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 (T0) and at a suburban-receptor site (T1), pooled according to two observed ventilation patterns (T0 → T1 influence and non-influence). T0 samples contained more Cu, Zn, and carbon whereas; T1 samples contained more of Al, Si, P, S, and K (p   < 0.05). Only SO4−2 increased in T1 during the influence periods. Oxidative potential correlated with Cu/Zn content (r = 0.74; p < 0.05) but not with biological effects. T1 PM10 induced greater hemolysis and T0 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.

► Transport-related changes in PM10 composition, oxidative potential and in vitro toxicity were studied. ► Cu, Zn, and carbon levels were predominant in urban PM10; receptor site PM10 was rich in soil elements. ► SO4−2 was the only component increased in PM10 from the receptor during the influence periods. ► PM10 oxidative potential correlates with Cu/Zn content but not with studied biological effects. ► Ventilation patterns had little effect on PM10 composition and toxicity.