Atmospheric Nitrogen Pollution Control Benefits the Coastal Environment.

Nitrogen is an essential nutrient and a major limiting element for the ocean ecosystem. Since the preindustrial era, substantial amounts of nitrogen from terrestrial sources have entered the ocean via rivers, groundwater, and atmospheric deposition. China serves as a key hub in the global nitrogen cycle, but the pathways, sources, and potential mitigation strategies for land-ocean nitrogen transport are unclear. By combining the CHANS, WRF-Chem, and WNF models, we estimated that 8 million tonnes (Tg) of nitrogen was transferred into the ocean in 2017 in China, with atmospheric deposition contributing 1/3. About half variation of the offshore chlorophyll concentration was explained by atmospheric deposition. The Bohai Sea was the hot spot of nitrogen input, estimated at 214 kg N ha-1, while other areas were around 25-51 kg N ha-1. The largest contributors are agricultural systems (4 Tg, 55%), followed by domestic sewage (2 Tg, 21%). Abatement measures could reduce nitrogen export to the ocean by 43%, and mitigating ammonia and nitrogen oxide emissions accounts for 33% of this reduction, highlighting the importance of addressing air pollution in resolving ocean pollution. The cost-benefit analysis suggests the priority of nitrogen reduction in cropland and transport systems for the ocean environment.

Spatial distribution and seasonal variation of trace hazardous elements contamination in the coastal environment.

Groundwater is the second largest water source for daily consumption, only next to surface water resources. Groundwater has been extensively investigated for its pollution level in urban areas. The groundwater quality assessments in industrial areas associated with every urban landscape are still lacking. In order to examine the spatial distribution characteristics, pollution levels, and sources of trace metals in the densely populated Chennai coastal region of Tamilnadu, India, physicochemical parameters and trace element concentrations have been determined in groundwater. 55 groundwater samples from Tamil Nadu's coastal region were collected and analyzed for physicochemical parameters such as pH, (EC), (TDS), and (TH) during the pre-monsoon (June 2015) and post-monsoon (January 2016) seasons. We used trace elements and analyzed them in this study (Mg, Zn, Pb, Ni, Co, Cu, Cr, and Fe). Furthermore, anthropogenic input from industries and power plants exacerbates the pollution of Ni, Mg, Fe, and Mn. Due to evaporites and anthropogenic input, samples with excessive salinity, total hardness, and water quality are considered unsuitable for irrigation or drinking. The results demonstrated that seasonal, geogenic, and anthropogenic influences all have a significant impact on the heterogeneous chemistry of groundwater.

CORAL-Catamaran for Underwater Exploration: Development of a Multipurpose Unmanned Surface Vessel for Environmental Studies.

CORAL (Catamaran fOr UndeRwAter expLoration) is a compact, unmanned catamaran-type vehicle designed and developed to assist the scientific community in exploring marine areas such as inshore regions that are not easily accessible by traditional vessels. This vehicle can operate in different modalities: completely autonomous, semi-autonomous, or remotely assisted by the operator, thus accommodating various investigative scenarios. CORAL is characterized by compact dimensions, a very low draft and a total electric propulsion system. The vehicle is equipped with a single echo-sounder, a 450 kHz Side Scan Sonar, an Inertial Navigation System assisted by a GPS receiver and a pair of high-definition cameras for recording both above and below the water surface. Here, we present results from two investigations: the first conducted in the tourist harbour in Pozzuoli Gulf and the second in the Riomaggiore-Manarola marine area within the Cinque Terre territory (Italy). Both surveys yielded promising results regarding the potentiality of CORAL to collect fine-scale submarine elements such as anthropic objects, sedimentary features, and seagrass meadow spots. These capabilities characterize the CORAL system as a highly efficient investigation tool for depicting shallow bedforms, reconstructing coastal dynamics and erosion processes and monitoring the evolution of biological habitats.

Noise pollution assessment and management in rare earth mining areas: a case study of Kollam, Kerala, India.

Noise pollution is an unintentional consequence of mining activities, needing rigorous assessment, monitoring, and mitigation techniques to reduce its impact on local residents and ecosystems. The study specifically examines the noise pollution from rare earth mining activities in the Neendakara-Kayamkulam (NK) coastal belt, Kollam, Kerala, India, a region rich in ilmenite, rutile, sillimanite, zircon, and monazite. Despite the known environmental and health impacts of noise pollution, there is limited specific data on its magnitude and sources in this region, as well as a lack of effective mitigation strategies tailored to rare earth mining operations. Studies have indicated that mining operations, such as the movement of heavy mineral sands, considerably elevate noise levels, which have an effect on the environment's quality and public health. This study seeks to fill the gap by geospatial mapping and assessing the noise levels and recommend measures to effectively mitigate noise pollution. Systematic noise measurements were conducted at 48 suitable locations within the NK coastal belt, including residential, commercial, industrial, coastal, and silence zones. The noise levels vary from 49.1 dB(A) near a religious place to 82.4 dB(A) near the local industry. The study employs geospatial noise mapping and land cover superimposition to implement class-specific mitigation measures for noise pollution in a coastal vicinity mixed land use area, including natural and vegetative barriers, operational scheduling, zoning, and land use planning.

Spatial and seasonal variations in trace metals in marine sediments from the Dubai coastal environment.

This study was conducted to assess sediment trace metals (Cd, Cr, Cu, Pb, Ni and Zn) contamination using a systematic approach by collecting sediment samples from 8 transects along the Dubai coastline, each 10 km long, and each transect included its nearshore sediment sampling station. Additionally, 10 sediment samples were collected from the Dubai creek and other potential sources of metal pollution. The sediment samples were collected in December and again in August. However, no significant difference in sediment metal concentration was found between the two sampling campaigns. The sediment trace metal concentrations (0.92-1.31 mg Cd/kg, 2.82-176.6 mg Cr/kg, 2.27-621.67 mg Cu/kg, 0.88-23.6 mg Pb/kg, 1.92-192.2 mg Ni/kg and 9.1-391.05 mg Zn/kg) showed considerable variability, except for Cd (1.08 ± 0.06 mg/kg, 5.55% variability). Despite this, no significant differences in sediment metal concentrations were found between the sampled transects. However, significant variations in Cr, Cu, Pb and Zn were evident between distances from the shoreline to offshore stations along the Dubai coast, and the nearshore locations presented clear evidence of elevated/maximum sediment metal concentrations. Most of the sediment trace metal concentrations, however, were found well within the sediment quality guidelines (SQGs) for nearshore sediments. Trace metal contamination hotspots, nonetheless, were identified at some nearshore stations as determined by metal level exceedance over the SQGs, background levels and the pollution load index, with limited potential ecological risk. Overall, the findings suggest that sediments in the Dubai coastal environment are mainly influenced by anthropogenic activities in stations located in the proximity of ship maintenance, ports, and industrial areas such as Dry Dock, Jaddaf, Jebel Ali Port, Wharfage, Hamriya and DUBAL.

Permanent Laser Scanner and Synthetic Aperture Radar Data: Correlation Characterisation at a Sandy Beach.

In recent years, our knowledge of coastal environments has been enriched by remotely sensed data. In this research, we co-analyse two sensor systems: Terrestrial Laser Scanning (TLS) and satellite-based Synthetic Aperture Radar (SAR). To successfully extract information from a combination of different sensors systems, it should be understood how these interact with the common environment. TLS provides high-spatiotemporal-resolution information, but it has high economic costs and limited field of view. SAR systems, despite their lower resolution, provide complete, repeated, and frequent coverage. Moreover, Sentinel-1 SAR images are freely available. In the present work, Permanent terrestrial Laser Scanning (PLS) data, collected in Noordwijk (The Netherlands), are compared with simultaneous Sentinel-1 SAR images to investigate their combined use on coastal environments: knowing the relationship between SAR and PLS data, the SAR dataset could be correlated to beach characteristics. Meteorological and surface roughness have also been taken into consideration in the evaluation of the correlation between PLS and SAR data. A generally positive linear correlation factor up to 0.5 exists between PLS and SAR data. This correlation occurs for low- or moderate-wind-speed conditions, whilst no particular correlation has been highlighted for high wind intensity. Furthermore, a dependence of the linear correlation on the wind direction has been detected.

Growth of the harmful alga, Prymnesium parvum (Prymnesiophyceae), after gradual and abrupt increases in salinity.

Prymnesium parvum is a euryhaline, toxin-producing microalga. Although its abundance in inland waters and growth potential in the laboratory is reduced at high salinity (>20), the ability of inland strains to adjust their growth after long-term residence in high salinity is uncertain. An inland strain of P. parvum maintained at salinity of 5 in modified artificial seawater medium (ASM-5) was subjected to the following treatments over five sequential batch culture rounds: ASM-5 (control); modified ASM at salinity of 30, raised with NaCl; modified ASM at salinity incrementally increased to 30 with NaCl; and Instant Ocean® at salinity of 30 (IO-30). Exponential growth rate (r) was reduced when salinity was increased from 5 to 30 in ASM but returned to control values during the second round. When salinity was incrementally increased, a reduction in r still occurred when salinity reached 25-30. Maximum density was reduced at salinity of 30 in ASM upon abrupt transfer or incremental increase, and compensation did not occur. Growth performance in IO-30 was comparable to control values. In conclusion, (i) long-term compensation for acute inhibitory effects of high salinity occurred for r but not maximum density, (ii) incremental increases in salinity did not prevent growth inhibition, suggesting the existence of a salinity threshold of 25-30 for onset of salinity stress, and (iii) the presence of a seawater-like salt mixture prevented growth inhibition by high salinity. These findings provide new insights on P. parvum's long-term ability to adjust its growth in environments of different salinity and ionic composition.

Types of coastlines and the evacuees' mental health: A repeated cross-sectional study in Northeast Japan.

Although the health risks and benefits of coastal areas have long been researched, these effects of the different types of coastlines have rarely been explored on the evacuees living near the coast, in a post-disaster context. Thus, this study aimed to explore, with the passing of years after a disaster, what kind of coastline is a useful public health resource as a post-disaster reconstruction approach in coastal environments that have suffered significantly from the tsunami disaster in northeast Japan in 2011. This study compared the evacuees' mental health based on proximity to the coast and the types of coastlines (artificial, semi-natural, and natural). Data were drawn from the Miyagi Prefectural Government surveys, which targeted almost all evacuees of the 2011 Great East Japan Earthquakes and Tsunami (n = 96,203). We applied a pooled Poisson regression model to a repeated cross-sectional dataset of evacuees' mental health between 2012 and 2016. Moderate psychological distress, measured via the Kessler Psychological Distress Scale (K6) score, was the dependent variable, while proximity to the coast and type of coastline were the independent variables. The estimated main effects of type of coastline indicated that overall associations between K6 ≥5 and all types of coastlines within a 1.6 km buffer of participants' residential space were not statistically significant (p > 0.05). However, among types of coastlines, the interaction terms of semi-natural coastline × year (2015 and 2016) were significantly associated with lower incidence rate ratios (IRR), which decreased in 2015 and 2016 (IRR: 0.88, 95%CI: 0.79-0.98; IRR: 0.78, 95%CI: 0.68-0.90, respectively). Further, we computed the marginal effects of coastline types for each year to observe differences in the impact on moderate psychological distress depending on different accessible coastline types within a distance of 1.6 km from the participants' living space. We found that, after the revision of the coastal act in 2014, the moderate mental stress of participants who lived around semi-natural coastlines significantly tended to be low (dy/dx: -0.04, 95%CI: -0.08-0.01 in 2015; dy/dx: -0.07, 95%CI: -0.11-0.04 in 2016). This finding can encourage policymakers to manage coastal areas with green infrastructure in the post-disaster reconstruction sustainably.

Diversity and Genetic Basis for Carbapenem Resistance in a Coastal Marine Environment.

Resistance to the "last-resort" antibiotics, such as carbapenems, has led to very few antibiotics being left to treat infections by multidrug-resistant bacteria. Spread of carbapenem resistance (CR) has been well characterized for the clinical environment. However, there is a lack of information about its environmental distribution. Our study reveals that CR is present in a wide range of Gram-negative bacteria in the coastal seawater environment, including four phyla, eight classes, and 30 genera. These bacteria were likely introduced into seawater via stormwater flows. Some CR isolates found here, such as Acinetobacter junii, Acinetobacter johnsonii, Brevundimonas vesicularis, Enterococcus durans, Pseudomonas monteilii, Pseudomonas fulva, and Stenotrophomonas maltophilia, are further relevant to human health. We also describe a novel metallo-ß-lactamase (MBL) for marine Rheinheimera isolates with CR, which has likely been horizontally transferred to Citrobacter freundii or Enterobacter cloacae In contrast, another MBL of the New Delhi type was likely acquired by environmental Variovorax isolates from Escherichia coli, Klebsiella pneumoniae, or Acinetobacter baumannii utilizing a plasmid. Our findings add to the growing body of evidence that the aquatic environment is both a reservoir and a vector for novel CR genes.IMPORTANCE Resistance against the "last-resort" antibiotics of the carbapenem family is often based on the production of carbapenemases, and this has been frequently observed in clinical samples. However, the dissemination of carbapenem resistance (CR) in the environment has been less well explored. Our study shows that CR is commonly found in a range of bacterial taxa in the coastal aquatic environment and can involve the exchange of novel metallo-ß-lactamases from typical environmental bacteria to potential human pathogens or vice versa. The outcomes of this study contribute to a better understanding of how aquatic and marine bacteria can act as reservoirs and vectors for CR outside the clinical setting.

Long-term quality record (1996-2018) of coastal sediments at the complex industrial site along the Jordanian coast of the Gulf of Aqaba.

To evaluate the effect of the industrial activities on the sediment quality, we investigated long-term records of physical and chemical properties of bottom-surface sediments from a complex industrial site along the Jordanian coast of the Gulf of Aqaba. Sediment samples were collected from 10 m depth once a year from six different stations (S1-S6) and analyzed for grain size, loss on ignition (LOI), organic carbon (OC), hydrogen sulfide (H2S), total nitrogen (TN), total phosphorus (TP), and heavy metal contents. Temporal variations show a constant/decreasing trend for H2S, OC, and LOI, whereas an increasing trend for TN and TP was observed. Heavy metal concentrations reveal almost constant trends over time for Cd, Cu, and Zn and a decreasing trend for Cr and Pb. Statistical analysis indicates that the differences between the different sampling stations were insignificant for almost all variables. However, some differences were observed, as the highest values were recorded in S3 and the lowest values in S1. The textural proprieties show no significant variation among sites. As a result, the sediment quality at the industrial site is comparable with that in other sites along the northern Gulf of Aqaba. Sediments at the industrial site appear to have attained steady-state equilibrium where basic environmental parameters are insignificantly modified from the baseline values of the area. The decreasing trend observed over time indicates a significant improvement in the environmental quality attributed to the stringent implementation of environmental regulation in Aqaba (e.g., zero discharge policy).

Candida tropicalis geographic population structure maintenance and dispersion in the coastal environment may be influenced by the climatic season and anthropogenic action.

Candida tropicalis is a pathogenic yeast with worldwide recognition as the second or third more frequently isolated species in Latin America, for both superficial and systemic infections. Because of its high prevalence, and growing clinical interest, it is essential to understand genetic variability patterns of this important Candida species in the tropics. Besides belonging to the human normal microbiota, C. tropicalis may be found in other warm blood animals and in the environment, including water and sand of beaches. The aims of the present study were to evaluate genotypic and phenotypic variability of 62 isolates of C. tropicalis obtained from the coastal environment in Northeast Brazil using microsatellite and MALDI-TOF/MS comparisons. There was a relatively low correspondence between these typing techniques employed. Therefore, further studies are needed to consolidate the use of MALDI-TOF/MS as a yeast typing tool. Nevertheless, the two methods employed demonstrated the heterogeneity of C. tropicalis in a coastal environment. We also found relative maintenance of the population structure within the same season, which may reinforce the idea that this species presents the potential to remain in the environment for a long period of time. In addition, highly related strains were found within different geographic points of collection, demonstrating that this strain may be dispersed at long distances, probably influenced by anthropogenic actions and driven by the sea tides and wind.

Normalized Method for Land Surface Temperature Monitoring on Coastal Reclaimed Areas.

The temporal analysis of land surface temperature (LST) has generally been studied using data from the same season, as temperature varies greatly over time. However, the cloud cover in thermal remotely sensed images and the coarse resolution of passive sensor system significantly limits data availability of same season for comparative temporal analysis in many parts of the world. To address this problem, we propose a new method for temporal monitoring of surface temperature based on LST normalization (LSTn); deploying the average open water temperature to normalize LST when monitoring temporal change in the surface temperature of newly coastal reclaimed areas. This method was applied in the Lingding Bay area, Guangdong Province, Southern China. Original LST and LSTn values were calculated for years 1987, 1997, 2007, and 2017. In contrast to the original LST, results show that LSTn can reduce seasonal variability when monitoring temporal change in surface temperatures. Additionally, LSTn revealed pronounced differences between the temperature of impervious surfaces and other land cover types. This method offers more robust detection of surface urban heat islands than original LST in newly developed coastal areas.

The Soothing Sea: A Virtual Coastal Walk Can Reduce Experienced and Recollected Pain.

Virtual reality (VR) distraction has become increasingly available in health care contexts and is used in acute pain management. However, there has been no systematic exploration of the importance of the content of VR environments. Two studies tested how interacting with nature VR influenced experienced and recollected pain after 1 week. Study 1 (n = 85) used a laboratory pain task (cold pressor), whereas Study 2 (n = 70) was a randomized controlled trial with patients undergoing dental treatment. In Study 1, nature (coastal) VR reduced both experienced and recollected pain compared with no VR. In Study 2, nature (coastal) VR reduced experienced and recalled pain in dental patients, compared with urban VR and standard care. Together, these data show that nature can improve experience of health care procedures through the use of VR, and that the content of the VR matters: Coastal nature is better than urban.

Mapping toxic mineral contamination: the southern oyster drill, S. haemastoma (L., 1767), as evaluable sentinel species.

The nickel, chromium, arsenic, cadmium, and lead content have been evaluated, by ICP-MS, in digestive gland of the amphiatlantic gastropod Stramonita haemastoma, sampled along the highly anthropized Gulf of Milazzo (Central Mediterranean). Concentrations notably higher than those reported in literature for other Mediterranean Muricidae have been recorded. The results also indicated a different impact in different sites, according to distribution and typology of human activities, whilst recorded seasonal variations might relate with rapid metabolic response. Such preliminary results suggest S. haemastoma may be considered a promising sentinel species for inorganic contamination in marine environment, especially in terms of short-medium-term exposure.

Polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs in the coastal seawater, surface sediment and oyster from Dalian, Northeast China.

A total of 46 polycyclic aromatic hydrocarbons (PAHs, 21 parent and 25 alkylated) were determined in seawater, surface sediment and oyster from coastal area of Dalian, North China. The concentration of Σ46PAHs in seawater, sediment, and oyster were 136-621 ng/L, 172-4700 ng/g dry weight (dw) and 60.0-129 ng/g wet weight (ww) in winter, and 65.0-1130 ng/L, 71.1-1090 ng/g dw and 72.8-216 ng/g ww in summer, respectively. High PAH levels were found in industrial area both in winter and summer. Selected PAH levels in sediments were compared with Sediments Quality Guidelines (ERM-ERL, TEL-PEL indexes) for evaluation probable toxic effects on marine organism and the results indicate that surface sediment from all sampling sites have a low to medium ecotoxicological risk. Daily intake of PAHs via oyster as seafood by humans were estimated and the results indicated that oyster intake would not pose a health risk to humans even 30 days after a oil spill accident near by. Water-sediment exchange analysis showed that, both in winter and summer, the fluxes for most high molecular weight PAHs were from seawater to sediment, while for low molecular weight PAHs, an equilibrium was reached between seawater and sediment.

Specific rhizobacterial resources: characterization and comparative analysis from contrasting coastal environments of Korea.

This study analyzed the rhizobacterial distribution from two coasts, which show contrasting climates and geographical and geological characteristics, to secure specific microbial resources. Furthermore, rhizobacteria were characterized and the results were comparatively analyzed with reference to the characteristics of two coastal environments. For this purpose, three representative halophyte species communities native to the Dokdo Islands and the East Sea coast of Korea were selected. Partial identification of rhizobacteria showed a clear difference between each sampling site and halophyte. Furthermore, isolates were characterized by their growth properties under NaCl or pH gradients related with previous geographical, geological, and climatic studies of the Dokdo Islands and the East Sea coast. A high proportion of the East Sea isolates showed halotolerance, but a high proportion of Dokdo isolates shared halophilic traits. Meanwhile, a higher proportion of East Sea isolates grew at a wider range of pH values than those of the Dokdo Islands. The results of our study suggest that unique rhizobacterial resources developed under specific rhizospheric conditions derived from halophytes interacting with their specific environment, even within the same coastal halophytic species. Therefore, this study proposes the necessity of securing characterized and unique microbial resources to apply to specific environments for the purpose of recovering and restoring sand dunes or salt-damaged agricultural lands.

Consequences of experimental cortisol manipulations on the thermal biology of the checkered puffer (Sphoeroides testudineus) in laboratory and field environments.

Anthropogenic climate change is altering temperature regimes for coastal marine fishes. However, given that temperature changes will not occur in isolation of other stressors, it is necessary to explore the potential consequences of stress on the thermal tolerances and preferences of tropical marine fish in order to understand the thresholds for survival, and predict the associated coastal ecological consequences. In this study, we used exogenous cortisol injections to investigate the effects of a thermal challenge on checkered puffers (Sphoeroides testudineus) as a secondary stressor. There were no significant differences between control and cortisol-treated fish 48h following cortisol treatment for swimming ability (using a chase to exhaustion protocol), blood glucose concentrations or standard metabolic rate. In the lab, control and cortisol-treated puffers were exposed to ambient (29.1±1.5°C), ambient +5°C (heat shock) and ambient -5°C (cold shock) for 4h and to evaluate the consequences of abrupt temperature change on puff performance and blood physiology. Following cold shock, control fish exhibited increases in cortisol levels and weak 'puff' performance. Conversely, fish dosed with cortisol exhibited consistently high cortisol levels independent of thermal treatment, although there was a trend for an attenuated cortisol response in the cortisol-treated fish to the cold shock treatment. A 20-day complementary field study conducted in the puffer's natural habitat, a tidal creek in Eleuthera, The Bahamas, revealed that cortisol-injected fish selected significantly cooler temperatures, measured using accumulated thermal units, when compared to controls. These results, and particularly the discrepancies between consequences documented in the laboratory and the ecological trends observed in the field, highlight the need to establish the link between laboratory and field data to successfully develop management policies and conservation initiatives with regards to anthropogenic climate change.

Metagenomic Analysis of Upwelling-Affected Brazilian Coastal Seawater Reveals Sequence Domains of Type I PKS and Modular NRPS.

Marine environments harbor a wide range of microorganisms from the three domains of life. These microorganisms have great potential to enable discovery of new enzymes and bioactive compounds for industrial use. However, only ~1% of microorganisms from the environment can currently be identified through cultured isolates, limiting the discovery of new compounds. To overcome this limitation, a metagenomics approach has been widely adopted for biodiversity studies on samples from marine environments. In this study, we screened metagenomes in order to estimate the potential for new natural compound synthesis mediated by diversity in the Polyketide Synthase (PKS) and Nonribosomal Peptide Synthetase (NRPS) genes. The samples were collected from the Praia dos Anjos (Angel's Beach) surface water-Arraial do Cabo (Rio de Janeiro state, Brazil), an environment affected by upwelling. In order to evaluate the potential for screening natural products in Arraial do Cabo samples, we used KS (keto-synthase) and C (condensation) domains (from PKS and NRPS, respectively) to build Hidden Markov Models (HMM) models. From both samples, a total of 84 KS and 46 C novel domain sequences were obtained, showing the potential of this environment for the discovery of new genes of biotechnological interest. These domains were classified by phylogenetic analysis and this was the first study conducted to screen PKS and NRPS genes in an upwelling affected sample.

First record of plastiglomerates, pyroplastics and plasticrusts along the beaches of Tamilnadu, Southeast coast of India.

Plastic litter affects coastal and marine ecosystems globally. This study represents the first record of pyroplastics and plasticrust in the beaches of Tamil Nadu, India. All samples were FTIR spectroscopically examined to confirm the polymer composition of the suspected plastics. The 16 plastic formations were found in TamilNadu, including six plastiglomerates nine pyroplastics and one plasticrust. Five types of polymers (PET, PP, PVC, PA, and PE) were found on the plastic matrices. The study also revealed that pyroplastics and plasticrust formed by degradation of plastics through weathering in the coastal environment. The present study also found that four types of marine fouling organisms such as oyster larvae, bryozoan, barnacle and polychaete worm were encrusted on the two pyroplastics. The emergence of these new forms of plastic raises concerns about their interactions with the environment and biota.

Leaching potentials of microplastic fibers and UV stabilizers from coastal-littered face masks.

Synthetic fibrous textiles are ubiquitous plastic commodities in everyday existence. Nevertheless, there exists a dearth of understanding regarding their environmental occurrence and the releasing capacities of associated additives. In this study, ten additives were determined in twenty-eight kinds of daily used plastic products including face masks, synthetic clothing, and food containers. Our results revealed that a typical kind of fibrous plastic, face masks, contained a greater variety of additives with UV stabilizers in particular, when compared to other plastic commodities. The above phenomena triggered our field investigation for the occurrence and release potentials of face mask fibers and the co-existing UV stabilizers into the environment. We further collected 114 disposed masks from coastal areas and analyzed their UV stabilizer concentrations. Results showed that the abundance of littered face masks ranged from 40-1846 items/km2 along the Yangtze Estuary, China; and UV stabilizers were of 0.3 ± 0.7 ng/g and 0.7 ± 1.7 ng/g in main bodies and ear ropes, respectively. The UV stabilizer concentrations in the field collected masks were only ∼7 % of their new counterparts, implying their potential leaching after disposal. By simulating the weathering scenario, we predict that a substantial amount of microplastics, with 1.1 × 1010 polypropylene fibers and 3.7 × 1010 polyester fibers, are probably be released daily into the coastal environment after face masks disposal; whereas the accompanied leaching amount of UV stabilizers was relatively modest under the current scenario.