Presence of microplastics in the groundwater of volcanic islands, El Hierro and La Palma (Canary Islands).

The increasing amount of plastic litter worldwide is a serious problem for the environment and its biodiversity, ecosystems, animal and human welfare and the economy. The degradation of these plastics leads to microplastics (MPs), which have been reported for the first time in groundwater in the Canary archipelago. This research investigates the presence of MPs at nine different points on La Palma and El Hierro, where samples were collected in galleries, wells and springs during the month of December 2022. Six different polymers were found with Fourier transform infrared spectroscopy (FTIR) - polypropylene (PP), polyethylene (PE), cellulose (CEL), polyethylene terephthalate (PET), polystyrene (PS) and polymethyl methacrylate (PMMA). The particle concentrations found ranged from 1 to 23 n/L, with a maximum particle size of 1900 µm, the smallest being 35 µm. PP and PE were the most common polymers found in the analysis, associated with the use of packaging, disposable products, textiles and water pipes, related to poorly maintained sewerage networks where leaks occur, allowing these MPs to escape into the environment and end up in groundwater. The detection of microplastic pollution in groundwater emphasises environmental hazards, including biodiversity disruption and water source contamination. Additionally, it presents potential risks to human health by transferring contaminants into the food chain and through respiratory exposure.

Assessing the Fate of Benzophenone-Type UV Filters and Transformation Products during Soil Aquifer Treatment: The Biofilm Compartment as Bioaccumulator and Biodegrader in Porous Media.

The fate of selected UV filters (UVFs) was investigated in two soil aquifer treatment (SAT) systems, one supplemented with a reactive barrier containing clay and vegetable compost and the other as a traditional SAT reference system. We monitored benzophenone-3 (BP-3) and its transformation products (TPs), including benzophenone-1 (BP-1), 4,4'-dihydroxybenzophenone (4DHB), 4-hydroxybenzophenone (4HB), and 2,2'-dihydroxy-4-methoxybenzophenone (DHMB), along with benzophenone-4 (BP-4) and avobenzone (AVO) in all involved compartments (water, aquifer sediments, and biofilm). The reactive barrier, which enhances biochemical activity and biofilm development, improved the removal of all detected UVFs in water samples. Among monitored UVFs, only 4HB, BP-4, and AVO were detected in sediment and biofilm samples. But the overall retained amounts were several orders of magnitude larger than those dissolved. These amounts were quantitatively reproduced with a specifically developed simple analytical model that consists of a mobile compartment and an immobile compartment. Retention and degradation are restricted to the immobile water compartment, where biofilm absorption was simulated with well-known compound-specific Kow values. The fact that the model reproduced observations, including metabolites detected in the biofilm but not in the (mobile) water samples, supports its validity. The results imply that accumulation ensures significant biodegradation even if the degradation rates are very low and suggest that our experimental findings for UVFs and TPs can be extended to other hydrophobic compounds. Biofilms act as accumulators and biodegraders of hydrophobic compounds.

Efficient removal of toxicity associated to wastewater treatment plant effluents by enhanced Soil Aquifer Treatment.

The regeneration of wastewater has been recognized as an effective strategy to counter water scarcity. Nonetheless, Wastewater Treatment Plant (WWTP) effluents still contain a wide range of contaminants of emerging concern (CECs) even after water depuration. Filtration through Soil Aquifer Treatment (SAT) systems has proven efficient for CECs removal although the attenuation of their associated biological effects still remains poorly understood. To evaluate this, three pilot SAT systems were monitored, two of them enhanced with different reactive barriers. SATs were fed with secondary effluents during two consecutive campaigns. Fifteen water samples were collected from the WWTP effluent, below the barriers and 15 m into the aquifer. The potential attenuation of effluent-associated biological effects by SATs was evaluated through toxicogenomic bioassays using zebrafish eleutheroembryos and human hepatic cells. Transcriptomic analyses revealed a wide range of toxic activities exerted by the WWTP effluents that were reduced by more than 70% by SAT. Similar results were observed when HepG2 hepatic cells were tested for cytotoxic and dioxin-like responses. Toxicity reduction appeared partially determined by the barrier composition and/or SAT managing and correlated with CECs removal. SAT appears as a promising approach to efficiently reduce effluent-associated toxicity contributing to environmental and human health preservation.

Microplastic removal in managed aquifer recharge using wastewater effluent.

Microplastic (MP) pollution has emerged as a pressing environmental issue, with its impacts on ecosystems and human health yet to be fully understood. This study aims to investigate the presence and distribution of MPs in the soil of a managed aquifer recharge (MAR) system, built with different reactive barriers of natural materials and irrigated with the secondary effluent of a wastewater treatment plant (WWTP). MPs were extracted from reactive barrier material following an approach based on the density separation of MPs with posterior oxidant digestion, combined with visual and chemical characterisation by Fourier-Transform Infrared Spectroscopy (FTIR). The results revealed the widespread occurrence of MPs in the MAR soil samples. MPs concentration in the different barrier materials ranged from 60 to 236 n kg-1. The most dominant morphologies were fragments (60%) and fibers (17%), and the most abundant colour was white (51%), followed by transparent MPs (20%). Polypropylene (PP) was detected in all the samples with an abundance of 47%, followed by polyethylene (PE, 34%). The interplay of barrier composition significantly influences the retention of MPs, with compost (T5) and woodchips (T4) exhibiting the most notable retention rates. Remarkably, the outer layers of the reactive barriers display superior retention compared to the deeper layers. The findings of this study demonstrate the good performance of the MAR system in retaining MPs and contribute to the growing body of knowledge on MPs pollution in freshwater systems while providing insights into the dynamics of MPs transport and accumulation in soil. Such information can inform the development of effective wastewater management strategies to mitigate the impacts of these pollutants on water resources and safeguard the environment.

Occurrence and ecological risk assessment of organic UV filters in coastal waters of the Iberian Peninsula.

This study aimed to assess the presence of 21 UVFs and metabolites in coastal regions of the Iberian Peninsula, to evaluate their environmental risk, and identify possible influential factors affecting their measured concentrations. Sampling was carried out in spring and summer to assess possible seasonal variations. UVFs were detected in 43 of the 46 sampling sites. Only 5 were found above LOD: BP4, OC, BP3 and metabolites BP1 and BP8. Samples collected in Mar Menor had the greatest variety of compounds per sample and the highest cumulative concentrations. The risk was characterized using Risk Quotients (RQ). BP1 showed a Low environmental Risk in 2 sites while for OC the RQ indicated a Moderate Risk in 22 points. The variables that contribute most to the variation are population density, sampling season, whether it was an open bay or not, and level of urbanization. The presence of WWTPs had a lower influence.

Factors driving PPCPs uptake by crops after wastewater irrigation and human health implications.

Currently, water scarcity affects more than three billion people. Nevertheless, the volume of treated wastewater discharged into the environment is estimated to exceed 100 m3 per inhabitant/year. These water resources are regularly used in agriculture worldwide to overcome water shortages. Such a practice, however, entails the uptake of waterborne pollutants, such as pharmaceuticals and personal care products (PPCPs), by crops and their further access to the food web, constituting an additional route of human exposure to PPCPs, with potential health outcomes. In this study, the occurrence of 56 PPCPs in tomatoes, lettuce, and carrot, together with soil and irrigation water, was evaluated using a QuEChERS-based methodology for extraction and LC-MS/MS for analysis. The influence of the selected cultivation conditions on the plant uptake levels of PPCPs was assessed. Two irrigation water qualities (secondary and tertiary treatment effluents), two soil compositions (sandy and clayey), two irrigation systems (dripping and sprinkling), and three crop types (lettuce, tomato, and carrot) were tested. Carrots showed the highest load of PPCPs (7787 ng/g dw), followed by tomatoes (1692 ng/g dw) and lettuces (1248 ng/g dw). The most translocated PPCPs were norfluoxetine (fluoxetine antidepressant main metabolite) (521 ng/g dw), and the anti-inflammatory diclofenac (360 ng/g dw). Nine PPCPs, are reported to be accumulated in crops for the first time. Water quality was the most important factor for reducing PPCPs' plant uptake. Overall, the best conditions for reducing PPCP uptake by crops were irrigation with reclaimed water by sprinkling in soils with higher clay content. The risk assessment performed revealed that the crops' consumption posed no risk to human health. This study serves as the first comprehensive assessment of the relevance of diverse cultivation factors on PPCPs' plant uptake under field agricultural practices.

Occurrence and fate of contaminants of emerging concern and their transformation products after uptake by pak choi (Brassica rapa subsp. chinensis).

Recovery and reuse of nutrients is a major challenge in agriculture. A new process contributing to a circular economy is the anaerobic digestion of food waste, which is a sustainable way of recycling nutrients as the digestate can be used as fertiliser in agriculture and horticulture. However, the digestate may be polluted with contaminants of emerging concern (CECs) that can be circulated back into the food chain, posing a risk to the environment and human health. In this work, the nutrient solution was spiked with 18 selected CECs frequently detected in food waste biogas facilities, and subsequent uptake and fate of these CECs were evaluated in pak choi grown in two different nutrient solutions (mineral and organic). All spiked compounds except two (propylparaben, fenbendazole) were taken up by pak choi plants, with perfluorobutanoic acid (PFBA) and sertraline displaying the highest concentrations (270 and 190 µg/kg fresh weight, respectively). There were no statistically significant differences in uptake between mineral and organic nutrient solutions. Uptake of per- and polyfluoroalkyl substances (PFAS) was negatively correlated with perfluorocarbon chain length and dependent on the functional group (r = -0.73). Sixteen transformation products (TPs) were tentatively identified using suspect screening, most of which were Phase II or even Phase III metabolites. Six of these TPs were identified for the first time in plant metabolism and their metabolic pathways were considered.

Distribution in marine fish and EDI estimation of contaminants of emerging concern by vortex-assisted matrix solid-phase dispersion and HPLC-MS/MS.

Due to their persistence or continuous discharge, toxic substances are present in the aquatic environment, and can bioaccumulate and biomagnify in the food web, generating a significant ecological risk and a threat to human health. The present study assess the occurrence and tissue (muscle, liver, stomach and gills) distribution of 59 anthropogenic contaminants of emerging concern (CECs) in marine fish from Brazil. A simpler and faster analytical methodology based on vortex-assisted matrix solid-phase dispersion (VA-MSPD) and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was developed and validated. Limits of quantification ranged from 3.31 to 114 ng g-1 dw with recovery rates between 60 and 140 % and relative standard deviation below 20 %. The ultraviolet filters 4-hydroxybenzophenone (4HB) (benzophenone-3 metabolite) and benzocaine (Et-PABA), and the antibacterial salicylic acid were frequently accumulated in muscle and liver at concentrations between 39.5 and 21.0 ngg-1 dw. The determined concentrations resulted to be lower than the tolerable daily intake recommended by the European Food Safety Authority (EFSA).

Using integrative samplers to estimate the removal of pharmaceuticals and personal care products in a WWTP and by soil aquifer treatment enhanced with a reactive barrier.

The need and availability of freshwater is a major environmental issue, aggravated by climate change. It is necessary to find alternative sources of freshwater. Wastewater could represent a valid option but requires extensive treatment to remove wastewater-borne contaminants, such as contaminants of emerging concern (CECs). It is urgent to develop not only sustainable and effective wastewater treatment techniques, but also water quality assessment methods. In this study, we used polar organic chemical integrative samplers (POCIS) to investigate the presence and abatement of contaminants in an urban wastewater treatment plant (WWTP) and in soil aquifer treatment (SAT) systems (a conventional one and one enhanced with a reactive barrier). This approach allowed us to overcome inter-day and intraday variability of the wastewater composition. Passive sampler extracts were analyzed to investigate contamination from 56 pharmaceuticals and personal care products (PPCPs). Data from the POCIS were used to estimate PPCPs' removal efficiency along the WWTP and the SAT systems. A total of 31 compounds, out of the 56 investigated, were detected in the WWTP influent. Removal rates along WWTP were highly variable (16-100 %), with benzophenone-3, benzophenone-1, parabens, ciprofloxacin, ibuprofen, and acetaminophen as the most effectively removed chemicals. The two SAT systems yielded much higher elimination rates than those achieved through the primary and secondary treatments together. The SAT system that integrated a reactive barrier, based on sustainable materials to promote enhanced elimination of CECs, was significantly more efficient than the conventional one. The removal of the recalcitrant carbamazepine and its epoxy- metabolite was especially remarkable in this SAT, with removal rates between 69-81 % and 63-70 %, respectively.

Binding of common organic UV-filters to the thyroid hormone transport protein transthyretin using in vitro and in silico studies: Potential implications in health.

Several anthropogenic contaminants have been identified as competing with the thyroid hormone thyroxine (T4) for binding to transport proteins as transthyretin (TTR). This binding can potentially create toxicity mechanisms posing a threat to human health. Many organic UV filters (UVFs) and paraben preservatives (PBs), widely used in personal care products, are chemicals of emerging concern due to their adverse effects as potential thyroid-disrupting compounds. Recently, organic UVFs have been found in paired maternal and fetal samples and PBs have been detected in placenta, which opens the possibility of the involvement of TTR in the transfer of these chemicals across physiological barriers. We aimed to investigate a discrete set of organic UVFs and PBs to identify novel TTR binders. The binding affinities of target UVFs towards TTR were evaluated using in vitro T4 competitive binding assays. The ligand-TTR affinities were determined by isothermal titration calorimetry (ITC) and compared with known TTR ligands. In parallel, computational studies were used to predict the 3-D structures of the binding modes of these chemicals to TTR. Some organic UVFs, compounds 2,2',4,4'-tetrahydroxybenzophenone (BP2, Kd = 0.43 µM); 2,4-dihydroxybenzophenone (BP1, Kd = 0.60 µM); 4,4'-dihydroxybenzophenone (4DHB, Kd = 0.83 µM), and 4-hydroxybenzophenone (4HB, Kd = 0.93 µM), were found to display a high affinity to TTR, being BP2 the strongest TTR binder (ΔH = -14.93 Kcal/mol). Finally, a correlation was found between the experimental ITC data and the TTR-ligand docking scores obtained by computational studies. The approach integrating in vitro assays and in silico methods constituted a useful tool to find TTR binders among common organic UVFs. Further studies on the involvement of the transporter protein TTR in assisting the transplacental transfer of these chemicals across physiological barriers and the long-term consequences of prenatal exposure to them should be pursued.

Beach showers as sources of contamination for sunscreen pollution in marine protected areas and areas of intensive beach tourism in Hawaii, USA.

In 2019, sands in nearby runoff streams from public beach showers were sampled on three islands in the State of Hawaii and tested for over 18 different petrochemical UV filters. Beach sands that are directly in the plume discharge of beach showers on three of the islands of Hawaii (Maui, Oahu, Hawai'i) were found to be contaminated with a wide array of petrochemical-based UV-filters that are found in sunscreens. Sands from beach showers across all three islands had a mean concentration of 5619 ng/g of oxybenzone with the highest concentration of 34,518 ng/g of oxybenzone at a beach shower in the Waikiki area of Honolulu. Octocrylene was detected at a majority of the beach shower locations, with a mean concentration of 296.3 ng/g across 13 sampling sites with the highest concentration of 1075 ng/g at the beach shower in Waikiki. Avobenzone, octinoxate, 4-methylbenzylidene camphor and benzophenone-2 were detected, as well as breakdown products of oxybenzone, including benzophenone-1, 2,2'-dihydroxy-4-methoxybenzophenone, and 4-hydroxybenzophenone. Dioxybenzone (DHMB) presented the highest concentration in water (75.4 ng/mL), whereas octocrylene was detected in all water samples. Some of these same target analytes were detected in water samples on coral reefs that are adjacent to the beach showers. Risk assessments for both sand and water samples at a majority of the sampling sites had a Risk Quotient > 1, indicating that these chemicals could pose a serious threat to beach zones and coral reef habitats. There are almost a dozen mitigation options that could be employed to quickly reduce contaminant loads associated with discharges from these beach showers, like those currently being employed (post-study sampling and analysis) in the State of Hawaii, including banning the use of sunscreens using petrochemical-based UV filters or educating tourists before they arrive on the beach.

Contaminants of emerging concern in marine areas: First evidence of UV filters and paraben preservatives in seawater and sediment on the eastern coast of Tunisia.

UV filters (UVFs) and paraben preservatives (PBs) are widely used components in many personal care products. However, there has been a rising concern for their endocrine-disrupting effects on wildlife once they reach aquatic ecosystems via recreative activities and wastewater treatment plants effluents. This study addresses UVFs and PBs occurrence in seawater and sediment impacted by tourism and sewage discharges along the coast of Mahdia, center East Tunisia. Samples of water and sediment were collected for 6 months from 3 coastal areas. Among the 14 investigated UVFs, 8 were detected in seawater and 4 were found in sediment. All PBs were present in seawater and only methylparaben (MePB) was detected in sediment. Benzophenone-3 (oxybenzone, BP3), benzocaine (EtPABA), and MePB were present in all water samples with concentrations in the ranges 16.4-66.9, 7.3-37.7, and 17.6-222 ng/L, respectively. However, the highest value, 1420 ng/L, corresponded to octinoxate (EHMC). In sediments, avobenzone (AVO), 4-methyl benzylidene camphor (4MBC), EHMC, 5-methyl-1-H-benzotriazole (MeBZT), and MePB were detected at concentrations within the range 1.1-17.6 ng/g dw, being MePB the most frequently detected (89%). MePB and MBZT presented the highest sediment-water partition coefficients and MePB also showed a positive correlation with total suspended solids' water content. Overall, pollutants concentrations remained rather constant along the sampling period, showing little seasonal variation. This study constitutes the first monitoring of UVFs and PBs on the Tunisian coastline and provides occurrence data for reference in further surveys in the country.

Mediterranean seagrass Posidonia oceanica accumulates sunscreen UV filters.

Certain ultra-violet filter (UVF) components of solar creams have negative impacts on coral reefs and have been prohibited in international tourism destinations (i.e., Hawaii, Florida, and Palau) to protect coral reefs. In the Mediterranean coasts which are also hotspots of international tourism and where endemic seagrass Posidonia oceanica forms extensive meadows, the accumulation of UVF components have not been studied. We report for the first time, that the rhizomes of P. oceanica internally accumulated UVFs BP3, BP4, AVO, 4MBC and MeBZT and the paraben preservative MePB. The components BP4 and MePB occurred in higher concentrations reaching up to 129 ng g-1 dw and 512 ng g-1 dw, respectively. This work emphasizes the need for more experimental studies on the effects of UVFs on seagrasses and check if we should follow suit to prohibit certain UVFs to protect this species as what has been done in other regions to protect corals.

Oxybenzone contamination from sunscreen pollution and its ecological threat to Hanauma Bay, Oahu, Hawaii, U.S.A.

Hanauma Bay is a 101-acre bay created by the partial collapse of a volcanic cone and once supported a vibrant coral reef system. It is the most popular swimming area in the Hawaiian Islands and has been reported to have averaged between 2.8 and 3.5 million visitors a year between the 1980s and the 2010s, with visitors averaging between 3000-4000 a day and peaking around 10,000-13,000 per day. Concentrations of oxybenzone and other common UV filters were measured in subsurface water samples and in sands from the beach-shower areas in Hanauma Bay. Results demonstrate that beach showers also can be a source of sunscreen environmental contamination. Hydrodynamic modeling indicates that oxybenzone contamination within Hanauma Bay's waters could be retained between 14 and 50 h from a single release event period. Focusing on only oxybenzone, two different Hazard and Risk Assessment analyses were conducted to determine the danger of oxybenzone to Hanauma Bay's coral reef system. Results indicate that oxybenzone contamination poses a significant threat to the wildlife of Hanauma Bay. To recover Hanauma Bay's natural resources to a healthy condition and to satisfactorily conserve its coral reef and sea grass habitats, effective tourism management policies need to be implemented that mitigate the threat of sunscreen pollution.

Development of a QuEChERS-based method for the analysis of pharmaceuticals and personal care products in lettuces grown in field-scale agricultural plots irrigated with reclaimed water.

The use of reclaimed water for agricultural irrigation is an increasingly common practice, which recently has found its own European regulatory frame. However, the partial removal of organic contaminants together with other xenobiotic substances in current wastewater treatment plants leads to the occurrence of residues of such pollutants in the treated effluents. Wastewater reclamation techniques are thus required to provide reclaimed water fitting the minimum quality standards set up for irrigation of crops intended for human consumption. This work describes the development and validation of a simple QuEChERS-based extraction and liquid chromatography quadrupole-linear ion trap mass spectrometry (LC-QqLIT-MS/MS) method for the simultaneous quantitative analysis of 55 pharmaceuticals and personal care products (PPCPs) in lettuces irrigated with treated wastewater and reclaimed water. The method showed good recovery rates (80-120%) and low detection limits (0.04-0.8 ng/g dw). In comparison with previous analytical methodologies, this method was simpler, faster and, in most cases, more sensitive. Moreover, is the first one analysing selected personal care products in lettuces. The proposed method was applied to assess the potential transfer of contaminants of urban origin in the use of reclaimed water in agriculture. The case study consisted in the evaluation of the lettuce uptake of the selected contaminants at field scale under two irrigation systems, two soil compositions, and two water types. Benzophenone-2, 4-hydroxybenzophenone, 1H-benzotriazole, 2-(2-Benzotriazol-2-yl)-p-cresol, nalidixic acid, diclofenac, carbamazepine 10,11-epoxy, N-des-methylvenlafaxine, and salicylic acid were transferred to all samples. Highest detected values corresponded to 4-hydroxybenzophenone (84.1 ng/g dw), benzophenone-2 (54.4 ng/g dw), and salicylic acid (53.8 ng/g dw). The best combination to minimize the transfer of the target contaminants from the irrigation water to the lettuces was sprinkling irrigation with water reclaimed by soil infiltration through reactive barriers, and clayey soil.

Anthropogenic contaminants in freshwater from the northern Antarctic Peninsula region.

This study aimed to evaluate the presence of ultraviolet filters (UV-Fs), benzotriazoles, pyrethroids and per- and polyfluoroalkyl substances (PFASs) in freshwater and wastewater from the northern Antarctic Peninsula region. All water samples analyzed contained UV-Fs residues and high concentrations were detected in anthropogenic impacted sites (< LOD up to 1300 ng/L). Likewise, benzotriazoles were detected in all water samples (< LOQ-920 ng/L). Regarding suspended particulate matter, almost all UV-Fs and all benzotriazoles were measured at concentrations ranging from < LOQ to 33 µg/g dry weight. Pyrethroids were also detected (< LOQ-250 ng/L) and their presence implies the existence of a gateway to the Antarctica Peninsula from other regions. The data confirmed the presence of PFASs (< LOD-7500 ng/L) in this area, in agreement with previous studies. In light of these results, extended monitoring in Antarctica should be carried out to perform a reliable environmental risk assessment leading to propose recommendations to minimize the anthropic impact.

Priority and emerging organic microcontaminants in three Mediterranean river basins: Occurrence, spatial distribution, and identification of river basin specific pollutants.

There is a worldwide growing use of chemicals by our developed, industrialized, and technological society. More than 100,000 chemical substances are thus commonly used both by industry and households. Depending on the amount produced, physical-chemical properties, and mode of use, many of them may reach the environment and, notably, the aquatic receiving systems. This may result in undesirable and harmful side-effects on both the human and the ecosystem's health. Mediterranean rivers are largely different from Northern and Central European rivers in terms of hydrological regime, climate conditions (e.g. air temperature, solar irradiation, precipitation), and socio-economics (e.g. land use, tourism, crop types, etc.), with all these factors leading to differences in the relative importance of the environmental stressors, in the classes and levels of the pollutants found and their environmental fate. Furthermore, water scarcity might be critical in affecting water pollution because of the lowered dilution capacity of chemicals. This work provides raw chemical data from different families of microcontaminants identified in three selected Mediterranean rivers (the Sava, Evrotas, and Adige) collected during two sampling campaigns conducted in 2014 and 2015 in three different matrices, namely, water, sediments, and biota (fish). More than 200 organic micropollutants were analyzed, including relevant groups like pharmaceuticals, personal care products, perfluorinated compounds, pesticides, pyrethroid insecticides, flame retardants, and persistent organic pollutants. Data obtained were summarized with some basic statistics for all compound families and matrices analyzed. Observed occurrence and spatial patterns were interpreted both in terms of compound physical-chemical properties and local environmental pressures. Finally, their spatial distribution was examined and their ecotoxicological risk in the water phase was assessed. This allowed locating, at each basin, the most polluted sites ("hot spots") and identifying the respective river basin specific pollutants (RBSPs), prioritizing them in terms of the potential ecotoxicological risk posed to the aquatic ecosystems.

Rapid and cost-effective multiresidue analysis of pharmaceuticals, personal care products, and antifouling booster biocides in marine sediments using matrix solid phase dispersion.

Currently, there are many contaminants of concern that need to be accurately determined to help assess their potential environmental hazard. Despite their increasing interest, yet few environmental occurrence data exist, likely because they are present at low levels and in very complex matrices. Therefore, multiresidue analytical methods for their determination need to be highly sensitive, selective, and robust. Particularly, due to the trace levels of these chemicals in the environment, an extensive extraction procedure is required before determination. This work details the development of a fast and cheap vortex-assisted matrix solid-phase dispersion-high performance liquid chromatography tandem-mass spectrometry (VA-MSPD-HPLC-MS/MS) method for multiresidue determination of 59 contaminants of emerging concern (CECs) including pharmaceuticals, personal care products, and booster biocides, in sediment. The validated method provided high sensitivity (0.42-36.8 ngg-1 dw quantification limits), wide and good linearity (r2 > 0.999), satisfactory accuracy (60-140%), and precision below 20% for most target analytes. In comparison with previous methods, relying on traditional techniques, the proposed method demonstrated to be more environmentally friendly, cheaper, simpler, and faster. The method was applied to monitor the occurrence of these compounds in sediments collected in Brazil, using only 2 g dw sediment samples, free-solid support, and 5 mL methanol as extraction solvent. The UV filter avobenzone, the UV stabilizer and antifreeze methylbenzotriazole, the preservative methylparaben, the fluoroquinolone antibiotic ciprofloxacin, and the biocides irgarol and 4,5-dichloro-2-octyl-4-isothiazolin-3-one were determined at concentrations in the range 1.44-69.7 ngg-1 dw.

Simultaneous degradation of 30 pharmaceuticals by anodic oxidation: Main intermediaries and by-products.

The anodic oxidation (AO) of 30 pharmaceuticals including antibiotics, hormones, antihistaminics, anti-inflammatories, antidepressants, antihypertensives, and antiulcer agents, in solutions containing different supporting electrolytes media (0.05 M Na2SO4, 0.05 M NaCl, and 0.05 M Na2SO4 + 0.05 M NaCl) at natural pH was studied. A boron-doped diamond (BDD) electrode and a stainless-steel electrode were used as anode and cathode, respectively, and three current densities of 6, 20, and 40 mA cm-2 were applied. The results showed high mineralization rates, above 85%, in all the tested electrolytic media. 25 intermediaries produced during the electrooxidation were identified, depending on the supporting electrolyte together with the formation of carboxylic acids, NO3-, SO42- and NH4+ ions. The formation of intermediates in chloride medium produced an increase in absorbance. Finally, a real secondary effluent spiked with the 30 pharmaceuticals was treated by AO applying 6 mA cm-2 at natural pH and without addition of supporting electrolyte, reaching c.a. 90% mineralization after 300 min, with an energy consumption of 18.95 kW h m-3 equivalent to 2.90 USD m-3. A degradation scheme for the mixture of emerging contaminants in both electrolytic media is proposed. Thus, the application of anodic oxidation generates a high concentration of hydroxyl radicals that favors the mineralization of the pharmaceuticals present in the spiked secondary effluent sample.

Fate and risk assessment of sulfonamides and metabolites in urban groundwater.

Antibiotics, such as sulfonamides (SAs), have recently raised concern as wastewater treatment plants (WWTPs) partly remove them, and thus, SAs continuously enter the aquifers. In this context, the aims of this work are to (1) investigate the temporal evolution of SAs and metabolites in an urban aquifer recharged by a polluted river; (2) identify the potential geochemical processes that might affect SAs in the river-groundwater interface and (3) evaluate the ecological and human health risk assessment of SAs. To this end, 14 SAs and 4 metabolites were analyzed in river and urban groundwater from the metropolitan area of Barcelona (NE, Spain) in three different sampling campaigns. These substances had a distinct behavior when river water, which is the main recharge source, infiltrates the aquifer. Mixing of the river water recharge into the aquifer drives several redox reactions such as aerobic respiration and denitrification. This reducing character of the aquifer seemed to favor the natural attenuation of some SAs as sulfamethoxazole, sulfapyridine, and sulfamethizole. However, most of the SAs detected were not likely to undergo degradation and adsorption because their concentrations were constant along groundwater flow path. In fact, the intensity of SAs adsorption is low as the retardation factors are close to 1 at average groundwater pH of 7.2 for most SAs. Finally, risk quotients (RQs) are used to evaluate the ecological and human health risks posed by single and mixture of SAs in river water and groundwater, respectively. Life-stage RQs of the SAs detected in groundwater for the 8 age intervals were low, indicating that SAs and their mixture do not pose any risk to human beings. Concerning the environmental risk assessment, SAs do not pose any risk for algae, fish and crustaceans as the RQs evaluated are further lower than 0.1.