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[Abstract] Polycyclic aromatic hydrocarbons (PAHs) in atmospheric particulate matter have adverse effects on human health, yet total PAH concentrations should overestimate the toxicity compared to the bioavailable amount of PAHs. To explore this hypothesis, we measured PAHs oral bioavailability in vitro in particulate matter with aerodynamic diameter lower than 10 µm (PM₁₀) using a test that mimics the human digestive system. This assay combines the use of simulated gastrointestinal fluids and a dialysis membrane to simulate intestinal absorption. Results show that oral PAH bioavailability was below 5%, with fluorene, anthracene, acenaphthene and phenanthrene as the most bioavailable PAHs. Data suggest no carcinogenic risk of oral bioavailable PM₁₀-bound PAHs following a health risk assessment via inhalation-ingestion by using benzo(a)pyrene-equivalent carcinogenic concentration and hazard indexes. To our best knowledge, this is the first research study of in vitro oral bioavailability estimation of PM₁₀-associated PAHs.

[Abstract] Soil stability includes both resistance, the ability to withstand a perturbation or stress, and resilience, the ability to recover to pre perturbation levels. The functional stability of soil microbial communities is of paramount importance for the ecosystem functioning. We investigated the differences in the stability (resistance and resilience) of three enzyme activities (hydrolytic, laccase and peroxidase) in three different forest (holm oak, black pine and beech) soils after addition of PAHs (phenanthrene, pyrene and benzo[a]pyrene) with different molecular weights. Furthermore, we proposed a new soil quality index (MAI) based on the measured enzyme activity values, useful to quantify the ecological impact of soil perturbations (PAH exposure in our case). The degradation rates of different PAHs follow their complexity, slowing with increasing of PAH molecular weight in all soil types. Moreover, we found higher microbial resistance to PAH perturbation in “broad scale” enzyme activity (hydrolase), in respect to the two “narrow-niche” enzyme activities (laccase and peroxidase). The results demonstrate a higher functional stability in soils with a higher content of recalcitrant organic matter (soil under pine), compared to soils with higher content of labile organic matter (soil under holm oak). In particular, laccase activity is less affected by phenanthrene and pyrene addition in soil under pine; peroxidase activity shows a higher resistance and resilience in soil under beech for all PAHs added. Resistance and/or resilience to PAH contamination, observed for hydrolytic functional stability in the three soils, is mainly due to the high diversity of enzymes expressing this type of catalytic activity.

The distribution of per- and polyfluoroalkyl substances (PFAS), alkylphenols, organotin compounds, phthalates, alkylated polycyclic aromatic hydrocarbons, current-use pesticides (CUPs) and personal care products (PCPs) was characterized in 29 surface sediments from two Spanish Iberian continental shelf areas (14 on the Atlantic and 15 on the Mediterranean coasts). Concretely, 115 organic contaminants were determined and a specific methodology was used for each contaminant group, including contaminants of emerging concern (CECs) and traditional ones, such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorinated pesticides (OCPs). PAHs, alkylated PAHs, alkylphenols and phthalates were found in all samples, showing mean concentrations per group higher than 20 ng/g (16-4974 ng/g d.w.) in the subregions under consideration (Galician, Cantabrian, Levantine-Balearic and Strait-Alboran). CUPs and PCPs were found in the majority of samples at very low concentrations of ng/g (1.4-46.8 ng/g d.w.), whereas organotins and PFAS were found principally in sediments from the Mediterranean subregions (2.5-3.9 ng/g d.w.). Different distribution patterns were observed for the contaminant groups and subregions under consideration as a consequence of the diverse predominant sources (industrial, urban, transport and agricultural activities) and environmental behavior (mainly hydrophobicity and persistence). Risk assessment confirmed the impact of phthalates, alkylphenols, PAHs and PCBs on Atlantic ecosystems and of alkylphenols, chlorpyrifos, phthalates, TBT, PAHs, OCPs and PCBs on the Mediterranean ones. Furthermore, the presence of CUPs, PCPs and PFAS in sediments from the Spanish continental shelf located between 2 and 31 km from the coast suggested that those contaminants may also provoke adverse effects on coastal marine ecosystems between their sources and their depositional areas. CAPSULE: Alkylphenols, phthalates and organotins may provoke

Global production of synthetic polymers, led by polyethylene (PE), rose steadily in the last decades, and marine ecosystems are considered as a global sink. Although PE is not biodegradable, in coastal areas it fragments into microplastics (MP) readily taken up by biota, and have been postulated as vectors of hydrophobic chemicals to marine organisms. We have tested this hypothesis using two organisms representative of the marine plankton, the holoplanktonic copepod Acartia clausi, and the meroplanktonic larva of the Paracentrotus lividus sea-urchin, and two model chemicals with similar hydrophobic properties, the 4-n-Nonylphenol and the 4-Methylbenzylidene-camphor used as plastic additive and UV filter in cosmetics. Both test species actively ingested the MP particles. However, the presence of MP never increased the bioaccumulation of neither model chemicals, nor their toxicity to the exposed organisms. Bioaccumulation was a linear function of waterborne chemical disregarding the level of MP. Toxicity, assessed by the threshold (EC10) and median (EC50) effect levels, was either independent of the level of MP or even in some instances significantly decreased in the presence of MPs. These consistent results challenge the assumption that MP act as vectors of hydrophobic chemicals to planktonic marine organisms

[Resumen] En la presente memoria se han desarrollado diversas metodologías analíticas para el análisis de pesticidas organoclorados en diferentes matrices ambientales. Se proponen distintas condiciones de separación cromatográfica empleando diferentes fases estacionarias y longitudes de columna consiguiendo separar 21 pesticidas organoclorados, así como varias opciones de inyección en cromatografía de gases: un sistema convencional de inyección split/splitless, sistemas de inyección split/splitless con temperatura programada (PSS), y un inyector on-column de grandes volúmenes (LVOCI), utilizando diseños de experiencias, que permiten determinar que variables influyen en la respuesta, y llevar a cabo la otpimización de las mismas. Se han alcanzado límites de detección muy bajos, con incrementos de sensibilidad de más de 30 veces para el inyector PSS y de tres órdenes de magnitud con el inyector LVOC en comparación con el inyector split/splitless, lo que permite determinar los pesticidas a niveles de ultratraza. Estos modos de inyección han permitido reducir el volumen de muestra que se necesita procesar, así como alguna etapa de concentración de los métodos de análisis. Se desarrollaron dos procedimientos para el análisis de pesticidas en muestras acuosas. Uno de ellos consiste en un método de extracción en fase sólida que emplea discos laminares con fase C18, que permiten un flujo de paso de muestra elevado, y no precisan del filtrado previo de la misma. El otro consiste en una microextracción líquido-líquido que precisa de pequeñas cantidades de muestra (10 mL) y disolvente (2 mL de acetato de etilo). Con ambos métodos se han alcanzado límites de detección que permiten la determinación de los pesticidas a los niveles establecidos por la legislación más restrictiva. Además se han evaluado las pérdidas de los pesticidas organoclorados por adsorción a los recipientes, que se minimizan por adición de un 20 %

[Resumen] En la presente memoria se han desarrollado diversas metodologías analíticas para el análisis de pesticidas organoclorados en diferentes matrices ambientales. Se proponen distintas condiciones de separación cromatográfica empleando diferentes fases estacionarias y longitudes de columna consiguiendo separar 21 pesticidas organoclorados, así como varias opciones de inyección en cromatografía de gases: un sistema convencional de inyección split/splitless, sistemas de inyección split/splitless con temperatura programada (PSS), y un inyector on-column de grandes volúmenes (LVOCI), utilizando diseños de experiencias, que permiten determinar que variables influyen en la respuesta, y llevar a cabo la otpimización de las mismas. Se han alcanzado límites de detección muy bajos, con incrementos de sensibilidad de más de 30 veces para el inyector PSS y de tres órdenes de magnitud con el inyector LVOC en comparación con el inyector split/splitless, lo que permite determinar los pesticidas a niveles de ultratraza. Estos modos de inyección han permitido reducir el volumen de muestra que se necesita procesar, así como alguna etapa de concentración de los métodos de análisis. Se desarrollaron dos procedimientos para el análisis de pesticidas en muestras acuosas. Uno de ellos consiste en un método de extracción en fase sólida que emplea discos laminares con fase C18, que permiten un flujo de paso de muestra elevado, y no precisan del filtrado previo de la misma. El otro consiste en una microextracción líquido-líquido que precisa de pequeñas cantidades de muestra (10 mL) y disolvente (2 mL de acetato de etilo). Con ambos métodos se han alcanzado límites de detección que permiten la determinación de los pesticidas a los niveles establecidos por la legislación más restrictiva. Además se han evaluado las pérdidas de los pesticidas organoclorados por adsorción a los recipientes, que se minimizan por adición de un 20 %