It is well established that exposure to Particulate Matter (PM) has negative effects on human health. Even though the current body of evidence provides much needed information on PM toxicity, there still remain key unanswered questions regarding the role of variations in its structural and compositional properties in inducing toxic effects. This research project aimed to determine the association of induced toxic effects in cell-free and cell-based assays with PM's physicochemical and mineralogical characteristics. To do so, we focused on three different particle types with specific characteristics needed for the purpose of this research project and hence, we used; (i) Crushed Rock Powders (CRPs) from the Panasqueira mine area in Portugal; (ii) PM10 from Makkah, Saudi Arabia; and a (iii) Certified Reference Material (CRM-ERMZC120). The genotoxicity and cytotoxicity of the CRPs were found to be dependent on their structural and compositional properties, in particular and perhaps specific to these samples, MnO, Zn, S, Cu, and clinochlore IIb2. The genotoxic and cytotoxic effects of Makkah PM10 were found to be associated with meteorological conditions on the day of sampling and which are used here as a proxy for PM10 sources and composition. We found that fine particles of whatever origin and anthropogenically-sourced secondary particles were associated with genotoxic and cytotoxic effects. Based on observations in cell-free and cell-based assays, it can be concluded that toxicity is dependent on (i) particles' chemistry and surface reactivity in cell-free assays; (ii) particle size and surface area in cell-based assays; and (iii) sometimes both factors in (i) and (ii). This study has highlighted the role of particularly chemical composition, and/or mineralogy in controlling the extent and/or nature of genotoxic and cytotoxic effects caused by particulates. Lastly toxicity assay data are reported for a widely available CRM, ERMCZ120, providing a common reference that can be used for comparative purposes for other researchers investigating the toxic effects of PM.
|Date of Award||1 Aug 2020|
- The University of Manchester
|Supervisor||David Polya (Supervisor) & Andrew Povey (Supervisor)|
- Air pollution, Particulate matter (PM), PM10, adverse health effects in humans, genotoxicity, cytotoxicity, DNA strand breaks, DNA damage, loss of viable cells, association with composition and source