The oxidative potential and biological effects induced by PM10 obtained in Mexico City and at a receptor site during the MILAGRO Campaign

As part of a field campaign that studied the impact of Mexico City pollution plume at the local, sub-regional and regional levels, we studied transport-related changes in PM10 composition, oxidative potential and in vitro toxicological patterns (hemolysis, DNA degradation). We collected PM10 in Mexico City (T-0) and at a suburban-receptor site (T-1), pooled according to two observed ventilation patterns (T-0 -> T-1 influence and non-influence). T-0 samples contained more Cu, Zn, and carbon whereas; T-1 samples contained more of Al, Si, P, S, and K (p < 0.05). Only SO4-2 increased in T-1 during the influence periods. Oxidative potential correlated with Cu/Zn content Cr = 0.74; p < 0.05) but not with biological effects. T-1 PM10 induced greater hemolysis and T-0 PM10 induced greater DNA degradation. Influence/non-influence did not affect oxidative potential nor biological effects. Results indicate that ventilation patterns had little effect on intrinsic PM10 composition and toxicological potential, which suggests a significant involvement of local sources. (C) 2011 Elsevier Ltd. All rights reserved.