Microplastic pollution in marine waters around the globe is increasing exponentially. This is the first comprehensive review which focuses on microplastics as a source and vector for metals, ...antibiotics, toxic chemicals, pathogenic bacteria (Vibrio cholerae), and Harmful Algal Bloom (HAB)-forming dinoflagellates across the continents through ballast water. Microplastics in ballast waters serve as ‘hotspots’ for the development and spread of multiple drug-resistant human pathogens through co-selection mechanisms. Microplastic inoculation at distant countries through ballast water may pose a serious threat to human health due to higher incidences of bacterial disease outbreaks and HABs. The 2017 ballast water management convention lacks a provision for on-board treatment of microplastic-contaminated ballast water. We conclude that there is a pressing need to include microplastics in the ballast water management convention as a hazardous material. Efficient on-board ballast water treatment strategies and effective limits for microplastics in ballast waters need to be developed.
Display omitted
•Metals, chemicals and antibiotics adsorb on microplastics in contaminated waters.•V. cholerae and HAB-producing species form biofilms on microplastics.•Ballast water transports microplastics and ‘plastisphere’ communities across continents.•Disease outbreaks and Harmful Algal Blooms can occur in the recipient country.•Ballast water convention should include microplastics as a hazardous material.
Microplastics represent a new kind of environmental pollutant that has recently attracted extensive attention and become a research hotspot. Microplastics are similar in size to the food items of ...many marine organisms and are thus, often consumed by them, with potentially harmful and toxic effects. We examined the effects of microplastics on the growth of the yellow seahorse Hippocampus kuda. Seahorses were split into three groups fed Mysis + microplastics + heavy metals (group A), Mysis + microplastics (group B), and Mysis alone (group C). We analyzed and compared the accumulations of microplastics and heavy metals among the groups and monitored seahorse growth following the different treatments. Body length, body weight, condition factor, specific growth rate, and survival rate were all lower in group A compared with the other groups, but there was no significant difference in any of the parameters between groups B and C. The accumulation of microplastics was similar in groups A and B, and the accumulation of heavy metals was similar in groups B and C. These results suggest that the effect of microplastics on seahorse growth is caused by the accumulation of heavy metals, rather than by the microplastics themselves.
•The effect of microplastics on seahorse growth is caused by the accumulation of heavy metals.•The results will give good suggestion for aquaculture of yellow seahorse.
This work studied the occurrence of microplastics in primary and secondary effluents and mixed sludge of a WWTP as well as in processed heat-dried sludge marketed as soil amendment. Sampled ...microparticles were divided into fragments and fibres, the latter defined as those with cylindrical shape and length to diameter ratio >3. We showed the presence of 12 different anthropogenic polymers or groups of polymers with a predominance of polyethylene, polypropylene, polyester and acrylic fibres together with an important amount of manufactured natural fibres. The smaller sampled fraction, in the 25–104 μm range, was the largest in both primary and secondary effluents. Fibres displayed lower sizes than fragments and represented less than one third of the anthropogenic particles sampled in effluents but up to 84% of heat-dried sludge. The plant showed a high efficiency (>90%) in removing microplastics from wastewater. However, the amount of anthropogenic plastics debris in the 25 μm - 50 mm range still released with the effluent amounted to 12.8 ± 6.3 particles/L, representing 300 million plastic debris per day and an approximate load of microplastics of 350 particles/m3 in the receiving Henares River. WWTP mixed sludge contained 183 ± 84 particles/g while heat-dried sludge bore 165 ± 37 particles/g. The sludge of the WWTP sampled in this work, would disseminate 8 × 1011 plastic particles per year if improperly managed. The agricultural use of sludge as soil amendment in the area of Madrid could spread up to 1013 microplastic particles in agricultural soils per year.
Display omitted
•We identified 12 different polymers in microplastics form wastewater and sludge.•High efficiency of secondary A2O treatments in removing microplastics.•Fibres displayed lower sizes than fragments and predominated in samples from sludge.•The plant releases 300 million plastic debris per day to its receiving river.•Sludge agricultural use is a major contributor in disseminating microplastic particles.
Wastewater treatment plants release a huge number of particles through effluent and sludge contaminating effluents and agricultural soils.
The marine microplastic (MMs) is an interdisciplinary problem. The polymer debris are ubiquitous (soil, hydrosphere, atmosphere) and the majority ends, transported by the freshwaters, in the global ...ocean system: from pelagial waters, surface gyres and benthos up to the animals at different trophic levels. Their quantitative, qualitative and eco-toxicological analyses, based on analytical, physical and chemical methods, are still a challenge due to the complex matrices, materials weathering, limited concentration, and size. Moreover, further fragmentation due to the waves and UV radiation leads to the constant increase of their surface. The aim of this article is to present the advantages, drawbacks and future perspectives of using SEM-EDX method in the analyses of marine polymer debris from macro to the nanoscale. Theoretical issues are presented in comparison to the commonly used approaches. The practical aspects will be discussed based on case studies. Examples of the results, high-resolution SEM pictures are included.
Display omitted
•Article addresses the problem of characterisation of ubiquitous microplastic debris.•SEM-EDX method applicability to MMs discussed in comparison to other techniques•The efficient and simpler than the currently-used approach to MMs analysis by SEM-EDX•The introduction to the rising complex problem of nanoplastics•Practical conclusions from case studies
Current study aimed to evaluate the microplastics abundance in the surface waters of Chabahar Bay for the first time. 21 neuston net water samples were collected from 7 stations. Microplastics were ...visually counted by stereomicroscope, sorted into 4 size categories, 4 shape categories, and identified by ATR-FTIR spectroscopy. Density of microplastics varied from 0.07 ± 0.03 to 1.14 ± 0.27 with an average density of 0.49 ± 0.43 particle·m−3. Microplastics were mostly found in the shape of fibers. 69% of analyzed particles were polyethylene and polypropylene. Main colors of the collected microplastics were white, blue and red. The results showed that the largest number of microplastics was found at station near populated area. Therefore, it can be concluded that, there is a pressing-need to investigate the distribution of microplastics in sediments and biota of this Bay as well as their effects on marine life and human health.
Display omitted
•Ubiquity of microplastics was documented for the first time in the surface waters of Chabahar Bay.•Microplastics were found in all the neustonic samples.•Fibers were the most abundance shapes of microplastics.•The highest microplastics were found at station near populated area.•69% of analyzed microplastics were polyethylene and polypropylene.
Plastic pollution is one of the most pressing environmental and social issues of the 21st century. Recent work has highlighted the atmosphere's role in transporting microplastics to remote locations ...S. Allen et al.,
12, 339 (2019) and J. Brahney, M. Hallerud, E. Heim, M. Hahnenberger, S. Sukumaran,
368, 1257-1260 (2020). Here, we use in situ observations of microplastic deposition combined with an atmospheric transport model and optimal estimation techniques to test hypotheses of the most likely sources of atmospheric plastic. Results suggest that atmospheric microplastics in the western United States are primarily derived from secondary re-emission sources including roads (84%), the ocean (11%), and agricultural soil dust (5%). Using our best estimate of plastic sources and modeled transport pathways, most continents were net importers of plastics from the marine environment, underscoring the cumulative role of legacy pollution in the atmospheric burden of plastic. This effort uses high-resolution spatial and temporal deposition data along with several hypothesized emission sources to constrain atmospheric plastic. Akin to global biogeochemical cycles, plastics now spiral around the globe with distinct atmospheric, oceanic, cryospheric, and terrestrial residence times. Though advancements have been made in the manufacture of biodegradable polymers, our data suggest that extant nonbiodegradable polymers will continue to cycle through the earth's systems. Due to limited observations and understanding of the source processes, there remain large uncertainties in the transport, deposition, and source attribution of microplastics. Thus, we prioritize future research directions for understanding the plastic cycle.
This study investigates microplastic (MPs) dynamics of a recently established surface flow 2100 population equivalent polishing constructed wetland (CW) receiving 1.4 ML per day of secondary treated ...wastewater. MPs type, size ranges and concentrations were measured along the CW at a 2-months sampling campaign. The CW received an average of 5·106 MPs per day (6 MPs per liter), mostly 100–1000 μm-sized synthetic fibers followed by fragments in the same size range. 95 % of MPs were retained, resulting in 0.30 ± 0.09 MPs per liter in CW effluent. Most MPs (97 %) were trapped within the first 20 % of the CW which consisted of a settling pond and shallow vegetated treatment cells and provided an areal removal rate > 4000 MP m−2 d−1. Data and microscopic analysis indicate MPs erosion and fragmentation in the CW. Turbidity and suspended solids were no indicator for MP removal due to water fowl activity, algal growth, and preferential flow conditions. This is the first study on MP dynamics in an independently operating full scale free water surface CW incorporated into a municipal wastewater treatment scheme. Surface flow CWs can retain MPs effectively but accumulation in CW sediments and substrate needs to be considered when further utilized or recycled.
Display omitted
•Microplastic dynamics of an 8000 m2 full-scale polishing wetland investigated•Different wetland units have different effectiveness for retaining microplastics.•Areal removal rate >4000 plastic particles m−2 d−1 reduced downstream export >95 %.•Surface flow constructed wetlands are capable of effective microplastic retention.•Turbidity or suspended solids are no reliable indicator of microplastics retention.
Conspectus The vast amount of plastic waste emitted into the environment and the increasing concern of potential harm to wildlife has made microplastic and nanoplastic pollution a growing ...environmental concern. Plastic pollution has the potential to cause both physical and chemical harm to wildlife directly or via sorption, concentration, and transfer of other environmental contaminants to the wildlife that ingest plastic. Small particles of plastic pollution, termed microplastics (>100 nm and <5 mm) or nanoplastics (<100 nm), can form through fragmentation of larger pieces of plastic. These small particles are especially concerning because of their high specific surface area for sorption of contaminants as well as their potential to translocate in the bodies of organisms. These same small particles are challenging to separate and identify in environmental samples because their size makes handling and observation difficult. As a result, our understanding of the environmental prevalence of nanoplastics and microplastics is limited. Generally, the smaller the size of the plastic particle, the more difficult it is to separate from environmental samples. Currently employed passive density and size separation techniques to isolate plastics from environmental samples are not well suited to separate microplastics and nanoplastics. Passive flotation is hindered by the low buoyancy of small particles as well as the difficulty of handling small particles on the surface of flotation media. Here we suggest exploring alternative techniques borrowed from other fields of research to improve separation of the smallest plastic particles. These techniques include adapting active density separation (centrifugation) from cell biology and taking advantage of surface-interaction-based separations from analytical chemistry. Furthermore, plastic pollution is often challenging to quantify in complex matrices such as biological tissues and wastewater. Biological and wastewater samples are important matrices that represent key points in the fate and sources of plastic pollution, respectively. In both kinds of samples, protocols need to be optimized to increase throughput, reduce contamination potential, and avoid destruction of plastics during sample processing. To this end, we recommend adapting digestion protocols to match the expected composition of the nonplastic material as well as taking measures to reduce and account for contamination. Once separated, plastics in an environmental sample should ideally be characterized both visually and chemically. With existing techniques, microplastics and nanoplastics are difficult to characterize or even detect. Their low mass and small size provide limited signal for visual, vibrational spectroscopic, and mass spectrometric analyses. Each of these techniques involves trade-offs in throughput, spatial resolution, and sensitivity. To accurately identify and completely quantify microplastics and nanoplastics in environmental samples, multiple analytical techniques applied in tandem are likely to be required.
PDF
