Use of Real-time Sensors to Characterise Human Exposures to Combustion Related Pollutants

Concentrations of black carbon and nitrogen dioxide have been collected concurrently using a MicrAeth AE-51 and an Aeroqual GSS NO(2) sensor. Forty five sampling events with a duration spanning between 16 and 22 hours have collected 10,800 5 min data in Birmingham (UK) from July to October 2011. The high temporal resolution database allowed identification of peak exposures and which activities contributed the most to these peaks, such as cooking and commuting. Personal exposure concentrations for non-occupationally exposed subjects ranged between 0.01 and 50 μg m(-3) for BC with average values of 1.3 ± 2.2 μg m(-3) (AM ± SD). Nitrogen dioxide exposure concentrations were in the range <LOD to 800 ppb with average concentrations of 23 ± 50 ppb. The correlation between personal exposures (PEs) and central site (A) concentrations was evaluated, with only NO(2) exposures averaged over the sampling event significantly correlating with central site levels. The PE/A ratio ranged between 1.1 (BC) and 0.2-0.7 (NO(2)) in the absence of combustion sources to 13 (BC) for subjects commuting in trains and 2.9 (NO(2)) for subjects cooking with gas appliances.