Dominant Shaping Research Articles

Benthic biofilms in riverine systems: A sink for microplastics and the underlying influences

Rivers are known as major pathways for transporting microplastics from terrestrial areas to the marine environment. However, the behavior of microplastics in terms of retention and transport within riverine systems remains unclear. While considerable efforts have been made to investigate the water column and sediment, limited attention has been given to understanding the interplay between microplastics and benthic biofilms. Therefore, this study aimed to examine the distribution of biofilm-trapped microplastics along the CaoE River and identify the factors influencing the immobilization of microplastics by benthic biofilms. The findings of this study revealed that benthic biofilms served as a sink of microplastics in the CaoE River, with an average abundance of 575 items/m2 in tributaries and 894 items/m2 in the main stream. The dominant shape of microplastics was fiber, while the primary polymer type was polyethylene terephthalate. The distribution of microplastics exhibited significant spatial heterogeneity, as indicated by their abundance and characteristics. In order to reveal the intriguing phenomenon, variations of influencing factors were estimated, including physicochemical characteristics of water, extracellular polymeric substances of benthic biofilms, and microbial communities of benthic biofilms. A partial least squares path modeling analysis was performed using these variables, revealing that water velocity and microbial diversity of benthic biofilms were the key factors influencing the interaction between microplastics and benthic biofilms. In summary, this study provides substantial evidence confirming the crucial role of benthic biofilms in the immobilization of microplastics, which expands concerns about microplastic pollution in the riverine systems. Furthermore, uncovering the underlying influences of microplastic-biofilm interactions will facilitate the development of effective strategies for the control and management of microplastic pollution.

Investigation of hearing loss in elderly vertigo and dizziness patients in the past 10 years.

Vertigo and hearing loss are both prevalent in the elderly. This study retrospectively analyzed hearing test results from elderly patients experiencing vertigo and dizziness at ENT outpatient over a 10-year period, in order to study the patterns of hearing loss in this patient population. Nine thousand three hundred eighty four patients over 50 years old underwent retrospective collection and screening of outpatient diagnosis, pure tone audiometry, acoustic immittance measurement (tympanogram) and auditory brainstem response (ABR) test. The patient's audiograms are divided into 7 subtypes according to a set of fixed criteria. Meanwhile, K-Means clustering analysis method was used to classify the audiogram. The Jerger classification of tympanogram in elderly patients with vertigo and dizziness showed the majority falling under type A. The leading audiogram shapes were flat (27.81% in right ear and 26.89% in left ear), high-frequency gently sloping (25.97% in right ear and 27.34% in left ear), and high-frequency steeply sloping (21.60% in right ear and 22.53% in left ear). Meniere's disease (MD; 30.87%), benign recurrent vertigo (BRV; 19.07%), and benign paroxysmal positional vertigo (BPPV; 15.66%) were the most common etiologies in elderly vestibular diseases. We observed statistically significant differences in hearing thresholds among these vestibular diseases (P < 0.001). K-Means clustering analysis suggested that the optimal number of clusters was three, with sample sizes for the three clusters being 2,747, 2,413, and 4,139, respectively. The ANOVA statistical results of each characteristic value showed P < 0.001. The elderly patients often have mild to moderate hearing loss as a concomitant symptom with vertigo. Female patients have better hearing thresholds than males. The dominant audiometric shapes in this patient population were flat, high-frequency gently sloping, and high-frequency steeply sloping according to a set of fixed criteria. This study highlights the need for tailored strategies in managing hearing loss in elderly patients with vertigo and dizziness.

Microplastics and phthalate esters release from teabags into tea drink: occurrence, human exposure, and health risks.

Tea, the most common infusion worldwide, is usually sold in teabags due to the ease of usage. The increase in the use of plastic materials in the food packaging industry has led to an increase in released contaminants, such as microplastics (MPs) and phthalates (PAEs), in various food products including teabags. In this research, the abundance and features of MPs as well as PAEs concentration were investigated in 45 teabag samples of different Persian and German brands. The abundance of MPs in the Persian and German teabag samples was averagely 412.32 and 147.28 items/single teabag, respectively. Also, average PAEs levels in the Persian and German teabag samples were 2.87 and 2.37 mg/g, respectively. The predominant size category of MPs was related to 100-250 μm. Fibers and transparent were the dominant shape and color of detected MPs in teabags, respectively. Polyethylene (PE) and nylon were the most common MP polymer types. The most prominent PAEs congeners in teabag samples were diethylhexyl phthalate (DEHP) and diisobutyl phthalate (DiBP). Furthermore, MP exposure hazard through tea ingestion was analyzed for children and adults. DEHP showed the cancer risk (CR) for children and adults. The findings of this research indicated that high MPs and PAEs levels are released from teabags into tea drinks. Considering a daily drinking of a volume of 150 and 250 mL tea by children and adults, 486 and 810 MPs may enter their bodies, respectively. Thus, tea prepared with teabag-packed herbs may pose a significant health risk for consumers.

Conservation Conflict: A Political Ecology Meta-Synthesis of East Africa

Protected areas (PAs) are often seen as a solution to the biodiversity crisis, however, such conservation intervention can drive environmental change and conflict. Despite being presented as neutral and technically informed, PA establishment is highly political, often concealing social, economic, and political factors. Political ecology research examines how dominant narratives shape PA establishment, helping to better understand multi-layered conflicts involving often marginalized communities, conservation actors and wildlife in East Africa. This paper presents a meta-synthesis of PA expansion in the region, revealing the intricate relationship between conservation and conflict. The analysis identifies four key themes: ‘commodification of wilderness’, ‘the war for biodiversity’, ‘community marginalization on the periphery’, and ‘conservation biopolitics’. By novel utilization of meta-synthesis methodology, this paper contributes two-fold: themes provide nuanced regional understandings of the processes driving conservation conflicts while drawing theoretical insights from case study research which reveal the general applicability of findings from political ecology research.

Statistical shape modeling of mean shape and principal variability of the human talar bone in the Chinese population.

The talar bone plays a crucial role in ankle biomechanics and stability. Understanding the shape variability of the talar bone within specific populations is essential for various clinical applications. In this study, we aimed to investigate the mean shape and principal variability of the human talar bone in the Chinese population using statistical shape modeling (SSM). CT scans of 214 tali were included to create SSM models. Principal component analysis was used to describe shape variation among the male, female, and overall groups. The largest amount of variation among three groups ranges from 17.2%-18.8% of each variation. The first seven principal components (modes) captured 62.4%-67.5% of the cumulative variance. No dominant shape of the talus was found. Male tali generally have a larger size than the female tali, with the exception of the articular surface of the anterior subtalar joint. SSM is an effective method of finding mean shape and principal variability. Considerable variabilities were noticed among these three groups and all principal modes of variation. No dominant talar model was found to represent the majority of tali, regardless the gender. Such information is crucial to improve the current understanding of talar pathologies and their treatment strategies.

Abundance, characteristics and seasonal variation of microplastics in a domestic sewage treatment plant in Nanjing, China

Sewage treatment plants are a potential route of microplastics (MPs) into the environment, hence it's urgent to investigate MPs in wastewater and sludge through lengthy sampling campaigns. In this study, a sewage treatment plant in Nanjing, China was chosen, seasonal variation of MPs in influent was analyzed by collecting samples during a 12-month sampling campaign (at monthly intervals over a one-year period). Abundance and characteristic of MPs from different treatment stages were also investigated. The results showed that there was a seasonal variation in the amount of MPs in influent and the abundance of MPs was significantly greater in summer than other seasons. The average MPs abundance was 41.0 items/L and 3.0 items/L in influent and effluent, with a total 92.6 % removal rate. Overall, 125–355 μm were the main size in each treatment section, with fibers dominant shape and transparent main color. Additionally, the primary polymer compositions of MPs were polyethylene (PE) and polypropylene (PP) using micro-Roman spectroscopy. The daily MPs emission from effluent and sludge was estimated to be 300 million and 1274 million items/d, demonstrating that the sewage treatment plant is an important source of MPs into the environment despite the high removal rate of MPs.

Spatio-temporal distribution of microplastic pollution in surface sediments along the coastal areas of Istanbul, Turkey

Microplastics (MPs) have become prevalent in various environmental compartments, including air, water, and soil, attracting attention as significant pollutant parameters. This study investigated the prevalence of MP pollution in surface sediments along Istanbul's Marmara Sea, encompassing the megacity and the Bosphorus. A comprehensive sampling approach was employed, covering 43 stations across four seasons and depths ranging from 5 to 70 m. The objective was to assess the impact of terrestrial, social, and industrial activities on MPs. The average concentrations varied per season, with fall, winter, spring, and summer values recorded as 2000 ± 4100, 1600 ± 3900, 4300 ± 12,000, and 9500 ± 20,300 particles/kg-DW. The study identified river stations in the Golden Horn and sea discharge locations as hotspots for high concentrations. Notably, the dominant shape shifted from fibers in fall, winter, and spring to fragments during summer, coinciding with mucilage occurrences. The study identified 11 different polymers, with polyethylene (44 %) and polypropylene (31 %) being the most common.

The distribution and characterisation of microplastics in air, surface water and sediment within a major river system

Rivers are key pathways for the transfer of microplastics (MP) to marine environments. However, there are considerable uncertainties about the amount of microplastics transported by rivers to the ocean; this results in inaccuracies in our understanding of microplastic quantity and transport by freshwater systems. Additionally, it has been suggested that rivers may represent long-term sinks, with microplastics accumulating in sediment due to their high density or other biological, chemical, and physical factors. The atmosphere is also an important pathway by which airborne microplastics may enter aquatic habitats. Here, we compare for first time microplastics type and concentration in these key environmental mediums (air, water and sediment) along a major river (Ganges), from sea to source to understand 1) the abundance, 2) the spatial distribution, and 3) characteristics. Mean microplastic abundance settling from the atmosphere was 41.12 MP m2 day−1; while concentrations in sediment were 57.00 MP kg−1 and in water were 0.05 MP L−1. Across all sites and environmental mediums, rayon (synthetically altered cellulose) was the dominant polymer (54–82 %), followed by acrylic (6–23 %) and polyester (9–17 %). Fibres were the dominant shape (95–99 %) and blue was the most common colour (48–79 %). Across water and sediment environmental mediums, the number of microplastics per sample increased from the source of the Ganges to the sea. Additionally, higher population densities correlated with increased microplastic abundance for air and water samples. We suggest that clothing is likely to be the prominent source of microplastics to the river system, influenced by atmospheric deposition, wastewater and direct input (e.g. handwashing of clothes in the Ganges), especially in high density population areas. However, we suggest that subsequent microplastic release to the marine environment is strongly influenced by polymer type and shape, with a large proportion of denser microplastics settling in sediment prior to the river discharging to the ocean.

Evaluating the climate projections for China through the lens of the simulations of planetary boundary layer height

The planetary boundary layer height (PBLH) plays an essential role in affecting many meteorological parameters in climate change, and it is closely associated with the concentration of near surface air pollutants as well. Uncertainty of simulating PBLH is large partly due to the complexity in the modulation of surface energy, and the behaviors of the climate models in reproducing PBLH have not been fully evaluated, which also limits the understanding of future changes in PBLH. Here by utilizing a multi-model ensemble of Coupled Model Intercomparison Project Phase 6 (CMIP6), we first thoroughly evaluate the capability of CMIP6 models in reproducing the spatial distribution of PBLH over China during the period of 1995–2014, revealing large discrepancies among the CMIP6 models. Meanwhile, inaccuracy of simulated meteorological parameters can lead to large deviations of PBLH in models, among which sensible heat flux (SHFLX) and near surface relative humidity (RH) show stronger modulation effects. To enhance the confidence of future projections, we apply a method by selecting the five models with the smallest biases and a high signal-to-noise ratio, and the results indicate that changes in PBLH under shared socioeconomic pathways exhibit a dipole pattern in both summer and winter. Specifically, PBLH is projected to decrease over North China and increase over Central China and South China in summer, while in winter PBLH tends to increase stronger in southern China and weaker in the northern flank. To reveal the mechanism governing the PBLH, we find that changes of PBLH is closely associated with surface energy. SHFLX and near surface RH are the dominant factors shaping the changes in the spatial heterogeneity of PBLH in the future. This study has important implications for the improvement of surface energy and PBLH in climate models in order to effectively predict the future changes of air pollutants.

Spatial heterogeneity of soil organic carbon and soil nutrients and their controlling factors in a small watershed in Northeast China

AbstractUnderstanding the spatial distribution of soil organic carbon (SOC) and soil nutrients is crucial for optimizing land management in watersheds. This study explored the spatial distribution of SOC, total nitrogen (TN) and total phosphorus (TP) in topsoil (0–20 cm) at a hilly small watershed site in Northeast China, and identified the controlling factors. The Gaussian mixture model optimally described SOC and TN with the ratio of nugget to sill variance (C0/[C + C0]) indicating moderate spatial dependence for SOC (63.7%) and TN (59.3%). TP was best modelled by the spherical model and demonstrated weak spatial autocorrelation and strong human influence, with a nugget to sill variance of 0.841. Land use significantly affected SOC, TN and TP contents, with the highest values recorded in woodland, followed by farmland and shrubland. Soil properties including bulk density (BD), gravel content (GC), moisture content (MC), soil porosity (SP) and the mean weight diameter (MWD) of water‐stable aggregates significantly correlated with SOC and TN content, but not with TP. Redundancy analysis revealed that soil properties (BD, GC and SP), topography (slope and aspect) and gully erosion contributed 55.7%, 24.7% and 4.3% of the spatial variation in SOC, TN and TP, respectively. Hence, these are the dominant factors shaping the spatial variation of SOC and soil nutrients at the site. These results can aid the further development of optimized land management strategies.

An Assessment of Microplastic Contamination in a Commercially Important Marine Fish, Harpadon nehereus (Hamilton, 1822)

Microplastic (MP) pollution is a prevalent and global threat to fish. MP contamination was investigated in Harpadon nehereus collected from the principal fishing harbors of India’s northwest coast. A total of 213 specimens were collected from the major fishing harbors of Gujarat state (Jakhau, Okha, and Jaffrabad) and Maharashtra state (Mumbai). In the laboratory, the morphometric parameters of the specimens, such as total length and body weight, were measured. The collected specimens were analyzed for MP isolation using the previously documented protocol. MPs were quantified under a stereomicroscope, and physical parameters were recorded. All the examined specimens were found to be contaminated with MPs, with an abundance of 6.98 ± 6.73 MPs/g. The maximum contamination of MPs was recorded at the study site in Jaffrabad, followed by Jakhau, Mumbai, and Okha. Morphometric analysis of MPs revealed threads to be the most dominant shape. Black and blue MPs with a 1–2 mm size were the predominant recorded types. The chemical composition of extracted MPs revealed polyethylene (PE), polystyrene (PS), and polyurethane (PU) as polymer compositions. Conclusively, the findings highlighted a greater menace to seafood safety due to trophic transfer, which causes a hazardous effect on human health.

Missed chances and unfulfilled hopes: Why do firms make errors in evaluating technological opportunities?

AbstractResearch AbstractThis study examines commission and omission errors in the evaluation of technological opportunities. Integrating structural and cognitive perspectives, we propose that inventors with more cohesive collaboration networks within the firm or geographically closer to the corporate headquarters exert greater influence on the dominant representations shaping opportunity evaluation within the firm. Thus, their inventions are more likely to be positively assessed, even if quality considerations suggest otherwise. Conversely, even when superior in quality, inventions from individuals with less cohesive collaboration networks within the firm or located far from the corporate headquarters are less likely to be positively evaluated, leading to omission errors. The study provides evidence based on 22 interviews and archival data from the mobile phone and personal digital assistant industry between 1990 and 2010.Managerial AbstractThis study examines commission and omission errors in decision‐making about technologies. Studying patent renewal decisions of 42 firms in the mobile phone and personal digital assistant industry between 1990 and 2010, we show that inventors with more cohesive collaboration networks within the firm or located close to the corporate headquarters have their inventions positively assessed even when of lower quality, leading to commission errors. On the other hand, inventors with less cohesive collaboration networks within the firm or located far away from the corporate headquarters have their inventions disregarded even when of higher quality, causing omission errors. These findings call for managerial vigilance in technology evaluation decisions, ensuring valuable ideas are not overlooked due to an inventor's network position or location.

Country's value priorities in health crisis: How dominant societal motivations shape COVID-19 severity

This paper presents two comprehensive studies examining how Schwartz's human values dimensions at the country level predict COVID-19 pandemic severity. Study 1 aggregated survey data across 89 countries from the European Social Survey and World Values Survey to assess societal-level conservation versus openness to change (CON-OTC) and self-enhancement versus self-transcendence (SE-ST) value-continuums. Study 2 developed an innovative archival measurement approach using 10 indicators to estimate these value dimensions for over 180 countries. Both studies employed multilevel modeling to test the relationships between country-level values and COVID-19 severity, measured through epidemiological indicators of transmission speed, case fatality rate, infection prevalence and mortality burden. Results revealed that the CON-OTC and SE-ST value-continuums showed consistent, significant negative associations with transmission speed and infection prevalence before adjusting for modernization, latitude, historical pathogen prevalence and government stringency across both studies. However, after accounting for these socioecological and policy covariates, the CON-OTC value-continuum positively predicted case fatality rate in both studies, implying conservation values could increase COVID-19 lethality. In contrast, across both studies, the SE-ST value-continuum negatively predicted case fatality rate after adjusting for the covariates, suggesting countries prioritizing self-enhancement values exhibited relatively lower pandemic severity and lethality when accounting for developmental, ecological, and policy factors. Accordingly, the studies advance theoretical understanding of how country's value priorities shape COVID-19 impact. Methodologically, these studies contribute through multilevel techniques that account for spatial dependencies, as well as an innovative ecological measurement. Overall, this research demonstrates the value of applying Schwartz's framework at a societal level to predict global health crises and pandemics.

Microplastic ingestion by adult milkfish Chanos chanos (Forsskål, 1775) in aquaculture system: The case of Butuan Bay, Philippines

The Philippines is an archipelago that relies on marine resources. Butuan Bay in the Philippines supports aquaculture, which can contribute to and can be impacted by plastic pollution. However, the microplastics (MP) in milkfish, an important aquaculture species in the area, are yet to be ascertained. This study determined the prevalence of microplastics in the surrounding seawater and in the gut of adult milkfish from cages in Butuan and Nasipit in Butuan Bay. Water samples in Nasipit and Butuan contain 0.20 items/L and 1.00 items/L, respectively. MPs in milkfish in Butuan (10.27 items/individual) were significantly higher than in Nasipit (5.40 items/individual). A total of 235 MPs in 29 out of 30 fish samples (97 %) from the two sites were detected. The dominant MP shape and color were fiber and blue, respectively. The presence of microplastics in the milkfish may indicate a possible risk to the fish species and human health.

Speciation-by-Extinction.

Extinction is a dominant force shaping patterns of biodiversity through time; however its role as a catalyst of speciation through its interaction with intraspecific variation has been overlooked. Here, we synthesize ideas alluded to by Darwin and others into the model of "speciation-by-extinction" in which speciation results from the extinction of intermediate populations within a single geographically variable species. We explore the properties and distinguishing features of speciation-by-extinction with respect to other established speciation models. We demonstrate its plausibility by showing that the experimental extinction of populations within variable species can result in speciation. The prerequisites for speciation-by-extinction, geographically structured intraspecific variation and local extinction, are ubiquitous in nature. We propose that speciation-by-extinction may be a prevalent, but underappreciated, speciation mechanism.

Occurrence and spatial distribution of microplastics in the intertidal sediments along the Oman Sea

Microplastics (MPs) have been found in marine systems more frequently. We aim to analyze the MPs abundances, distribution, and characteristics in the intertidal sediments along the Oman Sea. Samples were collected from 7 locations with three replicates. Density separation was used to extract MPs, which were then visually counted and categorized based on their size, shape, and color. MPs abundance ranged between 219.6 ± 38.3 particles.kg−1dw and 617.3 ± 99.9 particles.kg−1dw with a mean abundance of 315.4 ± 24.4 particles.kg−1 dw. Fragments and fibers were the dominant shapes. Red and blue colors were observed in 61.6 % of the collected MPs. In addition, 100–500 μm size range of MPs were more abundant. Micro-Raman spectroscopy analysis revealed polypropylene was the major polymer constituent. The present study revealed the widespread occurrence of MPs as anthropogenic pollutants throughout the Oman Sea and highlighted the urgent need for regulations and policies to reduce the entry of this material into marine environments.

Abundance, characteristics, and distribution of microplastics in Banda Sea and Seram Sea, Indonesia

This study recorded the abundance, characteristics, and distribution of microplastics (MPs) in the surface water in the Banda Sea and Seram Sea. The Banda Sea has known for its complex bathymetry with the shape of a basin in the west and a Sahul Shelf in the east. Due to its unique topography, it controls the water mass exchange in Indonesian waters. The Banda Sea and Seram Sea are dominated by the deep sea with bathymetry of more than 1000 m. Station observation consists of 5 stations in the Banda Sea and 3 stations in the Seram Sea. The microplastic abundance in the surface waters from the Banda Sea and Seram Sea ranged from 4.69 to 22.48 items/L with an average abundance of 14.07 items/L. The highest abundance of MPs was found in Station 1 of Banda Sea due to the closest to Ambon as the capital of Maluku Province. The dominant shape of MPs found such as fibre, fragment, and pellet. The polymer type of MPs found were PET, HDPE, LDPE, PVC, PP, and Nylon. Generally, the abundance of MPs on the surface of the deep-sea area was found lesser than in the coastal area since the MPs distributions are influenced by hydrodynamics and anthropogenic activity.

Fire influences ant diversity by modifying vegetation structure in an Australian tropical savanna.

Fire is a dominant ecological force shaping many faunal communities globally. Fire affects fauna either directly, such as by killing individuals, or indirectly, such as by modifying vegetation structure. Vegetation structure itself also modulates fire frequency and intensity. As such, faunal responses to fire need to be seen through the lens of variable fire activity and vegetation structure. Here, we incorporate information on fire activity and vegetation structure to enhance an understanding of the response of ants to long-term (17-year) experimental fire treatments in an extremely fire-prone tropical savanna in northern Australia. A previous analysis revealed limited divergence in ant communities after five years of experimental fire treatment. Hence, we first investigated the extent to which ant communities diverged over a subsequent 12 years of treatment. We then assessed the relative contribution of fire treatment, cumulative fire intensity (fire activity) and woody cover to responses of ant species frequency of occurrence, richness and composition. We found that, even after 17 years, fire treatments explained little variation in any ant response variable. In contrast, woody cover was a strong predictor for all of them, while fire activity was a moderate predictor for abundance and richness. Ant species occurrence and richness increased in open habitats receiving higher levels of fire activity, compared with plots with higher vegetation cover experiencing low (or no) fire activity. Moreover, species composition differed between plots with high and low vegetation cover. Our findings provide experimental support to the principle that the effects of fire on fauna are primarily indirect, via its effect on vegetation structure. Furthermore, our results show that a 'uniform' fire regime does not have uniform impacts on the ant fauna, because of variability imposed by interactions between vegetation structure and fire activity. This helps explain why there is often a weak relationship between pyrodiversity and biodiversity, and it lessens the need for active management of pyrodiversity to maintain biodiversity. This article is protected by copyright. All rights reserved.

The occurrence and distribution of microplastic contamination in Qara-sou river, Iran: incidence, quantification, and qualification

ABSTRACT In the current study to investigate the characte – rization of Microplastic – released into the Qara-Sou river, Kermanshah, Iran, 12 sampling sites were surveyed along a 100 km stretch of the river. The maximum and minimum numbers of MPs were about 10,000 and 45,000 items per m3. The average concentration of MPs in the Qara-sou river was 23,666 ± 12147 items per m3. The dominant size and shape of MPs ranged from 0.025 to 1 mm (~44%) and fiber shapes (~78%). In addition, SEM-EDS analyses confirmed the presence of carbon-dominant peaks with O, Ca, Fe, Al, and Si. FTIR spectra have identified some MPs in the PVC, PU, PS, PE, and nylon polymer categories. A high level of MPs was discharged into the Qara-sou river, which should be attracting the attention of the community and decision-makers to reduce damage to the environment and human health.

Characterization and Quantification of Surficial Sediment Microplastics and Its Correlation with Heavy Metals, Soil Texture, and Flow Velocity

Investigating the presence of microplastics in the Pasig River, the highest plastic-emitting river in the Philippines and one of the ocean’s leading contributors of these materials, is highly relevant. In this study, surficial sediments in eight stations along the main channel of the Pasig River were analyzed for microplastic content, heavy metals, and soil texture. The microplastics were categorized according to shape, color, and size. The polymer type was determined using infrared spectroscopy. The number of microplastics was correlated with heavy metals, soil texture, and flow velocity. The results show that the dominant shape, color, size, and polymer type were fragment, color white, size range from 0 to 500 μm, and polyvinyl alcohol, respectively. Downstream stations 5 and 8 had the highest microplastic concentration. The number of microplastics showed a positive moderate correlation with percent sand (r = 0.40) and clay (r = 0.42), and a negative high correlation with percent silt (r=-0.80). For microplastics and heavy metals, a positive moderate correlation was observed for iron (r = 0.52) and zinc (r = 0.58), while a negative weak correlation was present for lead (r=-0.06). Microplastics and flow velocity showed weak correlations demonstrating that the accumulation in the bottom river sediment may be based on the proximity of the plastic source rather than on the flowing water with plastic sources. Results reflect the diverse influences on the Pasig River which is surrounded by informal settlements, manufacturing industries, urban offices, and residential areas. More plastic management initiatives and better implementation of existing laws should be done by the government.