The US National Institute for Occupational Safety and Health has made software available that it says will enable mining companies to monitor worker exposure to respirable crystalline silica more effectively (RCS).
The 'field analysis of silica tool' (FAST) is a significant improvement because it allows the determination of a worker’s exposure to RCS dust immediately after their shift, the institute says. Traditional methods require companies to send samples to a commercial lab for analysis.
RCS is a major inhalation hazard for mine workers. It can lead to silicosis, lung cancer, coal workers’ pneumoconiosis (CWP) also known as black lung, tuberculosis and chronic obstructive pulmonary disease (COPD).
In March, Niosh announced that it had developed a portable, field-based method for monitoring levels of airborne silica in mines. It also said that it was developing an associated software application.
FAST, which is available as a beta version only, works with commercially available Fourier transform infrared (FTIR) analysers and is accurate for coal mines. The results from samples collected in other types of mines should be considered approximations because the possible presence of other minerals may decrease the accuracy of the quantification model, Niosh says.
Future versions of FAST will improve accuracy for samples from other commodity types aside from coal, and potentially extend the system beyond mining.
Global action needed
The occupational risks of silica are a major concern for a range of stakeholders. In June, the International Commission on Occupational Health (ICOH) called for global action to reduce silica exposure in high-risk occupations to help tackle tuberculosis (TB). Despite efforts to control TB, it remains ninth in the top ten causes of death globally, with 10.4m new cases arising in 2016, the ICOH said.
In the same month, most of the provisions of the US standard for RSC came into effect. The standard for general industry and maritime established an eight-hour, time-weighted average (TWA), permissible exposure limit (Pel) of 50µg/m3.
In August, the Occupational Safety and Health Administration made available online a set of frequently asked questions (FAQs) on the standard for RCS in construction, plus six training videos. The videos give instruction on methods for controlling exposure to silica dust when performing common construction tasks or using construction equipment, such as handheld power saws, jackhammers, drills and grinders.