A chemical and toxicological comparison of urban air PM10 collected duringwinter and spring in Finland

We have used a new high-volume, low-cutoff inertial impactor (HVLI) in a pi lot study on chemical characterization and toxicity testing of ambient air PM10 in Helsinki, Finland. Ambient air PM10 was collected at 1100 L/min in 2- to 4-day periods. Two different PM10 samples were selected to represent wintertime combustion type and springtime resuspension type particulate mat ter (PM) pollution. The most abundant water-soluble ions and elements were analyzed by ion chromatography and inductively coupled plasma mass spectrom etry, respectively. The proinflammatory activation [NO and interleukin 6 (I L-6) production] and viability of cultured murine RAW 264.7 macrophages wer e tested in 24-h incubations with increasing mass doses (30-2000 mu g per 1 0(6) cells) from the collected PM10 samples. The winter sample had a higher assessed PM2.5 fraction and sulfate content, and lower chloride, sodium, c alcium, aluminum, copper, manganese, and especially iron contents than the spring sample. Both PM10 samples induced dose-dependent NO production in mu rine macrophages, and the springtime PM10 produced also a strong, dose-depe ndent IL-6 production. In conclusion, the HVLI proved to be a suitable tech nique for short-term collection of relatively large ambient air PM masses, enabling extensive chemical characterization and toxicity testing from the same samples.