In vivo and In vitro Assessment of Particulate Matter Toxicology

Abstract

Exposure to ambient particulate matter (PM) can have profound adverse effects on human health. Epidemiology studies have revealed associations between ambient PM and health effects ranging from increased hospital admissions to increased mortality rate. Factors such as particle size, surface area, and composition appear to influence how the body reacts to the inhaled PM. In vivo studies using humans and animals have provided insight into the toxicity of different types of PM, in terms of lung and vascular functions as well as inflammatory and oxidative stress markers. In vitro studies using human cells are allowing elucidation of pathophysiological mechanisms underlying observed in vivo effects. The most common pathway proposed for respiratory effects is the production of reactive oxygen species (ROS) causing oxidative stress in mammalian cells. Cardiovascular effects may also be caused by release of pro-inflammatory and pro-oxidant mediators from the lungs, but autonomic imbalance and translocation of PM to systemic circulation are also postulated as potential mechanisms.