Modifies a noun

• silica: These methods were then applied to develop and test hypotheses about the impact on exposure patterns of respirable silica and dust.

• dust: Respirable dust: Is not visible to the eye nor to some optical microscopes.

• particle: Production and toxicity of respirable silica particles from biomass burning.

• fiber: Respirable fibers can penetrate to the " deep " lung area.

• fiber: Repeated or prolonged inhalation of excessive concentration of respirable fibers may cause permanent lung injury " [ 4 ] .

• fibres/ml: For these categories, exposure should be kept below the clearance limit of 0.01 respirable fibres/ml of air.