The efficacy of polycyclic aromatic compound (PAC) diagnostic and weathering ratios was tested on a weathered petroleum-contaminated site located in the boreal region of northern Ontario, Canada. The site, a former petroleum distribution terminal (1920-1998) with documented spills and adjacent industrial activity (e.g., cement manufacturing), exhibited mixed petrogenic and pyrogenic PAC sources. Contaminated soil from the site was analyzed for unbranched, alkylated (Cn), nitrogen-, sulfur-, and oxygen-containing PACs using GC-MS-SIM, while hydrocarbon fraction concentrations based on effective carbon number were previously determined by GC-FID. Results underscore the limitations of several conventional diagnostic ratios in resolving mixed-source contamination, as overlapping chemical fingerprints from multiple inputs (diesel, fuel residues, and combustion byproducts) and site-specific weathering processes obscured clear source attribution. Weathering ratios may be used to observe changes in PAC composition over time and predict toxicity. Four weathering ratios suggested in earlier studies were validated: i. fluorene/(C1-anthracene/phenanthrenes), ii. C3-naphthalenes/(C2-anthracene/phenanthrenes), iii. dibenzothiophene/(C4-anthracene/phenanthrenes), and iv. benzo[e]pyrene/benzo[a]pyrene. Three newly proposed weathering ratios indicated weathering: i. acenaphthenone/acenaphthene (<1), ii. anthraquinone/anthracene (<1), and iii. benzanthrone/anthracene (>1). Novel weathering ratios may be established during photolysis, biodegradation, and other site weathering mechanisms for application to legacy polluted sites where the timing of contamination is unknown.
This study aims to evaluate seawater quality in concentrated coastal cage aquaculture areas of Quang Ninh Province by integrating the Water Quality Index (WQI), multivariate statistical methods, and the Random Forest machine learning model. Seawater samples were collected from 25 representative sites during two survey campaigns conducted in June and December 2024. A total of 15 water quality parameters, including salinity, pH, dissolved oxygen (DO), total suspended solids (TSS), ammonium (NH4+), phosphate (PO43-), and heavy metals (As, Cd, Pb, Cr, Cu, Zn, Mn, Fe, and Hg), were analyzed and compared with the applicable environmental standards. The results indicate pronounced spatial and temporal variability in seawater quality. During the June 2024 survey, many monitoring sites recorded WQI values ranging from fair to poor, mainly due to increased TSS, NH4+, and several heavy metals, reflecting the significant influence of high-density cage aquaculture activities. In contrast, during the December 2024 survey, seawater quality improved markedly, with most sites attaining good to excellent WQI levels. This improvement is associated with the significant reduction in aquaculture activities following the impact of Typhoon Yagi (September 2024), which altered nutrient inputs and environmental conditions in the study area. Correlation analysis, PCA, and HCA revealed a shift in the mechanisms controlling water quality from anthropogenic impacts toward natural processes such as hydrodynamic mixing and sediment remobilization. The Random Forest model identified Zn as the primary controlling factor for WQI during the first campaign, whereas Fe and TSS played more important roles during the second campaign. The model also provided valuable insights into the key factors controlling water quality variations, demonstrating its effectiveness as a robust tool for environmental assessment in coastal aquaculture systems. This study shows that integrating WQI with multivariate statistical analyses and machine learning models is an effective approach for comprehensive seawater quality assessment, while also providing a scientific basis for environmental monitoring and the sustainable management of coastal aquaculture under the increasing occurrence of extreme climate events.
Urban Construction and Demolition (C&D) waste governance is a critical lever for advancing Sustainable Development Goal (SDG) 11, yet conventional disposal statistics are often distorted by administrative performance incentives. Here, we propose an interference-free indicator, the number of illegal C&D waste dumping sites (NDS), derived from sub-meter satellite imagery (error rate < 5%) to quantify governance gaps across 22 Chinese megacities. By coupling NDS with GDP data, we develop the "Beautiful City Construction Process Index" (beta), which normalizes economic output against unregulated waste burdens through arctangent transformation (scaled 0-100). beta delineates three urban development archetypes: pioneer cities (beta >= 88.8; eg, Shanghai, Shenzhen) that decouple economic growth from waste generation; follower cities (beta 81.7-88.8; eg, Beijing, Chongqing) in transitional phases; and lagging cities (beta < 81.7; eg, Tianjin, Harbin) trapped in high-waste/low-efficiency trajectories. Slope-threshold diagnostics (+/- 25% of the GDP-NDS baseline slope = 4.5) confirm nonlinear Environmental Kuznets Curve behavior at the urban scale, while spatial analysis uncovers significant north-south and basin-scale disparities. The NDS-beta framework is globally scalable, requiring only open-access satellite imagery and GDP data, and offers policymakers a replicable tool for targeted interventions, SDG 11 progress tracking, and bias-free benchmarking of urban environmental performance.
This study employed an environmental forensic approach to evaluate the terrestrial gamma radiation dose rate (TGRDR) across Niger State, Nigeria, and to determine the influence of geology on natural background radioactivity and potential radiological risks. A total of 739 in-situ measurements were obtained using a portable NaI(Tl)/BGO gamma survey meter (Gf Instruments, 2016), while geographic coordinates were recorded with a Garmin GPS. Spatial data were analyzed and mapped using ArcGIS to establish dose rate distribution patterns and identify potential hotspots. The results showed that the TGRDR varied with the underlying geological formations. The Migmatite Gneiss Complex (igneous terrain) recorded the highest mean value of 68.1 +/- 1.6 nGy h-1, followed by the Metasedimentary Complex (metamorphic terrain) with 45.1 +/- 9.7 nGy h-1. In contrast, the Enagi Formation (Nupe Sandstone Basin, sedimentary terrain) showed the lowest mean value of 42.4 +/- 2.9 nGy h-1. The overall mean TGRDR across all formations was 63.1 nGy h-1, slightly above the global average of 59 nGy h-1 as recommended by UNSCEAR. Spatial distribution maps revealed elevated radiation zones in areas dominated by granitic and migmatitic rocks, particularly around Suleja, Rijau, and New-Bussa. Radiological hazard parameters were computed to assess potential human exposure. The Radium Equivalent Activity (Raeq) was 140.45 Bq kg-1, while the Gamma Index (I gamma) and Alpha Index (I alpha) were 0.516 and 0.197, respectively. The External (Hex) and Internal (Hin) hazard indices were 0.378 and 0.486, both below the recommended limits. The Annual Effective Dose Equivalent (AEDE) was 0.310 mSv y-1 (indoor) and 0.0774 mSv y-1 (outdoor), also within acceptable safety thresholds. However, the Annual Gonadal Dose Equivalent (AGDE) exceeded the permissible limit of 323.54 Bq kg-1, suggesting potential long-term reproductive risks. The Excess Lifetime Cancer Risk (ELCR) of 0.2709 was slightly below the global reference value of 0.29 set by UNSCEAR. From an environmental forensic perspective, the elevated TGRDR in migmatite gneiss and granitic terrains is attributed to uranium- and thorium-bearing minerals that are naturally enriched in these rocks. The findings indicate that while background radiation levels in Niger State remain generally safe, continuous monitoring is recommended in high-dose regions. The radiometric database and spatial model developed in this study provide a valuable reference for environmental management, land-use planning, and forensic evaluation of natural radiation sources.
Subsurface water is a vital resource in arid environments. This study investigated spatiotemporal differences in heavy metal concentrations and associated health risks with subsurface water in various parts of Bikaner City, Rajasthan, India. Eighty subsurface water samples were collected from 20 locations in the pre-monsoon and monsoon seasons and analyzed for arsenic (As), chromium (Cr), copper (Cu), manganese (Mn), lead (Pb), uranium (U), and zinc (Zn). Contamination was assessed using multiple indices, including the contamination factor (CF), degree of contamination (C-d), modified degree of contamination (mC(d)), geo-accumulation index (I-geo), pollution load index (PLI), potential ecological risk index (PERI), heavy metal pollution index (HPI), metal index (MI), carcinogenic risk index (CRI), and hazard quotient (HQ) . Pb and U were determined to be the most concerning pollutants, especially during monsoon season. The sampling locations of Raisar and Khara appear to be contaminant hotspots. Metal health risk assessment indicates that hazard index (HI) of more than 1 was found in As, Cr, Cu, Pb, and U. Lead had maximum HI followed by U in both children and adults. Chromium and Pb were cancerous metals present in subsurface waters. Total cancer risks (TCRs) during the pre-monsoon and monsoon seasons were above permissible limits. Future work should include a larger number of samples and further assess potential contamination sources.
Industrial activities and traffic emit a wide array of pollutants that pose significant threats to human health, necessitating the comprehensive monitoring of both inorganic and organic pollutants in major cities. In this study, date palm (DP) and Arabic-damas (AD) were selected as potential biomonitoring tools to assess the levels of polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) in Riyadh City, Saudi Arabia. Sigma PAH levels in DP ranged from 288 to 1653 ng g-1 (dry weight), while AD ranged from 179 to 1501 ng g-1. The total concentration of the carcinogenic PAHs was greater in DP with 192.4 ng g-1 compared to 134.6 ng g-1 in AD. Phenanthrene (PHE) was the dominant PAH in both plants, with higher PAH concentrations observed in industrial areas (southeast and southwest) compared to residential northern regions. PTE Concentrations, including As, Co, Pb, Zn, Ni, and Cd, were lower than global averages. Diagnostic ratios indicated that traffic emissions and petrogenic sources were the primary contributors to PAH contamination. Both plants showed similar PAH patterns, with low molecular weight (LMW) PAHs being the most prevalent. The study concludes that both DP and AD are effective bioindicators of traffic-related pollution, with AD being more practical, and efficient due to its widespread use in Riyadh. Overall, these findings underscore the effectiveness of plant leaves as biomonitoring tools for evaluating the impact of urban activities on the surrounding environment, particularly PTEs and PAH air pollution.
This study investigates how atmospheric particulate matter (PM) imprints on rainwater composition across six districts of Central India during pre-monsoon and post-monsoon seasons. It provides a critical forensic insight into chemical composition, pollution origins, seasonal distribution and transformation pathways. Over 96 sampling days, atmospheric PM frequently exceeded Indian national standards, with PM2.(5) ranging from 28.9-92.5 & micro;g.m(-)& sup3; in pre-monsoon and 28.5-96.2 & micro;g.m(-)& sup3; in post-monsoon, while PM10 ranged from 82.8-152.8 & micro;g.m(-)& sup3; and 70.6-157.6 & micro;g.m(-)& sup3;, respectively. The rural hotspots dominated during pre-monsoon, and urban hotspots dominated during post-monsoon, indicating a seasonally shifting pollution footprint. Chemical fingerprinting revealed SO42- as the predominant ionic species, followed by Ca2+, NH4+, and Mg-2,(+) while elemental analysis showed recurrent enrichment of Ca, Al, Mg, Fe, K, Zn, Mn, Pb, and Ni. The compositional patterns indicate mixed contributions from crustal resuspension, agricultural ammonia, anthropogenic combustion sources, and secondary aerosol formation. The peaked PM2.(5)/PM10 ratios (0.7-0.8) and NO3-/SO42, NH4+/SO42-, and (SO42-+NO3-)/(Ca2++Mg2+) fractional ratio suggested mixed contributions from fine anthropogenic aerosols and coarse crustal dust, with stronger fine-particle accumulation during PostM. Rainwater chemistry exhibited strong neutralisation potential by Ca2+, and substantial non-sea-salt SO42- and NO3- contributions, conceding regionally transported and locally generated nss-pollutants. The correlation analysis revealed a significant PM-rainwater coupling, highlighting wet-scavenging and shared-source pathways. The long-term reanalysis trends (2002-2024) of SO42-, NH4+, and PM revealed co-variability between aerosols, and convectively driven first-flush removal of accumulated contaminants. The overall findings offer a critical region-specific chemical baseline for Central India and inform regulatory interventions to mitigate deposition-linked ecological risks. It further strengthens the future research on aerosol-cloud processes and interactions, convective precipitation variability and climate-sensitive air pollution pathways in semi-arid tropical environments.
Both Microplastics (MPs) and Heavy Metals (HMs) are among many other toxic substances that deteriorate ecosystems and organisms. The degradation of larger plastic debris results in MPs but may also be manufactured purposely as small pellets or as powders to serve commercial purpose; furthermore, if not handled properly, they will end up accumulating in the ecosystem. HMs are also used extensively in agriculture and some industries which eventually is for producing human beneficials; nevertheless, their enormous leaching into the environment is widely known for being disastrous to public health. This study monitored both of these dangerous substances, as well as major cations, in multiple interlinked surface water locations of the Sulaymaniyah Governorate; additionally, the chemicals were corelated and compared to other regional and worldwide studies. Ecological risk assessment (ERA) was also affixed to evaluate the problem more and warn the public about it. Seasonal comparison between winter and spring was done, and winter had more abundance of MPs and in some of the metals.
The escalating urban expansion of Guwahati, Assam, critically threatens the ecological integrity of the Brahmaputra River through the uncontrolled release of untreated sewage. This extensive investigation of water quality along a crucial urban stretch addresses a knowledge gap concerning sewage contamination's impacts. Samples were taken from 18 strategically selected sites throughout monsoon and non-monsoon periods. Cluster analysis, information entropy, and principal component analysis were utilized to assess the samples' physicochemical and biological properties. The average BOD results of 83.62 +/- 36.40 mg/L at sewage discharge locations indicate a high amount of biodegradable organic matter. However, river water BOD levels remain unsuitable (13.08 +/- 5.16 mg/L), indicating inadequate self-purification potential. Water TOC levels were high (3.64 +/- 2.35 mg/L) during non-monsoon periods due to low-flow discharge of organic-loaded sewage. Water safety concerns were raised when the downstream river water of the L9 sewage source had a maximum pathogen load of 5.4 & times; 104 during the monsoon. Non-monsoon river water EWQI ranged from 65.92 to 192.53; monsoon ranged from 106.70 to 361.58. The cluster analysis (CA) categorized all sampling sites into two distinct clusters. Overall, a strong correlation existing between the identified principal components and domestic wastewater discharge in the river basin was found through principal component analysis (PCA). Urban sewage has a major impact on the river water quality, giving crucial information for policymakers trying to protect this key riverine ecosystem in a fast-urbanizing world. This study offers a model for measuring and regulating water quality in anthropogenic-pressured river systems.
The sediment samples collected from 22 stations along the Kocaba & scedil; Stream (NW T & uuml;rkiye) were analyzed to determine the concentrations of 10 potentially toxic elements (Al, Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, Zn), their possible sources, contamination status, and associated environmental, ecological, and human-health risks. The potentially toxic elements concentrations (unit in mg kg(-1)) were listed as follows: Fe (33 022) > Al (24 748) > Mn (8 693) > Zn (2 099) > Co (630) > Cu (346) > Ni (188) > Pb (166) > Cr (20) > Cd (0.11). Enrichment factor (EF) analysis revealed that Mn had the highest mean EF value. According to the geo-accumulation index (I-geo), Cd and Co were classified as "uncontaminated," whereas Mn showed "moderate to heavy contamination." Contamination factor (CF) results indicated very high contamination for Co, Cu, Mn, Pb, and Zn. According to the pollution load index (PLI), Mn showed high contamination. Ecological risk analysis showed moderate potential ecological risk for Cu and Pb. Correlation and factor analysis revealed that Al, Cu, Fe, Pb, Cr and Ni originated from natural and anthropogenic sources, and Co originated from anthropogenic sources. Although non-carcinogenic risks were negligible (HQ < 1), carcinogenic risk values for Cr and Pb exceeded the acceptable range, indicating potential human-health concerns. Overall, the findings suggest that the use of Kocaba & scedil; Stream for irrigation should be carefully monitored due to potential long-term health considerations.
This study investigates the down-core distribution of rare earth elements (REEs) in sediment from Pookode Lake, a tropical highland lake located in the Western Ghats of southwest India. The felsic bedrock-dominated catchment and strong monsoonal forcing make the lake an effective archive for tracing geochemical inputs and environmental changes. A 233 cm-long sediment core spanning the last similar to 1400 years (600-2000 cal AD) was analyzed for REE concentrations and redox-sensitive anomalies (Ce/Ce* and Eu/Eu*). The sediments exhibit consistent light REE (LREE) enrichment, moderate middle REE (MREE), and heavy REE (HREE) depletion when normalized to Post-Archean Australian Shale (PAAS). remobilization. The upper continental crust affinities indicate stable felsic provenance with minimal post-depositional alteration. Cluster analysis identifies seven geochemical zones reflecting temporal variations in sediment input, redox dynamics, and catchment changes. Ce/Ce* values suggest largely oxic depositional conditions, with a distinct suboxic interval during similar to 1700-1400 cal AD, coincident with wetter phases of the Little Ice Age. In contrast, consistently strong positive Eu/Eu* anomalies (2.4-4.6) demonstrate continuous input of plagioclase-rich material and indicate dominance of physical erosion over chemical weathering, particularly during the last millennium. Elevated Sigma REE concentrations and REE ratios in the upper core signify enhanced terrestrial sediment delivery, marking a transition from primarily monsoon-driven variability to increasing anthropogenic influence. Comparison with regional Western Ghats records confirms a shared felsic source and monsoon control, while the dated framework highlights cumulative human impacts in recent centuries. Overall, the results demonstrate the utility of REE geochemistry as a robust proxy for disentangling climate-driven and anthropogenic controls on erosion and sediment dynamics in tropical lake systems.
Groundwater is a major natural source of water. Groundwater pollution can occur due to the overuse of fertilizers and the specific geography of the area. The objective of this study was to assess the hydrogeochemical characteristics and overall quality of groundwater and its suitability for both irrigation and domestic purposes. Groundwater samples were collected in the Chengalpattu District using the grid method, and sampling locations were determined using GPS in this study. The key parameters, including pH, electrical conductivity (EC), total dissolved solids (TDS) and major ions, are determined for water quality. The indicators such as Sodium Adsorption Ratio (SAR), Sodium percentage (Na%), Residual Sodium Carbonate (RSC), Residual Sodium Bicarbonate (RSBC), Magnesium Hazard (MH), Kelly's Index (KI), Permeability Index (PI) and Potential Salinity (PS) were estimated for assessing the irrigation and drinking suitability of the groundwater samples. The spatial map was drawn to illustrate the distributions effectively. The Gibbs plot indicates that the interaction between rock and water serves as the primary mechanism governing groundwater chemistry within the study area. The water type was determined through the application of Piper's plot analysis. The US Salinity Laboratory diagram showed that most of the samples were C2S1 or C3S1, which means they had low sodium content. This means that the groundwater is good for irrigation. The Wilcox diagram illustrates the water samples for autumn across all classes, with the majority of samples indicating excellent to permissible quality. The study concluded that the water from the area is acceptable for both domestic and agricultural usage.
This study investigates the activity concentrations of 40K,2 & sup3;8U,2 & sup3;2Th, and 1 & sup3;7Cs in beach sands collected from the & Ccedil;e & scedil;me Peninsula (& Idot;zmir, T & uuml;rkiye) using a NaI(Tl) gamma-ray spectrometer. 40K, 238U, 232Th and 137Cs activity concentrations in beach sands range from 68.7 +/- 8.3 to 620.8 +/- 24.9 Bqkg-1, 3.5 +/- 1.9 to 56 +/- 7.5 Bqkg-1, LLD to 112.5 +/- 10.6 Bqkg-1 and 7.3 +/- 2.7 to 53.8 +/- 7.3 Bqkg-1, respectively. The mean activity concentrations were determined as 265 Bq & centerdot;kg-1 (40K), 26 Bq & centerdot;kg-1 (2 & sup3;8U), 28 Bq & centerdot;kg-1 (2 & sup3;2Th), and 25 Bq & centerdot;kg-1 (1 & sup3;7Cs). Radiological risk parameters (absorbed dose rate (D), radium equivalent activity (Raeq), annual effective dose (AEDE), annual gonadal dose equivalent (AGDE), excess lifetime cancer risk (ELCR), and internal/external hazard indices (Hin, Hex)) were calculated to determine the radiological risks due to the gamma ray exposure for beach sands of & Ccedil;e & scedil;me peninsula. The results were compared with the world limit values and the results of the literatures. All measured values were below internationally accepted limits, indicating that the beaches of the & Ccedil;e & scedil;me Peninsula pose no significant radiological health risk.
This study investigated fine particulate matter (PM2.5) in Welkom, South Africa, a legacy mining town. PM2.5 was sampled over 12 months at two sites, an Industrial Site and a Residential Site located only 5.6 km apart, to assess total concentrations, PM2.(5) chemical composition, soot, black carbon (BC), UV-absorbing particulate matter (UV-PM), and the geographical origin of air masses. At the Industrial Site, the annual mean PM2.5 concentration was 14.7 & micro;g/m & sup3; (0.17-66.3 & micro;g/m & sup3;), while the Residential Site recorded a markedly lower mean of 6.47 & micro;g/m & sup3; (0.17-24.3 & micro;g/m & sup3;). Mean soot levels were 1.07 & times; 10(-5) m(-1) (0.01-5.52 & times; 10(-5) m(-1)) at the Industrial Site and 1.10 & times; 10(-5) m(-1) (0.014-5.50 & times; 10(-5) m(-1)) at the Residential Site. BC concentrations averaged 1.9 & micro;g/m & sup3; (0.028-8.01 & micro;g/m & sup3;) at the Industrial Site and 0.6 & micro;g/m & sup3; (0.2-2.8 & micro;g/m & sup3;) at the Residential Site. UV-PM averaged 1.6 & micro;g/m & sup3; (0.006-5.22 & micro;g/m & sup3;) at the Industrial Site and 0.8 & micro;g/m & sup3; (0.1-3.1 & micro;g/m & sup3;) at the Residential Site. Clustered back-trajectory analysis further showed that northerly and easterly air masses carried the highest PM2.5, soot, BC, and UV-PM levels. Across all pollutants, higher concentrations at the Industrial Site highlight the influence of local combustion sources, resuspended dust, and industrial activities.
This study investigates the impact of non-sewered sanitation systems (NSS) on groundwater quality in peri-urban areas of Islamabad, Pakistan. Groundwater samples were collected from five locations served with septic tanks and pit latrines during dry and wet seasons. The study revealed significant contamination, particularly during the wet season, with high levels of ammonium-nitrogen (NH4+-N) (43 mg/L in wet season vs. 19 mg/L in dry season), Chemical Oxygen Demand (COD) (52 mg/L in wet season vs. 29 mg/L in dry season), and E. coli (> 23 CFU/100 ml) in both wet and dry season. The Water Quality Index (WQI) indicated that most groundwater samples were "unfit for drinking" with a notable deterioration during the wet season. During the dry season, 47% of samples were classified as "marginal" (WQI <= 100), while 53% were "poor" (WQI 100 - 200). In the wet season, nearly all samples fell into the "poor" (WQI 100 - 200) and "very poor" quality (WQI >200). The Principal Component Analysis and Multi Linear Regression (PCA-MLR) determined that high NH4+-N and COD in groundwater takes its genesis from anthropogenic sources and increasing distance between NSS and groundwater well improves water quality. Thus, groundwater in the area is unsuitable for drinking, domestic, and agricultural needs. The study highlights the critical importance of proper construction, operation, and maintenance of NSS to prevent groundwater contamination and protect community health.
This study investigates the seasonal variability and spatial distribution of key air pollutants across 20 distinct sites in Srinagar, Kashmir Valley, India, from summer 2022 to spring 2023. Using calibrated handheld sensors, five ambient air quality parameters, including carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), PM2.5, and PM10, were monitored across diverse land use categories, such as residential, commercial, industrial, institutional, and ecologically sensitive zones. The results revealed distinct seasonal and spatial variations in pollutant concentrations, with winter showing the highest pollution levels due to increased combustion for heating purposes, reduced atmospheric dispersion, and temperature inversions. Commercial and industrial zones recorded the highest PM10 and CO levels, while ecologically sensitive zones consistently exhibited the lowest concentrations. Statistical analysis (two-way ANOVA with post-hoc tests) confirmed that these seasonal and land-use differences were highly significant (p < 0.05), supporting the robustness of the observed trends. Spatial interpolation using the Inverse Distance Weighting (IDW) method highlighted pollution hotspots and visualized seasonal shifts in distribution. The results highlight the combined influence of land use, meteorological conditions, human activity density, and topography on air quality in a high-altitude urban environment. This study provides the first seasonally resolved, site-specific air quality dataset across diverse land-use zones in Srinagar, filling a critical monitoring gap for high-altitude Indian cities and informing local mitigation strategies. Findings underscore the need for season-specific interventions and demonstrate the utility of low-cost sensors for high-resolution environmental monitoring and evidence-based urban planning.
Source apportionment through factorization is a common method for identifying sources of air pollution. Both PCA and DN-PMF have assumptions, strengths, and limitations. Assigning sources to factors is inherently subjective and can introduce bias. PCA for the number of sources, C-PMF and DN-PMF is performed on data from three cities which were sampled at the same time, 16 April 2017 to 18 April 2018. The DN-PMF was able to give seasonal information to support the source apportionment. Results of the PCA included 6 factors for Thohoyandou and Pretoria and 7 factors for Cape Town. At the two large city sites, the C-PMF presented a dominant coal emissions source (29% and 35.6%) yearly and a strong biomass source during winter (24% and 17%). The dominant yearly source shifted to vehicular emissions with the DN-PMF model in Pretoria and Cape Town (41% and 12%) and coal burning at Thohoyandou (33%). By considering the mixing layer and meteorological conditions the factors shifted while keeping the dominant Cl-Pb and Cu-Zn tracer combinations.
This study highlights the hydrogeochemical characteristics and geothermometry of the Taptapani geothermal spring, located along the lineament in the Eastern Ghats Granulite terrain of Ganjam district, Odisha (India). Water samples were collected during pre-monsoon, monsoon, and post-monsoon periods in 2021. Various physico-chemical parameters, including temperature, pH, electrical conductivity (EC), total dissolved solids (TDS), major ions (Ca2+, Mg2+, Na+, K+, HCO3-, F-, SO4-), and toxic trace elements (Fe, Cr, Zn, Cd, Cu, Mn, Ni, and Pb), were measured. Spring exhibits a natural sulfurous odour and is slightly basic, with a pH of 7.2 and a temperature of 42 degrees C, exceeding ambient levels due to deep meteoric fluid circulation influenced by a high geothermal gradient. TDS and EC values were recorded as 243.3 mg/l and 380.1 & micro;S/cm, respectively. Geochemical characteristics of the spring water are governed by the lithology of the region. Sodium (Na+) dominates the cation budget, while bicarbonate (HCO3-) dominates the anion budget, classifying the geothermal water as Na-HCO3 type. Reservoir temperatures estimated using Na-K and Na-K-Ca geothermometers ranged from 122-135.4 degrees C and 140.5-152.4 degrees C, respectively. Based on the Water Quality Index (WQI), the spring was categorized as having poor water quality (WQI > 100), establishing a baseline reference for environmental forensic applications. While most ionic compositions were within permissible limits, except for fluoride (F-: 3.8-4.7 mg/l, average 4.20 mg/l), cadmium (Cd: 17-22 ppb, average 19.3 ppb), and nickel (Ni: 32-53 ppb, average 43 ppb) levels exceeded WHO (2022) and BIS (2012) standards. Parameters such as sodium percentage (Na%), sodium absorption ratio (SAR), residual sodium carbonate (RSC), magnesium absorption ratio (MAR), and Kelly Index (KI) were analyzed to assess irrigation suitability. Effective treatments like adsorption, membrane filtration, electrocoagulation, photocatalysis, and ion exchange can remove elevated elemental concentrations from thermal water.
Coal mining is major source of heavy metal contamination in soil and water. Present research was conducted to evaluate the spatial distribution, metal levels, and associated human health hazards of different heavy metals. Samples were obtained from coal mining areas of Chakwal and Khushab districts, Punjab, Pakistan. Atomic absorption spectrophotometry (AAS) was used for analyzing samples. Results demonstrated that there were marked spatial and inter-district variations in concentration of metals including Cadmium (Cd), Lead (Pb), Zinc (Zn), Copper (Cu), Nickel (Ni), and Chromium (Cr). For health hazard evaluation estimated daily intake (EDI), hazard quotient (HQ), hazard index (HI), and lifetime cancer risk (LCR) were calculated for both elders and children. In both districts, ingestion emerged as the primary exposure pathway. In contrast to adults' children were found to be more sensitive to these hazards due to their higher exposure relative to body weight. In Chakwal, elevated HI values were noticed for Cd in children (HI = 1.63), with Cr surpassing tolerable LCR range (LCR = 1.528E-04). Similarly, in Khushab, HI values for Cd outpaced the safety levels in both children and adults with statistically significant LCR values recorded for Cr and Cd in children. Soil samples were confirmed to be more hazardous compared to water. All HI and LCR values were within tolerable ranges in water samples. In conclusion, the findings emphasize the need for regular environmental monitoring and novel strategies to manage heavy metal accumulation in coal mining areas.
