Dominant Pollutants Research Articles

Heavy metal concentration, potential ecological risk assessment and enzyme activity in soils affected by a lead-zinc tailing spill in Guangxi, China

In 1976, a tailing dam collapse accident at the Xingping Lead–Zinc Mine in Guangxi Province, China, led to the spillage of mining wastewater and sludge into downstream agricultural lands in Side Village. Heavy metal concentrations, soil pollution and soil enzyme activity were analysed to understand the pollution characteristics of the agricultural lands along the Side stream by this accident. The tailing soil (TS), natural forest soil without spill contamination (NFS) and four representative agricultural soils were selected. The four agricultural soil sites located at the entrance of the stream to the agricultural soil (EnS), the upstream region (US), the middle stream (MS) and at the exit of the stream (ExS) from the village, respectively. The results showed that the soil pH values and heavy metal concentrations were in the order of tailing soil TS > ExS > MS > US > EnS > NFS. The concentration of Pb ranked highest among the analysed elements followed by Zn, Cd, Mn and Cu. The concentrations of Pb, Zn, Cd Mn and Cu 10530.41, 1708.58, 8.32, 885.61 and 104.51 mg kg−1, respectively. Soil pollution assessments by single pollution index, synthesis pollution index and individual/comprehensive potential ecological risk analysis explicated all the soils reached the heavily polluted level and presented extremely high ecological risk grades. Pb, Zn and Cd were the dominant pollutants. The soil enzyme activities of invertase, protease and urease exhibited the opposite distribution pattern as those of the heavy metal concentrations, while the inversely results were observed for the activity of catalase.

Occurrence and distribution of microplastics in surface sediments from the Gulf of Thailand

This study investigated the distribution and characteristics of microplastics in surface sediments of the Gulf of Thailand (GoT), and discussed the correlation between sediment grain size and microplastic content. The results indicate the abundance of microplastics is 150.4 ± 86.2 pieces/kg dry weight, representing a medium microplastic pollution level compared to other sea areas. Small microplastics (0.5–1 mm) take up >70% of total microplastic numbers. Fibrous microplastics are the dominant component of microplastics. According to micro-Fourier transform infrared spectroscopy, rayon (37%) and polyester (PES: 16%) are the most typical polymer types found in sediments. The results imply that secondary microplastics are the dominant pollutant, while fibrous microplastics are mainly from municipal sewage discharge. We also find that inconspicuous correlation between grain size and microplastics, which is caused by the multi-sources and different flow field. This study deepens our understanding of the environmental risks posed by microplastics to marine ecosystems in the GoT.

Bioaccumulation of mining derived metals in blood, liver, muscle and otoliths of two Arctic predatory fish species (Gadus ogac and Myoxocephalus scorpius)

Mining activities can cause adverse and long-lasting environmental impacts and detailed monitoring is therefore essential to assess the pollution status of mining impacted areas. Here we evaluated the efficacy of two predatory fish species (Gadus ogac i.e. Greenland cod and Myoxocephalus scorpius i.e. shorthorn sculpin) as biomonitors of mining derived metals (Pb, Zn, Cd and Hg) by measuring concentrations in blood, liver, muscle and otoliths along a distance gradient near the former Black Angel Pb–Zn mine (West Greenland). We detected metals in all tissues (except Cd and Hg in otoliths) and sculpin generally displayed higher concentrations than cod. For both species, concentrations were generally highest closest to the dominant pollution source(s) and gradually decreased away from the mine. The clearest gradient was observed for Pb in blood and liver (both species), and for Pb in otoliths (sculpin only). Similar to dissolved concentrations in seawater (but in contrast to bottom sediment), no significant decrease was found for Zn, Cd and Hg in any of the tissues. This demonstrates that by including tissues of blood (representing recent accumulation) and otolith (representing more long-term exposure signals) in the sampling collection, the temporal information on contaminant exposure and accumulation can be extended. We therefore conclude that both fish species are suitable as biomonitors near Arctic mine sites and, moreover, that blood and otoliths can serve as important supplementary monitoring tissues (in addition to liver and muscle traditionally sampled) as they provide extended temporal information on recent to long-term contaminant exposure.

Historical evolutions of sediment quality in bays under serious anthropogenic influences in China, basing on fuzzy comprehensive assessment of heavy metals.

Fuzzy comprehensive assessment was applied, for the first time, to investigate the sediment environmental quality and compare the historical variations of heavy metal pollution in Daya Bay and Jiaozhou Bay, which are representative for sub-tropical and temperate zone of China, respectively. Results shown the Daya Bay had undergone three contrasting stages in the past 100years. Before 1980s, the sediment was not contaminated by metals and its quality generally conformed to class I of China National Standard for marine sediment quality. During from 1980s to 2000s, however, Daya Bay's environment had experienced significant deterioration. The metal concentrations were significantly higher than the background values, suggesting that there was a sharp increase of metal input. The category of sediment quality fell to class II and class III. Copper was the dominant pollutant during that time. The good thing is sediment quality of Daya Bay has improved to class I since 2000s, and chromium turned to be the major pollutant. As for the Jiaozhou Bay, enrichment of heavy metal was generally not detected and the sediment quality strictly conformed to class I during the recent 90years. Chromium and zinc were the major pollutants in this bay.

Assessment of Surface Water Quality by Using Multivariate Statistical Analysis Techniques: A Case Study of Nhue River, Vietnam

The aim of this study is to assess the spatial variability and to determine the main contamination sources in surface water quality of the Nhue River, Viet Nam by using multivariate statistical analysis techniques, including principal component analysis (PCA) and cluster analysis (CA). Eight water quality parameters were measured at 21 sites along the Nhue River and its tributaries during irrigated periods from 2016 to 2019. The spatial variability of water quality in the Nhue River and its tributaries was determined separately from cluster analysis. The result determined two tributaries, including Yen Xa Canal (NT9 monitoring site) and To Lich River (NT3 monitoring site) leading to severe pollution at To Bridge (N4 monitoring site) region in the Nhue River. The PCA determined a reduced number of two principal components that explained 47.75% of the total variation in the data. The first PC indicated that water temperature (WT) and pH are the dominant polluting factors which are attributed to craft villages, domestic sewage and industrial wastewater. Following is nitrate nitrogen NO3¯ in the second PC which is related to fertilizer application in the farms nearby. The results indicated that CA multivariate statistical analysis technique is useful for the assessment of the spatial water quality variability in a river which has a number of tributaries.

Location of areas of emission of pollutants when poor urban air quality is detected

Air pollution constitutes an environmental risk, evidenced in large urban centres. This work applies a methodology capable of detecting the areas of emission of pollutants when episodes of poor urban air quality are observed. This is carried out coupling air quality indices proposed by United States Environmental Protection Agency with the receptor model known as Nonparametric Trajectory Analysis. As a control case, observed concentrations (2013-2015) in Bahia Blanca (Argentina) were analysed, highlighting particulate matter as a dominant pollutant for episodes of poor air quality. Likewise, the application of the methodology allowed to reduce the number of possible stationary emission sources by 75%, and to highlight the implication of nearby linear sources. The strength of the methodology lies in visualising in real time, or in diagnostic mode, the potential areas of emission and their significance.

Analysis of epidemic safety of drinking water of the bukhara region

The article presents the results of a study of the quality of drinking water in the central water supply of the Bukhara region according to sensory, toxicological, microbiological and parasitological indicators. The dominant pollutants of drinking water were identified and their possible negative impact on the health of consumers of water from this source was determined. It was established that the studied water samples comply with national and international requirements, including those on epidemic safety.

Location of areas of emission of pollutants when poor urban air quality is detected

Air pollution constitutes an environmental risk, evidenced in large urban centres. This work applies a methodology capable of detecting the areas of emission of pollutants when episodes of poor urban air quality are observed. This is carried out coupling air quality indices proposed by United States Environmental Protection Agency with the receptor model known as Nonparametric Trajectory Analysis. As a control case, observed concentrations (2013-2015) in Bahia Blanca (Argentina) were analysed, highlighting particulate matter as a dominant pollutant for episodes of poor air quality. Likewise, the application of the methodology allowed to reduce the number of possible stationary emission sources by 75%, and to highlight the implication of nearby linear sources. The strength of the methodology lies in visualising in real time, or in diagnostic mode, the potential areas of emission and their significance.

Analysis of epidemic safety of drinking water of the bukhara region

The article presents the results of a study of the quality of drinking water in the central water supply of the Bukhara region according to sensory, toxicological, microbiological and parasitological indicators. The dominant pollutants of drinking water were identified and their possible negative impact on the health of consumers of water from this source was determined. It was established that the studied water samples comply with national and international requirements, including those on epidemic safety. In the aspect of the foregoing, water quality assessment of the central water supply in the Bukhara region was carried out according to sensory, toxicological, microbiological and parasitological indicators for the compliance of their values with current national and international requirements. The closest connection of many parasitoses with the hydroecological factor is also determined by the fact that the life cycles of their pathogens proceed with the obligatory participation of various animals that act as intermediate hosts and carriers of parasites (fish, mollusks, crustaceans, mosquitoes, etc.), which are massive aquatic organisms. The stages of development of pathogens that enter the external environment, in turn, are closely related to the hydroecological factor.

Використання методу домінуючого динамічного забруднювача для управління екологічною безпекою систем очищення промислових стоків

Використання методу домінуючого динамічного забруднювача для управління екологічною безпекою систем очищення промислових стоків

Faecal pollution affects abundance and diversity of aquatic microbial community in anthropo-zoogenically influenced lotic ecosystems

The aquatic microbiota is known to be an important factor in the sustainability of the natural water ecosystems. However, the microbial community also might include pathogens, which result in very serious waterborne diseases in humans and animals. Faecal pollution is the major cause of these diseases. Therefore, it is of immense importance to assess the potential impact of faecal pollution, originating from both anthropogenic and zoogenic sources, on the profile of microbial communities in natural water environments. To this end, the microbial taxonomic diversity of lotic ecosystems in different regions of Norway, representing urban and rural areas, exposed to various levels of faecal pollution, was investigated over the course of a 1-year period. The highest microbial diversity was found in rural water that was the least faecally polluted, while the lowest was found in urban water with the highest faecal contamination. The overall diversity of the aquatic microbial community was significantly reduced in severely polluted water. In addition, the community compositions diverged between waters where the dominant pollution sources were of anthropogenic or zoogenic origin. The results provide new insight into the understanding of how faecal water contamination, specifically that of different origins, influences the microbial diversity of natural waters.

Concentration of phthalate esters in indoor and outdoor dust in Kocaeli, Turkey: implications for human exposure and risk.

The interest in phthalate esters (PAEs) has increased in recent years because elevated phthalate levels have been detected in environmental matrices and they have certain adverse effects on human health. Indoor dust from 90 homes and outdoor (street) dust from outside these homes were collected in Kocaeli province between February and April 2016 and analyzed for eight PAEs. The total indoor dust concentrations of eight PAEs (Σ8PAEs) ranged from 21.33 μg g-1 to 1802 μg g-1 (median, 387.67 μg g-1), significantly higher than outdoor dust concentrations (0.16-36.85 μg g-1 with median 4.84 μg g-1). Di-2-ethylhexyl phthalate (DEHP) was the most dominant pollutant in both indoor and outdoor environments with a median value of 316.02 μg g-1 and 3.89 μg g-1, respectively, followed by di-n-butyl phthalate and butylbenzyl phthalate (BBP). DEHP was measured within the range of 198.54-816.92 μg g-1 and BBP within the range of 15.52-495.33 μg g-1 in homes with PVC coating, significantly higher than the levels in homes with parquet and tiled floor (p<0.05). Monte Carlo simulation was applied to probabilistically estimate exposure to PAEs and associated carcinogenic risk. The Σ5PAE median values of non-dietary ingestion and dermal absorption exposure were estimated as 1.57 μg kg day-1 and 0.007 μg kg day-1 for children and 0.09 μg kg day-1 and 0.04 μg kg day-1 for adults while inhalation route exposure to PAE in dust was at a negligible level for both groups. Children were more exposed to PAEs through ingestion route (92.74% to 99.54% of the total exposure) while adult exposure through ingestion routes (62-68.4%) and dermal absorption (29.74% and 31.87% of the total exposure) were comparable. The mean cancer risk level via non-dietary ingestion of DEHP for children was 2.33×10-6, about eight times higher than the levels for adults. The risk levels of about 16% of adults and 95% of children are greater than the threshold value of 10-6 when the population is exposed to DEHP in indoor dust. Looking from the viewpoint of child health, the most effective method to reduce exposure among the measured PAEs is to keep the release of DEHP under control, especially in indoor environment, and to take precautions to reduce exposure.

Source Identification and Water-Quality Assessment of Dissolved Heavy Metals in the Jiulongjiang River, Southeast China

Liang, B.; Han, G.; Liu, M.; Yang, K.; Li, X., and Liu, J., 2020. Source identification and water-quality assessment of dissolved heavy metals in the Jiulongjiang River, Southeast China. Journal of Coastal Research, 36(2), 403–410. Coconut Creek (Florida), ISSN 0749-0208.With the aggravation of ecological deterioration, dissolved heavy metals in coastal rivers do not only affect the quality of local drinking water, but also pose ecological risks to the ocean. To identify the sources and ecological effects of dissolved heavy metals in the Jiulongjiang River water, concentrations of six dissolved heavy metals (Al, Fe, Mn, Cu, Zn, and Ba) were measured using an inductively coupled plasma mass spectrometer. The results showed that the dissolved heavy metals can be categorized into three groups: the dominant elements (Mn and Fe, >100 µg/L), moderately abundant elements (Ba and Al, 10–100 µg/L), and less abundant elements (Zn and Cu, <10 µg/L), of which Mn was the dominant pollutant in the drainage basin by comparing with the guidelines for drinking water. The Pearson correlation matrix exhibited a similar result for Fe, Cu, and Ba. The principal component analysis explained that Ba, Zn, and Cu were attributed to agricultural inputs affected by upland cultivation; Al, Fe, and Cu were controlled by input of crustal materials and agricultural contribution; Mn and Zn were affected by a mixed source of natural weathering and anthropogenic activities. The water-quality index suggested that water in the Xixi Stream was worse than in the Beixi Stream and the Nanxi Stream. The health risk assessment results indicated that there were no health risks or potential carcinogenic concern via daily intake and dermal absorption. The fluxes of dissolved heavy metals in this study were lower than other worldwide rivers during the dry season, of which Mn and Fe were the dominant elements pouring into the ocean through Xiamen Bay. The fluxes of dissolved heavy metals between the wet season and the dry season in the Jiulongjiang River might be controlled by different water discharge quantity.

Cytogenotoxic potential of a hazardous material, polystyrene microparticles on Allium cepa L.

Plastic pollution represents a global concern for the biodiversity conservation, ecosystem and public health. The polystyrene is one of the dominant pollutants in both terrestrial and aquatic ecosystem. This work measured the hazardous nature of 100 nm micropolystyrene (MPS) using 25, 50, 100, 200, and 400 mg/L concentrations in terms of oxidative stress, morphotoxicity and cytogenotoxicity in Allium cepa. The results were compared with the positive control (PC) (400 mg/L chlorpyrifos). MPS significantly (p < 0.05) reduced the root length while induced the production of hydroxyl, superoxide radicals with a concomitant increase in DPPH scavenging activity and lipid peroxidation as compared to the negative control. The significant decrease in mitotic index with respect to the negative control (MI: 23.855 ± 5.336 %; lowest MI: 3.88 ± 1.042 %) showed the cytotoxic nature of MPS. Genotoxicity was assessed by various chromosomal and nuclear aberrations. The highest 3.029 ± 0.403 % (PC: 3.09 ± 0.535 %) chromosomal abnormality index and 2.31 ± 0.338 % (PC: 1.178 ± 0.095 %) nuclear abnormality index were observed. MPS down-regulated the expression of plant CDKA encoding gene: cdc2, an important cell cycle regulator. The overall results indicated that MPS could induce cytogenotoxicity through the exacerbation of ROS production and inhibition of cdc2.

Denitrifying Microbial Community Structure and bamA Gene Diversity of Phenol Degraders in Soil Contaminated from the Coking Process.

Phenolic compounds are the dominant pollutants in soils contaminated by the coking industry. Ring opening by the hydroxylase gene (bamA) is the key step in the benzoyl-CoA degradation pathway under anaerobic conditions, and a broad spectrum of microorganisms possesses this functional gene, including denitrifiers. The present study analyzed the community structure of denitrifying bacteria and the diversity of the bamA gene for mixed cultures enriched from soil collected at a coking industrial site and then grown under nitrate-reducing conditions on phenol or p-hydroxybenzoate (4HBA), a key intermediate product of anaerobic phenol degradation. Illumina sequencing of the 16S rRNA gene showed different bacterial compositions between the two cultures. The dominant phyla were Proteobacteria, Armatimonadetes, and Planctomycetes in the phenol culture and Proteobacteria and Bacteroidetes in the 4HBA culture. Phylogenetic analysis further demonstrated that bamA genes were associated with four clusters of bacteria, three of known bacteria and one of uncultured bacteria. The diversity of the bamA gene differed from that reported in anaerobic aromatic degradation cultures, suggesting that these enriched cultures may contain new strains unique to coking-contaminated soils. The present study further validates the potential application of this functional gene as a marker for anaerobic biodegradation processes in enrichment cultures from contaminated soil.

Sistematik Filogenetik Pseudomonas Strain Indigenous Pendegradasi Liniar Alkilbenzen Sulfonat

Linear Alkylbenzene Sulphonate (LAS) was the dominant pollutant in the river ecosystem. Indigenous strains of Pseudomonas in river ecosystem had highly potency to LAS degradation. This research was carried out to study relationship of indigenous strains of LAS degrading to Pseudomonas strains. Indigenous strains of bacteria of LAS degrading were characterized based on ARDRA (Amplified Ribosomal 16S rDNA Restriction Analysis) and 16S rDNA sequence. Result of the research shows that Pseudomonas strain J and R which LAS degrading from detergent polluted river ecosystem based on 16S rDNA sequence, isolate J has 98.37% similarity and it has relationship to P. pseudoalcaligenes LMG 1225T whereas isolate R has 84.86% similarity and related to P. stutzeri phen8.

Kualitas Fisik dan Kimia Sungai Citarum yang bermuara ke Waduk Cirata di Wilayah Kabupaten Cianjur

Pollution prevention must be carried out in the upstream, middle and downstream parts. One of the Citarum watersheds located in the middle part is the Cirata reservoir. Pollution in the Cirata reservoir does not only originate from the reservoir environment, but also from rivers that flow into the Cirata reservoir. Cirata Reservoir besides being a Hydroelectric Power Plant (PLTA) unit, this reservoir is also used by the community for fish farming in the Floating Net Pool (KJA) technique. This study aims to determine the most dominant pollutants contaminating the Cirata reservoir. Test of river and reservoir water quality is carried out with the help of lab tests by Labkesda. The research data was obtained by obtaining clean water quality test data from several 3 estuary points of the river flow to the Cirata reservoir and 4 centers of Cirata reservoir number of 40 samples. Data processing techniques are carried out using data mining, namely Exploratory Data Analysis. The lab parameter test results, which are compared with the Permenkes No. 32 Year 2017 standard, show that the majority of the physical and chemical quality parameters of the Citarum River which empties into the Cirata Reservoir are still within the required threshold. Most river and reservoir water samples have water quality that qualifies as clean water. Five samples (12.5%) in turbidity parameters and 1 sample (2.5%) in color samples did not qualify as clean water. This is possible because the sampling is too close to the mainland. Temperature parameters of 20 samples (50%) do not qualify as clean water is possible because of the lag time of sampling. The results of the analysis showed that the distance of pollutant sources, the amount of pollutant sources, and environmental conditions around the sampling significantly with temperature, TDS, turbidity, color, pH, nitrogen, iron, hardness, manganese, fluoride, and cyanide.

Association of exposure to metallic components in fine particles and respiratory mortality

TPS 761: Health effects of pollution sources and components, Johan Friso Foyer, Floor 1, August 28, 2019, 3:00 PM - 4:30 PM Background/Aim: Epidemiological studies suggested that the association between short-term exposure to fine particulate matter (PM2.5) and mortality or morbidity was possibly due to some chemical components of PM2.5. However, findings were inconsistent for the responsible PM2.5 components. This study aimed to examine the city-specific association of short-term exposure to PM2.5 metallic components with daily respiratory mortality in 6 major South Korean cities for 2011-2015. Methods: We obtained daily 24-hour concentrations of PM2.5 mass and chemical components measured every day or every third day for 2011-2015 at single monitoring sites located in residential areas of six major South Korean cities: Seoul, Busan, Daegu, Gwangju, Daejeon, and Ulsan. We focused on lead, nickel, silicon, vanadium, copper, and zinc that showed the associations with mortality in previous epidemiological studies. We also computed daily respiratory death counts for the same study period and area from death certificate data. Using Generalized Addictive Models, we estimated relative risks (RRs) of daily respiratory mortality for interquartile range increases in daily PM2.5 and metallic component concentrations for 0 to 7 previous days, while controlling for a long-term time trend and meteorology. Results: PM2.5 was marginally or significantly associated with respiratory mortality in 3 out of the 6 major South Korean cities (RR=1.073-1.107). The associations for metallic components varied across the 6 cities. However, in the second largest city with large major ports, Busan, there was strong positive associations with vanadium (RR=1.102, 95% confidence interval=1.033-1.175) and nickel (1.138, 1.061-1.221). RRs for vanadium and nickel tended to be higher in the cities with higher daily concentrations. Conclusion: Our findings showed that metallic components responsible for PM2.5-associated respiratory mortality differed across major South Korean cities depending on dominant pollution sources, suggesting large health effects of oil combustion-related PM2.5 components in major port cities.

Spectral diagnosis of wire arc additive manufacturing of Al alloys

Online nondestructive testing for quality control is a critical direction for research in additive manufacturing in the future. In this study, for the first time, optical emission spectroscopy was employed to probe the arc characteristics in the wire arc additive manufacturing (WAAM) of an Al alloy and to detect its structural features. The arc characteristics, such as spectral intensity, electron density, and electron temperature, were calculated based on the atomic emission spectral lines. The resulting structural features of the deposited layers, namely the forming width, composition, grain size, and porosity defects, were analyzed, and a correlation between the arc characteristics and the structural features was proposed. The arc cathode size, which changed with the number of deposited layers, controlled the arc energy distribution. Hence, the forming width had an approximately linear relation with the spectral intensity of Mg (a constituent of the alloy used for the wire feed) and the electron density. The porosity in the alloy was observed to be caused by H, which was a dominant pollutant in the process. Furthermore, the correlation between the porosity and H spectral intensity was observed to be approximately linear. However, no significant correlation between the grain size and the spectrum was noticeable. The results from this study establish the applicability of spectral diagnosis of the forming size and the porosity in WAAM.

Inhibition of UDP-glucuronosyltransferases (UGTs) by bromophenols (BPs)

Bromophenols (BPs) are important organic compounds which have become dominant pollutants during these years. Our present study investigated the potential inhibition behaviour of BPs on the activity of one of the most important phase II drug-metabolizing enzymes (DMEs), UDP-glucuronosyltransferases (UGTs). Recombinant UDP-glucuronosyltransferases (UGTs)-catalyzed glucuronidation of 4-methylumbelliferone (4-MU) was utilized as the probe reaction. 100 μM of BPs was utilized as the inhibition screening concentrations, and the complete inhibition profile of UGT isoforms by BPs was obtained. UGT1A7 was the most vulnerable UGT isoform towards BPs. Some structure-activity relationship for the inhibition of UGTs by BPs was found, and this relationship can be furtherly explained by the hydrophobic contacts of BPs with the activity cavity of UGTs using in silico docking method. The inhibition kinetics determination showed that the inhibition kinetic parameter Ki value was calculated to be 2.85, 3.99 and 31.00 μM for the inhibition of UGT1A3, UGT1A7, and UGT2B7 by representative BPs, 2,4,6-TBP. Combined with in vivo exposure concentration of 2,4,6-TBP, in vitro-in vivo extrapolation (IVIVE) was employed to demonstrate the moderate possibility for the inhibition of UGT1A3 and UGT1A7 by 2,4,6-TBP. In conclusion, our study gave the full description towards the inhibition of BPs towards UGT isoforms, which will provide a new perspective for elucidating the toxicity mechanism of bromophenols (BPs).