Characterization and removal efficiencies of microplastics discharged from sewage treatment plants in Southeast Spain.

Microplastics (MPs) are ubiquitous pollutants that can effectively harm different ecosystems. The information on the relative contribution of wastewater treatment plants (WWTPs) to the surrounding environment is important, in order to understand ecological health risks and implement measures to reduce their presence. This focus article presents a quantitative assessment on the relative concentration and types of MPs delivered from four WWTPs located at the Southeast of Spain. Samples from WWTPs were collected throughout a four-year period, comprising more than 1,200 L of analyzed wastewater and 3,215 microparticles isolated. Density extraction with 1.08 g/mL NaCl salt solution was systematically used as the main separation method, in a simple and reliable manner, and repeat extraction cycles did not play any significant impact on the study outcomes. The four WWTPs had removal efficiencies between 64.3% and 89.2% after primary, secondary, and tertiary treatment phases, without diurnal or daily variations. Advanced treatment methods displayed a lower removal rate for fibers than for particulate MPs. The abundance of MPs was always higher and with a lower mean size in wastewater samples collected in Autumn than for the rest of seasons. MPs dumped from WWTPs in large quantities into the environment are meant to be regarded as an important point source for aquatic and terrestrial environments.

A holistic approach on the impact of microplastic discharge from WWTPs to the neighboring environment in Southeast Spain.

The present study investigated the release of microplastics (MPs) from wastewater treatment plants (WWTPs) to the neighboring environment, including marine and coastal sediments, and fish. Here, we comprehensively investigated MP abundance in 34 samples of marine sediment, corresponding to 5,530.5 g of sediment (d.w.) collected at -8.0 m, -12.5 m, and -24.0 m, 69 samples of coastal sediment, accounting for 13,617.4 g (d.w.) from 17 different beaches from Mar Menor, and stomach and intestine of 17 fish samples of Sparus aurata, in the vicinity of Cartagena, a port city in Southeast Spain. The results showed that MPs were detected in all marine sediment samples, with an average abundance of 19.4 ± 2.4 items/kg (d.w.), in coastal sediments, with an average abundance of 52.5 ± 5.3 items/kg (d.w.), and fish samples, with an average of 8.2 ± 1.4 items per individual. The contribution of MPs from WWTPs to marine sediments is expected to be slow, as effluents were mostly dominated by fiber and film shapes, and by polymers less dense than seawater. There were no significant variations in the MP abundance of marine sediments after the atmospheric phenomenon named DANA, although a significant smaller MP size was reported, indicating a high mobility for tiny sizes. The same results were revealed for coastal sediment, although variations after DANA were statistically significant. Coastal sediment samples closer to WWTPs and agricultural fields with plastic mulching displayed higher MP concentrations, and an increase in the removal rate of MPs from WWTP effluents was negatively correlated with a decrease in MPs from fish collected. This study highlights the importance of sewage treatment plants in transporting MPs to the aquatic and terrestrial surrounding environment, which warrants further research on human health risks associated to MP pollution.

First evidence of microplastics isolated in European citizens' lower airway.

Microplastics (MPs) have been detected in all environmental locations, including the atmosphere. However, few studies have investigated the presence of airborne MPs in the human respiratory system. Our research purpose was to investigate these pollutants in the lower human airways of 44 adult European citizens, using bronchoalveolar lavage fluid (BALF) collection as a minimally invasive method, that enables the detection of these pollutants in living patients. We studied the relationship between the patients' life habits and physiological parameters, based on background information and medical and occupational history, and the concentration of MPs isolated from their respiratory systems. Our results indicate that most MPs were in the form of microfibers (MFs) (97.06%), with an average concentration of 9.18 ± 2.45 items/100 mL BALF, and only 5.88% (0.57 ± 0.27 items/100 mL BALF) were particulate MPs, without a significant relationship with environmental, physiological, or clinical factors. The average size was 1.73 ± 0.15 mm, with the longest dimension (9.96 mm) corresponding to a polyacrylic fiber. Taken together, the results demonstrated the occurrence of MPs in the lower human airway, although more studies are necessary to elucidate the negative effects these pollutants could induce in the human respiratory system and its associated diseases.

Weathering indices of microplastics along marine and coastal sediments from the harbor of Cartagena (Spain) and its adjoining urban beach.

Marine and coastal sediments from the harbor of Cartagena (Spain) and its adjoining beach were investigated regarding their microplastic burden. Fibers accounted for 47.62% and 61.66% in marine and coastal sediments, respectively, followed by films (31.43% and 18.76%) and fragments (20.95% and 18.65%). Polyvinyl (36.07%), polypropylene (21.31%), and polyethylene (18.03%) were isolated for marine sediments, and low-density polyethylene (40.71%), polypropylene (20.16%), and acrylate (11.37%) for coastal sediments. Highest concentrations were found in the deepest marine sediments (24.0 m) and in the furthest zone from the seashore for coastal sediments (18 m). Carbonyl index increased in the intermediate area (12.5 m) for marine sediments (0.51), whilst vinyl index was maximum for the deepest samples (1.94), reporting Norrish type I and II reactions, respectively. Coastal sediments collected close to the high tide line displayed the highest average values for both indices, 1.57 and 1.29, respectively, indicating a higher exposition to weathering variables.

Commercial Gilthead Seabream (Sparus aurata L.) from the Mar Menor Coastal Lagoon as Hotspots of Microplastic Accumulation in the Digestive System.

This paper presents the results on the presence and characterization of microplastics (MP) in the gastrointestinal tract of gilthead seabream (Sparus aurata L.), a species of commercial interest from the Mar Menor coastal lagoon in Southeast Spain. This is the first time that microplastic ingestion is recorded in any species from this semi-enclosed bay. Stomach and intestine from a total of 17 specimens captured by local fishermen were processed, and microplastic particles and fibers found in all of them were displayed. Overall, 40.32% (279/692) of total isolated microparticles proved to be microplastics; i.e., <5 mm, as identified by FTIR spectroscopy. The average value by fish was 20.11 ± 2.94 MP kg-1, corresponding to average concentrations of 3912.06 ± 791.24 and 1562.17 ± 402.04 MP by kg stomach and intestine, respectively. Four MP forms were isolated: fiber (71.68%), fragment (21.15%), film (6.81%), and microbead (0.36%), with sizes ranging from 91 µm to 5 mm, an average of 0.83 ± 0.04 mm, and no statistically significant differences between mean sizes in stomach and intestine samples (F-test = 0.004; p = 0.936). Nine polymer types were detected, although most of fibers remained unidentified because of their small size, the presence of polymer additives, or closely adhered pollutants despite the oxidizing digestion carried out to eliminate organic matter. No significant correlation was found between main biological parameters and ingested microplastics, and high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyethylene polypropylene (PEP), and polyvinyl (PV) were identified as the most abundant polymers. The average microplastic ingestion in this study area was higher than those reported in most studies within the Mediterranean Sea, and closely related to microplastic pollution in the surrounding area, although with a predominance of fiber form mainly due to fishery activities.

Membrane bioreactor and rapid sand filtration for the removal of microplastics in an urban wastewater treatment plant.

This paper discusses about the role of two different wastewater treatment technologies in the abatement of microplastics (MPs) from the final effluent of an urban wastewater treatment plant (WWTP); i.e., membrane bioreactor technology (MBR) and rapid sand filtration (RSF). For this purpose, a WWTP with these two technologies was monitored for 18 months. The average microplastic concentration was 4.40 ± 1.01 MP L-1 for the influent, 0.92 ± 0.21 MP L-1 for MBR, and 1.08 ± 0.28 MP L-1 for RSF, without statistically significant differences for MPs removal between both technologies (F-test = 0.195, p = 0.661). The main MP forms isolated in our study were fibers (1.34 ± 0.23 items L-1), followed by films (0.59 ± 0.24 items L-1), fragments (0.20 ± 0.09 items L-1), and beads (0.02 ± 0.01 items L-1). All of them probed to be statistically significant reduced after both technologies, but without statistically significant differences between them. The MP removal efficiency was 79.01% and 75.49% for MBR and RSF, respectively, although higher for microplastic particulate forms (MPPs), 98.83% and 95.53%, than for fibers, 57.65% and 53.83% for MBR and RSF, respectively, displaying a selective removal of particulate forms against microfibers. Fourteen different plastic polymers were identified in the influent, only persisting low-density polyethylene (LDPE), nylon (NYL), and polyvinyl (PV) in RSF effluent, and melamine (MUF) after MBR treatment. The MP size ranged from 210 µm, corresponding to NYL fragment form in the influent, to 6.3 mm, corresponding to a red microfiber also from the influent. The maximum MP average size significantly decreased from MBR (1.39 ± 0.15 mm), to RSF (1.15 ± 0.08 mm) and influent (1.05 ± 0.05 mm) (F-test = 4.014, p = 0.019), exhibiting the fiber selection carried out by these advanced technologies for wastewater treatment.

Microplastics in an urban wastewater treatment plant: The influence of physicochemical parameters and environmental factors.

This paper presents the abundance, concentration and variability of microplastics (MP) in an urban wastewater treatment plant (WWTP), according to different water parameters and environmental factors, their possible sources and removal efficiency. A total of 352.6 L of wastewater from four stages of the treatment process were processed following a standardized extraction protocol by density separation, trinocular microscopic identification and polymeric analysis by Fourier transform infrared spectroscopy. MP comprised a 46.6% of total microlitter, with a statistically significant removal of 90.3% in the final effluent of the WWTP. Five different shapes were isolated; i.e. fragment, film, bead, fiber, and foam. The most prominent MP forms in the final effluent were fragments and fibers, with the most common size class being 400-600 µm. Seventeen different polymer families were identified, with low-density polyethylene being the most prevalent one (52.4%) in a film form (27.7%), mostly from agriculture greenhouses near the sewage plant and single plastic bags (it is noted that only a year ago consumers are charged for them in Spain). Influent wastewater with high concentrations of suspended solids proved to have a low MP burden with a larger MP size, possibly due to a hetero-aggregation with particulate matter. Agglomeration of polystyrene and polyethylene terephthalate with organic material is also suggested, both with surface energies higher than 25 mN m-1 enough for a high biofouling rate. The sewage plant cushions sharp-point microplastic concentrations during the warm season, allowing a stable performance of the WWTP.

Abundance, morphology and chemical composition of microplastics in sand and sediments from a protected coastal area: The Mar Menor lagoon (SE Spain).

This paper presents the abundance and ubiquitous presence of microplastics in a protected coastal zone located in the southeast of Spain: The Mar Menor lagoon, an important tourist destination in this region. Seventeen sampling sites, corresponding to both intertidal and backshore points, were collected during winter 2017 and 2018, being situated in different protected areas according to international, European and Spanish environmental policies. The main objectives of the study were to examine microplastics in both protected and non-protected areas, and to test the importance of local activities on their presence. Northwest samples reported higher average microplastic concentrations than samples collected in the southeastern part of the coastal lagoon, likely due to the extensive use of sludge from wastewater treatment plants besides the fragmentation of low density polyethylene from plastic greenhouses, being microplastic films also higher for northwest than for southeast samples. Moreover, large inter-site differences observed in microplastic concentrations also demonstrated that local activities, mainly tourism and fishery, may play an important role as microplastic sources. The extensive amount of 17 different polymer types identified in this paper, much higher than most reported in similar studies, together with the variety of colors of microplastics most of them in a fragmented form (59.4%) and mainly detected in urban beaches, should be related to the geographical situation of this coastal lagoon, together with enormous environmental passives accumulated over the past 50 years. Only polyvinyl ester resins proved to be statistically higher in non-protected than in protected zones, probably related to their use in manufacturing boat hulls, although sources and pathways for microplastics are always difficult to assess. Measures to avoid microplastic pollution should be taken through educational programs, with also a clear commitment from plastic producers and transformers.

Ansiedad, depresión y autoestima en población general, transeúntes y consumidores de sustancias adictivas / Anxiety, depression and self-esteem in homeless, general population, and substance users

Los trastornos por uso de sustancias coexisten en algunos pacientes con diferentes manifestaciones clínicas de ansiedad y del estado de ánimo, a su vez variables como la autoestima guardan una estrecha relación en el curso y evolución de éstos. En el presente estudio se investiga los trastornos por consumo de sustancias, el transeuntismo y los niveles de ansiedad, depresión y autoestima. La investigación se desarrolla en la ciudad de Castellón con un total de 258 sujetos, divididos en un grupo clínico subdividido en consumidores de cocaína, heroína, heroína combinada con cocaína, cannabis, alcohol y sujetos en programa de mantenimiento con metadona (PMM), un grupo de población general y otro grupo de transeúntes, evaluados mediante el cuestionario STAI, BDI, RSES y una entrevista que recoge aspectos biopsicosociales y clínicos. Los resultados mostraron una mayor gravedad clínica en depresión y ansiedad rasgo en consumidores de heroína inhalada, así como una mayor ansiedad estado y menor autoestima en el grupo de transeúntes. Se puede desprender de los resultados que el consumo de sustancias correlaciona con mayores niveles de ansiedad rasgo y depresión, así como la exclusión social con una menor percepción de autoestima y mayor ansiedad estado

Substance use disorders coexist in some patients with different clinical manifestations of anxiety and mood, in turn variables as self-esteem keep a narrow relation in the course and evolution of these. The present study investigates the relationship between the substance use disorders, the homelessness and the levels of anxiety, depression and self-esteem. Research is carried out in the city of Castellón, with a total of 258 subjects, divided into a clinical group subdivided into cocaine, heroin, heroin combined with cocaine, cannabis, alcohol users and patients in methadone maintenance program (MMP), an general population group and a group of homeless, evaluated through the questionnaire STAI, BDI, RSES and an interview that gathers biopsychosocial and clinical aspects. Results showed a more severe clinical depression and trait anxiety in consumers of inhaled heroin, as well as increased state anxiety and lower self-esteem in the group of homeless. It can be inferred from the results that the substance use correlates with higher levels of trait anxiety and depression and social exclusion with a lower perception of self-esteem and increased anxiety state