Distribution of micropollutants in estuarine and sea water along the Portuguese coast.

This work provides the first spatial distribution report of micropollutants (MPs) in the entire Portuguese coast, comprising the ocean shore (sea water, SW) and whenever possible the nearest river discharging on it (estuarine water, EW). This surface water monitoring programme aimed to assess the spatial distribution of 37 MPs with a wide chemical nature, including some substances prioritized by the European Union Directive 39/2013/EU and contaminants of emerging concern targeted in the Watch List of Decisions 495/2015/EU and 840/2018/EU. The risk quotients were estimated in each sampling point for the detected MPs. High concentrations of diclofenac, tramadol and carbamazepine were determined, the latter with medium to high risk for algae. Some pharmaceuticals and perfluorooctanesulfonic acid (PFOS) were broadly distributed, maybe due to the direct discharge into the sea. Atrazine and alachlor were found in the majority of the samples, with alachlor levels often considered as medium to high risk.

Dual enantioselective LC-MS/MS method to analyse chiral drugs in surface water: Monitoring in Douro River estuary.

This work presents the development of an enantioselective method to quantify chiral drugs (CDs) in surface water and its application in the Douro River estuary monitoring. Different classes of CDs were targeted, including 23 compounds, namely beta-blockers, antidepressants, one beta2-adrenergic agonist, non-steroidal anti-inflammatory drugs, stimulants, and some illicit drugs as cocaine (COC) and its metabolites, and amphetamines. The analytical method was based on an innovative application of solid phase extraction (SPE), followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) using a triple quadrupole analyzer. The ground-breaking approach of SPE consists in the use of Oasis® MCX cartridges to pre-concentrate 500 mL of water samples, allowing the simultaneous extraction of acidic, basic and neutral analytes, rather than the conventional recovery of basic compounds only. Two chiral columns were used for enantiomeric separation in reverse elution mode, a Chirobiotic™V and a Pirkle type Whelk-O®1, for basic and acidic compounds, respectively. The method validation demonstrated good linearity (r2 > 0.99), selectivity and sensitivity, with method detection limits between 0.01 and 2.66 ng L-1 and method quantification limits between 0.02 and 5.71 ng L-1. The developed method was successfully applied to monitor daily variations along one week in surface waters collected in 5 locations of the Douro River estuary. Tramadol (TRM) and its metabolite N-desmethyltramadol (NDT), presented high concentrations near the affluent of a tributary river, while the second eluted enantiomer of O-desmethyltramadol (ODT) was found at high concentrations at the mouth of the Douro River. The metabolite NDT was quantified at higher concentrations than TRM. Venlafaxine (VNF) was found at high concentrations near the affluent of the same tributary river, but its metabolite, O-desmethylvenlafaxine (ODV), was found at concentrations 3 times higher. COC was found every day at all sampling points along the estuary, with slight variations.

Monitoring of the 17 EU Watch List contaminants of emerging concern in the Ave and the Sousa Rivers.

The occurrence of micropollutants in the environment is a matter of high concern. Some regulations have been published in the last years and a Watch List of contaminants of emerging concern (CECs) for European Union monitoring of surface water was launched in the Decision 2015/495, including three estrogens (estrone, E1; 17-ß-estradiol, E2; and 17-α-ethinylestradiol, EE2), four pharmaceuticals (diclofenac and the macrolide antibiotics azithromycin, clarithromycin and erythromycin), an anti-oxidant (2,6-ditert-butyl-4-methylphenol, BHT), an UV filter (2-ethylhexyl 4-methoxycinnamate, EHMC), some pesticides (methiocarb and the neonicotinoids imidacloprid, thiacloprid, thiamethoxam, clothianidin and acetamiprid) and two herbicides (oxadiazon and triallate). This study provides the first spatial and seasonal monitoring campaign in the Ave and the Sousa Rivers for the all set of the 17 Watch List CECs (not reported yet for any country), in order to assess their occurrence, distribution, frequency and risk assessment. It also highlights the need of extend the study to other regions and environmental matrices to investigate the occurrence and possible sources of contamination of CECs, aiming to give insights for decision makers to define mitigation strategies for a more sustainable water policy.

A review on environmental monitoring of water organic pollutants identified by EU guidelines.

The contamination of fresh water is a global concern. The huge impact of natural and anthropogenic organic substances that are constantly released into the environment, demands a better knowledge of the chemical status of Earth's surface water. Water quality monitoring studies have been performed targeting different substances and/or classes of substances, in different regions of the world, using different types of sampling strategies and campaigns. This review article aims to gather the available dispersed information regarding the occurrence of priority substances (PSs) and contaminants of emerging concern (CECs) that must be monitored in Europe in surface water, according to the European Union Directive 2013/39/EU and the Watch List of Decision 2015/495/EU, respectively. Other specific organic pollutants not considered in these EU documents as substances of high concern, but with reported elevated frequency of detection at high concentrations, are also discussed. The search comprised worldwide publications from 2012, considering at least one of the following criteria: 4 sampling campaigns per year, wet and dry seasons, temporal and/or spatial monitoring of surface (river, estuarine, lake and/or coastal waters) and ground waters. The highest concentrations were found for: (i) the PSs atrazine, alachlor, trifluralin, heptachlor, hexachlorocyclohexane, polycyclic aromatic hydrocarbons and di(2-ethylhexyl)phthalate; (ii) the CECs azithromycin, clarithromycin, erythromycin, diclofenac, 17α-ethinylestradiol, imidacloprid and 2-ethylhexyl 4-methoxycinnamate; and (iii) other unregulated organic compounds (caffeine, naproxen, metolachlor, estriol, dimethoate, terbuthylazine, acetaminophen, ibuprofen, trimethoprim, ciprofloxacin, ketoprofen, atenolol, Bisphenol A, metoprolol, carbofuran, malathion, sulfamethoxazole, carbamazepine and ofloxacin). Most frequent substances as well as those found at highest concentrations in different seasons and regions, together with available risk assessment data, may be useful to identify possible future PS candidates.