Studies of Concentrated Ambient Particles Provide a Causal Link
The fine particle concentrator is a new technology that can capture ambient particles from the air and deliver selected concentrations to exposure chambers, where biological responses can be monitored and compared with those exposed to filtered air.
Studies of concentrated ambient particles (CAPs) have been safely performed with humans and animals, and extracts of the CAPS have been used for in vitro studies of lung cells.
Advantages of studies with concentrated ambient particles are that they use “real-world” particles, and that they allow exposures at high enough concentrations to assess a range of responses. Disadvantages are that exposures can be variable in mass and composition from day to day and hour to hour.
Studies of human volunteers using CAPs have shown acute lung inflammation and changes in blood indices and heart rate variability. Animal studies support potential pulmonary inflammation, blood changes, and alterations of specific cardiac endpoints. Overall, these studies have shown that ambient particles target the heart and blood vessels, in addition to the lung, and suggest that specific components in CAPs may differentially affect these tissues.
Investigators conclude that “results have provided a causal link between PM exposure and human adverse health effects.”
Ghio, AJ, and Huang, Y-CT. Exposure to Concentrated Ambient Particles (CAPs): A Review. Inhalation Toxicology 2004;16:53-59.
The National Library of Medicine [www.ncbi.nlm.nih.gov/PubMed] offers the abstract online.
