Effect of air quality on oxidative stress and elemental levels in hair and urine of Italian and Chilean students

In this study, urinary oxidative stress biomarkers and the concentrations of 41 elements were determined in the hair and urine of students from two universities: one located in Rome and one in Santiago, Chile. In addition to biological samples, PM10 samples were collected and analyzed elemental content and oxidative potential (OP; measured using cell-free DCFH, AA, and DTT assays). All elements were analyzed by ICP-MS and HG-AFS (1,2); while oxidative stress biomarkers were determined by HPLC/MS-MS. The final concentration of the analytes was expressed in μg/g of creatinine to normalize values with respect to urine dilution variability (3). When processing the data, the influence of some variables related to the participating students was evaluated, such as age, sex, body mass index, smoking and diet. The average PM10 concentration was 26 μg m-3 in Rome and 71 μg m-3 in Santiago, Chile, indicating significantly different inhalation exposure levels in the two areas. In particular, levels of Cu, Mo, Sn, and Sb, tracers of non-combustive vehicular traffic (mechanical abrasion of brakes; 4,5), showed significantly higher concentrations in Chilean PM10 samples compared to Italian ones. The OP values measured by the DCFH and AA assays were also clearly higher at the Chilean site, confirming a significant contribution of non-combustive vehicle traffic to the oxidative potential of dust. The different elemental concentrations in PM10 translated into different metal and metalloid accumulation levels in the two studied biological matrices. The elements that presented the most significant differences between Italian and Chilean students in both biological matrices were Cs, Hg, Mg, Mo, Rb, Sr, Tl, Zn. On the contrary Al, and Sn varied significantly in urine and hair, not in reference to the geographical area but depending on the participant's gender. References [1] Astolfi, M. L., Protano, C., Marconi, E., Massimi, L., Piamonti, D., Brunori, M., ... & Canepari, S. (2020). International Journal of Environmental Research and Public Health, 17(6), 1911. [2] Astolfi, M. L., Protano, C., Marconi, E., Massimi, L., Brunori, M., Piamonti, D., ... & Canepari, S. (2020). Analytical methods, 12(14), 1906-1918. [3] Buonaurio, F., Borra, F., Pigini, D., Paci, E., Spagnoli, M., Astolfi, M. L., ... & Tranfo, G. (2022). Toxics, 10(5), 267. [4] Thorpe, A., & Harrison, R. M. (2008). Science of the total environment, 400(1-3), 270-282. [5] Massimi, L., Ristorini, M., Simonetti, G., Frezzini, M. A., Astolfi, M. L., & Canepari, S. (2020). Environmental Pollution, 266, 115271.