Pulmonary functions in tannery workers A cross sectional study

Transcription

1 Indian J Physiol Pharmacol 2014; 58(3) : Pulmonary Functions in Tannery Workers 205 Original Article Pulmonary functions in tannery workers A cross sectional study Vasanthi Chandrasekaran 1 *, K. Dilara 2 and R. Padmavathi 2 Departments of 1 Arthroscopy & Sports Medicine, 2 Physiology, Sri Ramachandra University, Porur, Chennai Abstract Tannery workers are at potential exposure to detrimental agents rendering them vulnerable to respiratory and dermal problems. Thus by performing pulmonary functions among leather tannery workers, we can decipher the effect of chromium and leather dust on lung functions and also the decline of respiratory functions with increasing years of exposure to leather dust. Pulmonary functions were assessed for 130 tannery workers and compared with the 130 unexposed office workers. Pulmonary function measurements namely FVC, FEV1, FEF25-75% and PEFR were measured using portable data logging Spirometer (KOKO Spirometer). The observed pulmonary functions of Tannery workers in this study showed a reduction in FEV1, FVC, FEV1/FVC ratio, FEF25-75 and PEFR in relation to their predicted values and also compared to the unexposed. Smokers showed a decline in pulmonary functions compared to the non smokers because smoking acts as an additional risk factor in the development of respiratory illnesses. It is worthy to mention that the pulmonary function values correlate negatively with the duration of exposure to leather dust. So this study could provide base line information based upon which legal implementation of preventive measures could be undertaken. Introduction Occupational lung diseases make a significant contribution among the global burden of occupational illnesses throughout the world. Since the lung has large surface area, high vascularity and thin alveolar epithelium, it is in contact with environmental pollutants. These illnesses occur as a result of repeated, long term exposure to irritating or toxic substances in the working place. The lungs show fibrotic and proliferative changes due to dust exposure over longer periods of time (1). This impairs the *Corresponding author : Dr. Vasanthi Chandrasekaran, Departments of Arthroscopy & Sports Medicine, Sri Ramachandra University, Porur, Chennai; uvasanthi83@gmail.com (Received on November 18, 2013) oxygen saturation of the blood which ultimately deranges the functioning of all the systems in the body. Since the occupational exposure occurs over a period of years, the occupational diseases are often preventable. Leather tanning is the process by which chemical preservation of raw hide is done by binding of various chemicals like chromium salts. There are over 2000 tanneries in our country. The leather industry being an employment intensive sector provides job to about 2.5 million people, belonging to the weaker sections of the society. This puts large population at a risk of exposure to harmful chemicals. Cost incurred due to ill health of the tannery workers will become a big economic burden to the society. Health hazards among tannery workers have been documented by many authors in the past. Exposure to chromium has been implicated as the causative

2 206 Chandrasekaran, Dilara and Padmavathi Indian J Physiol Pharmacol 2014; 58(3) factor. A cross sectional survey done by Shukla et al at Kanpur have demonstrated that the higher prevalence of medical complaints among tannery workers was for low back trouble (61%), asthma (38%) and hand dermatitis (23%) (2). Rastogi et al have shown that chronic exposure to chromium compounds among tannery workers can lead to increased pulmonary morbidity in the form of occupational asthma, chronic bronchitis, allergic bronchitis or pulmonary tuberculosis (3). The pulmonary function tests have paved way towards scientific approach in diagnosis, prognosis and management of respiratory disorders by the early recognition of their decline in industrial workers. Documentation of decline in pulmonary function of tannery workers was done in northern India.Similar studies have not been performed in South India. In Tamilnadu, Vellore district is a major leather processing centre, with an estimated 50,000 tannery workers. Thus by performing pulmonary functions among leather Tannery workers, we can bring to limelight, the effect of chromium and leather dust on lung functions and also the decline of respiratory functions with increasing years of exposure to leather dust. Materials and Methods This cross sectional study was conducted among Tannery workers at Ambur, Vellore District. A total of 260 male subjects were included in the study. Out of this, 130 will be Tannery workers (exposed group) and 130 will be office workers (unexposed group). Subjects having more than two years of working experience were included in the study. Exclusion criteria include subjects having active tuberculosis or subjects who have undergone recent abdominal or eye surgeries. Clearance from the Institutional ethical committee were obtained prior to the conduction of the study. Permission from the workers was obtained after explaining the protocol and benefits to them. Information about demographic details, socio economic status, nutritional status, occupational history, smoking history and history of respiratory illnesses was obtained by using a study questionnaire. The time required for the complete administration of the questionnaire was approximately 20 minutes. General examination and detailed respiratory system was performed and clinical examination findings were noted in the proforma. Stadiometer was used to measure the standing height in centimeters. Weight was recorded in kilograms using the portable weighing machine. Pulmonary function measurements namely Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV1), Forced expiratory Flow Rate 25-75% (FEF25-75%) and Peak Expiratory Flow Rate (PEFR) was measured using portable data logging Spirometer (KOKO Spirometer). The procedure for performing spirometry was explained to the subjects. They were seated in a chair and nose clips were used to prevent air leakage from the nose. They were instructed to take a large breath to full inspiration through the nose. The mouthpiece was placed into the subject s mouth and he was asked to place his lips and teeth around the mouth piece to form a tight seal. He was instructed to breathe out hard and quickly for at least 6 seconds until all the air is expelled. At least 30 seconds was left between efforts to enable the patient to recover. A minimum of three and a maximum of eight efforts were attempted. The shape of the flow/volume or volume/time curves was observed to detect poor effort. A bronchodilator reversibility test was done in subjects having FVC, FEV1 and FEF 25-75% less than 80% of the predicted value. A beta 2 selective sympathomimetic drug (salbutamol 100 mcg) 2 puffs was given and after 15 minutes PFT was repeated. Pre/Post graph comparison was done to assess the effectiveness of the bronchodilator. If two of three measurements (FVC, FEV1 and FEF25-75%) improve, then it can be said that the patient has a reversible airway obstruction that is responsive to medication. Statistical analysis Data analysis was performed using R software. Data is represented as Mean±SD. Comparison tests of significance used are independent t test and chi

3 Indian J Physiol Pharmacol 2014; 58(3) Pulmonary Functions in Tannery Workers 207 square test. Pearson s correlation analysis was used for assessing the association of pulmonary function parameters with exposure parameters. P value less than 0.05 was taken to be significant. Results The anthropometric measurements of the two groups are shown in Table I. All the parameters were similar in both exposed and unexposed group as p value is more than Pearson correlation analysis between duration of exposure and pulmonary parameters shows that pulmonary function correlates negatively with duration of exposure as the r value was negative. Correlation was statistically significant except for FEV1/FVC ratio. Depending on the years of exposure to leather dust, the exposed group were broadly divided into two categories: Category 1: 2-10 yrs of exposure (n=90) and Category 2: yrs of exposure (n=40). Workers working in tanneries for more than 11 years showed a significant decrease in their pulmonary functions except FEV1/FVC ratio (Table III). From table IV it is clear that pulmonary function values were significantly reduced in smokers than non smokers. This indicate the additional detoriative effect of smoking on lung function. Spirometric assessment in workers has revealed the predominance of reduction in FEF 25-75% in exposed group. They also showed restrictive (17%) and mixed (11%) pattern (Table V). TABLE I : Comparison of pulmonary functions among Exposed and Unexposed groups. TABLE II : Correlation between duration of exposure & pulmonary function. Parameter Duration of exposure to leather dust r p FVC FEV FEV1/FVC Ratio PEFR FEF TABLE III : Comparison of pulmonary functions between different years of exposure to leather dust in the exposed group. Pulmonary 2-10 yrs of yrs of P functions exposure to exposure to value leather dust leather dust (n=90) (n=40) FVC (L) 3.25± ± (L) 2.81± ± /FVC 0.86± ± PEFR (L/Sec) 7.06± ± FEF (L) 3.39± ± Data is represented as Mean±Standard deviation. Analysis of data was done by independent sample t test. TABLE IV : Comparison of pulmonary function between smokers and non smokers in the exposed group. Smokers Non smokers P (n=29) (n=101) value FVC (L) 2.04± ± (L) 1.82± ± /FVC 0.87± ± PEFR (L/Sec) 4.61± ± FEF 25-75(L) 2.36± ± Data is represented as Mean±Standard deviation. Analysis of data was done by independent t test. Parameters Exposed Unexposed P (n=130) (n=130) value Age (yrs) 36.04± ± Body mass index (kg/m 2 ) 23.7± ± FVC (Litres) 2.92± ± FEV1 (Litres) 2.52± ± FEV1/FVC Ratio 0.86± ± PEFR (L/sec) 6.27± ± FEF (Litres) 3.01± ± TABLE V : Comparison of pulmonary patterns among exposed and unexposed. Pattern Exposed Unexposed Normal 38 (29%) 113 (87%) Reduction in FEF 25-75% 56 (43%) 12 (9%) Restrictive 22 (17%) 5 (4%) Mixed 14 (11%) 0 (0%) Analysis of data was done by Independent sample t test. Pulmonary function parameters were significantly reduced in exposed group compared to unexposed. BMI: Body mass index, FVC: Forced vital capacity, FEV1: Forced expiratory volume in one second, PEFR: peak expiratory flow rate; FEF 25-75: forced expiratory flow rate. Discussion This study was done to assess the respiratory health

4 208 Chandrasekaran, Dilara and Padmavathi Indian J Physiol Pharmacol 2014; 58(3) status of the tannery workers who are at a prolonged exposure to chromium and leather dust. The observed pulmonary functions of Tannery workers in this study showed a reduction in FEV1-2.52±0.68 (L), FVC ±0.8 (L), FEV1/FVC ratio-0.86±0.62, FEF ±1.09 (L) and PEFR ±1.95 (L) in relation to their predicted values and also compared to the unexposed. The tannery workers who are exposed to leather dust for longer duration (> 11 years) had statistically significant reduction in pulmonary functions except FEV1/FVC ratio. Our observations are consistent with Halim issever et al who postulated that the lung functions were lower in people who was working for more than 13 years (4). The reasons are attributed to long term exposure to chemicals like chromium salts, acidic compounds and various solvents. The other contributing factor is working in an environment where fungi multiply and provoke allergic reactions. There is a negative correlation between duration of exposure and pulmonary function values. This is consistent with the findings of Shahzad et al (5). The reduction in pulmonary function with duration of exposure was also substantiated by Linderberg et al (6). The workers showed a statistically significant decline in FEV1, FVC and FEF25 75 measurements taken on a Thursday afternoon as compared to those taken on a Monday morning on exposure to 2 gm Chromium (VI). Halim issever et al has also found that respiratory complaints disappeared in 81 (30.8%) workers during their holidays (4). In our study smokers showed a decline in pulmonary functions compared to the non smokers because smoking acts as an additional risk factor in the development of respiratory illnesses. Similar observation was made by Khurram Shahzad et al that smokers are at an increased risk of developing asthma as odds ratio was 2.22 (5). It is well known fact that smoking causes both airway disease and parenchymal disease by increasing neutrophilic infiltration, mucosal glandular hypertrophy and alveolar wall destruction (7). Thus smoking is found to aggravate airway disease in tannery workers. Spirometric assessment in the exposed group has showed normal pattern (29%), reduction in FEF25-75% alone (43%), restrictive pattern (17%) and mixed pattern (11%). Many authors have observed a predominance of obstructive pattern in tannery workers. (3, 4). Though our study did not record any cases of bronchial asthma in the exposed group, we have observed a predominant reduction in FEF25-75%. Many studies indicate that the forced expiratory flow at the 25 and 75% of the pulmonary volume (FEF ) might be considered as a measure of the caliber concerning distal airways, particularly in subjects with normal (8). Thus, FEF may be foreseen as a possible marker of early bronchial impairment (9). Therefore, small airways disease (SAD) as defined by a reduction in FEF and normal spirometry (normal and FVC) may be a marker for early allergic or inflammatory involvement of the small airways as in the case of bronchial asthma. Thus our study assumes importance in bringing out the early markers of an obstructive disease which will help us to prevent the occupational exposure. Among the respiratory morbidity in the tannery workers, the cases of occupational asthma (5%) were more prominent than any other respiratory illnesses (2). From the literature review, it is seen that the hexavalent chromium is quickly absorbed from the lungs into the blood and binds to the hemoglobin in the red blood cells. This impairs the oxygen carrying capacity leading onto respiratory morbidity. (10) This mechanism occurs through inhalational route. On dermal exposure, chromium binds with cutaneous proteins of tannery workers to generate complex antigens which lead to hypersensitivity. The resultant contact dermatitis could be predisposing condition to the onset of bronchial asthma (11). Humid environment where raw leather is wetted for several procedures, presents a suitable environment for the proliferation of microorganisms (12). Colonies of fungi may develop, specifically Aspergillus niger and Penicillium glaucum. Respiratory diseases caused by inhalation of mold spores such as atopic asthma, hypersensitivity pneumonitis, allergic bronchopulmonary aspergillosis and allergic fungal sinusitis are well recognized in tannery workers (13). Constant exposure to huge amount of fungal propagules is a significant risk factor for allergic conditions (14).

5 Indian J Physiol Pharmacol 2014; 58(3) Pulmonary Functions in Tannery Workers 209 Conclusion Limitations of the study This study has highlighted the respiratory health status of the tannery workers in Tamilnadu. Poor working conditions, exposure to array of chemicals including chromium and biological hazards are part and parcel of a tannery worker s life. Under these circumstances, their respiratory health is comprised to a considerable extent. So this study could provide base line information based upon which legal implementation of preventive measures could be undertaken. In order to prevent respiratory disorders among tannery workers, we suggest that medical surveillance, including pre-employment and periodic medical checkups, should be done that includes pulmonary function tests. This medical screening can protect workers from developing chronic respiratory disorders by allowing the early recognition of respiratory obstruction and then, possibly, the removal of sensitive workers from that area of the workplace before chronic impairment develops. Being a cross sectional study, we could not demonstrate the causal association between the exposure of chromium and ventilatory dysfunction.measurement of serum, urine chromium levels and air pollution levels in the working place and its correlation with the decline in pulmonary function could not be established. Future scope of the study We are planning to extend the study with a larger sample size and try to reveal all the possible respiratory morbidity among tannery workers by performing other investigations. We would also like to design appropriate personal protective equipment for the workers. This study can be extended to determine the halt in the further deterioration of respiratory impairment after implementation of preventive strategies. References 1. Andrew MC. In: Occupational lung diseases. Thurlbeck s Pathology of the Lung. 3 rd edition New York. Thieme: 2005; Shukla FG, Oryae FU, Rahmanb VK, Burdorfe A. Respiratory disorders, skin complaints, and low-back trouble among tannery workers in Kanpur. Am Indust Hyg Ass J 1997; 58: Rastogi SK. Occupational health risks among the workers employed in leather tanneries at Kanpur. Ind J Occupat Environ Med 2008; 22: Halim, Issevera K, Sat O, Ayhan OB, Hapcioglua N. Respiratory Problems in Tannery Workers in Istanbul. Indoor Built Environ 2007; Shahzad. Prevalence and determinants of asthma in adult male leather tannery workers in Karachi, Pakistan: A cross sectional study. BMC Pub Health 2006, 6: Lindberg E, Hedenstierna G. Chrome plating: symptoms, findings in the upper airways, and effects on lung function: Arch Environ Health 1983; 38(6): Abboud RT. Effect of smoking on plasma neutrophil elastase levels. J Lab Clin Med 1986; 108(4): Lipworth BJ. Effects of airway caliber on lung delivery of nebulised salbutamol. Thorax 1997; 52: Ciprandi. Bronchial hyper reactivity and spirometric impairment in patients with seasonal allergic rhinitis. Resp Med 2004; 98: Benedova D. Cytogenic effects of hexavalent chromium in chrome platters. Mutation Res 2002; 514: Lockman LE. Case report: allergic contact dermatitis and newonset asthma. Chromium exposure during leather tanning. Can Fam Phys 2002; 48: Brunekreef B. Associations between questionnaire reports of home dampness and childhood respiratory symptoms. Sci Tot Environ 1992; 127(1-2): Gelincik AA. The effect of indoor fungi on the symptoms of patients with allergic rhinitis in Istanbul. Indoor Built Environ 2005; 14(5): Sinha S, Sridhan, PV. Present and future assessment of noise level in the Neyveli region. J Environ Stud Policy 1999; 2(1): 1 13.