Air quality and elemental concentrations in hair and urine of Italian and Chilean university students

The monitoring of human biological matrices (hair, urine) can provide information on inhalation exposure through direct measurement of chemical substance concentrations in different matrices (exposure and effect indicators). Elemental concentrations constitute one of the most widely used and reliable indicators of exposure. In this study, the concentrations of 41 elements were evaluated in the hair and urine of students from two universities: one located in Rome and one in Santiago, Chile. In addition to biological sampling, PM10 samples were collected on both university campuses using low-flow samplers (0.5 L min-1), on which elemental content and oxidative potential (OP; measured using DCFH, AA, and DTT acellular assays) analyses were performed. All elemental analyses were conducted using inductively coupled plasma atomic emission spectroscopy (ICP-MS) and atomic fluorescence spectroscopy (HG-AFS; 1,2). The influence of some variables related to participating students such as age, gender, body mass index, smoking, and diet was assessed on the obtained data. The average PM10 concentration was 26 μg m-3 in Rome and 71 μg m-3 in Santiago, Chile, indicating significantly different levels of inhalation exposure in the two areas. In particular, levels of Cu, Mo, Sn, and Sb, which are tracers of non-combustive vehicular traffic (mechanical abrasion of brakes; 3,4), 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 levels of metal and metalloid accumulation 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, Li, Mo, Sb, and Sr. On the contrary, Cu, Al, and Sn varied significantly in both urine and hair not in reference to the geographical area but depending on the gender of the participants. The possible increase in oxidative stress levels in the urine of subjects exposed to the air in Santiago, will be verified by the analysis of effect markers, such as oxo-guanine and other DNA and RNA oxidation products. Keywords: biomonitoring, metals, PM10, oxidative potential, human biological matrices, public health Bibliography [1] Astolfi ML et al. 2020. DOI: 10.3390/ijerph17061911 [2] Astolfi ML et al. 2020. DOI: 10.1039/C9AY01871A [3] Thorpe A and Harrison RM 2008. DOI: 10.1016/j.scitotenv.2008.06.007 [4] Massimi L et al. 2020. DOI: 10.1016/j.envpol.2020.115271