the long term effects of exposure to perlite dust were studied, while in the second one, its acute effects. In our study, a whole population is under study, based on their permanent residential area and not just their working place.

The only epidemiological studies in general population available regarding both exposure to perlite and bentonite mining dust are the ones concerning the Milos’ island.27,28 Both these studies are limited by the fact that other risk factors of respiratory disease (e.g. smoking) were not taken into account in the analysis. Moreover, there were not used data concerning the perlite and bentonite dust concentration in ambient air and their potential to exceed the officially set limits. This element probably plays a crucial role, given that in both the studies that took place in Turkey and Taiwan demonstrating an adverse effect on respiratory health of the workers, exposure exceeded the official set limits. Likewise, in the case described by Gibbs and Pooley pneumonociosis was a result of prolonged heavy exposure to calcium montmorillonite. On the contrary, in an older study29 concerning 152 workers occupied in perlite mining and processing factories that were exposed to perlite dust for up to 23years within the official set limits, there was no evidence of pneumoconiosis by using chest radiography or pulmonary functional tests.30 In conclusion, we believe that the exposure degree is a major determinant of the impact of mineral dust on general health level of Milos’ population and especially its respiratory aspect, a subject that needs further discussion and investigation.

Conclusion

The prevalence of the patients with COPD in Milos Island is 5.5%). The majority of the study population (77.9%) was not exposed to perlite, bentonite, caoline or asbestos. Among the participants that reported occupational exposure we found no correlation between COPD presence and exposure to mineral dust. The exposure degree of the population probably plays a crucial role in the impact of mineral dust on its general health level.

Acknowledgements

The present study is under the auspices of the Hellenic Thoracic Society and has been funded from Angelini Pharma Hellas in terms of Corporate Social Responsibility.

Conflict of interest

The author declares no conflict of interest.

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