Riassunto

Objectives To estimate a threshold value for the respirable quartz dust concentration and silicosis incidence (1/1, ILO 1980/2000) in the German porcelain worker cohort.

Methods Forty incident cases occurred among 17,144 workers. Estimation of the relationship to cumulative respirable quartz dust exposures by using Cox regression with restricted cubic splines (7 knots or less) and fractional polynomials (degrees 5 or less). Threshold estimates were obtained by subtracting candidate values from the time-dependent concentration data (setting the result to zero if negative) and recalculating cumulative exposure.

Results Best threshold estimate was 0.25 mg/m3 (95% confidence interval: 0.15 to 0.30 mg/m3).

Conclusions A concentration threshold for silicosis risk is plausible. A threshold Cox model fitted the data significantly better than a nonthreshold model, summarized the cohort information without a loss in extracted information and more simply than restricted cubic splines and fractional polynomials.

Keywords

porcelain worker, quartz dust, Respirable quartz, silicosis, threshold value

Articoli correlati che potrebbero interessarti

Perry Gottesfeld, Damian Andrew, Jeffrey Dalhoff

Silica Exposures in Artisanal Small-Scale Gold Mining in Tanzania and Implications for Tuberculosis Prevention

Journal of Occupational and Environmental Hygiene. Vol. 12, Iss. 9, September 2015

Matthias Möhner, Norbert Kersten, Johannes Gellissen

Chronic obstructive pulmonary disease and longitudinal changes in pulmonary function due to occupational exposure to respirable quartz

Vol. 70, Iss. 1, January 2013