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Diet is an important pathway for microplastic exposure. This study examined distinct edible seaweed products sold at ethnic food stores in Mexico for microplastic contamination, as well as the exposure of the Asian ethnic minority and local population to microplastics. Microplastics were extracted from seaweed samples using a wet oxide digestion with hydrogen peroxide followed by zinc chloride density separation. They were subsequently detected, quantified, and the polymer type was determined via microscopic inspection and Fourier transform infrared spectroscopy. Microplastic contamination was detected in all samples, with an average abundance of 24.0 ± 9.4 items g -1 . Fibrous-shaped (61 %) and non-colored (57 %) microplastics were prevalent. Microplastics with sizes smaller than 0.2 mm prevailed (60 %), and they have the potential to penetrate gut barriers and endanger human health. Polymers identified consisted of polyethylene-polypropylene, polyamide, cellophane, rayon, and polyethylene terephthalate. According to pollution load index values, seaweed samples were minimally contaminated with microplastics, with values ranging between 3.7 and 6.0. The estimated yearly intake of microplastic from seaweed consumption by the South Korean and Chinese populations in Mexico was 5.8 × 10 4  ± 2.3 × 10 4 and 5.7 × 10 4  ± 4.9 × 10 4 , respectively. This study's findings highlight the importance of improved control measures for minimizing microplastics in foods for export., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Inadvertent human exposure to microplastics by the ingestion of microplastic-contaminated processed foods poses health risks and new preventative issues; nevertheless, investigations analyzing microplastic occurrences in commercially dried fish for direct human consumption are scarce. This study assessed the abundance and characteristics of microplastics in 25 commercially sold dried fish products (4 supermarkets, 3 street vendors, and 18 traditional agri-product farmers' markets) from two widely consumed and commercially important Chirostoma species (C. jordani and C. patzcuaro) in Mexico. Microplastics were detected in all the samples examined, with abundances ranging from 4.00 ± 0.94 to 55.33 ± 9.43 items g -1 . C. jordani dried fish samples had higher mean microplastic abundance (15.17 ± 5.90 items g -1 ) than the C. patzcuaro dried fish samples (7.82 ± 2.90 items g -1 ); nevertheless, there was no statistically significant difference in microplastic concentrations between the samples. The most prevalent type of microplastic was fiber (67.55%), followed by fragment (29.18%), film (3.00%), and sphere (0.27%). Non-colored microplastics (67.35%) predominated, while microplastic sizes varied from 24 to 1670 μm, with sizes less than 500 μm (84%) being the most common. ATR-FTIR analysis revealed polyester, acrylonitrile butadiene styrene, polyvinyl alcohol, ethylene-propylene copolymer, nylon-6 (3), cellophane, and viscose in the dried fish samples. Overall, this study's findings are the first in Latin America to demonstrate microplastic contamination in dried fish for human consumption, underscoring the need for developing countermeasures to prevent plastic pollution in fish-caught regions and reduce the risks of human exposure to these micropollutants., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Concern over microplastics has grown tremendously, and they have been found in all environmental compartments; yet, much remains unknown regarding their impact on a variety of human-consuming food products. Here, we contribute to ongoing research by screening the 15 most popular commercial brands of packaged food ice cubes in Mexico City for microplastics. Microplastics were detected in 100% of the samples evaluated, with concentrations ranging from 19 ± 4 to 178 ± 78 L -1 . There was a significant difference in the microplastic concentration across samples. The mean microplastic concentration was 79 ± 47 L -1 , and the main types were polypropylene, polyethylene, polyvinyl alcohol, tygon polymer, sealing ring gardena 2824 large, polyamide 6, and cellophane. Moreover, microplastics that are fibrous (87%), non-colored (54%), and less than 300 μm in size (63%), were found to be more prevalent. The SEM-EDX analysis showed heterogeneous structural and morphological characteristics of microplastics, as well as traces of Si, S, Ti, Ca, Al, and Na. Furthermore, we estimate that ice cube consumption in Mexico City can result in the inadvertent ingestion of 4.9 × 10 2 ± 3.4 × 10 2 -1 × 10 4 ± 7.2 × 10 3 microplastics annually. The findings of the study revealed that microplastics were identified in ice cubes and can be conveyed to humans, stressing the need of managing and eradicating such contamination from our food., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The growing global concern about human exposure to microplastics necessitates research into their occurrence, fate, and effects. Recent advancements in analytical methods have fostered research and improved understanding of microplastics in a variety of human tissue and biological samples, including blood, liver, lung, placenta, kidney, spleen, sputum, and feces, etc. Given the rapid expansion of this research topic, it is imperative to assess and introduce them to a broader audience. This article for the first time conducts a systematic review of the literature on microplastics in human biological samples, their objectives, current efforts, and key findings. This review offers an in-depth analysis of the research approaches employed, spanning from sampling to detection to quantification of microplastics, as well as an overview of their occurrence and characteristics to understand the level of microplastic exposure in the human body. It also provides a detailed analysis of existing contamination control procedures and attempts to build consistent cross-contamination prevention measures. Finally, we provide the reader with the guidelines on current microplastic research strategies, highlighting future directions. Overall, this synthesis will assist researchers in developing a multifaceted understanding of contemporary microplastic investigations in human biological samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Microplastics in the human diet have become a worldwide concern. To date, microplastics in urban drinking water supplies, such as decentralized drinking-water refill kiosks, have not been studied and are a pressing concern since they are so closely tied to human life and have a significant influence on health. This study evaluated the occurrence and characteristics of microplastics in 63 drinking water samples collected from decentralized refill kiosks in the Mexico City metropolitan area. All of the sampled drinking water contained microplastics in concentrations ranging from 11 to 860 microplastics L -1 . The detected microplastics were mostly fiber (65 %), followed by fragment (28 %), and film (7 %). They were mainly composed of polyethylene terephthalate, polyamides, vinyl polymers, polyacetal, and cellophane in sizes ranging from 20 μm to 5 mm, with 75 % of them accounting for sizes <300 μm. SEM-EDX analysis revealed weathered microplastics, biota adherence, and the presence of inorganic elements on the surface of microplastics. We estimate that Mexico City residents inadvertently ingest 42 microplastics L -1 , with an annual exposure of around 1.47 × 10 4 microplastics per adult and 6.73 × 10 3 microplastics per child. Therefore, future research is needed to strengthen drinking water refill kiosk guidelines and standards for better microplastic management. This study serves as a wake-up call to many developing countries that use similar urban water systems, drawing their attention to global microplastic contamination of drinking water., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

While atmospheric microplastics have attracted scientific attention as a significant source of microplastic contamination in the environment, studies in large population centers remain sparse. Here we present the first report on the occurrence and distribution of atmospheric microplastics in Mexico City (Latin America's second most densely populated city), collected using PM 10 and PM 2.5 active samplers at seven monitoring stations (urban, residential, and industrial) during the dry and wet seasons of 2020. The results showed that microplastics were detected in all of the samples examined, with mean microplastic concentrations (items m -3 ) of 0.205 ± 0.061 and 0.110 ± 0.055 in PM 10 and PM 2.5 , respectively. The spatial distribution of microplastics showed seasonal variation, with greater abundances in locations closer to industrial and urban centers. There was also a significant difference in microplastic concentrations in PM 10 and PM 2.5 between the dry and wet seasons. The mean PM 2.5 /PM 10 ratio was 0.576, implying that microplastics were partitioned more towards PM 2.5 than PM 10 in Mexico City. Fibers were the most prominent shape (>75 %), and blue was the most common color (>60 %). The size characteristics indicated microplastics of varying lengths, ranging from 39 to 5000 μm, with 66 % being <500 μm. Metal contaminants such as aluminum, iron, and titanium were detected using SEM-EDX on randomly selected microplastics. The microplastics were identified as cellophane, polyethylene, polyethylene terephthalate, polyamide, and cellulose (rayon) using ATR-FTIR spectral analysis. Our findings unravel the extent and characteristics of atmospheric microplastics in the Mexico City metropolitan area, which will aid future research to better understand their fate, transport, and potential health risks, demanding more investigations and close monitoring., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Free refill drinking water kiosks are an essential sustainable water supply system for people in metropolitan areas worldwide. Despite their importance in urban settings, the impact of microplastic contamination remains elusive. Here, we investigated the occurrence and characteristics of microplastics in drinking-water samples collected from 22 self-distributed refill kiosks located in 14 multiuse urban parks spread across nine municipalities in Mexico City (Mexico). The results showed that microplastics were detected in all the samples, with an overall mean concentration of 74.18 ± 48.76 microplastics L -1 . The abundance of microplastics was significantly different between sampled kiosks, ranging from 23 ± 11.31 to 202 ± 28.39 microplastics L -1 . There were more fibrous microplastics (88%) than fragments (9%) and films (3%), with the majority (56%) being <200 μm in length. They were predominantly transparent (85%), with only a few being colored (15%; blue, red, green, and brown). Attenuated Total Reflection-Fourier-transform infrared spectroscopy further revealed microplastics of various polymer types, including polyvinyl alcohol, high-density polyethylene, polypropylene, polyvinyl acetate, ethylene vinyl alcohol, acrylic, alkyd resin, and viscose. Based on our findings, drinking water from urban refill kiosks exposes children more than adults to microplastics. Furthermore, the steps that should be taken at urban refill kiosks to prevent microplastic pollution while offering recreational services to people have been highlighted. Therefore, this first study serves as a wake-up call to urban water management to improve the safety of water from emerging pollutants like microplastics in the infrastructure of refill kiosks., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The analysis of microplastics in various environmental matrices is becoming more prevalent in almost every region of the world. Microplastics are underreported depending on how they are extracted and analyzed, and their magnitude and impacts are unknown or unstudied. This paper aims to synthesize a concrete assessment of the important factors that underpin microplastics data underreporting. Our analysis revealed that there is considerable evidence to highlight data underreporting on microplastic abundance and characteristics, which stems from a combination of partial evaluation, economic constraints, recovery efficiency of microplastic extraction, filter pore size used for microplastic separation, and the detection limit of the quantification and characterization method. The majority of unreported data fell into the category of significantly smaller-sized microplastic particles (1-300 μm), which are known to be more harmful to the environment and human health. Recommendations toward the improvement of methodologies for improving microplastic data, as well as the critical areas that will drive standardization ahead, are addressed., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The development and applications of effective analytical techniques for identification and quantification of microplastics in diverse spheres are increasing in the scientific arena. Nile Red (NR) staining has progressed as a low-cost, simple-to-use approach for analyzing the environmental impact of a wide spectrum of microplastics (e.g., ≥ 3 µm - ≤ 5 mm; polyethylene, polypropylene, and polyvinyl chloride etc.). Given the recent surge of research into this methodology, it is critical to examine the findings and present future directions. Herein, we review accomplishments to date of the current protocols describing the sample preparation, staining and fluorescence conditions, contamination measures, and data analysis based on 56 field observations focusing on microplastic pollution and NR staining technique. Additionally, we discuss the challenges in current analyses towards standardization and recommendations related to it. Finally, we conclude that, despite methodological discrepancies, the NR method has emerged as a viable standalone substitute for visual identification; yet not all that fluoresce with NR are microplastics, which necessitates extensive sample preparation or additional spectroscopy techniques for chemical analysis to validate the results. This article informs the reader about how the NR technique is advancing microplastic research and identifies current needs for future advancements., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Microplastics can have several negative consequences on a variety of organisms, and their prevalence in marine ecosystems has become a major concern. Researchers have recently focused their attention on the world's largest gulf, the Gulf of Mexico (GoM), to determine and assess the impact of microplastic pollution on various environmental compartments (i.e., water, sediment, and biota). This paper critically reviews the analytical methodologies as well as summarizes the distribution, accumulation, sources, and composition of microplastics in a handful of studies (n = 14) conducted in the Gulf of Mexico (GoM) covering countries like the USA (n = 10) and Mexico (n = 4). Current quality control measures with respect to sampling and microplastic extraction are summarized. Of 14 studies reviewed, 47% primarily focused on examining sediments for microplastics, with biota and water comprising 35% and 18%, respectively. The abundance ranged from 31.7 to 1392 items m -2 and 60-1940 items kg -1 in sediment, 12-381 particles L -1 in water, and 1.31-4.7 particles per fish in biota. Irregular shaped fragments were the most abundant, followed by fiber, film, foam, hard, and beads etc. Different polymer types of microplastics have been found, including polyethylene, polypropylene, polystyrene, polyamide, nylon, and rayon etc. According to published research, 46 out of 100 fish thriving in this region are susceptible to microplastic ingestion. Although microplastic concentration in the GoM is among the highest found worldwide, the determination of microplastic contamination is still a growing field of research and methodological discrepancies largely limit the realization of establishing a baseline information on the microplastic abundance of the GoM. In this respect, considerable efforts must be dedicated towards evaluating their distribution and exposure levels; thereby, major challenges and future research directions are briefly discussed., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

There has been an ever-increasing attention over years for investigating microplastics in feces of lower to higher trophic organisms from diverse environments. Focusing on the standardization of methodologies for reliable generation and comparison of data is one of the important aspects in microplastic area. This first review, comprising 20 studies in total, critically summarizes and compares the methodological approaches for the determination of microplastics in feces as well outlines the levels and characteristics of microplastics detected in feces worldwide. Contaminations and QA/QC measures are also discussed. Despite variations among the approaches, most studies (n = 12) described herein rely on the digestion processes involving H 2 O 2 (n = 7) and KOH (n = 6) for the separation of microplastics, whereas very few included wet sieving (n = 5), density separation using NaCl (n = 3) and NaI (n = 1) and enzymatic digestion (n = 2). Microscopical sorting and spectroscopic methods such as infrared and Raman were combined for identification and characterization of microplastics. The detected microplastics varied by size, shape, color and polymer types and the differences in reporting units of microplastic abundance make comparison across studies difficult. Taking advantage of the current knowledge, our review identified analytical challenges and suggested appropriate methods on research into microplastic contamination in feces. This work will serve as a valuable information of available analytical methods for examining microplastics in feces and will stimulate further research to advance our understanding of microplastics from feces., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The continuously increasing presence of micro- and nanoplastics contamination in numerous food products for human consumption is threatening and their potential health effects towards humans remain uncertain. At present, investigations on packaged beverages (e.g. bottled drinking water, beer, milk and refreshments) have received scientific attention and represent an important part of microplastic research as humans are orally exposed to these anthropogenic contaminants every day. Rapid and effective detection methods are important to quantify micro- and nanoplastic particles with a great accuracy as well as to identify their sources and characteristics. A number of methods are currently in use to assess microplastics in packaged beverages; however, the great variations in methods and data acquisition render difficulties when comparing the results and developing the protocols. Based on the challenges, this paper aims to provide a comprehensive understanding of emerging technological approaches, points out the current limitations from sample preparation to quantification and present recommendations. From the results of our analysis, we postulate an example framework that can be applied to different types of drinking products for investigating micro- and nanoplastics. Overall, this review will serve as a first step towards harmonization of micro- and nanoplastic monitoring efforts and a point of reference to help direct future researches focusing on drinking products intended for human consumption., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Microplastics accumulation is an emerging environmental issue and a threat to marine life and human health. There is a growing number of investigations on the abundance and distribution of microplastics in different water bodies and biota worldwide, with relatively few studies conducted in Latin America, however, the current knowledge of microplastics sources, occurrence, transport, fate and potential impacts remains largely unexplored. This review presents the current trends and advances of microplastics on a lesser known region of the world by compiling the research performed to date in different environmental compartments. The sampling techniques and methods for microplastics extraction in the existing literature data are also summarized. Among 78 published studies reviewed, 34% of studies were from Brazil and 46% of studies have mainly focused on biota. The main findings showed that microplastics are not negligible across Latin America significantly varying in their distribution, with the prevalence of fibers comprising 62% of the total. Polyethylene, polypropylene, polyethylene terephthalate and polystyrene have been identified as the most common polymer types, accounting for 80% of the total. Limited studies and lack of standardized methodologies render difficulties to establish fundamental information on microplastics abundance and types in most countries of this region. Therefore, this review will primarily serve as a baseline when evaluating the environmental relevance of microplastics in Latin America and would stimulate discussions focusing on this topic, calling for more research in future., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Investigating wide range of food products of direct human consumption for microplastics is critical to understand the routes of contamination and assess the risks in microplastics uptake by humans. However, microplastics knowledge for many beverage products excluding beers is still lacking. Here, common beverages (n = 57; 27 brands) such as soft drinks (n = 19), energy drinks (n = 8), cold tea (n = 4) and beer (n = 26) were targeted for microplastics occurrences in Mexico and their shape, size, surface morphology and polymer composition were analyzed. Microplastics were detected in 48 out of 57 samples tested. The results identified microplastics of various forms (fibers and fragments) and sizes (0.1-3 mm) of colors (blue, red, brown, black and green), in amounts ranging from not detected to 28 ± 5.29 particles/L. Micro-Raman spectroscopy identified particles as polyamide, poly(ester-amide), acrylonitrile-butadiene-styrene and poly(ethylene-terephthalate) indicating microplastics contamination of synthetic textiles and packaging origin in the beverage products. Finally, this paper discusses that human excreta could act as a vehicle for the dispersion and accumulation of microplastics into terrestrial and aquatic environments. Combined, it is the first study to investigate microplastics contamination on soft drinks, energy drinks and cold tea and to document the material composition of microplastics from beverage products., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Microplastics have become an inevitable component of our environment. Worldwide, free public fountains are common and one of the best sources of drinking water which are being installed with one of the viewpoints of reducing single-use plastics bottle consumption. However, the state of knowledge on how microplastics might be affecting in those free public drinking fountains is unknown. In this study, free drinking water fountains from 42 metro stations in Mexico City were being looked into for the occurrence of microplastics and investigated their shape type, size, abundance, distribution, polymer composition and surface morphology. Microplastics were detected in all the samples analyzed. The results revealed the significant abundance of microplastics ranging from 5 ± 2 to 91 ± 14 L -1 in drinking water with an overall average of 18 ± 7 microplastics L -1 . Transparent fibers (69%) were predominant in the identified microplastics followed by blue (24%) and red colored (7%) fibers. The most frequent microplastics dimensions ranged between 0.1 and 1 mm which is approximately 75% of the total microplastics. Micro-Raman spectroscopy analysis indicated that microplastics contained in drinking water were mainly polyesters (poly (trimethylene terephthalate)) and epoxy resin suggesting the possible contribution of wastewater discharges for microplastics contamination. Thus, this study findings show that free public drinking water fountains are potential microplastics hotspot for human consumption and provide useful references for mitigation measures., Competing Interests: Declaration of competing interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Degradation of the organophosphorus pesticide has been studied using the marine isolate, Streptomyces venezuelae ACT1. The organism exhibited a specific growth rate of 0.371h(-1) and the organophosphorus hydrolase activity rate as 0.273h(-1). Hence the organism was found to be very effective towards the pesticide degradation. Further the substrate assimilation and inhibition model of the organism were demonstrated using Monod and Haldane model equations which depicted that the inhibition model fits well for both the cell growth and enzyme activity. The maximum specific growth rate and the enzyme activity rate were found to be 0.571h(-1) and 0.472h(-1), respectively. Effect of P0/X0 ratio on degradation and COD reduction rate revealed that higher these ratios raise the degradation rate and the COD reduction rate., (Copyright © 2012 Elsevier Ltd. All rights reserved.)