Predictive Equations for Lung Function Based on a Large Occupational Population in NorthThe currently used predictive equations of lung function in North China were derived from early study and have not been updated for nearly two decades. Methods: Using American Thoracic Society (ATS) standards, sexspecific spirometric predictive equations for forced vital capacity (FVC), forced expiratory volume in one second (FEV 1 ), ratio of FEV 1 to FVC (FEV 1 %) and forced expiratory flow at 25-75% of forced vital capacity (FEF 25-75% ) were derived from 2,897 asymptomatic, lifelong non-smokers (1,208 males, 1,689 females) from a large occupational population in North China.Stepwise multiple regressions were carried out to identify the best predictors of lung function parameters and predictive equations. Independent variables considered for inclusion in predictive equations including age, height, weight and chest circumference were examined. Results: Age and height were found to be necessary variables for all lung function parameters. Weight was a significant variable in only half of our equations. Chest circumferences (expired or inspired) was excluded as they are not practical in use. Data from 255 apparently healthy non-smokers were used to validate the equations by comparing percentage predicted values and proportion of subjects with normal predicted values with those from the study group, and a high accordance was obtained. Other equations published and used in North China do not appear to offer advantages over these equations. Conclusions: These newly developed predictive equations should ideally be applied to calculate lung function for adult individuals and populations as

. This paper predicted their potential toxicity to human using bronchoalveolar lavage technique on the basis of comparisons with positive reference materials (quartz and chrysotile) and negative reference materials (titanium dioxide and alumina (SAFFIL) fibre). All rats dosed with dust showed some increase in lung weight relative to the saline control, though the only significant differences were seen between the rats dosed with quartz or chrysotile and those dosed with saline. From the morphological observation of lavage cells, a benign reaction of macrophages to CF and CFC was observed, whereas a series of changes in macrophages was involved in rats dosed with quartz and chrysotile. CF and CFC did not induce a significant increase in the total cell count or percentages of neutrophils and lymphocytes in bronchoalveolar lavage. The two materials tested had much lower toxicity than that of quartz and chrysotile, and were comparable with the effect induced by titanium dioxide and SAFFIL fibre which had minimal toxicity. The present work provides a scientific basis for the setting of occupational health standards for carbon fibre and carbon fibre composite dust in the workplace. (J Occup Health 2001; 43: 75-79)

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