What parameters adversely impact lung function of workers exposed to respirable crystalline silica?

![CDATA[The findings from this study and others presented in the literature indicate that the current exposure standard is not adequate to protect workers respiratory health. The results of electron micrographs show that particle size and shape of the crystalline silica particles that some workers are exposed to relate to the sampling efficiency curve for respirable dust. The recently introduced IS013138 (2012) "Sampling conventions for airborne particle deposition in the human respiratory system", presents new particle size conventions for sub-micron particles that can reach the alveolar part of the lung by deposition. The conventional method AS2985-2009 refers mainly, to particles, with a theoretical median aerodynamic diameter of 4.25 ~m that can reach the lung by penetration. In the current study particles both smaller and larger than 4.25 ~m were measured in accordance with AS2985-2009. A weakness of the AS2985-2009 standard however, is that sampling larger particles may not provide an accurate estimate of risk where particles less that 2 ~m are considered to be much more hazardous. In this study it is also suggested that the particle shape (morphology) is a key factor which warrants further investigation when assessing the impact particles have on the lung. The main aim of this study is to assess exposure and what impact exposure has on lung function for quarry workers in Queensland. The exposure assessment presented in this study will evaluate the risk of exposure to RCS and contributing factors including Exposure profile; Particle size distribution; and Morphology.]]