title: Silica Exposure and Effect on Peak Expiratory Flow: Slate Pencil Workers' Study.
abstract: BACKGROUND
  Peak expiratory flow (PEF) is a spirometric test that detects obstructive changes in the respiratory tract; has good correlation with the FEV1; and is much less expensive, simpler, and easier to perform under field conditions than FEV1. Chronic silicosis is also known to have obstructive features in advanced stages. Thus, this study was performed to assess the effect of silica exposure on PEF and the factors related to it.
  
  
  METHODS
  The present study was carried out among 193 slate pencil cutting workers of Multanpura village of Madhya Pradesh, India. An interview technique was used to record demographic characteristics and occupational history on a predesigned form, which included a questionnaire regarding occupational history and silica-related respiratory morbidities. This was followed by a complete medical examination and measurement of PEF using a spirometer.
  
  
  RESULTS
  The mean age was 43.35 ± 11.31 y, and the mean duration of exposure was 18.72 ± 9.33 y. In the present study, PEF was found to be significantly reduced in those age ≥40 y, those who were female, those having duration of exposure >10 y, and those having respiratory morbidity, whereas the reduction in PEF was statistically nonsignificant for smokers.
  
  
  CONCLUSIONS
  Higher age, female sex, higher duration of exposure, and respiratory morbidity were found to be important correlates of PEF.
authors.affiliation: National Institute of Miners' Health, Nagpur, India.
authors.forename: Rajnarayan Ramshankar
authors.initials: RR
authors.lastname: Tiwari
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D066192:Manufacturing Industry; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D010366:Peak Expiratory Flow Rate / Q000187:drug effects*; D012307:Risk Factors; D012737:Sex Factors; D012822:Silicon Dioxide / Q000633:toxicity*; D012829:Silicosis / Q000209:etiology / Q000503:physiopathology*; D013147:Spirometry; D011795:Surveys and Questionnaires; D013997:Time Factors
chemical_list: D012822:Silicon Dioxide
keywords: India; PEF; silica; silicosis; slate pencil cutters