Microplastics (MPs) accumulation in farmland has attracted global concern. Smallholder farming is the dominant type in China's agriculture. Compared with large-scale farming, smallholder farming is not constrained by restrictive environmental policies and public awareness about pollution. Consequently, the degree to which smallholder farming is associated with MP pollution in soils is largely unknown. Here, we collected soil samples from both smallholder and large-scale vegetable production systems to determine the distribution and characteristics of MPs. MP abundance in vegetable soils was 147.2-2040.4 MP kg-1 (averaged with 500.8 MP kg-1). Soil MP abundance under smallholder cultivation (730.9 MP kg-1) was twice that found under large-scale cultivation (370.7 MP kg-1). MP particle sizes in smallholder and large-scale farming were similar, and were mainly <1 mm. There were also differences in MP characteristics between the two types of vegetable soils: fragments (60%) and fibers (34%) were dominant under smallholder cultivation, while fragments (42%), fibers (42%), and films (11%) were dominant under large-scale cultivation. We observed a significant difference in the abundance of fragments and films under smallholder versus large-scale cultivation; the main components of MPs under smallholder cultivation were PP (34%), PE (28%), and PE-PP (10%), while these were PE (29%), PP (16%), PET (16%), and PE-PP (13%) under large-scale cultivation. By identifying the shape and composition of microplastics, it can be inferred that agricultural films were not the main MP pollution source in vegetable soil. We show that smallholder farming produces more microplastics pollution than large-scale farming in vegetable soil.
In this study, estuarine water samples were collected at diverse hot spots in Miri River Estuary, East Malaysia to appraise the geochemical processes, which controls the river water quality. The collected water samples were analysed for various physicochemical parameters (insitu parameters, nutrients, major ions and trace metals), including stable isotopes (oxygen and hydrogen). Suspended solids are also extracted from the water samples and analysed for trace metals. Standard graphs, Piper plot, Gibbs diagram, water quality indices, geochemical modelling and statistical analysis were used for the data analysis. The acquired water quality data was compared with national and international guidelines for the suitability of water for various purposes. Interpretation of data reveals that the estuarine water quality is deemed unsuitable to be used for both drinking and irrigation purposes. Overall, the elemental concentrations are increasing from downstream to river mouth. Based on pollution indices (HEI and Cd), downstream region shows high vulnerability to metal pollution due to anthropogenic disturbance. Isotope values of river water indicate direct atmospheric precipitation with minimal evaporation. Factor analysis reveals that seawater influx, urban pollution, domestic and agricultural discharges at the downstream region are the main controlling factors to the river water quality. It is also deduced that suspended solids play a vital role in the adsorption and desorption of trace metals in the estuarine water. The outcome of this study provides a comprehensive information on pollution status of Miri estuary, which helps the policy makers to practice sustainable management of this water resource for Miri community.
Plastic can be degraded into microplastic (<5 mm) and has been polluting worldwide marine environment and negatively impact human health. Microplastics in marine organisms are still understudied in Malaysia, let alone from a subclass Elasmobranchii. Five tropical shark species (Carcharhinus dussumieri, Carcharhinus sorrah, Chiloscyllium hasseltii, Chiloscyllium punctatum, and Scoliodon laticaudus) were examined for the presence of microplastics. 74 sharks were sampled from the local wet market and 100 % of samples contained microplastics. A total of 2211 plastic particles were found in gastrointestinal tracts (GIT) and gills, where 29.88 ± 2.34 particles per shark (mean ± SEM). Black (40.07 %) and fiber (84.44 %) microplastics were the most dominant. Extracted microplastic sizes ranged from 0.007 mm to 4.992 mm. This study suggests that microplastic uptake is gender-related for some shark species. A subsample of microplastics (10 %) was used for polymer type identification, where polyester was recorded the highest (43.95 %).
The uncontrolled or continuous release of effluents from wastewater treatment plants leads to the omnipresence of pharmaceutical active compounds (PhACs) in the aquatic media. Today, this is a confirmed problem becoming a main subject of twin public and scientific concerns. However, still little information is available about the long-term impacts of these PhACs on aquatic organisms. In this review, efforts were made to reveal correlation between the occurrence in the environment, ecotoxicological and health risks of different PhACs via toxicological evaluation by zebrafish (Danio rerio). This animal model served as a bioindicator for any health impacts after the exposure to these contaminants and to better understand the responses in relation to human diseases. This review paper focused on the calculation of Risk Quotients (RQs) of 34 PhACs based on environmental and ecotoxicological data available in the literature and prediction from the ECOSAR V2.2 software. To the best of the authors' knowledge, this is the first report on the risk assessment of PhACs by the two different methods as mentioned above. RQs showed greater difference in potential environmental risks of the PhACs. These differences in risk values underline the importance of environmental and experimental factors in exposure conditions and the interpretation of RQ values. While the results showed high risk to Danio rerio of the majority of PhACs, risk qualification of the others varied between moderate to insignifiant. Further research is needed to assess pharmaceutical hazards when present in wastewater before discharge and monitor the effectiveness of treatment processes. The recent new advances in the morphological assessment of toxicant-exposed zebrafish larvae for the determination of test compounds effects on the developmental endpoints were also discussed. This review emphasizes the need for strict regulations on the release of PhACs into environmental media in order to minimize their toxicity to aquatic organisms.
The introduction of plastic sectors has resulted in the presence of microplastics (MPs) in water systems, which has become a global issue that has attracted scientific and community awareness. MPs can be detected in a variety of sources such as beauty products, manufacturing effluent, or fishing activities. This study examined the repercussions posed by MPs' prevalence on land and marine environments and human health issues. Henceforth, remediation technologies must be introduced to shift out MPs from the water supplies in order to sustain the environmental quality for future generations, the benefits and drawbacks of the technology applied. This study also portrays difficulties encountered in MP research as the hurdles must be mastered in order to properly comprehend the MPs. The cooperation between nations is the most critical aspect in fully tackling MP issues as it can be easily carried by wind or water and its damage can be larger than predicted.
Groundwater is a primary natural water source in the absence of surface water bodies. Groundwater in urban environments experiences unprecedented stress from urban growth, population increase, and industrial activities. This study assessed groundwater quality in terms of arsenic and heavy metal contamination in three industrial areas (Shahdara, Jhilmil, and Patparganj), Delhi, India. The water quality was assessed over a 3-year time interval (i.e., 2015 and 2018). The groundwater constituents investigated were As, Fe, Cr, Cd, Ni, Zn, Mn, Cu, and Pb. Metal index and heavy metal pollution indexes were estimated to assess groundwater pollution. The health risk was evaluated in terms of non-carcinogenic and carcinogenic risk assessment. Patparganj industrial area saw increment in concentration for Cu 0.23 mg/L (2015)-0.85 mg/L (2018), Zn 0.51 mg/L (2015)-7.2 mg/L (2018), Fe 0.32 mg/L (2015)-0.9 mg/L (2018), Cr 0.21 mg/L (2015)-0.26 mg/L (2018), Mn 0.14 mg/L (2015)-0.25 mg/L (2018), Ni 0.04 mg/L (2015)-0.34 mg/L (2018), and As 0.01 mg/L (2015)-0.18 mg/L (2018). Cd and Pb concentrations were observed to decrease by 40-90 % and 85-99% for all the three industrial areas. Metal index and heavy metal index values were found to be >1 for all locations. The risk quotient value > 1 was observed for all locations in the year 2015 but was found to increase further to a range of RQ 10-62 in the year 2018, inferring increased non-carcinogenic risk to consumers. The carcinogenic risk was significant with respect to Fe (0.2-0.7), Zn (0.001-0.007), and As (0.002-0.003) for all locations in the year 2015. This study concludes that groundwater in the three industrial areas is highly polluted and is not fit for human consumption. Further studies are required to explore possible control measures and develop methods to mitigate groundwater pollution, sustainable management, and optimized use to conserve it for future generations.
Land exploitation for mining sector may leave a series of environmental impacts on our ecosystem if not appropriately managed. Therefore, the present study attempts to evaluate the various environmental aspects due to abandoned metal mining including former iron ore, bauxite, and tin mining lands in view of its hydrogeochemical behavior. Mine-impacted waters and sediments were ascertained from former mining ponds, mine tailings, and impacted streams for interpretation of aqueous and sediment geochemistry, major and trace elements, hydrochemical facies, chemical weathering rate and CO2 consumption, and water quality classification. Results indicated that the environmental impact of the long-abandoned iron ore mine was still evident with some high concentration of metals and acidic pH. Higher concentrations of Fe and Mn in water were noticeable in some areas while other trace elements (Pb, Zn, As, Cd, Cr, and Cu) were found below the recommended guideline values. Sediment quality reflected the trend of water quality variables mainly associated with metal(loid) elements, resulting in potential ecological risk, classified as having low to moderate risk. There were variations in terms of hydrochemical facies of the waters suggesting the influence of minerals in water. The chemical weathering rate suggests that contribution of carbonate mineral weathering was more important (up to 60%) than silicate weathering. The resulting CO2 consumption by mineral weathering was estimated to be in the range of 1.7-9.8 × 107 mol/year (former bauxite and tin mining areas can act as temporary sinks for CO2). Water quality classifications according to several chemical indices (Kelly's ratio, sodium absorption ratio, soluble sodium percentage, residual sodium carbonate, magnesium absorption ratio, and permeability index) were also discussed in regards to mine water reuse for irrigation purpose. The findings suggest that a holistic approach that integrates all important hydrogeochemical aspects is essential for a thorough evaluation of the implication of medium- to long-term mining exploitation on its surrounding ecosystems. This would be beneficial in light of restoration potential of degraded mining land so as for future mitigation strategies in the mining sector.
Air surface temperature (AST) is a crucial importance element for many applications such as hydrology, agriculture, and climate change studies. The aim of this study is to develop regression equation for calculating AST and to analyze and investigate the effects of atmospheric parameters (O3, CH4, CO, H2Ovapor, and outgoing longwave radiation (OLR)) on the AST value in Iraq. Dataset retrieved from the Atmospheric Infrared Sounder (AIRS) at EOS Aqua Satellite, spanning the years of 2003 to 2016, and multiple linear regression were used to achieve the objectives of the study. For the study period, the five atmospheric parameters were highly correlated (R, 0.855-0.958) with predicted AST. Statistical analyses in terms of β showed that OLR (0.310 to 1.053) contributes significantly in enhancing AST values. Comparisons among selected five stations (Mosul, Kanaqin, Rutba, Baghdad, and Basra) for the year 2010 showed a close agreement between the predicted and observed AST from AIRS, with values ranging from 0.9 to 1.5 K and for ground stations data, within 0.9 to 2.6 K. To make more complete analysis, also, comparison between predicted and observed AST from AIRS for four selected month in 2016 (January, April, July, and October) has been carried out. The result showed a high correlation coefficient (R, 0.87 and 0.95) with less variability (RMSE ≤ 1.9) for all months studied, indicating model's capability and accuracy. In general, the results indicate the advantage of using the AIRS data and the regression analysis to investigate the impact of the atmospheric parameters on AST over the study area.
Non-point source (NPS) pollution has become a vital contaminant source affecting the water environment because of its wide distribution, hydrodynamic complexity, and difficulty in prevention and control. In this study, the identification and evaluation of NPS pollution risk based on landscape pattern were carried out in the Hanjiang River basin above Ankang hydrological section, Shaanxi province, China. Landscape distribution information was obtained through land use data, analyzing the contribution of "source-sink" landscape to NPS pollution through the location-weighted landscape contrast index. Using the NPS pollution risk index to identify and evaluate the regional NPS pollution risk considering the slope, cost distance, soil erosion, and precipitation erosion affect migration of pollutants. The results showed that (i) the pollution risk was generally high in the whole watershed, and the sub-watersheds dominated by "source" landscapes account for 74.61% of the whole basin; (ii) the high-risk areas were distributed in the central, eastern, and western regions of the river basin; the extremely high-risk areas accounted for 12.7% of the whole watershed; and the southern and northern regions were dominated by forestland and grassland with little pollution risk; (iii) "source" landscapes were mostly distributed in areas close to the river course, which had a great impact on environment, and the landscape pattern units near the water body needed to be further adjusted to reduce the influence of NPS pollution.
Despite the nutritional benefits, bivalves like mussels are also an excellent aquatic heavy metal biomonitoring agent due to their high tolerance to varying levels of temperature, salinity and oxygen, as well as pollutants. Although the accumulated toxic heavy metals may not exert direct negative impacts on the mussels, such toxicants in mussel tissues can give harmful effects on human body when consumed in toxic quantities and/or over prolonged period. The booming of urban and industrial activities, and consequently the increment of runoffs, as well as wastewater effluents and leaching, further exacerbated the magnitude of this issue. Hence, continuous monitoring of heavy metal contents in mussels is vital to ensure its compliance with food safety regulations, protecting consumers at large. This review paper discusses the occurrence of heavy metals in mussels especially that of Perna viridis in Malaysia and other parts of the world since year 2000 until 2021. Heavy metal concentration data and patterns from various coastal and/or estuaries were compared. Where applicable, statistical data that indicate variations between sampling sites, sampling months or years and chemical treatments for heavy metal removal were critically reviewed. Health risk assessment findings were also discussed. More importantly, related chemical-based interventions to minimize and/or eliminate toxic heavy metals from mussels are also reviewed.
Concentrations, sources and interactions between black carbon (BC) and polycyclic aromatic hydrocarbons (PAHs) were investigated in 42 sediment samples collected from riverine, coastal and shelf areas in Peninsular Malaysia. The concentrations of BC measured by benzene polycarboxylic acid (BPCA) method and PAHs showed broad spatial variations between the relatively pristine environment of the East coast and developed environment of the West and South coast ranging from 0.02 to 0.36% dw and 57.7 ng g-1 dw to 19,300 ng g-1 dw, respectively. Among diagnostic ratios of PAHs, the ratios of Ant/(Ant+Phe) and LMW/HMW drew the clearest distinctions between the East coast versus the West and South coast sediments indicating the predominance of petrogenic sources in the former versus pyrogenic sources in the latter. PAHs significantly correlated with BC and total organic carbon (TOC) in the sediments (p
One of the molecular chemical markers used to identify anthropogenic inputs is linear alkylbenzenes (LABs) that cause serious impacts in the bays and coastal ecosystems. The surface sediments samples collected from the East Malaysia, including Brunei bay to estimate the LABs concentration and distribution as molecular markers of anthropogenic indicators. Gas chromatography-mass spectrometry (GC-MS) was used after purification, fractionation the hydrocarbons in the sediment samples to identify the sources of LABs. The analysis of variance (ANOVA) and Pearson correlation coefficient were applied to analyze the difference between sampling stations' significance at p
Microplastic (MP) pollution is a serious global environmental problem, particularly in marine ecosystems. However, the pollution patterns of MPs in the ocean and atmosphere, particularly the sea-air interrelationship, remain unclear. Therefore, the abundance, distribution patterns, and sources of MPs in the seawater and atmosphere of the South China Sea (SCS) were comparatively investigated. The results showed that MPs were prevalent in the SCS with an average abundance of 103.4 ± 98.3 items/m3 in the seawater and 4.62 ± 3.60 items/100 m3 in the atmosphere. The spatial analysis indicated that the pollution patterns of seawater MPs were mainly determined by land-based discharge and sea surface currents, whereas atmospheric MPs were predominantly determined by air parcel trajectory and wind conditions. The highest MP abundance of 490 items/m3 in seawater was found at a station near Vietnam with current vortices. However, the highest MP abundance of 14.6 items/100 m3 in the atmosphere was found in air parcels with low-speed southerly winds from Malaysia. Similar MP compositions (e.g., polyethylene terephthalate, polystyrene, and polyethylene) were observed in the two environmental compartments. Furthermore, similar MP characteristics (e.g., shape, color, and size) in the seawater and atmosphere of the same region suggested a close relationship between the MPs in the two compartments. For this purpose, cluster analysis and calculation of the MP diversity integrated index were performed. The results showed an obvious dispersion between the two compartment clusters and a higher diversity integrated index of MPs in seawater than in the atmosphere, thus implying higher compositional diversity and more complex sources of MPs in seawater relative to the atmosphere. These findings deepen our understanding of MP fate and patterns in the semi-enclosed marginal sea environment and highlight the potential interrelationship of MPs in the air-sea system.
Jurong Formation underlies part of Southern Johor Bahru which comprises well cemented and consolidated volcanic-sedimentary rocks. The study aims to assess quality and hydrogeochemistry of rock aquifer in Jurong Formation at Southern Johor Bahru which is mainly overlain by rhyolitic tuff. It also evaluates the differences in quality and hydrogeochemistry of rhyolitic tuff aquifer found in source and floodplain zones of South-West Johor Rivers Basin. In this study, a total of nine samples from four wells, namely TW1-TW4, were collected at foothills of Gunung Pulai (TW1) and Iskandar Puteri (TW2-TW4) in Southern Johor Bahru. The samples were examined for physiochemical parameters. The groundwater in the study area is fresh and non-saline with hardness of soft to hard. The pH of groundwater in source zone is significantly higher than in floodplain zone. Meanwhile, the hardness of groundwater in source zone is significantly lower than in other deep wells in floodplain zone as more calcite mineral is present. The concentration of manganese, iron and zinc is lower at source zone than floodplain zone. Three facies of water types were encountered during the study such as CaNaHCO3 in TW2, CaHCO3 in TW1 and TW3 and CaCl2 in TW4. The deep wells in floodplain zone are susceptible to saline intrusion. Finally, the groundwater quality in the study area is found to control by rock weathering especially silicates and carbonates, rainfall and proximity to seawater. This suggests the major control on groundwater chemistry is due to leaching of volcanic rocks and dissolution on calcite infillings. In conclusion, the groundwater is clean and safe in general although pH value is slightly acidic closer to straits and magnesium's presence in higher concentration at TW2.
The study aims to assess long-term radiological exposure risks and effects to both industrial workers and occupants living in the near vicinity of local tailing processing plants. The detrimental effects of licensing exemption were studied by comparing contaminated soil collected from 7 unlicensed-by the Atomic Energy Licensing Board-tailing processing plants with soil from control location. It was found that the average concentration of 226Ra, 232Th, and 40 K for all seven processing plants fell between the range of 0.1 ± 0.0-7.21 ± 0.1 Bqg-1, 0.1 ± 0.0-16.34 ± 0.27 Bqg-1, and 0.18 ± 0.01-1.74 ± 0.01 Bqg-1, respectively, showing observable indication of soil contamination with Technologically Enhanced Naturally Occurring Radioactive (TENORM) material. The annual effective dose was calculated which showed that most samples exceeded the recommended value of the ICRP of 1 mSvy-1 for non-radiation workers. Assessment of radiological hazards in the environment was done by calculating the radium equivalent value; revealing the exposure risk posed by the contaminated soil is substantial. Using the relatable inputs, the RESRAD-ONSITE computed code revealed that the dose due to internal exposure via inhalation of radon gas contributes the most to the overall exposure. The covering of the contaminated soil with a clean layer is effective in reducing external dose but ineffective for radon inhalation. RESRAD-OFFSITE computer code also revealed that the contribution of exposure via contaminated soil in the neighbouring vicinity is below the recommended 1 mSvy-1 threshold but still contributes to a significant amount cumulatively when considering other exposure pathways as well. The study proposes the introduction of clean cover soil as a viable option in reducing external dose from contaminated soil as 1 m of clean cover soil is able to reduce dose exposure by 23.8-30.5%.
Microplastics (MPs) have become a prevalent environmental concern, exerting detrimental effects on marine and terrestrial ecosystems, as well as human health. Addressing this urgent issue necessitates the implementation of coordinated waste management policies and strategies. In this study, we present a comprehensive review focusing on key results and the underlying mechanisms associated with microplastics. We examine their sources and pathways, elucidate their ecological and human health impacts, and evaluate the current state of waste management policies. By drawing upon recent research and pertinent case studies, we propose a range of practical solutions, encompassing enhanced recycling and waste reduction measures, product redesign, and innovative technological interventions. Moreover, we emphasize the imperative for collaboration and cooperation across sectors and jurisdictions to effectively tackle this pressing environmental challenge. The findings of this study contribute to the broader understanding of microplastics and provide valuable insights for policymakers, researchers, and stakeholders alike.
Malaysia is bounded by the South China Sea with many islands that support species megadiversity and coral reef ecosystems. This study investigates the distribution of microplastics (MPs) in the surface water around the four marine park islands (Perhentian, Redang, Kapas, and Tenggol) during COVID-19. The global pandemic has reset human activities, impacting the environment while possibly reducing anthropogenic contributions of microplastic pollution near the South China Sea islands. It was found that Pulau Perhentian recorded the most abundance of MPs (588.33 ± 111.77 items/L), followed by Pulau Redang (314.67 ± 58.08 items/L), Pulau Kapas (359.8 ± 87.70 items/L) and Pulau Tenggol (294.33 ± 101.64 items/L). Kruskal-Wallis analysis indicates a significant difference in total MPs abundance between islands. There are moderate correlations between salinity, pH, temperature and MPs variability. Among these parameters, only temperature is significant (p
This study presents the kinetics and thermodynamics of biomass pyrolysis. The kinetics of the pyrolysis process was estimated using ten kinetic models from three different mechanisms, namely chemical reaction, diffusion, and nucleation and growth. Results showed that each pyrolysis subdivision was described by a different reaction model, signifying the complex nature of the pyrolysis process. The average values of activation energy determined from the kinetic models for empty fruit bunch, coconut shell, bamboo, and cardboard are 10.2-64.6 kJ/mol, 18.7-186.2 kJ/mol, 8.0-70.8 kJ/mol, and 13.1-277.3 kJ/mol, respectively. The biomass pyrolysis is endothermic and non-spontaneous and would require external energy to initiate the degradation process. The findings are helpful in characterizing the thermal degradation of biomass in exploring its potential as a source of alternative solid fuel.
Microplastics (MPs) pose a threat to ecosystems due to their capacity to bind with toxic chemicals. While the occurrence of MPs in aquatic environmental matrices like water, sediments, and biota is well studied, their presence in the atmosphere remains less understood. This study aimed to determine the presence of airborne MPs and their characteristics through ground-based sampling in the coastal city of Kuala Nerus, Terengganu, Malaysia. Airborne MP samples were collected using passive sampling technique in December 2019. MPs were manually counted and identified using a stereomicroscope based on their colour and shape. The average deposition rate of airborne MPs during the sampling period was 5476 ± 3796 particles/m2/day, ranging from 576 to 15,562 particles/m2/day. Various colours such as transparent (38%), blue (25%), black (20%), red (13%), and others (4%) were observed. The predominant shape of airborne MPs was fibres (> 99%). The morphology structure of MPs observed using a scanning electron microscope (SEM) showed a cracked surface on MPs, suggesting weathering and irregular fragmentation. Further elemental analysis using energy dispersive X-ray spectroscopy (EDS) showed the presence of heavy metals such as aluminium (Al) and cadmium (Cd) on the surface of MPs, attributed to the adsorption capacities of MPs. Polymer types of airborne MPs were analysed using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), which revealed particles composed of polyester (PES), polyethylene (PE), and polypropylene (PP). The preliminary findings could provide additional information for further investigations of MPs, especially in the atmosphere, to better understand their sources and potential human exposure.
Presently, microplastic pollution has emerged as a growing environmental risk around the world. Nevertheless, knowledge of the occurrence and characteristics of microplastics in tropical agricultural soil is limited. This study investigated the pollution of surface soil microplastics in two agricultural farms located at Klang Valley, Malaysia. An extraction method based on density separation by using saturated extraction solution (sodium sulfate, ρ = 2 g cm-3 and sucrose, ρ = 1.59 g cm-3 with a ratio 1:1, v/v) was carried out. The study revealed the mean particle size of soil microplastics with 3260.76 ± 880.38 μm in farm A and 2822.31 ± 408.48 μm in farm B. The dominant types of soil microplastics were fragments and films with major colors of white (59%) and transparent (28%) in farm A, while black (52%) and white (37.6%) in farm B. Representatives of soil microplastics detected polymers of polyvinyl chloride (PVC), high density polyethylene (HDPE), polycarbonate (PC), and polystyrene (PS). The sources of plastic products were black and white plastic pipes, black plastic films for vegetation, fertilizer bottles, plastic water containers and polystyrene storage boxes, and the breakdown processes, contributed to the microplastic pollution in these farms. The outcomes of this study will establish a better understanding of microplastic pollution in tropical agricultural soil in the Southeast Asian region. The findings would be beneficial as supportive reference for the endeavor to reduce microplastic pollution in agricultural soil.