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Microplastics (MPs) have become pervasive in the environment, posing a threat to the environment, living organisms, and human health. Therefore, MPs have been extensively investigated in bodies of water, soils, and the atmosphere. However, there is limited information about MPs contamination in drinking water sold in plastic packaging from underdeveloped countries. In this study, we analyzed water samples from 10 different common brands of bottled water to detect and characterize MPs using stereomicroscopic and FTIR techniques. Oral consumption of MPs per capita was also estimated. Interestingly, our findings demonstrated that MPs were present in every brand. The average abundance of MPs varied from 14 ± 6.8 particles/L to 56 ± 23 particles/L, with a mean of 35 ± 19 particles/L in all brands. This number of MPs in the studied country was comparatively higher than those found in other countries. MPs were found in four different shapes (fibers, fragments, films, and beads), with fibers dominating the samples (90%). MPs were sorted into eight different colors, with the transparent one accounting for about 66% of the overall count, and 94% of the MPs were

Kuakata beach, known as Daughter of Sea in Bangladesh, has drawn a growing number of tourists from all over the world, leading to the higher use of single plastic products. This study was a first attempt to describe the occurrence, spatial distribution, and ecological risk of microplastics (MPs) in Kuakata beach sediments. A total of 24 surface sediment samples were collected from the intertidal zone of the beach, and MPs were extracted using the density separation method and a stereomicroscope. Fourier transform infrared (FTIR) spectroscopy was used for qualitative and quantitative identification. The results revealed that the average MPs in the beach sediment were 232 ± 52 items kg–1 dry weight, which was much higher than many other sandy beaches throughout the world. Analyses of variance showed a significant (p < 0.01) difference among the mean abundance of MPs in sampling points. Fibers were dominated in every sampling point with an average of 123 ± 27 item kg–1. Most of the MPs observed were colored (60%), and the rest were transparent (40%). It was found that the size range of 1–5 mm MPs constituted over half (55%) of total MPs covering an average value of 127 ± 34 items kg–1. Three polymer types were identified in the sediment samples through FTIR analysis which followed the decreasing order of polyethylene terephthalate > polyethylene > polypropylene. Correlation analysis showed a positive relationship between the abundance of MPs and the finer grain size of sediment (p = 0.055; r = 0.7), indicating grain size-controlled the density of MPs. The pollution load index was assessed to estimate the ecological risk and found that the beach sediment of Kuakata belonged to the risk category I of the pollution index. This investigation provided preliminary information on MPs pollution in the marine ecosystem that the policymakers can use to take appropriate management approaches.

Toxic metal pollution is a global issue, and the use of metal-accumulating plants to clean contaminated ecosystems is one of the most rapidly growing ecologically beneficial and cost-effective technologies. In this study, samples of sediment and three mangrove species (Excoecaria agallocha, Avicennia officinalis, Sonneratia apetala) were collected from the world’s largest mangrove forest (along the Northern Bay of Bengal Coast) with the aim of evaluating metal concentrations, contamination degrees, and phytoremediation potentiality of those plants. Overall, the heavy metals concentration in sediment ranged from Cu: 72.41–95.89 mg/kg; Zn: 51.28–71.20 mg/kg; Fe: 22,760–27,470 mg/kg; Mn: 80.37–116.37 mg/kg; Sr: 167.92–221.44 mg/kg. In mangrove plants, the mean concentrations were in the order of E. agallocha > A. officinalis > S. apetala. The mean (± SD) concentration of each metal in the plant tissue (root) was found following the descending order of Fe (737.37 ± 153.06) > Mn (151.13 ± 34.26) > Sr (20.98 ± 6.97) > Cu (16.12 ± 4.34) > Zn (11.3 ± 2.39) mg/kg, whereas, in the leaf part, the mean concentration (mg/kg) of each metal found in the order of Fe (598.75 ± 410.65) > Mn (297.27 ± 148.11) > Sr (21.40 ± 8.71) > Cu (14.25 ± 2.51) > Zn (12.56 ± 2.13). The contamination factor (CF) values for the studied metals were in the descending order of Cu > Sr > Zn > Fe > Mn. The values of Igeo (Geo-accumulation index) and CF showed that the area was unpolluted to moderately polluted by Zn, Fe, Mn, Cu and Sr. Enrichment factor (EF) values in both sampling stations portrayed moderate to minimum enrichment. Phytoremediation potentiality of the species was assessed by bio-concentration factor (BCF) and translocation factor (TF). BCF values showed less accumulation for most of the heavy metals (1). However, the BCF value depicts that Mn was highly bioconcentrated in E. agallocha, but the translocation on leaves tissue were minimum, which reveals that E. agallocha is phytoextractor for Mn, and accumulated in root tissues. All the examined plants can be used as phytoextractors as they have bioconcentration factors 1. However, A. officinalis is clearly more suitable for metal extraction than S. apetala and E. agallocha in terms of hyper-metabolizing capabilities.

Globally, both natural water bodies and aquaculture systems are being severely contaminated by heavy metals due to rising anthropogenic activities. Fish living in aquatic environments can easily accumulate metals in their bodies, which can then be transferred to consumers and put them at risk. In this study, metal concentrations (Pb, Cd, Cr, As, Mn, Cu, Zn) in different organs (gill, liver, and muscle) of farmed and wild Barramundi (Lates calcarifer) fish from the northern Bay of Bengal were evaluated to quantify and compare contamination levels and related human health risk. Heavy metal concentrations were higher in liver tissues of farmed Barramundi than in wild Barramundi, with the following relative mean values in the liver, gills, and muscle: Zn > Cu > Pb > Mn > Cd > Cr > As; Zn > Cr > Cu > Pb > Mn > Cd > As; Zn > Pb > Cu > Cr > Mn > Cd > As; Zn > Pb > Cu > Cr > Mn > Cd > As; and Zn > Pb > Cu > Cr > Mn > Cd > As, respectively. The differences in heavy metal accumulation observed between farmed and wild fish were probably related to the differences in their environmental conditions and dietary element concentrations. However, ANOVA indicated that the variation of metals in wild and Barramundi was not statically significant. Pb concentrations in the liver tissue of farmed Barramundi exceeded the national and international threshold limits, whereas concentrations of other metals were within the limit. Among the examined organs in both fish species (wild and farmed), muscle had the lowest concentration compared to others, and liver was the target organ for Pb, Cu, and Cd accumulations. Metals such as Zn and Mn exhibited higher concentration in the gills. However, all the studied heavy metals were below the maximum permissible limits of national and international standards, but the mean concentrations of Pb and Cd values in the liver of farmed Barramundi exceeded all international and national guidelines. Based on the contamination factors (CF) and pollution indices (PLI and MPI), the degree of contamination in the fish organs was as follows: gills > liver > muscle. The major accumulation tissues for both farmed and wild fish were found to be the gills (MPI = 0.970) and the liver (MPI = 0.692). Based on the estimated daily intake (EDI), the fish samples examined in this study are safe for human consumption as within the recommended daily allowance (RDA) range established by various authorities. According to the Target Hazard Quotient (THQ) and Carcinogenic Risk (CR) calculations, though the Barramundi fishes depicted no potential hazard to humans, farmed fish posed a higher health risk than wild fish.

Abstract Hangzhou Bay is facing severe anthropogenic perturbation because of its geographic position. We studied species-specific bioaccumulation of metals in commercially important fishes and shellfishes, and calculated the potential human health hazards through their consumption, which has not been reported earlier from this area. The hierarchy of metal concentration in organisms was in the decreasing order of Zn (10.32 ± 7.13) > Cu (2.40 ± 2.66) > As (0.42 ± 0.26) > Cr (0.11 ± 0.08) > Cd (0.07 ± 0.07) > Pb (0.05 ± 0.02) > Hg (0.012 ± 0.009). Except for Cd and As concentrations in fishes, metal concentrations have not exceeded the national and international guideline values. P. laevis and P. trituberculatus were the most bioaccumulative of the species studied. According to the non-carcinogenic risk assessment, children were more susceptible to metal contamination than adults. The carcinogenic risk (CR) values indicated that children were likely to experience carcinogenic threats for taking cancer-causing agents As and Cd through fish consumption. In terms of organisms, intake of two crab species, P. trituberculatus and E. sinensis, as well as the oyster species P. laevis, could be detrimental to consumers.

The world has already experienced the severe adverse effects of COVID-19 at every level. When it became understood that the COVID-19 infection is spread in the community via respiratory transmission from humans, then the widespread use of plastic-made personal protective equipments (PPEs) like face masks and hand gloves tremendously increased throughout the world. Although it has reduced the spreading of virus, however, careless disposal or mismanagement of these single use PPEs has created another major concern for the environment, as plastics are a known source of environmental contamination. On one hand, they are infected with SARS-CoV-2, while on the other, they act as a carrier or vector or pathway for other pathogens or diseases, and hence can increase the degree of continuing the pandemic. Besides, there might be a chance that plastics or microplastics may be responsible for introducing new pathogenic viruses or bacteria to humankind. As such, it is clear that more research needs to be conducted to clarify this fact, and its underlying mechanisms. In this review, we briefly explored how PPE used in the COVID-19 pandemic aggravated existing microplastic pollution, how they could act as disease routes or vectors, and how they could introduce new pathogens to the terrestrial and marine environment. Addressing these questions may create awareness of plastic use, waste management, and enact relevant policy which may protect our environment and health.

The lower Meghna River, the easternmost part of the Ganges Delta, faces severe anthropogenic perturbations as it receives a huge discharge and industrial effluents. To measure the metal concentrations and human health hazards, edible tissues of 15 commercially important fish species were collected from the local fish markets and the lower Meghna River, Bangladesh. Trace and heavy metals such as Pb, Cr, Cu, Zn, Mn, Fe, Hg, Ni, Ca, Co, Se, Rb, Sr, and As were detected using the Energy Dispersive X-ray Fluorescence (EDXRF) method. The hierarchy of mean metal concentrations obtained was: Fe (162.198 mg/kg) > Zn (113.326 mg/kg) > Ca (87.828 mg/kg) > Sr (75.139 mg/kg) > Cu (36.438 mg/kg) > Se (9.087 mg/kg) > Cr (7.336 mg/kg) > Mn (6.637 mg/kg) > Co (3.474 mg/kg) > Rb (1.912 mg/kg) > Hg (1.657 mg/kg) > Ni (1.467 mg/kg) > Pb (0.521 mg/kg) > As (BDL). Based on the metal concentration obtained, the carnivorous species contained more metals than omnivores and herbivores. Similarly, the euryhaline and benthic feeder fishes had more metals than the stenohalines and demersal fishes. The metal pollution index (MPI) suggested that the highly consumed fish species Tilapia (Oreochromis mossambicus) and Rui (Labeo rohita) accumulated higher metals than other fishes. Both the Targeted Hazard Quotient (THQ) and Hazard Index (HI) values for adult and child consumers were −6 to 10−4), but the CR exposure of Pb was negligible for all the consumers. The correlation, principal component analysis (PCA), and cluster analysis were conducted to identify the sources of metals identified from the fish tissue. The results indicated that the probable sources of the pollutants were anthropogenic, arising from agricultural activities, electroplating materials, and lubricants used near the study area. However, the present study showed a different metal concentration in the samples at different levels but within the threshold levels non-carcinogenic and carcinogenic health risks; hence, the fishes of the area, in general, are safe for human consumption.

Skeletonema dohrnii is a common red tide microalgae occurring in the coastal waters and throughout the world. The associated heterotrophic or autotrophic bacteria play vital roles in regulating algal growth, production, and physiology. In this study, we investigated the detailed bacterial community structure associated with the growth of S. dohrnii’s using high-throughput sequencing-based on 16S rDNA. Our results demonstrated that Bacteroidetes (48.04%) and Proteobacteria (40.66%) in all samples accounted for the majority of bacterial populations. There was a significant linear regression relationship between the abundance of bacterial phyla and culture time. Notable shifts in bacterial community composition were observed during algal growth: Flavobacteriales accounted for the vast majority of sequences at the order level. Furthermore, the relative abundance of Rhodobacterales was gradually reduced during the whole growth process of S. dohrnii (0–12 days). However, beyond that, the relative abundance of Marinobacter was slowly increasing. It is noteworthy that five fluorophores (Peaks T1, T2, I, M, and A) were detected during the growth stage of S. dohrnii. The characteristic indexes (fluorescence index, humification index, and biological index) of chromophoric dissolved organic matter (CDOM) also varied with the culture time. In addition, the taxa of bacteria had certain effects on CDOM and they were inextricably linked to each other.

During the autumn of 2017, a study was conducted to assess the zooplankton community composition in three sections (two latitudinal, going from Japan to the equator, and one longitudinal on the equator) of the Western Pacific Ocean. A total of 384 species of zooplankton adults and 21 groups of zooplankton larvae were identified, with copepods being the predominant taxon. The common dominant species across the three sections were Acrocalanus gibber, Canthocalanus pauper, Oithona similis, Paracalanus aculeatus, and Oncaea venusta. Zooplankton abundance was the highest in the equator section, with a mean abundance of 258.94 ± 52.57 ind./m3. Comparatively, a low abundance was recovered from the Subtropical Countercurrent (STCC) region, while the highest abundance holding stations were located in the eastern equatorial and North Equatorial Countercurrent (NECC) regions. Pearson’s correlation, canonical correspondence analysis, and other methods were used to analyze the relationship between environmental factors and zooplankton. We found that the Shannon–Wiener diversity index and Pielou’s uniformity index were significantly correlated (p < 0.05) with concentrations of nitrite and chlorophyll a. The distribution of zooplankton was also limited by nutrients, chlorophyll a, and dissolved oxygen. In addition, we reveal differences in the abundance of species in the equatorial and latitudinal seas. We found that not only temperature and nutrient salinity, but also ocean currents and the movement of water masses, influence the distribution of zooplankton communities in the Western Pacific.

The elemental ratios in phytoplankton are important for predicting biogeochemical cycles in the ocean. However, understanding how these elements vary among different phytoplankton taxa with physiological changes remains limited. In this paper, we determine the combined physiological–elemental ratio changes of two phytoplankton species, Scrippsiella trochoidea (Dinophyceae) and Heterosigma akashiwo (Raphidophyceae). Our results show that the cell growth period of S. trochoidea (26 days) was significantly shorter than that of H. akashiwo (32 days), with an average cell abundance of 1.21 × 104 cells·mL−1 in S. trochoidea and 1.53 × 105 cells·mL−1 in H. akashiwo. The average biovolume of S. trochoidea (9.71 × 103 μm3) was higher than that of H. akashiwo (0.64 × 103 μm3). The physiological states of the microalgae were assessed based on elemental ratios. The average ratios of particulate organic nitrogen (PON) to chlorophyll-a (Chl-a) and particulate organic carbon (POC) to Chl-a in S. trochoidea (57.32 and 168.16) were higher than those of H. akashiwo (9.46 and 68.86); however, the ratio of POC/PON of the two microalgae was nearly equal (6.33 and 6.17), indicating that POC/Chl-a may be lower when the cell is actively growing. The physiological variation, based on the POC/Chl-a ratio, in different phytoplankton taxa can be used to develop physiological models for phytoplankton, with implications for the marine biogeochemical cycle.

Genome-wide association studies have shown a strong association of single-nucleotide polymorphisms (SNPs) in the near vicinity of the TMEM18 gene. The effects of the TMEM18-associated variants are more readily observed in children. TMEM18 encodes a 3TM protein, which locates to the nuclear membrane. The functional context of TMEM18 and the effects of its associated variants are as of yet undetermined. To further explore the effects of near-TMEM18 variants, we have genotyped two TMEM18-associated SNPs, rs6548238 and rs4854344, in a cohort of 2352 Greek children (Healthy Growth Study). Included in this study are data on anthropomorphic traits body weight, BMI z-score and waist circumference. Also included are dietary energy and macronutrient intake as measured via 24-h recall interviews. Major alleles of rs6548238 and rs4854344 were significantly associated with an increased risk of obesity (odds ratio = 1.489 (1.161-1.910) and 1.494 (1.165-1.917), respectively), and positively correlated to body weight (P = 0.017, P = 0.010) and waist circumference (P = 0.003, P = 0.003). An association to energy and macronutrient intake was not observed in this cohort. We also correlated food intake and body weight in a food choice model in rats to Tmem18 expression in central regions involved in feeding behavior. We observed a strong positive correlation between TMEM18 expression and body weight in the prefrontal cortex (PFC) (r = 0.5694, P = 0.0003) indicating a potential role for TMEM18 in higher functions related to feeding involving the PFC.