Oxidative potential of the inhalation bioaccessible fraction of PM10 and bioaccessible concentrations of polycyclic aromatic hydrocarbons and metal(oid)s in PM10.

Atmospheric particulate matter (PM) has been related to numerous adverse health effects in humans. Nowadays, it is believed that one of the possible mechanisms of toxicity could be the oxidative stress, which involves the development of reactive oxygen species (ROS). Different assays have been proposed to characterize oxidative stress, such as dithiothreitol (DTT) and ascorbic acid (AA) acellular assays (OPDTT and OPAA), as a metric more relevant than PM mass measurement for PM toxicity. This study evaluates the OP of the bioaccessible fraction of 65 PM10 samples collected at an Atlantic Coastal European urban site using DTT and AA assays. A physiologically based extraction (PBET) using Gamble's solution (GS) as a simulated lung fluid (SLF) was used for the assessment of the bioaccessible fraction of PM10. The use of the bioaccessible fraction, instead of the fraction assessed using conventional phosphate buffer and ultrasounds assisted extraction (UAE), was compared for OP assessment. Correlations between OPDTT and OPAA, as well as total and bioaccessible concentrations of polycyclic aromatic hydrocarbons (PAHs) and metal(oid)s, were investigated to explore the association between those compounds and OP. A correlation was found between both OP (OPDTT and OPAA) and total and bioaccessible concentrations of PAHs and several metal(oid)s such as As, Bi, Cd, Cu, Ni, and V. Additionally, OPDTT was found to be related to the level of K+.

Multi-class organic pollutants in atmospheric particulate matter (PM2.5) from a Southwestern Europe industrial area: Levels, sources and human health risk.

The occurrence of 50 multi-class pollutants comprising 18 polycyclic aromatic hydrocarbons (PAHs), 12 phthalate esters (PAEs), 12 organophosphorus flame retardants (OPFRs), 6 synthetic musk compounds (SMCs) and 2 bisphenols was studied in atmospheric particulate matter (PM2.5) samples collected at an industrial area focused on automotive manufacturing located at the Southwestern Atlantic European region (Vigo city, Spain) during 1-year period. Among all quantitated pollutants in PM2.5 samples, bisphenol A (BPA) was the most predominant with an average concentration of 6180 pg m-3, followed by PAHs comprising benzo(b+j)fluoranthene (BbF + BjF) and benzo(g,h,i)perylene (BghiP), accounting for 546 pg m-3 and 413 pg m-3 respectively. In addition, two OPFRs concerning tris(chloropropyl) phosphate (TCPP) and triphenyl phosphine oxide (TPPO) were the next following the concentration order, accounting for 411 pg m-3 and 367 pg m-3 respectively; being butyl benzyl phthalate (BBP) the most profuse PAE (56.1 pg m-3 by average). High relative standard deviations (RSDs) were observed during the whole sampling period, while statistically significant differences were only observed for PAHs concentrations during cold and warm seasons. Furthermore, some water-soluble ions and metal(oid)s were analysed in PM2.5 samples to be used as PM source tracers, whose concentrations were quite below the target levels set in the current legislation. Data obtained from principal component analysis (PCA) and PAHs molecular indices suggested a pyrogenic and petrogenic origin for PAHs, whereas occurrence of the remaining compounds seems to be attributed to resources used in the automotive industrial activity settled in the sampling area. Moreover, although a substantial anthropogenic source to PM2.5 in the area was observed, marine and soil resuspension contributions were also accounted. Finally, carcinogenic and non-carcinogenic risks posed by PM2.5-bound pollutants inhalation were assessed, being both averages within the safe level considering the whole period.

Selenium species determination in foods harvested in Seleniferous soils by HPLC-ICP-MS after enzymatic hydrolysis assisted by pressurization and microwave energy.

Fast, green, automated, highly efficient and accurate methodology for extracting selenium species in foods samples (Brazil nut, golden berries and heart of palm) harvested in seleniferous soils by using pressurized-assisted enzymatic hydrolysis (PAEH) and microwave-assisted enzymatic hydrolysis (MAEH) were optimized. After foods defatting or drying, selenium species were released using protease XIV and enzyme activator in 7 and 12 min for PAEH and MAEHmethods, respectively. Inductively coupled plasma - mass spectrometry (ICP-MS) and high performance liquid chromatography (HPLC) coupled with ICP-MS detection were used to assess total selenium and selenium species contents in the enzymatic extracts. Analytical performances, such as limits of quantification (0.032-0.599 µg g-1 and 0.014-0.240 µg g-1 for PAEH and MAEH, respectively), repeatability (11-14.5%) and accuracy of the over-all procedures were established. Selenomethionine (SeMet) were detected in all analyzed samples and selenocystine (SeCys2) in Brazil nut; however, SeMet and SeCys2 levels were only quantified in Brazil nut. Inorganic selenium species were not detected in any sample. The presence of SeMet and SeCys2 and the absence of oxidized selenium methionine (SeOMet) in the enzymatic extracts were confirmed by Orbitrap mass spectrometry.