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.
Microplastics are widespread contaminants, virtually present in all environmental compartments. However, knowledge on sources, fate and environmental concentration over time and space still is ...limited due to the laborious and varied analytical procedures currently used. In this work we critically review the methods currently used for sampling and detection of microplastics, identifying flaws in study design and suggesting promising alternatives. This work provides insights on bulk sample collection, separation, digestion, identification and quantification, and mitigation of cross-contamination. The sampling of microplastics will improve in representativeness and reproducibility through the determination of bulk sample volume, filter's pore size, density separation and digestion solutions, but also through use of novel methods, such as the enhancement of visual identification by staining dyes, and the generalized use of chemical characterization.
•Methods of sampling and detection of microplastics vary between groups.•Sampling and separation of microplastics needs to be standardized.•Removal of organic matter through digestion improves identification.•Visual inspection can be improved, chemical identification is essential.•Mitigation of cross-contaminations is required to validate the results.
Display omitted
•Polystyrene microplastics (PS-MPs) cause pulmonary cytotoxicity by inducing ROS.•PS-MPs is associated with impaired pulmonary barrier by depleting ZO proteins.•PS-MPs inhalation ...increases the risk for chronic obstructive pulmonary disease.
Microplastics (MPs) have become a global environmental concern. Recent studies have shown that MPs, of which the predominant type is often polystyrene (PS; known as PS-MPs), can extend to and affect remote, sparsely inhabited areas via atmospheric transport. Although exposure to inhaled MPs may induce lung dysfunction, further experimental verification of the pulmonary toxic potential of MPs and the mechanism underlying the toxicity is needed. Here we used normal human lung epithelial BEAS-2B cells to clarify the association between pulmonary toxicity and PS-MPs. Results revealed that PS-MPs can cause cytotoxic and inflammatory effects in BEAS-2B cells by inducing reactive oxygen species formation. PS-MPs can decrease transepithelial electrical resistance by depleting zonula occludens proteins. Indeed, decreased α1-antitrypsin levels in BEAS-2B cells suggest that exposure to PS-MPs increases the risk for chronic obstructive pulmonary disease, and high concentrations of PS-MPs can induce these adverse responses. While low PS-MP levels can only disrupt the protective pulmonary barrier, they may also increase the risk for lung disease. Collectively, our findings indicate that PS-MP inhalation may influence human respiratory health.
Microplastics (<5 mm) are ubiquitous in the marine environment, occurring in both sediments and surface waters worldwide. However, few studies have documented the presence of microplastics and tire ...wear particles in coastal rivers. A survey of microplastics and low-density tire wear particles (≥63 μm) in the sediment and surface water of the three major tributaries within the Charleston Harbor estuary was conducted. Intertidal sediment, subtidal sediment, and sea surface microlayer concentrations ranged from 0 to 652 microplastics/m2, 3–4,375 microplastics/kg wet weight, and 3–36 microplastics/L, respectively. Blue fibers and tire wear particles were the two most abundant microplastic types observed, constituting 26.2% and 17.1%, respectively, of total microplastics. Tire wear particles were primarily identified by morphology, and ATR-FTIR analysis was conducted for a small subset (n = 5) of larger particles (≥500 μm). The present study provides the first microplastic field assessment of low-density tire wear particles in estuarine tributaries.
Display omitted
•Microplastics were widely distributed in the water and sediments of each river.•Blue fibers and tire wear particles were the two most abundant microplastic types.•Morphological and analytical evidence of tire wear particles in the environment
After over 20 years of research on microplastic (MP) pollution, there are important areas of study which are still at the inception. In particular, between 2020 and 2023 new findings on MP have ...emerged, which open new sub-categories of MP research. These research areas include sea surface MP ejection, direct and indirect MP influence on climate and hydrological cycle, small and nano-sized MP analysis and the relationship between MP size and abundance. Not reported or barely mentioned in previous reviews, these globally-relevant findings are here highlighted and discussed with aim to promote their further research that will potentially result in new evidence of detrimental effects of MP pollution on the biosphere.
Display omitted
It is of environmental significance to study the leaching performance of additives from microplastics (MPs) and further evaluate the toxicity of leachate to microalgae. Here, we investigated the ...effects of accelerated aging on characteristics, leaching, and toxicity of commercial lead chromate pigmented MPs. Results show that aging of MPs caused surface cracks and fragmentation, increased their surface area and carbonyl contents, and promoted the release of lead chromate pigment. Chromium (Cr) and lead (Pb) tend to leach under acidic condition, rather than neutral and alkali environment. Aging treatment facilitates the leaching performance and a high concentration of NaCl solution also favors the leaching process. Toxicology experiments demonstrate that only high concentration of leachate (>10 μg L−1) exerted significant inhibitory influence (p < 0.005) on cell photosynthesis of Microcystis aeruginosa. The growth inhibition of algal cells remarkably increased with increasing leachate concentrations. We observed more inhibiting effects on cell growth and photosynthesis using the leachates of aged MPs. Longer aging time leads to more release of Cr and Pb, rendering higher toxicity to microalgae. These novel findings will benefit us from assessing the leaching behavior of additives in MPs and their toxicological risks to aquatic organisms.
Display omitted
•Aging of microplastics promoted the release of pigments.•Growth inhibition of algal cells increased with increasing leachate concentrations.•More inhibiting effects on cell growth and photosynthesis under aging conditions were observed.•Longer aging time led to more release of Cr and Pb, rendering higher toxicity to microalgae.
Accelerated aging promotes the release of pigments from MPs and increases the toxicity of leachate to Microcystis aeruginosa.
The ubiquitous prevalence of microplastics pollution has raised concerns about microplastics' potential risks and impacts on the global environment. However, the potential human health risks and ...impacts of microplastics remain largely unexplored. By providing an overview regarding the interaction of microplastics and human health, this review extends current knowledge on the potential impacts of microplastics pollution on humans from an environmental health perspective. The paper firstly presents the characteristics of microplastics as well as the status of global microplastics pollution. As for human health, the potential hazards of microplastics are reflected by toxic chemical components, vectors of contaminants, and physical damage. Extensive microplastic pollution on ecosystems due to human activities leads to inevitable human exposure, which may occur by dietary, inhalation and/or skin contact. Accordingly, microplastics exposure is closely associated with human health. This study explores the potential interactions of microplastics with the biological organization at various levels, including chemical, cellular, tissue, organ, and system levels. The review concludes by highlighting five urgent perspectives and implications for future research on microplastics: 1) Developing a standard terminology and research methods; 2) Reinforcing microplastics pollution governance; 3) Exploring innovative strategies and technologies; 4) Engaging the public and change behaviour; and 5) Adopting a transdisciplinary approach.
Display omitted
•Evidence about potential human health risks of microplastics exposure•Interactions of microplastics with environmental health on different levels•Address the complex environmental health issues of microplastics pollution•Five urgent perspectives and implications for future research on microplastics
Microplastics (MPs) are characterized by small particle sizes (<5 mm) and are widely distributed in the soil environment. To date, little research has been conducted on investigating the effects of ...MPs on the soil microbial community, which plays a vital role in biogeochemical cycling. In the present study, we investigate the influence of two particle sizes of MPs on dissolved organic carbon (DOC) and its relative functional groups, fluxes of greenhouse gases (GHGs), and the bacterial and fungal communities in fertilized soil. The results showed that a 5% concentration of MPs had no significant effect on soil DOC, whereas the formation of aromatic functional groups was accelerated. In fertilized soil, the existence of MPs decreased the global warming potential (GWP) as a result of a reduction in N2O emissions during the first three days. A potential mechanism for this reduction in N2O emissions might be that MPs inhibited the phylum Chloroflexi, Rhodoplanes genera, and increased the abundance of Thermoleophilia on day 3. An increase in N2O emissions was observed on day 30, mainly due to the acceleration of the NO3− reduction and a decrease in the abundance of Gemmatimonadacea. The CH4 uptake was significantly correlated with Hyphomicrobiaceae on day 3 and Rhodomicrobium on day 30. In soil with MPs, Actinobacteria replaced Proteobacteria as the dominant phylum. Larger MPs increased the richness (Chao1) and abundance-based coverage estimators (ACE) and diversity (Shannon) of the bacterial community on day 3, whereas these decreased on day 30. The richness and diversity of the fungal community were also reduced on days 3 and 30. Smaller MPs increased the community richness and diversity of both bacterial and fungal communities in fertilized soil. Our findings suggest that MPs have selective effects on microbes and can potentially have a serious impact on terrestrial biogeochemical cycles.
Display omitted
•Smaller particle size microplastics could accelerate the aromatic matters’ formation.•Microplastics in fertilized soil could reduce N2O emission.•Actinobacteria replaced Proteobacteria as the Dominant phylum in microplastics soil.•Microplastic size effect was shown on alpha diversity.•Microplastics influenced the co-occurrence network among different microorganisms.
Main findings: Microplastics decreased the global warming potential of soil. Particle size affected alpha diversity, and Actinobacteria replaced Proteobacteria as the dominant phylum in soil with microplastics.
Microplastics (MPs) have globally been detected in aquatic and marine environments, which has raised scientific interests and public health concerns during the past decade. MPs are those polymeric ...particles with at least one dimension <5 mm. MPs possess complex physicochemical properties that vary their mobility, bioavailability and toxicity toward organisms and interactions with their surrounding pollutants. Similar to nanomaterials and nanoparticles, accurate and reliable detection and measurement of MPs or nanoplastics and their characteristics are important to warrant a comprehensive understanding of their environmental and ecological impacts. This review elaborates the principles and applications of diverse analytical instruments or techniques for separation, characterization and quantification of MPs in the environment. The strength and weakness of different instrumental methods in separation, morphological, physical classification, chemical characterization and quantification for MPs are critically compared and analyzed. There is a demand for standardized experimental procedures and characterization analysis due to the complex transformation, cross-contamination and heterogeneous properties of MPs in size and chemical compositions. Moreover, this review highlights emerging and promising characterization techniques that may have been overlooked by research communities to study MPs. The future research efforts may need to develop and implement new analytical tools and combinations of hyphenated technologies to complement respective limitations of detection and yield reliable characterization information for MPs. The goal of this critical review is to facilitate the research of plastic particles and pollutants in the environment and understanding of their environmental and human health effects.
Display omitted
•Separation, characterization and identification approaches for microplastics are summarized.•Principles, applications, advantages and limitations of each approach are discussed.•AFM and hybrid AFM techniques are proposed as emerging characterization platforms.•Standard experimental procedures and reliable characterization methods are on demand.
PDF
