PM arising from WTS activity has elevated trace metal concentrations and, as a consequence, increased oxidative potential.
Other contributors to the burden of airborne particulates include PM arising from flaring of volatile hydrocarbons at refineries and/or incomplete combustion of unused or fugitive hydrocarbons at petrochemical plants.
These observations prompt a number of questions about the health impact of exposure to elevated levels of PM10 2.5 and PM2.5 and about the specific toxicity of PM arising from wildfires in this region.
Outdoor concentrations for pollutants such as NO2, CO, and PM often arise from the same combustion emissions sources, such as motor exhausts.
The oxidative stress mediated by PM may arise from direct generation of ROS or be related to altered function of mitochondria or NADPH-oxidase (nicotinamide adenine dinucleotide phosphate-oxidase) and activation of inflammatory cells capable of generating ROS, reactive nitrogen species, and oxidative DNA damage (Gonzalez-Flecha 2004; Risom et al. 2005).
Oxidative stress mediated by PM may arise from direct contact with reactive oxygen species on the surface of particles that deposit in the lungs, soluble compounds such as transition metals or organic compounds that enter the bloodstream, or activation of inflammatory cells capable of generating reactive oxygen and nitrogen species (Risom et al. 2005).
For example, preclinical markers of IHD have been associated with TRAP or PM partly arising from traffic (Künzli et al. 2005).
Although this approach effectively decreases the overall air quality burden the waste management system poses on an urban center, communities in proximity to WTSs suffer from enhanced traffic flow and increased particulate matter (PM) levels arising from vehicular tailpipe/nontailpipe emissions and dust releases from laden trucks (Fuller and Baker 2001; Restrepo et al. 2004).
In addition, oxidative stressors resulting from PM exposure may arise from organic compounds and from activation of inflammatory cells capable of generating reactive oxygen species (ROS) and reactive nitrogen species (RNS) (Risom et al. 2005).
This behaviour contrasted with anthropogenic non-primary PM which mainly arises from secondary formation and consequently shows only gradual changes in concentrations.
