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322 Prevalence of occupational exposure to respirable crystalline silica in the metal working industries: transferring research into industrial practice
  1. Cláudia Fernandes,
  2. Cláudia Ribeiro,
  3. Rita Aguiã,
  4. Mónica Henriques
  1. CATIM – Technological Centre for the Metal Working industry, Porto, Portugal


Introduction The exposure to respirable crystalline silica (RCS) in some industrial processes within the metal working industry is a recognised occupational hazard, mainly due to the classification of RCS as a group 1 carcinogen to the respiratory system, and the severity of the exposure consequences.

Methods This study was conducted based on the determination of the concentration of airborne RCS particles and the evaluation of its risk level among metal workers placed in 15 industrial SME’s and 130 workplaces. The study was conducted in two industrial processes:

  1. foundry;

  2. other processes with the exposure risk.

Occupational personal exposure to RCS was measured in all workers exposed using the NIOSH method 7500.

Result The range of RCS concentrations are:

  1. global sample is 1,159 mg/m3 – (0,006 mg/m3);

  2. foundry 0,093 mg/m3;

  3. other processes 0,018 mg/m3.

For the 130 workplaces monitored, 82 were higher than the permitted limit recommended by the Standard NP 1796: 2014. The processes with higher risk of exposure are those within ‘pure foundry’ such as metal melting, casting, sand moulding, pouring and repairing furnace.

Discussion The average concentrations of RCS for the assessed workplaces were higher than the exposure limits by NP 1796:2014. An intervention plan for each SME was designed encompassing measures at different levels aiming the promotion of health and wellbeing in the workplaces. Due to the severity of the exposures consequences urgent actions must be taken in the workplaces. The inclusion of measures that go beyond the definition of ‘simple’ personal protective equipment (PPE) are needed to raise the level of prevention. Such interventions are well seen by SME but conditioned by operational and budgeting issues. The information on this study, about occupational processes and individual tasks and the corresponding levels of RCS exposure can guide future needs for intervention in critical areas.

  • Occupational Health
  • respirable crystalline silica
  • transferring research into practice

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