ABSTRACT
This chapter discusses principles relating to the lung response to exposure to particulate matter in the work environment. In the work environment, the health hazards resulting from the exposure to them is of particular importance because they are a common feature and their biological effects are often insidious. The threshold limit value refers to the airborne concentration of particles and represents conditions under which it is believed that nearly all workers may be repeatedly exposed day after day without adverse health effects. Regarding chemical substances present in inhaled air as suspensions of particles, the potential hazard depends on particle size as well as mass concentration. Particles penetrate into the human body through the respiratory system, causing a local effect on the lungs and other parts of the system and then passing into the blood stream and causing systemic effects. For insoluble particles, the site of deposition in the respiratory system is of fundamental importance.
