Table 2.

Basic parameters needed for risk assessment of inhaled particles

Parameter	Purpose
Particle size, shape, density	Estimate inhalation and lung region-specific deposition fraction
Particle surface area, reactivity, solubility	Evaluate mode of action and local or systemic effects
Multiple exposure or dose groups	Describe dose–response relationship; estimate benchmark dose
Biological significance of response	Evaluate severity and relevance to humans
Body and lung weight; target lung region surface area and volume	Normalize dose from animals to humans