Primary Pollution Sources Research Articles

Seasonal trends and light extinction effects of PM2.5 chemical composition from 2021 to 2022 in a typical industrial city of central China

This study investigates the concentrations, chemical compositions, and sources of PM2.5 in Huangshi, China. Daily average PM2.5 levels ranged from 8.43 to 193.08 μg m−3, with an annual mean of 54.13 μg m−3, exceeding China's annual secondary standard of 35 μg m−3. Seasonal mean concentrations peaked in winter and were lowest in summer. Organic carbon (OC) and elemental carbon (EC) had annual means of 4.89 μg m−3 and 0.94 μg m−3, respectively. Water-soluble inorganic ions (WSIIs) accounted for 52.17% of PM2.5, with NO3−, SO42−, and NH4+ being the major components. The NO3−/SO42− ratio averaged 1.65, indicating a transition from coal combustion to vehicle emissions as the primary pollution source. Chemical mass reconstruction revealed that NH4NO3, (NH4)2SO4, and organic matter (OM) accounted for 65.3% of PM2.5 mass. Seasonal variations in light extinction (bext) highlighted the impact of secondary inorganic salts on visibility, with an annual average bext of 346.30 ± 246.98 Mm−1. Airmass clusters and potential source region analysis suggested PM2.5 and its components were primarily originated from local and nearby regions. These findings underscore the effectiveness of local pollution control measures, changing pollution sources, and the necessity for targeted emission controls to improve air quality and visibility in urban areas.

Assessment of Metal Pollution in Umm el-Surab Archaeological Layers, Northeast Jordan

This study aims to assess the extent of the anthropogenic pollution of Area A at the Umm el-Surab archaeological site, Jordan. It examines the concentrations of 21 metals from four Roman, Byzantine, and early and late Ayyubid-Mamluk layers. The site, located near Bosra and Umm el-Jimal, was continuously settled from the Roman till the Islamic periods. The chemical analysis and pollution indices (enrichment and contamination factors (EF, CF), and geo-accumulation index Igeo) show low enrichment in Zn, K, Sr, Na, Pb, Ba, Li, Mn, Mg, Mo, and Cu, and moderate enrichment in Cd, Ag, Ca, As, and Ni. Co is significantly enriched in one sample and moderately enriched in the other ones. The results show pollutant metals more enriched in the Byzantine layer than the rest of the layers. A likely primary source of the limited pollution is organic fuels and their firing product of ash, while a likely secondary source might be the pottery fragments spread in the layers. The results agree with the fact that the site was rural with limited industrial activities, especially metal production, like iron and copper, that would have increased the concentration of the analyzed metals.

Exploring the scale effect of nonpoint source pollution risk on water quality in Lake Basins of Central Yunnan Plateau using the Minimum Cumulative Resistance model.

Nonpoint source (NPS) pollution has emerged as the predominant water environment issue confronting plateau lakes in central Yunnan. Quantitative analysis of the impact of NPS pollution on water quality constitutes the key to preventing and controlling water pollution. However, currently, there is a dearth of research on identifying NPS pollution risks and exploring their relationship with water quality based on the Minimum Cumulative Resistance (MCR) model in the plateau lake basins of central Yunnan. Particularly, studies on the spatial heterogeneity of the impact of NPS pollution on water quality from a multi-scale perspective are scarce. Therefore, this study focuses on three typical lake basins in the Central Yunnan Plateau-Fuxian Lake, Xingyun Lake, and Qilu Lake (the Three Lakes). Utilizing the MCR model to identify NPS pollution risks, the study analyzes seven different scales, including sub-basins, riparian buffer zones (100 m, 300 m, 500 m, 700 m, and 1,000m) and lakeshore zones, to reveal the multi-scale effects of NPS pollution on water quality through correlation analysis. The results indicate that: (1) Over 60% of the areas in the Three Lakes Basin are at high or extremely high risk, mainly concentrated in flat terrain and around inflow rivers; (2) The area of NPS pollution from paddy field source landscape (PFSL) is greater than that from construction land source landscape (CLSL), and the high-risk areas of NPS pollution are also larger for PFSL compared to CLSL; (3) The mean resistance values of PFSL and CLSL show a significant negative correlation with monthly mean values of water quality indexes (NH3-N, TP, CODCr), with the 1,000 m riparian buffer zone scale showing the greatest correlation with most water quality indexes, especially NH3-N; (4) The correlation between the mean resistance value of CLSL and the monthly mean values of water quality indexes is significantly higher than that of PFSL, indicating a greater impact of CLSL on water quality compared to PFSL. In summary, PFSL and CLSL are the primary sources of NPS pollution in the Three Lakes Basins. The 1,000 m riparian buffer zone scale is the most sensitive to the impact of NPS pollution on water quality. This study provides scientific references for landscape pattern optimization and precise control of NPS pollution risks in the Central Yunnan Plateau lake basins and offers a new research perspective for exploring multi-scale effects of NPS pollution on water quality.

Contamination Features and Quantitative Source Apportionment of Potentially Toxic Elements in the Urban Surface Soil, the Case of Hamedan, West of Iran.

In this study, a total of 180 surface soil samples were collected from a control area and residential, commercial, and industrial regions of Hamedan, Iran during the fall season in 2023. Contents of analyzed elements were then determined using ICP-OES. The results illustrated that the average contents of As, Cd, Cu, Mn, Ni, and Pb were 1.17-2.26 times greater than those reported as local background values, while the mean contents of As, Cd, and Cu were respectively 3.41, 1.25, and 1.00 times greater than the background contents for Iran by implying the possible human sources of these PTEs. The cumulative average ecological risk value with 81.9, demonstrated moderate ecological risk across the study area. The results of source apportionment showed that the PTEs contamination in the soil of the study area mainly originates from the anthropogenic activities (65.6%) and traffic emissions as the primary pollution source (47.3%) had the highest contribution to the PTE pollution in the study area. In conclusion, by providing a useful approach to identifying the sources and contributions of toxic elements across different functional areas, this study has the potential to guide future efforts aimed at managing and mitigating the pollution caused by metal elements.

Pollution Characteristics, Risk Assessment and Source Identification of Heavy Metals in Surface Sediments from the Cage Fish Farm of Poyang Lake, China

ABSTRACT With the development of cage culture, increasing heavy metals concentrations are being taken into sediments. The accumulation of heavy metals in sediments may cause long term environmental issues and pose threat to human health. Fourteen surface sediment samples were collected to assess the contamination status and potential ecological risk of heavy metals, and identify their potential sources from the cage fish farm of Poyang Lake. The concentrations of Cu, Pb, Zn, Cd, Cr, As and Ni in the sediments were measured by ICP-MS. The geo-accumulation index, enrichment factor and potential ecological risk index were implied to evaluate their pollution levels and ecological risk. The principal component analysis was used to identify their potential sources. The results showed that all of the examined heavy metals content exceeded their background values. These heavy metals (except Cd, Cr and As) presented moderately polluted level. Cu showed significant enrichment, Zn, Pb and Ni exhibited moderate enrichment, As and Cd presented minimal enrichment. Cu and Cd posed a moderate ecological risk, and the other heavy metals posed a low ecological risk. The comprehensive potential ecological risk was associated with considerable ecological risk. Cage culture, smelting, mining and agriculture activities were their primary pollution sources.

Extensive investigation of seasonal and spatial fluctuations of BTEX in an industrial city with a health risk assessment

There are many pollutants in the air that can be harmful to human health. Their impact varies based on factors such as the kind of pollutant, duration of exposure, and concentration levels. Volatile organic compounds are particularly significant carcinogens among the various pollutants present in the air. Consequently, people who are exposed to these harmful airborne pollutants suffer permanent consequences. This study examines the properties of BTEX compounds—benzene, toluene, ethylbenzene, and xylene—as well as their sources and risk assessments throughout a one-year period from March 21, 2019, to March 20, 2020, in Karaj, Iran’s largest industrialized city. First, utilizing a geographical information system that covered the entire city, 17 locations within Karaj were chosen for this purpose. Then, samplings were carried out in the spring, summer, autumn, and winter months with the NIOSH 1501 method. During the research period, 68 samples of BTEX compounds were collected. The adsorption of these contaminants on the activated carbon adsorbents was performed using an environmental sampling pump with a flow rate of 0.2 L/min for 1 h. The samples were subsequently prepared using a carbon disulfide solution and injected into a GC-FID for analysis. In this research, the average annual concentration of BTEX compounds in the air of Karaj city was obtained at 33.01 µg/m3. Autumn and spring had the highest and lowest average concentrations of BTEX compounds, respectively. In addition, sites 5 and 8 had the highest average annual concentrations of these pollutants. The sourcing conducted in this study showed that transportation and fuel consumption, as well as industries, were the primary sources of pollution in the city. In addition, the excess lifetime cancer risk was higher than the guideline value in some sites and lower in others. Furthermore, the Hazard Quotients were lower than 1, but in general, the citizens of Karaj were at serious risk from exposure to this group of pollutants.

Ratios of organic mass to organic carbon in fine particulate matter at urban sites in China and Korea during winter and summer.

This study evaluates the composition and seasonal characteristics of fine particulate matter (PM2.5) during winter and summer through simultaneous measurements conducted at the Gwangju Institute of Science and Technology in South Korea and the Changping campus of Peking University in China. PM2.5 samples were concurrently collected at both sites, and chemical analyses were conducted to quantify various components, including carbonaceous materials, ionic species, and metals. Although the average PM2.5 concentrations were comparable between the two sites, there were distinct differences in the concentrations of major components. Organic indicator compounds were analyzed to discern the contributions of primary and secondary pollution sources. Changping displayed a mix of primary and secondary pollution, characterized by higher concentrations of primary organic carbon (POC) such as polycyclic aromatic hydrocarbons and hopanes, compared to Gwangju. In contrast, Gwangju demonstrated a higher prevalence of secondary organic carbon (SOC), particularly water-soluble organic carbon not related to biomass burning (WSOCnbb) and various polar organic compounds. The organic mass to organic carbon (OM/OC) ratios estimated using the mass balance method revealed significant differences, with Gwangju showing a higher ratio of 2.3 compared to 1.9 at Changping, indicating a greater influence of secondary pollutants at Gwangju. Additionally, both Changping and Gwangju exhibited higher OM/OC ratios in summer (Changping: 2.0, Gwangju: 2.5) compared to winter (Changping: 1.8, Gwangju: 2.2), indicating seasonal differences in organic mass contributions to PM2.5. These findings underscore the importance of accounting for spatial and seasonal variations in air pollution studies and suggest that updating commonly used OM/OC ratios could enhance the reliability of research outcomes.

Personal noise exposure patterns and health implications in urban work environments

Noise-induced hearing loss remains a preventable occupational health concern, contingent on timely detection and mitigation of excessive workplace noise. However, the lack of effective identification of at-risk workers often results in the neglect of safety measures that could prevent hearing loss. To address this, personal noise exposure measurements, using noise dosimeters, were conducted on 50 individuals across diverse urban work environments, including work from home, offices, outdoor settings, and mixed-use spaces. The results demonstrated significant variations in noise exposure levels among different environments. Outdoor and mixed-use environments exhibited the highest average dose percentages, while home-based workers had the lowest exposure. A strong correlation between noise levels above 80 dB and increased dose percentages emphasized the need to reduce high-noise exposure times. Additionally, the study integrated quantitative dosimeter measurements with qualitative data from a questionnaire survey to provide a holistic understanding of the participants' perception on noise pollution. Traffic emerged as the primary source of noise pollution, with a substantial number of respondents experiencing stress and ear infections attributed to noise exposure. The research underscores the importance of personalized noise dosimetry in assessing health implications, emphasizing the need for awareness and preventative measures to mitigate health risks in urban work environments.

Impacts of an intensive traditional mariculture model on offshore environments as evidenced by dissolved organic matter and bacterial communities

Mariculture is a key protein source and economic driver but traditional methods pollute coastal waters, hindering sustainable development. Current research on the ecological impacts of mariculture mainly focuses on specific pollutants and lacks an assessment of the biogeochemical impacts of mariculture discharge. This study examined Xiangshan Bay, a representative intensive mariculture area in China, to explore the impact of mariculture tailwater discharge on water quality, focusing on dissolved organic matter (DOM) and bacterial communities. Based on the fluorescence excitation-emission matrix combined with parallel factor analysis, a characteristic fluorescence component C4 was identified in mariculture tailwater (intensity of 40 ± 4 %, n = 8), while higher C4 components (47 ± 3 %, n = 15) were found throughout the bay. Humic-like components from riverine input (C1 + C2: 32 ± 3 %, n = 15) and protein-like components from domestic sewage (C5: 2 ± 1 %, n = 15) were significantly lower in the seawater samples, indicating the strong influence of mariculture tailwater on the entire DOM structure of the bay. The bacterial community structure showed a response consistent with DOM, as revealed by nonmetric multidimensional scaling analysis. This showed that bacterial communities in mariculture tailwater and bay water samples clustered together, independent of riverine input. The SourceTracker model indicated that mariculture tailwater (91 ± 5 %) predominantly contributed to the bacterial community, with minimal contributions from riverine input (< 5 %). Co-occurrence network analysis further showed that under long-term high-intensity mariculture discharge, the C4 component became the core DOM and was closely associated with the bacterial community. The results here demonstrate the profound impact of traditional mariculture on coastal water quality and show that riverine input is not the primary pollution source in this region, providing clear directions for coastal environmental restoration efforts.

Driving factors of the distribution of microplastics in the surface soil of the typical uninhabited and habited areas in the Qinghai–Tibet plateau, China

Microplastics (MPs) are widely detected in the soil of the Qinghai–Tibet Plateau with increasing economic activities. However, studies concerning the driving factors affecting the presence of these surface soil MPs for the typical regions with different geographic conditions are still lacking. Here we chose three representative regions (Ali, Yushu, and Haixi) from east to west across the plateau to investigate the distribution and further explore the contributing factors of surface soil MPs. The Spearman rank correlation, Geodetector, Random Forest Regression and Principal Component Analysis were used to unveil how the driving factors influence MPs distribution across the plateau. The results revealed that the MPs abundance, type, size, color and polymer across the Ali, Yushu, and Haixi were different. Microplastic abundance was inversely correlated with the distance from roads and residential areas, but was positively related to precipitation. Moreover, traffic elements were the primary source of MPs pollution in the Ali and Yushu but residential activities were the leading source of MPs contamination in the Haixi. Besides, backward trajectory simulations suggested that atmospheric transport may also contribute to the presence of soil MPs in the representative regions. These results further indicated that different regions may require different measures for controlling MPs pollution in surface soil. This study provides new insights into the distribution and source of MPs and further offers valuable methodology for future research aimed at uncover driving factors contributing MPs pollution across different regions with various geographical conditions.

Analysis of Atomization Performance of Linear Laval Nozzle under Varied Water Pressures Based on VOF and DPM Models

Particulate matter from coal and stone operations is a primary air pollution source. The traditional nozzle requires high-pressure conditions, and the atomization droplets are large and uneven. This paper aims to study a linear Laval nozzle and investigate the impact of water pressure on atomization performance. The volume of fluid (VOF) model and discrete phase model (DPM) of Fluent are used to simulate the internal and external fields of the nozzle and analyze the velocity, droplet size, and atomization angle. The results show that the optimized water pressure parameters are 0.1 MPa with an air pressure of 0.5 MPa. Droplets in the middle are smaller, while those on the sides are larger. Compared to traditional nozzles, the water pressure is reduced by over 90%, and the Sauter mean diameter (SMD) decreases by over 50%. Moreover, the theoretical spray angle increases by approximately 150%.

Pollution-source fractionation and quantification-based assessment of surface water quality in Saigon River, Vietnam: implications for sustainable management strategies

ABSTRACT The current study fractionated pollution sources and investigated the impacts of seasonal and tidal variations on Saigon River’s surface water quality. Ninety-six water samples were collected across dry and rainy seasons, covering ebb and flood tides, and analysed for 19 parameters. During the dry season, ebb tide showed higher levels of electrical conductivity, sulfate, chloride, sodium, and potassium. During the rainy season, ebb tide exhibited greater concentrations of ammonium, total nitrogen, and phosphorus. The water quality index was significantly lower during the dry season’s ebb tide compared to the flood tide but remained similar in both tidal phases during the rainy season. Four primary pollution sources were quantified, with seawater intrusion and agricultural activities contributing 62.68% and 28.54%, respectively, to water quality degradation. Briefly, the river’s surface water quality was inferior during the dry season compared to the rainy season, primarily due to seawater intrusion and agricultural activities, requiring remediation.

Identification of proper species that can be used to monitor and decrease airborne Sb pollution.

Heavy metal concentrations, which have increased continuously in the environment this century due to anthropogenic factors, severely threaten human and environmental health. Antimony (Sb) is one of the most toxic and harmful heavy metals in terms of human and environmental health. Therefore, the priority research subjects are monitoring the alteration of Sb pollution in the airborne and reducing pollution. This study was conducted to conclude the proper species to monitor and drop airborne Sb contamination on trees grown in Düzce, the 5th most polluted European city. This study examined samples taken from Pseudotsuga menziesii, Cupressus arizonica, Pinus pinaster, Picea orientalis, and Cedrus atlantica, and the Sb concentration changes based on tree species, route, tissue, and age range in the last 40years were evaluated. The study hypothesizes that Sb concentration varies depending on (1) tree species, (2) direction, (3) plant tissue, and (4) age range, all confirmed in this study. In conclusion, the maximum concentrations were achieved in the outer bark and east (5.45µgg-1) and north directions (6.72µgg-1), with high traffic density. In addition, the mining and industrial places (sources of metal pollution) are not close to the study area. Therefore, it was concluded that traffic pollution was the primary source of Sb pollution in the study area. The study revealed that C. arizonica is the most suitable species for monitoring and reducing the change in Sb pollution because the highest Sb concentration (4.47µgg-1) in wood (the largest organ) was obtained in C. arizonica.

A novel hybrid features grey incidence model and its application in identifying key factors influencing air pollution in Jiangsu Province

Accurately assessing the key factors influencing air pollution is crucial for effective air pollution control. To address this need, we propose a novel Hybrid Features Grey Incidence Model (HFGIM), which integrates geometric feature differences from both proximity and similarity perspectives. Firstly, we extract geometric feature difference vectors of proximity and similarity from time series data and measure the overall feature difference degree by calculating vector norms. Secondly, we calculate the relative feature differences and information contribution rates of proximity and similarity to derive the hybrid feature differences coefficient between sequences, thereby obtaining the hybrid features incidence degree. After detailing the model’s properties and modelling steps, we introduce the Cross-sectional Data Hybrid Features Grey Incidence Model (C-HFGIM) and the Panel Data Hybrid Features Grey Incidence Model (P-HFGIM) for handling cross-sectional and panel data, respectively. Applying HFGIM, we identified the key pollutants and primary pollution source indicators of air pollution in Jiangsu Province. We also compared HFGIM with other classical grey incidence models to verify the proposed model’s effectiveness. Based on the analysis results, we propose policy recommendations for air pollution control in Jiangsu Province.

Assessing pollution vulnerability in groundwater: A case study of Kala Shah Kaku industrial complex

ABSTRACT Various factors, such as industrialization, population growth, and urbanization, have caused water quality and availability to decline worldwide, resulting in water crises in many regions and millions of annual deaths from water-related diseases. The study aimed to assess the groundwater quality in Kala Shah Kaku, an industrial area in central Punjab, Pakistan. Groundwater samples from six locations were analyzed for physical and chemical parameters and heavy metals. The results revealed that Kala Shah Kaku's groundwater is unsuitable for drinking due to exceeding the physical and chemical parameters range. The study identified industrial effluents from nearby industries as the primary source of pollution in the area's groundwater. These findings emphasize the urgent need for remedial measures to address industrial pollution and protect groundwater resources in Kala Shah Kaku.

Sulfide-enhanced carboxymethyl cellulose stabilised nano zero-valent iron for chromium(VI) mitigation in water: Evidence from batch and column studies

The primary source of chromium pollution in water is industrial operations such as electroplating, leather tanning, and textile manufacture, which use chromium for its ability to resist corrosion. Hexavalent chromium (Cr(VI)), the most detrimental variant, presents significant health hazards, such as cancer. It is crucial to effectively manage and decrease chromium levels to protect human and environmental health, especially in industrial regions where its presence in water is a persistent issue. This work examined the removal of Cr(VI) by sulfidated carboxymethyl cellulose stabilised nano zerovalent iron (S-CMC-nZVI). S-CMC-nZVI exhibited outstanding uniformity and corrosion resistance. Batch experiments revealed that several factors influenced the degree to which S-CMC-nZVI particles eradicated Cr(VI). The parameters to be considered included pH, initial Cr(VI) concentration, coexisting ions, and S/Fe molar ratio. When the sulfur to iron molar ratio was increased from 0 to 0.4, Cr(VI) removal efficiency increased from 73.89 % to 99 %. A pseudo-second-order kinetic model described Cr(VI) removal, and the Langmuir isotherm model determined the highest adsorptive capacity (311.02 mg/g). The presence of bicarbonate and nitrate anions have minimal inhibitory effects on removal of Cr(VI). Experiments on polluted groundwater showed that synthesised nanoparticles may remove Cr(VI) over a long time. Column investigations showed that increasing S-CMC-NZVI concentration increased Cr(VI) removal. The Adsorption, reduction and coprecipitation were major processes responsible for Cr(VI) removal. The research demonstrates that S-CMC-nZVI is a promising material for the in-situ remediation of Cr(VI)-contaminated groundwater.

Pinus eldarica (L.) bark as urban atmospheric trace element pollution bioindicator: pollution status, spatial variations, and quantitative source apportionment based on positive matrix factorization receptor model.

In this study, a total of 180 Pinus eldarica bark samples were collected from different regions of Hamedan megacity, Iran, in 2023, and contents of Cd, Cr, Cu, Mn, Ni, Pb, and Zn in the samples were determined using ICP-OES. The results illustrated that the average contents of all the analyzed elements were greater than those in the background contents, which presumably demonstrated anthropogenic sources of these potentially toxic elements (PTEs). The greatest concentrations of the analyzed PTEs for different functional areas were observed in specimens collected from commercial or industrial areas, indicating the impact of human entries. The I-geo values were in the range of "unpolluted to moderately polluted" to "moderately to heavily polluted", PI showed "moderate to very high pollution", and PLI reflected high to very high pollution levels for the whole study area. Additionally, the cumulative mean value of ecological risk (RI) was found to be 152, demonstrating moderate ecological risk across the study area. The results of positive matrix factorization (PMF) showed that the PTE contamination in the air of Hamedan could mainly have an anthropogenic origin (82.7%) and that the traffic emissions as the primary pollution source (33.6%) make the highest contribution to the PTE pollution and ecological risks in the study area. In residential areas, demolition and construction activities could be considered the main sources of PTEs, while in commercial and industrial areas traffic emissions and industrial emissions, could be regarded as the main sources of such pollution, respectively. In conclusion, this study provides a useful approach to identifying the sources and contributions of the toxic elements in different functional areas and can inform future endeavors that aim at managing and controlling metal element pollution.

Global microplastic fiber pollution from domestic laundry

The rapid expansion of fast fashion has significantly increased microplastic fiber (MPF) release during laundry practices, accounting for approximately one-third of primary microplastics entering the ocean. Currently, a significant gap exists in global-scale research on the release of MPFs from washing textiles. This study introduces an innovative empirical model to assess the spatial distribution of MPF emissions. The model estimates an annual global emission of 5.69 million tons of MPFs from laundry. Of this total, machine washing accounts for the majority (93.7 %), with hand washing contributing the remaining 6.3 %. As the primary source of MPF pollution, Asia's emissions reach 3.71 million tons, far exceeding those of North America (1.18 million tons) and Europe (0.45 million tons). The primary issue is that wastewater management efficiency varies significantly worldwide. In Asia, there is persistently high discharge of MPFs into natural waters, and the removal efficiency of wastewater treatment plants is still comparatively low. In contrast, the United States and many European countries exhibit better MPF retention. The global nature of this challenge mandates international collaboration for comprehensive environmental conservation. Our study provides the first high-resolution global distribution map of MPF emissions and discharge into natural waters, establishing a data foundation for global and regional management of microplastics originating from household laundry sources.

Assessment of risk intensity in the triffa plain aquifer: Integration of hazard quantification, land use analysis, dynamic vulnerability GCITF, and DRASTIC method

This study aims to assess the level of groundwater pollution risk in the Triffa Plain, stemming from various pollution sources, with a specific focus on agricultural intensification and excessive pesticide use. Data were collected from ABHM (the Moulouya Hydraulic Basin Agency) and ORMVAM (Regional Office of Moulouya Agricultural Development), and a field visit was conducted in July 2023. The study utilized two main methodologies for mapping risk intensity: the COST 620 action and overlaying vulnerability maps with the land use (LU) factor. Vulnerability maps were generated using the original DRASTIC method and the new dynamic vulnerability assessment method, GCITF.The research approach involved comparing the COST 620 risk index (Ri) and the land use risk index (LU) to identify the most suitable method for the study area. Due to challenges in inventorying various point sources of pollution, the study focused on mapping the primary sources of pollution (diffuse, point, and linear). The key findings indicate that the predominant pollution intensity in the region is high, covering 60.66% of the total surface area. These results closely align with those obtained using the European COST 620 approach and the spatial distribution of nitrates. The study demonstrates the reliability of integrating the GCITF method in assessing groundwater contamination risk, highlighting the significant negative impacts of agricultural activities on the Triffa Plain aquifer, primarily due to uncontrolled pesticide and fertilizer use and point sources of pollution.This study suggests that implementing targeted technical solutions for specific pollution sources is crucial for reducing contamination in the Triffa Plain. These pollution risk intensity maps can assist planners and decision-makers in understanding the origin of pollution and identifying necessary actions to minimize contamination risk, contributing to better groundwater management and protection in the region.

Occurrence and risk assessment of endocrine-disrupting chemicals in wastewater treatment plants in the Chaohu Lake Basin

Introduction: Endocrine-disrupting chemicals (EDCs) in effluent and residual sludge from wastewater treatment plants (WWTPs) pose significant environmental and human health risks due to their persistence, bioaccumulation, and difficulty in detection and degradation. This study investigates the environmental exposure and risks associated with EDCs in effluent and sludge from four WWTPs: Tangxi River (TXH), Zipeng Mountain (ZPS), Lianxi (LX), and Wang Xiaoying (WXY).Methods: Environmental exposure indexes of EDCs were assessed in the effluent and sludge of the four WWTPs across four seasons (spring, summer, autumn, and winter) from October 2017 to October 2018. Detection rates of various pollutants, their seasonal and spatial characteristics, and removal rates were analyzed. Positive matrix factorization (PMF) was used for source analysis under influent data, and an ecological risk assessment was conducted using the risk quotient (RQ) method.Results: The study found 4-n-nonylphenol (NP) and di-2-ethylhexyl phthalate (DEHP) had 100% detection rates in the effluent of all four WWTPs, while only DEHP showed a 100% detection rate in the sludge. Bisphenol A (BPA) exhibited the highest concentration in the TXH effluent during autumn. Benzo(a)pyrene (B(a)P) was detected only in the sludge during spring and summer and in the effluent of TXH and WXY. PMF source analysis indicated industrial wastewater discharge as the primary source of pollutants. Ecological risk assessment revealed a high RQ for estriol (E3) in TXH effluent during autumn, and DEHP presented a potential carcinogenic risk through drinking water.Discussion: The findings highlight significant seasonal and spatial variations in EDC concentrations and removal rates across the WWTPs. The persistent presence of DEHP and the high-risk levels of E3 in specific seasons underscore the need for improved treatment processes and stricter industrial discharge regulations to mitigate EDC-related risks. Further research is recommended to explore advanced detection and degradation techniques for EDCs in WWTPs.