Comparison of how ambient PMc and PM2.5 influence the inflammatory potential. (December 2013)

• Record Type: Journal Article
• Authors: Ferguson, Matthew D.; Migliaccio, Chris; Ward, Tony
• Is Part Of: Inhalation toxicology. Volume 25:Number 14(2013)
• Page Start: 766
• Page End: 773
• Publication Date: 2013-12
• Subjects: Pulmonary toxicology -- Animal models -- Periodicals; Pulmonary toxicology -- Periodicals; Air -- Pollution -- Health aspects -- Periodicals; 616.200471
• DOI: 10.3109/08958378.2013.847993
• Languages: English
• ISSNs: 0895-8378

Abstract

<abstract> <title>Abstract</title> <p>Airborne particulate matter (PM) is one of the six criteria air pollutants currently regulated by the U.S. Environmental Protection Agency (EPA), with existing ambient standards for PM<sub>2.5</sub> and PM<sub>10</sub>. Currently there are no health-based regulations for the size fraction between 2.5 and 10 µm, commonly known as the coarse fraction (PM<sub>c</sub>). The present study investigates current gaps in knowledge for PM<sub>c</sub> including exposure toxicity and PM ratios (PM<sub>c</sub>:PM<sub>2.5</sub>) in PM<sub>10</sub>. Throughout the world, all the three PM size fractions have been shown to be associated with adverse impacts. Recent studies have shown that PM<sub>c</sub> can be more detrimental to susceptible populations when directly compared to PM<sub>2.5</sub>, and that the PM<sub>c</sub> fraction in PM<sub>10</sub> can account for the majority of the inflammatory response from PM<sub>10</sub> exposure. In our studies we utilized a bone marrow-derived mouse macrophage <italic>in vitro</italic> system to compare the inflammatory potential of PM<sub>c</sub>, PM<sub>2.5</sub> and mixtures of the two. The result was a linear increase in interleukin(IL) -1β with increasing levels of exposure to winter and summer PM<sub>c</sub>, as compared to PM<sub>2.5</sub>, which exhibited logarithmic growth. Also, exposure to PM<sub>10</sub> as a function of PM<sub>2.5</sub> and PM<sub>c</sub> mass ratios showed that IL-1β and TNF-α levels increased synergistically with a greater burden of PM<sub>c</sub>. Endotoxin content in the PM did not correlate with these results, suggesting that other activators in PM<sub>c</sub> are likely responsible for activating the NF-κB pathway and the inflammasome.</p> </abstract>