**Abstract**

Particulate matter (PM) is a mixture of solid particles and liquid droplets found in the air, and it is one of the most harmful air pollutants. When inhaled, it affects the pulmonary system, cardiovascular systems, and other tissues. The size, composition, and deposition of PM, mainly related to fine and ultrafine particulate matter, are factors that determine the harmful effects of exposure to particles. Among the main effects is the inducer of ROS production, and consequently oxidative tissue damage in target organs and other responses, mediated by inflammatory cytokines and cellular stress response. The main pathway through which particles are potent mediators of oxidative stress is the damage caused to DNA and lipid molecules, whereas the proinflammatory response involves an immune response against PM, which in turn, it is related to cell stress responses observed by heat shock proteins (HSPs) expression and release. Thus, the ability of an organism to respond to PM inhalation requires anti-oxidative, anti-inflammatory, and cellular stress defenses that can be impaired in susceptible subjects as people with chronic diseases as diabetes and obesity. In this chapter, we discuss the mechanistic aspects of PM effects on health and present some animal research models in particle inhalation studies.

**Keywords:** air pollution, fine particulate matter, oxidative stress, animal models
