Determination and Prediction of Respirable Dust and Crystalline-Free Silica in the Taiwanese Foundry Industry.

Ching-Tang Kuo,Ta-Yuan Chang,Fen-Fen Chiu,Bo-Ying Bao

doi:10.3390/ijerph15102105

Abstract

Background: Respirable crystalline silica (RCS) has been recognized as a human carcinogen; however, the measurement and analysis of RCS in small-scale foundries is rare and difficult. This study aimed to measure respirable dust and RCS levels among 236 foundry workers in Taiwan and used these data to establish predictive models for personal exposure. Methods: Personal sampling of various production processes were measured gravimetrically and analyzed using the X-ray diffraction method. Multiple linear regression was used to establish predictive models. Results: Foundry workers were exposed to geometric means and geometric standard deviations of 0.52 ± 4.0 mg/m3 and 0.027 ± 15 mg/m3 for respirable dust and RCS, respectively. The highest exposure levels were observed among workers in the sand blasting process, with geometric means of 1.6 mg/m3 and 0.099 mg/m3 for respirable dust and RCS, respectively. The predictive exposure model for respirable dust fitted the data well (R2 = 0.75; adjusted R2 = 0.64), and the predictive capacity for RCS was higher (R2 = 0.89; adjusted R2 = 0.84). Conclusions: Foundry workers in the sand blasting process may be exposed to the highest levels of respirable dust and RCS. The developed models can be applied to predict respirable dust and RCS levels adequately in small-scale foundry workers for epidemiological studies.

Highlights

Many studies have reported on the association between exposure to respirable crystalline silica (RCS) and adverse health effects, including silicosis, lung cancer, non-malignant respiratory disease, and possibly kidney disease [1,2,3,4,5]
Values of respirable dust and Respirable crystalline silica (RCS) were found both in Factory B (0.83 mg/m3 ; 0.092 mg/m3 ), no significant differences were observed between factories
This study identified that, in Taiwan, foundry workers in the sand blasting process had the highest levels of both respirable dust and RCS

Summary

Introduction

Many studies have reported on the association between exposure to respirable crystalline silica (RCS) and adverse health effects, including silicosis, lung cancer, non-malignant respiratory disease, and possibly kidney disease [1,2,3,4,5]. The Occupational Safety and Health Administration (OSHA) in the United States recently established a new permissible exposure limit (PEL) of 50 μg/m3 to reduce the risk of silicosis, lung cancer, other lung diseases, and kidney disease [10,11]. This study aimed to measure respirable dust and RCS levels among 236 foundry workers in Taiwan and used these data to establish predictive models for personal exposure.

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Methods

Results

Discussion

Conclusion