Personal and indoor exposure to nanoparticles and its relationship to biological markers

Exposure to particulate matter (PM) and its components is associated with negative health outcomes. It is hypothesised that the channel through which these effects are expressed is via the mechanism of inflammation and oxidative stress. In order to assess the relationship between exposure and health outcomes in different personal and indoor exposure environments (Homes, Office, Commuter mode, Restaurant, Shisha lounge, Busy traffic site and Control environments), the association between exposure to PM/PM components and changes in local/systemic inflammation and oxidative stress biomarkers (EBC-nitrate, EBC-nitrite, EBC-pH and urinary 8-oxodG), alterations in autonomic and lung functions respectively were measured. The acute/elevated exposures showed significant increases in EBC nitrate and nitrite immediately after exposure but EBC-pH and urinary 8-oxodG, did not significantly change in post exposure measurements. In some of the exposure scenario, significant correlations were observed between the pollutants measured and the biomarkers. Urinary metals were also analysed and compared with biomarkers and PM/PM components. Indoor PM mass-size distribution, showed that PM prevailed in the 250 – 500 nm and the 2500 – 5000 nm size range. Na, Fe, Mn, Ca and Mg prevailed in the coarse mode (2500 – 5000 nm) and toxic metals such as Mn, Cu, V, Ni, Pb and Sn were observed. Si, S, K and Fe were the most prevalent elements observed in the particles collected analysed with TEM/EDS. The increases observed in post exposure measurements, significant correlations observed between the biomarkers and the measured PM/PM bound components in the different environments and alterations in lung function, suggests that exposure to PM/PM bound components have the ability to cause inflammation/oxidative stress thereby affecting human health. This study shows that biomarker expression after exposure can be used to measure acute responses