Extraction, identification, and environmental risk assessment of microplastics in commercial toothpaste

Microplastics, their abundance, and distribution in water and sediments in North Chennai, India: An assessment of pollution risk and human health impacts

Plastic particles, measuring <5 mm in size, mainly originate from larger plastic debris undergoing degradation, fragmenting into even smaller fragments. The goal was to analyze the spatial diversity and polymer composition of microplastics (MPs) in North Chennai, South India, aiming to evaluate their prevalence and features like composition, dimensions, color, and shape. In 60 sediment samples, a combined count of 1589 particles were detected, averaging 26 particles per 5 g-1 of dry sediment. The water samples from the North Chennai vicinity encompassed a sum of 1588 particles across 71 samples, with an average of 22 items/L. The majority of MPs ranged in size from 1 mm to 500 μm. The ATR-FTIR results identified the predominant types of MPs as polystyrene, polyvinyl chloride, polyethylene, polyethylene terephthalate, and polypropylene in sediment and water. The spatial variation analysis revealed high MPs concentration in landfill sites, areas with dense populations, and popular tourist destinations. The pollution load index in water demonstrated that MPs had contaminated all stations. Upon evaluating the polymeric and pollution risks, it was evident that they ranged from 5.13 to 430.15 and 2.83 to 15,963.2, which is relatively low to exceedingly high levels. As the quantity of MPs and hazardous polymers increased, the level of pollution and corresponding risks also escalated significantly. The existence of MPs in lake water, as opposed to open well water, could potentially pose a cancer risk for both children and adults who consume it. Detecting MPs in water samples highlights the significance of implementing precautionary actions to alleviate the potential health hazards they create.

Understanding microplastic pollution: Tracing the footprints and eco-friendly solutions

Microplastics (MPs) pollution has emerged as a critical environmental issue with far-reaching consequences for ecosystems and human health. These are plastic particles measuring <5 mm and are categorized as primary and secondary based on their origin. Primary MPs are used in various products like cosmetics, scrubs, body wash, and toothpaste, while secondary MPs are generated through the degradation of plastic products. These have been detected in seas, rivers, snow, indoor air, and seafood, posing potential risks to human health through the food chain. Detecting and quantifying MPs are essential to understand their distribution and abundance in the environment. Various microscopic (fluorescence microscopy, scanning electron microscopy) and spectroscopy techniques (FTIR, Raman spectroscopy, X-ray photoelectron spectroscopy) have been reported to analyse MPs. Despite the challenges in scalable removal methods, biological systems have emerged as promising options for eco-friendly MPs remediation. Algae, bacteria, and fungi have shown the potential to adsorb and degrade MPs in wastewater treatment plants (WWTPs) offering hope for mitigating this global crisis. This review examines the sources, impacts, detection, and biological removal of MPs, highlighting future directions in this crucial field of environmental conservation. By fostering global collaboration and innovative research a path towards a cleaner and healthier planet for future generations can be promised.

Occurrence, transport, and toxicity of microplastics in tropical food chains: perspectives view and way forward

Microplastics, which have a diameter of less than 5 mm, are becoming an increasingly prevalent contaminant in terrestrial and aquatic ecosystems due to the dramatic increase in plastic production to 390.7 million tonnes in 2021. Among all the plastics produced since 1950, nearly 80% ended up in the environment or landfills and eventually reached the oceans. Currently, 82-358 trillion plastic particles, equivalent to 1.1-4.9 million tonnes by weight, are floating on the ocean's surface. The interactions between microorganisms and microplastics have led to the transportation of other associated pollutants to higher trophic levels of the food chain, where microplastics eventually reach plants, animals, and top predators. This review paper focuses on the interactions and origins of microplastics in diverse environmental compartments that involve terrestrial and aquatic food chains. The present review study also critically discusses the toxicity potential of microplastics in the food chain. This systematic review critically identified 206 publications from 2010 to 2022, specifically reported on microplastic transport and ecotoxicological impact in aquatic and terrestrial food chains. Based on the ScienceDirect database, the total number of studies with "microplastic" as the keyword in their title increased from 75 to 4813 between 2010 and 2022. Furthermore, various contaminants are discussed, including how microplastics act as a vector to reach organisms after ingestion. This review paper would provide useful perspectives in comprehending the possible effects of microplastics and associated contaminants from primary producers to the highest trophic level (i.e. human health).

Microplastics in oral healthcare products (OHPs) and their environmental health risks and mitigation measures

The environmental input of microplastics from personal care products has received significant attention; however, less focus has been paid to oral healthcare products. The present study assessed the occurrence of microplastics in commercially available oral healthcare products such as toothbrushes, toothpastes, toothpowder, mouthwash, dental floss, and mouth freshener spray that have a pan-India distribution. The extracted microplastics were quantified and characterised using a microscope and ATR-FTIR. All products showed microplastic contamination, where toothbrushes showed the maximum particles (30-120 particles/brush) and mouth freshener sprays (0.2-3.5 particles/ml) had the least abundance. Fragments, fibres, beads, and films were the various shapes of microplastics observed, where fragments (60%) were dominant. Various colours such as pink, green, blue, yellow, black, and colourless were observed, where colourless (40%) particles were dominant. Microplastics were categorized into three sizes: <0.1 mm (63%), 0.1-0.3 mm (35%), and >0.3 mm (2%). Four major types of polymers, such as polyethylene (52%), polyamide (30%), polyethylene terephthalate (15%), and polybutylene terephthalate (3%), were identified. Risk assessment studies such as Daily Microplastics Emission (DME), Annual Microplastics Exposure (AME), and Polymer Hazard Index (PHI) were carried out. The DME projection for India was the highest for mouthwash (74 billion particles/day) and the least for mouth freshener sprays (0.36 billion particles/day). The AME projection for an individual was the highest in toothbrushes (48,910 particles ind.-1 yr.-1) and the least in mouth freshener sprays (111 particles ind.-1 yr.-1). PHI shows that the identified polymers fall under the low-to high-risk categories. This study forecasts the community health risks linked to microplastics in oral healthcare products and suggests mitigation strategies. It has the potential to shape environmental policy development in response.

Detection and Identification of Various Microplastics in Different Orthodontic Adhesives

Background Microplastics are acknowledged as significant environmental contaminants. The clinical use of dental materials, particularly adhesives containing plastic polymers, can give rise to the production of plastic micro- and nanoparticles, which subsequently find their way into the environment. The aim of the study was to detect different microplastics and identify them in various orthodontic adhesives. Materials and methods Four different light cure orthodontic adhesives, including Transbond XT (3M Unitek, Monrovia, CA), Ormco Enlight (Ormco, Orange, CA), Orthofix SPA (Orthofix, Verona, Italy), and Aqualine LC (Tomy International Inc, Tokyo, Japan), were collected and placed in separate Eppendorf tubes. Microplastics present in each adhesive were identified using scanning electron microscopy. Subsequently, each specimen was suspended in hydrogen peroxide, placed within a shaking incubator, and analyzed using Fourier transform infrared spectroscopy (FTIR) to identify the type of polymer. Results The scanning electron microscope shows the surface morphology and the most predominant types of microplastics identified were fibers, fragments, and pellets. FTIR results showed the presence of several major functional groups, including hydroxyl, amine, ester, fluoro, and halo groups. Conclusion When contrasted with the quantity of microplastic waste generated by other sectors like the textile, cosmetic, and fishing industries, the microparticulate waste stemming from dental adhesives has a minimal effect on environmental deterioration. Strategies for addressing this concern should give precedence to reducing the use of these materials and adopting effective recovery methods, which could potentially involve recycling processes.

Microplastics exposure: implications for human fertility, pregnancy and child health

Plastics found in our everyday environment are becoming an increasing concern for individual and population-level health, and the extent of exposure and potential toxic effects of these contaminants on numerous human organ systems are becoming clear. Microplastics (MPs), tiny plastic particles, appear to have many of the same biological effects as their plastic precursors and have the compounded effect of potential accumulation in different organs. Recently, microplastic accumulation was observed in the human placenta, raising important questions related to the biological effects of these contaminants on the health of pregnancies and offspring. These concerns are particularly heightened considering the developmental origins of health and disease (DOHaD) framework, which postulates that in utero exposure can programme the lifelong health of the offspring. The current review examines the state of knowledge on this topic and highlights important avenues for future investigation.

Detection and quantification of various microplastics in human endometrium based on laser direct infrared spectroscopy

The pollution of microplastics (MPs) has received widespread attention with the increasing usage of plastics in recent years. MPs could enter the human body and exist in the circulatory system. Endometrium, with rich blood vessels, acts as an essential role in human health and female fertility. However, there is no study reporting the MPs exposure in human endometrium. We collected the endometrium samples to detect the presence of MPs qualitatively and quantitatively via laser direct infrared. We found that there was a total of 13 types of MPs existing in the collected samples, among which 6 special types of MPs were with both high abundance and high detection rate. The abundance of these MPs ranged from 0 to 117 particles/100 mg, with a median abundance of 21 particles/100 mg. Most detected MPs, accounting for 88.35 %, were in small size (20-100 μm). Among small-size MPs, ethylene-acrylic acid copolymer ranked first while polyethylene accounted for the largest proportion among large-size MPs (100-500 μm). Correlation analysis indicated there was no significant relationship between age and MP abundance or BMI and MP abundance. We also designed a questionnaire to investigate lifestyle and daily habits, aiming at revealing the potential relationship between MP exposure and living habits. We discovered that some drinking habits and chewing gum were significantly correlated with a higher level of MP exposure. For the first time, we identified the presence of MPs in human endometrium and clarified the potential connections between MP exposure and lifestyle. Further studies are still necessary to explore more underlying information.

Airborne microplastics: A narrative review of potential effects on the human respiratory system

There has been growing evidence showing the widespread of airborne microplastics (AMPs) in many regions of the world, raising concerns about their impact on human health. This review aimed to consolidate recent literature on AMPs regarding their physical and chemical characteristics, deposition in the human respiratory tract, translocation, occurrence from human studies, and toxic effects determined in vitro and in vivo. The physical characteristics influence interactions with cell membranes, cellular internalization, accumulation, and cytotoxicity resulting from cell membrane damage and oxidative stress. In addition, prolonged exposure to AMP-associated toxic chemicals might lead to significant health effects. Most toxicological assessments of AMPs in vitro and in vivo have demonstrated that oxidative stress and inflammation are major mechanisms of action for their toxic effects. Elevated reactive oxygen species production could lead to mitochondrial dysfunction, inflammatory responses, and subsequent apoptosis in experimental models. To date, there has been some evidence suggesting exposure in humans. However, the data are still insufficient, and adverse human health effects need to be investigated. Future research on the existence, exposure, and health effects of AMPs is required for developing preventive and mitigation measures to protect human health.

When microplastics meet electroanalysis: future analytical trends for an emerging threat

Microplastics are a major modern challenge that must be addressed to protect the environment, particularly the marine environment. Microplastics, defined as particles ≤5 mm, are ubiquitous in the environment. Their small size for a relatively large surface area, high persistence and easy distribution in water, soil and air require the development of new analytical methods to monitor their presence. At present, the availability of analytical techniques that are easy to use, automated, inexpensive and based on new approaches to improve detection remains an open challenge. This review aims to outline the evolution and novelties of classical and advanced methods, in particular the recently reported electroanalytical detectors, methods and devices. Among all the studies reviewed here, we highlight the great advantages of electroanalytical tools over spectroscopic and thermal analysis, especially for the rapid and accurate detection of microplastics in the sub-micron range. Finally, the challenges faced in the development of automated analytical methods are discussed, highlighting recent trends in artificial intelligence (AI) in microplastics analysis.

TiO2 nanoparticles combined with polystyrene nanoplastics aggravated reproductive toxicity in female mice via exacerbating intestinal barrier disruption

BACKGROUND

TiO2 nanoparticles (NPs), a widely used food additive in the food industry, have been shown to aggravate the progress of metabolic diseases. Nanoplastics (NPLs) are an emerging contaminant widely present in the food system and have been shown to induce ovarian disorders in mammals. Noteworthy, they can be ingested by humans through 'contaminated' food, whereas the potential toxicity of NPLs and TiO2 NPs combined remains unclear. In the present study, we investigated the potential effects and mechanisms of co-exposure to polystyrene (PS) NPLs and TiO2 NPs on the ovary in female mice.

RESULTS

Our results revealed that the co-exposure of TiO2 NPs and PS NPLs caused significant injury to ovarian structure and function, but individual exposure had no effect. Moreover, compared to the TiO2 NPs group, co-exposure aggravated the intestinal barrier damage in mice, increasing the bioaccumulation of TiO2 NPs in the ovary. After being supplemented with the oxidative stress inhibitor N-acetyl-l-cysteine, the expression of ovarian antioxidant genes increased, and the ovarian structural and functional injury in co-exposure mice reverted to normal levels.

CONCLUSION

The present study demonstrated that co-exposure to PS NPLs and TiO2 NPs can cause more severe female reproductive dysfunction and deepens the toxicological insights between NPLs and NPs. © 2023 Society of Chemical Industry.

A novel simplified method for extraction of microplastic particles from face scrub and laundry wastewater

Microplastic pollution in different environmental matrices is a serious concern in the recent times. Personal care products and washing of synthetic fabrics are some of the main sources of microplastic pollution. In this work, a novel simplified, effective and sustainable method for extraction of microplastic particles from face scrub and laundry wastewater was developed. Different parameters affecting the extraction were analysed and the extraction process was optimised. The extraction efficiency of the proposed method was found to be ~ 94.1 ± 1.65%, which was slightly better than the previously available method with an advantage of ease in extraction and lesser time and resource consuming. The developed method was used to demonstrate the extraction of microplastic particles from 12 face scrub samples with different brands. It was found that the samples contained microplastic particles of varying size. The physical and chemical structure intactness of microplastic particles during the extraction was also analysed and found to be acceptable. The developed extraction method was also applied for the extraction of microfibers from the laundry wastewater. It was found that this proposed method is suitable to make the cleaner extracted samples for an easy and more effective qualitative and quantitative analysis of MPs.

A Complete Guide to Extraction Methods of Microplastics from Complex Environmental Matrices

Sustainable development is a big global challenge for the 21st century. In recent years, a class of emerging contaminants known as microplastics (MPs) has been identified as a significant pollutant with the potential to harm ecosystems. These small plastic particles have been found in every compartment of the planet, with aquatic habitats serving as the ultimate sink. The challenge to extract MPs from different environmental matrices is a tangible and imperative issue. One of the primary specialties of research in environmental chemistry is the development of simple, rapid, low-cost, sensitive, and selective analytical methods for the extraction and identification of MPs in the environment. The present review describes the developments in MP extraction methods from complex environmental matrices. All existing methodologies (new, old, and proof-of-concept) are discussed and evaluated for their potential usefulness to extract MPs from various biotic and abiotic matrices for the sake of progress and innovation. This study concludes by addressing the current challenges and outlining future research objectives aimed at combating MP pollution. Additionally, a set of recommendations is provided to assist researchers in selecting appropriate analytical techniques for obtaining accurate results. To facilitate this process, a proposed roadmap for MP extraction is presented, considering the specific environmental compartments under investigation. By following this roadmap, researchers can enhance their understanding of MP pollution and contribute to effective mitigation strategies.

Residential houses - a major point source of microplastic pollution: insights on the various sources, their transport, transformation, and toxicity behaviour

Municipal wastewater has been considered as one of the largest contributors and carriers of microplastics to the aquatic environment. However, the various residential activities that generate municipal wastewater are equally significant whenever the source of microplastics in aquatic system is accounted. However, so far, only municipal wastewater has received wide attention in previous review articles. Hence, this review article is written to address this gap by highlighting, firstly, the chances of microplastics arising from the usage of personal care products (PCPs), laundry washing, face masks, and other potential sources. Thereafter, the various factors influencing the generation and intensity of indoor microplastic pollution and the evidence available on the possibility of microplastic inhalation by humans and pet animals are explained. Followed by that, the removal efficiency of microplastics observed in wastewater treatment plants, the fate of microplastics present in the effluent and biosolids, and their impact on aquatic and soil environment are explored. Furthermore, the impact of aging on the characteristics of microsized plastics has been explored. Finally, the influence of age and size of microplastics on the toxicity effects and the factors impacting the retention and accumulation of microplastics in aquatic species are reviewed. Furthermore, the prominent pathway of microplastics into the human body and the studies available on the toxicity effects observed in human cells upon exposure to microplastics of different characteristics are explored.

Microplastic content of over-the-counter toothpastes - a systematic review

Background: Microplastic particles are used as ingredients in personal care products such as face washes, shower gels and toothpastes and form one of the main sources of microplastic pollution, especially in the marine environment. In addition to being a potential pollutant to the environment, the transfer of microplastics to humans can become a severe threat to public health. This systematic review was conceptualized to identify evidence for the presence of and characteristics of microplastics in toothpaste formulations. Methods: The PICOS Criteria was used for including studies for the review. Electronic databases of Scopus, Embase, Springer Link, PubMed, Web of Science and Google Scholar were searched, as well as hand and reference searching of the articles was carried out. The articles were screened using the software application, Covidence® and data was extracted. Results: This systematic review showed that toothpastes from China, Vietnam, Myanmar and the UAE, reported no evidence of microplastics and those from Malaysia, Turkey and India reported the presence of microplastics. The shape of the microplastics present in these toothpastes were found to be granular, irregular with opaque appearance and also in the form of fragments and fibers and the percentage weight in grams ranged from 0.2 to 7.24%. Malaysia releases 0.199 trillion microbeads annually from personal care products into the environment and toothpastes in Turkey release an average of 871 million grams of microplastics annually. Similarly, in India, it has been reported that 1.4 billion grams of microplastic particles are emitted annually from toothpaste. Conclusions: The findings of this systematic review provide evidence that toothpastes, at least in some parts of the world, do contain microplastics and that there is a great risk of increase in the addition of microplastics to the environment by the use of toothpaste.

Unaccounted Microplastics in the Outlet of Wastewater Treatment Plants—Challenges and Opportunities

Since the 1950s, plastic production has skyrocketed. Various environmental and human activities are leading to the formation and accumulation of microplastics (MPs) in aquatic and terrestrial ecosystems, causing detrimental effects on water, soil, plants, and living creatures. Wastewater treatment plants (WWTPs) are one of the primary MP management centers meant to check their entry into the natural systems. However, there are considerable limitations in effectively capturing, detecting, and characterizing these MPs in the inlet and outlet of WWTPs leading to “unaccounted MPs” that are eventually discharged into our ecosystems. In order to assess the holistic picture of the MPs’ distribution in the ecosystems, prevent the release of these omitted MPs into the environment, and formulate regulatory policies, it is vital to develop protocols that can be standardized across the globe to accurately detect and account for MPs in different sample types. This review will cover the details of current WWTP adoption procedures for MP management. Specifically, the following aspects are discussed: (i) several processes involved in the workflow of estimating MPs in the outlet of WWTPs; (ii) key limitations or challenges in each process that would increase the uncertainty in accurately estimating MPs; (iii) favorable recommendations that would lead to the standardization of protocols in the workflow and facilitate more accurate analysis of MPs; (iv) research opportunities to tackle the problem of ‘missing MPs’; and (v) future research directions for the efficient management of MPs. Considering the burgeoning research interest in the area of MPs, this work would help early scientists in understanding the current status in the field of MP analysis in the outlet of WWTPs.

In vivo degradation of polyethylene terephthalate using microbial isolates from plastic polluted environment

Accumulation of plastics alarms a risk to the environment worldwide. As polyethylene pterephthalate (PET) degrades slowly and produces hazardous substances, therefore, it is now essential to eliminate plastic wastes from the environment. Given that, the current study is concerned with PET degradation potential of naturally occurring microbial strains isolated from plastic waste dumping sites, Sarcina aurantiaca (TB3), Bacillus subtilis (TB8), Aspergillus flavus (STF1), Aspergillus niger (STF2). To test the biodegradability of PET films, the films were incubated for 60 days at 37 °C with the microorganisms designated as TB3, TB8, STF1, STF2 and the microbial consortium (TB3+TB8+STF1+STF2) in Minimal Salt Medium and Bushnell Hass Broth. Hydrophobicity, viability, and total protein content of isolates were investigated. Using Field Emission Scanning Electron Microscopy and Fourier Transform Infrared Spectrophotometry to measure variations in functional groups and carbonyl index on PET surface, biodegradation process was affirmed by fissures and modified surfaces. Results revealed that the microbial consortium (S. aurantiaca + B. subtilis + A. flavus + A. niger) that the weight loss of PET films was 28.78%. The microbial consortium could be used to treat PET waste, posing no health or environmental risks. The developed microbial consortium has the potential to degrade PET, hence can be employed for eliminating PET in plastic contaminated sites.

Distribution of microplastics present in a stream that receives discharge from wastewater treatment plants

The presence of microplastics (MPs) in freshwater systems that receive discharge of urban effluent implies a great environmental impact. In order to be able to generate proposals that solve this problem, it is necessary to know in detail the contributions of different MPs sources. The aim of this work was to study the contribution of urban sewage discharge to MPs pollution in a stream that runs through a medium-sized city. The spatial distribution of MPs with sizes between 100 μm and 1.5 mm present in surface water was measured and their characteristics, dimensions, shapes and identification were determined. Physical-chemical parameters of the stream water were measured, and a decrease in water quality was found due to wastewater treatment plants. The main source of MPs was effluent from the plants (97% of the total MPs), while the rest came from storm drains and discharge of tributaries. The maximum concentration of MPs found was around 72,000 MP/L (equivalent to 53 million MPs/s), at a point after discharge from both plants. Around 70% of MPs correspond to microfibers with a mean length of around 300 μm and a mean width of around 15 μm, and they are mainly polyethylene fibers. The remaining 30% of MPs are particles with lengths of around 140 μm. The transport of MPs between a point located after discharge of the plants and another point located about 3 km further on was studied, and no significant variation was found in the concentration of MPs. Electrical conductivity was used as a conservative tracer of MPs concentration. This work presents for the first time a detailed analysis of different contributions of MPs to a freshwater system in South America, which receives discharge of wastewater treatment plants, evidencing its important role in pollution.

Food and human safety: the impact of microplastics

Plastic waste pollution is one of the biggest problems in the world today. The amount of plastic in the environment continues to increase, and human exposure to microplastic (MP) has become a reality. This subject has attracted the attention of the whole world. The MP problem has also been noticed by the scientific community. The term microplastic is mostly used to define synthetic material with a high polymer content that can have a size range from 0.1 to 5000 µm. This paper aims to characterize the routes of exposure to MP, define its pollution sources, and identify food types contaminated with plastics. This review addresses the current state of knowledge on this type of particles, with particular emphasis on their influence on human health. Adverse effects of MP depend on routes and sources of exposure. The most common route of exposure is believed to be the gastrointestinal tract. Sources of MP include fish, shellfish, water as well as tea, beer, wine, energy drinks, soft drinks, milk, salt, sugar, honey, poultry meat, fruits, and vegetables. Studies have shown that particles of PET, PE, PP, PS, PVC, PA, and PC are the most frequently found in food.