Simultaneous inboard and outboard, inflight measurements of ultrafine particle concentrations

Inboard and outboard particle number concentrations are reported from 12 flights from the FAAM BAe-146. The data show that the concentrations pre take off and post landing are dominated by external sources. The concentrations in the cabin are generally lower than outside and pre-take off peak after the doors have closed in 75% of cases. In flight cabin events were associated with either ingress of external particles, or particles generated by the airframe. The airframe events were sporadic in nature, and often associated with changing engine conditions. In over 50% of cases, in cabin particle events were observed on approach, with no increase in outboard concentrations. Supporting aerosol composition data showed that non-exhaust, non-airport sources also influence the cabin air quality, including the presence of lubrication oil. The average number concentration exposure was between 6800 and 10,800 cm−3 per flight and, during a fume event, the average organic mass concentration exposure was 5.85 µg m−3 for the flight. The mass concentration exposure and associated average concentration are below UK workplace exposure limits for non-hazardous dusts and PM10 24-h air quality standards.