Maximal expiratory flow volume values evaluation among female quartz grinders

used test for serial distribution of airway obstruction [2] and in Background: A recent review in silica dust exposed diagnosing chronic obstructive workers focused on airway obstruction and the variables disease in surveys of air pollution used were forced vital capacity (FVC), FEV1 and FEV1%. etc. Tests of peak flow (PEF), MEFR Original Article Nellore Mohan Rao, Ramnath Takiar, Yashwant K. Sharma National Institute of Occupational Health (ICMR), Ahmedabad ­ The maximal expiratory flow volume (MEFV) values i.e., and even FEV reflect the air flow 1 peak expiratory flow (PEF), FEF75, FEF50 and FEF25 are resistance offered chiefly by central not only useful to differentiate obstructive and restrictive ‘larger’ airways, where as tests of type of functional abnormalities, but also the site of airway MMEF maximal flow at 50 and 25 obstruction i.e., larger airways by PEF, FEF75 or smaller percent of VC reflect airflow airways by FEF50, FEF25. Hence, studies on MEFV values characteristics of peripheral or are needed. Aims: To identify the site of airway obstruction smaller airways revealing superiority among female quartz grinders. Settings and Design: of MEFV values (PEF, FEF, FEF Quartz grinding industry workers in Chota Udepur 50 in identifying the site of obstruction. (Gujarat) by cross sectional study. Materials and Methods: The MEFV values were measured among 106 female quartz grinders using SP-10 computerized Two recently reviewed articles on spirometer and predicted and percentage of predicted lung function in silica dust exposed values were derived.The average MEF values were workers [5,6] indicated both restrictive compared according to age (<24; 25-34; 35-44 and >45 (R) and obstructive (O) type of yrs). The percentage predicted MEFV values were abnormalities. These were based on compared between normal and chest X-ray abnormal the conventional spirometric (silicosis and silico-tuberculosis) workers and between variables i.e., FVC, FEV1 and FEV normal and abnormal spirometry (restrictive (R), Studies on analysis of MEFV values obstructive (O) and R+O) workers. Statistical Analysis: in silica dust exposed found evidence Summary statistics, ANOVA and χ2-test. of small airways obstruction in Results: Significantly high reduction in MEFV values in Singapore quarry workers > 45 yr. Workers; significant loss in silicosis and Indian quarry workers. The Indian silicotuberculosis pronouncing higher in silicotuberculosis study pointed out that the effects are workers; significantly higher impairment R+O type of probably due to smoking than dust functional abnormal than other type of abnormalities. exposure. The MEFV values were not These indicated that site of obstruction is both in larger evaluated in relation to age and chest and smaller airways. Conclusions: The MEFV values X-ray abnormalities. Hence, in this indicated that the site of obstruction is in both in smaller present report MEFV values are 380016, India For correspondence: Dr. N. Mohan Rao, Respiratory Physiology Department, National Institute of Occupational Health (ICMR), Ahmedabad 380 016, India. E-mail: [email protected] , FEF 25 )