USEPA Limits Research Articles

Rational designing of ZIF-67-derived Co3O4 nanocomposite with hierarchical porous structure and extensive peroxidase mimetic activities for highly sensitive colorimetric detection of nitrite in drinking water.

A simple, fast, and cost-effective colorimetric nitrite (NO2-)sensor based on ZIF-67-derived Co3O4 nanocomposite (ZCo-2 NC) structurehas been developed. The prepared colorimetric sensor (ZCo-2 NC) was employed to sensitively detect NO2- in drinking water system by the exhibition of promising peroxidase-mimicking nanozyme-like features. The sensor manifest well-determined sensing response with excellent linear and wide range of NO2- sensitivity (0.001-0.810μM). The lower detection-limit (LOD) and lower quantification-limit (LOQ) were 0.14 ± 0.05nM and 0.72 ± 0.05nM, respectively, which is far below the US-EPA limit (21.7μM). Further, the sensor alsoprovidesstrong selectivity response to NO2-, better reversibility (12 cycles), and commendable stability of 10weeks. In addition, it also perceived astonishing practicality towards NO2- in real water samples. Thus, this study opens a new pathway for the sensitive detection of NO2- in drinking water for future endeavor.

Immobilization of Pb2+, CrO42−, Hg2+, and Cd2+ in Coal Fly Ash/PP-g-MHBP-Based Geopolymers

Contamination by heavy metals (HMs) such as Pb, Cd, Cr, and Hg poses significant risks to the environment and human health owing to their toxicity and persistence. Geopolymers (GPs) have emerged as promising materials for immobilizing HMs and reducing their mobility through physical encapsulation and chemical stabilization. This study explored the novel use of isotactic polypropylene functionalized in the molten state with maleinized hyperbranched polyol polyester (PP-g-MHBP) as an additive in coal fly ash (CFA)-based GPs to enhance HM immobilization. Various characterization techniques were employed, including compressive strength tests, XRD, ATR-FTIR, SEM-EDX, XPS analyses, and TCLP leaching tests, to assess immobilization effectiveness. These results indicate that although the addition of PP-g-MHBP does not actively contribute to the chemical interactions with HM ions, it acts as an inert filler within the GP matrix. CFA/PP-g-MHBP-based GPs demonstrated significant potential for Cd2+ immobilization up to 3 wt% under acidic conditions, although the retention of Pb2+, CrO42−, and Hg2+ varied according to the specific chemistry of each metal, weight percentage of the added metal, matrix structure, and regulatory standards. Notably, high immobilization percentages were achieved for CrO42− and Hg2+, although the leaching concentrations exceeded US EPA limits. These findings highlight the potential of CFA/PP-g-MHBP-based GPs for environmental applications, emphasizing the importance of optimizing formulations to enhance HM immobilization under varying conditions.

Analysis of Heavy Metal Pollution in the Water of the Halda River: A Distinctive Breeding Habitat for Carp Fish in Bangladesh.

The present study aimed to assess the heavy metal concentrations in water from different sampling sites of the Halda River, the only natural breeding ground of Indian major carps. We have analysed the contamination level and seasonal variations of heavy metals (viz. Fe, Cu, Zn, Cr, Cd and Pb). The favourability of the breeding environment was assessed by different contamination indices. Samples were collected from six sampling sites for four different seasons, and the metal concentrations were determined for water samples using Flame atomic absorption spectrophotometer. The obtained order of mean concentrations of heavy metals for four seasons was winter>spring>monsoon>pre-monsoon, and the assessed mean concentrations (mg/L) of heavy metals follow the trend: Fe (9.129)>Pb (0.033)>Zn (0.024)>Cr (0.017)>Cu (0.012)>Cd (0.002). The concentration of Fe was found above the permissible limit set by the World Health Organization (WHO) (Guidelines for Water Quality) and ECR (1997), and the concentrations for Pb were found above the USEPA (2006) limit in all four seasons. Contamination indices (heavy metal pollution Index [HPI] and metal index [MI]) indicate that during winter and monsoon, the river water metal condition is critical (HPI>100) and the sites are moderately as well as slightly (1<MI<2) affected by the studied heavy metals. Contamination indices, such as contamination factors (Cf), degree of contamination (Cdeg) and the pollution load index (PLI), demonstrate the fact that Fe and Pb remarkably contaminated the studied sampling sites. The Pearson correlation matrix and the principal component analysis (PCA) revealed that the studied metals are connected by their sources, which can be geological or anthropogenic. Urgent initiatives need to be taken, and effective strategies must be implemented to control the different sources responsible for the entry of heavy metals into the Halda River water.

Risk assessment and seasonal variation of atmospheric ammonia in Ondo State, Nigeria

The environment is impacted by atmospheric ammonia (NH3) in a number of ways, including the global nitrogen cycle, ecology, and the production of secondary particles. Our findings present an unparalleled depiction of the temporal and geographical properties of atmospheric NH3 in and around this megacity, based on long-term, continuous measurements of NH3 at various locations in Ondo State. The increase in atmospheric ammonia during this anthropogenic era is believed to pose a significant threat to humanity, with scientists linking it to a rise in global warming and climate change. KP-826 multiple gas detector was used to investigate ammonia gas in five locations within Ondo state and its correlation with meteorological parameters was examined in this study. The selection of Dumpsite, Cattle rearing farm and Poultry farm was purposeful because of their involvement in the production of ammonia gas. The mean concentration of NH3 (ppm) during wet season was 3.87 ± 1.60 and for dry season was 5.87 ± 1.60. The mean temperature (°C) in wet conditions is 32.51 ± 1.27, which is a little lower than the mean (33.51 ± 1.25) in dry conditions. The mean wind speed (in m/s) during wet conditions is 1.21 ± 0.32, which is greater than the mean wind speed (in m/s) during dry conditions of 1.11 ± 0.32. The mean value of humidity for wet situations is 72.08 ± 2.31, which is a little lower than the mean value for dry conditions, which is 76.07 ± 2.31. This work evaluated the potential health risks associated with NH3. The total hazard quotient (THQ) for adult was 1.30 × 10–6 for children 1.50 × 10–6. The children's HQ ranged from 2.41 to 4.15. The adult's ranged from 8.70 to 15.13. However, it was discovered that the health risk posed by breathing in atmospheric NH3 was far higher than the USEPA limits, where HQ > 1.

Assessment of the activity concentration of radon and its health hazard in surface water around the Rooppur Nuclear Power Plant (RNPP) site, Bangladesh

ABSTRACT Radon is a colourless, unscented, radioactive inert gas. As a gaseous element, Rn-222 can be effectively breathed in, leading to a health hazard. The main objective of this study is to measure the amount of Rn-222 concentration in surface water and its associated health hazards around the Rooppur Nuclear Power Plant (RNPP) construction site area in Bangladesh. Twenty water samples were collected each year (2022 and 2023) from different specific locations of the Padma River and investigated for radon concentration through a Durridge RAD7 detector with RAD H2O accessories. The range of radon activity in surface water measured from 0.070 ± 0.035 to 0.385 ± 0.211 BqL−1 with a mean activity of 0.194 ± 0.114 BqL−1 in the year 2022 and in the year 2023, the range of radon activity in surface water measured from 0.035 ± 0.070 to 0.455 ± 0.239 BqL−1 with an average activity of 0.228 ± 0.140 BqL−1. All the radon concentration results were below the recommended limits of WHO (100 BqL−1) and USEPA (11.1 BqL−1). The ranges of annual effective dose (AED) were from 0.1911 to 1.051 µSvy−1 and from 0.095 to 1.242 µSvy−1 in the years 2022 and 2023, respectively, which were lower than the AED recommended by WHO (0.1 mSvy−1). The mean values of excess lifetime cancer risk are 0.0021 × 10−3 and 0.0025 × 10−3 in the years 2022 and 2023, respectively, which were lower than the average standard value recommended by UNSCEAR (0.29 × 10−3). The result of this investigation can be applied as baseline data for radon concentration measurement in the under-construction nuclear power plant site area vicinity of Bangladesh.

Health risk assessment of lead and cadmium exposure from food and snuff in Pakistani population

BackgroundSmokeless tobacco (SLT) is a tobacco-based product consumed without burning or smoking. Snuff, commonly known as naswar, is a widely used SLT product in Pakistan. This study is designed to investigate the concentrations of lead (Pb) and cadmium (Cd) in snuff and their associated health risks to consumers. MethodsBlood samples from snuff consumers and non-consumers were analyzed for Pb and Cd concentrations. Additionally, samples of drinking water and wheat flour were also analyzed for Pb and Cd. Health risk assessments were calculated using hazard quotient (HQ) and incremental lifetime cancer risk (ILCR) for Pb and Cd. ResultsSnuff consumers had significantly higher blood-Pb and blood-Cd levels compared to non-consumers. Approximately 38.5 % of snuff consumers were found to exceed blood-Pb levels from the safe limits (10 µg dL⁻¹) of the World Health Organization (WHO), while 48.9 % of snuff consumers were found to exceed blood-Cd levels from the WHO safe range of 0.03–0.12 µg dL⁻¹. Snuff samples contained Pb and Cd concentrations ranging from 5.3 to 22.4 µg g⁻¹ and 0.5–2.2 µg g⁻¹, respectively. Drinking water and wheat flour samples were found within the safe limits for Pb and Cd concentration, suggesting snuff as the primary source of exposure. Health risk assessments indicated elevated HQ values, for Pb (38.9 %) and Cd (14.3 %) detected in snuff, surpassing the safe HQ threshold of 1. Concerning ILCR from snuff, values for Pb were within the acceptable range, but alarmingly 100 % of samples for Cd exceeded the safe limits of USEPA (1.0×10⁻⁴), indicating a significant cancer risk in snuff users. ConclusionThis study highlights the exceeded Pb and Cd concentrations in snuff as well as also reporting significant carcinogenic and non-carcinogenic health risks to consumers. These findings emphasized the urgent need for regulatory bodies to ensure the safety of snuff before selling in the market. Public Health Professionals should also initiate educational campaigns to raise awareness among consumers and manufacturers about various health risks associated with the snuff.

Assessment of contamination level of radon (222Rn) in drinking water around Tulsishyam geothermal area and Savarkundla fault in Saurashtra, India.

This study aimed to estimate radon concentrations in groundwater and surface water to evaluate radon (222Rn) contamination in drinking water within the Amreli region of Saurashtra, Gujarat, India. Water samples from 84 sites, covering about 3000km2, were analyzed using the RAD7 device from Durridge Instruments. Samples were collected in 250ml radon-tight bottles. Radon concentrations ranged from 0.1 to 13.6Bq/L, averaging 4.52Bq/L. At three sites (P9, P29, P35), radon levels exceeded the USEPA limit of 11.1Bq/L. P9 and P29 are near the Tulsishyam geothermal area, while P35 is close to the Savarkundla fault. Geothermal fluids in Tulsishyam may facilitate radon migration, and swarm-type earthquakes near Savarkundla could also contribute to radon migration. Concurrently, physicochemical parameters like Potential of Hydrogen (pH) and Total Dissolved Solid (TDS) were measured, with no significant correlation found between radon levels and these parameters. Samples were taken from tube wells with depths ranging from 105 to 750 feet, averaging 359 feet. A strong and significant correlation (0.83) was observed between radon concentration and water depth. Health risks from radon exposure were assessed by estimating annual effective dose rates for different age groups through ingestion and inhalation. In some instances, the annual effective dose rate surpassed the WHO-recommended value of 100µSv/year. However, in most instances, the presence of radon in the water does not indicate a significant radiological risk.

Impact of COVID-19 Lockdown on Inhaled Toxic Elements in PM2.5 in Beijing: Composition Characterization and Source-Specific Health Risks Assessment

In early 2020, China experienced a mass outbreak of a novel coronavirus disease (COVID-19). With an aim to evaluate the impact of emission variations on toxic element species in PM2.5 and the health risks associated with inhalation exposure during COVID-19, we collected PM2.5 filter samples in Beijing from January 1 to February 28, 2020. Positive matrix factorization (PMF) and a health risk (HR) assessment model were used to assess the health risks of the toxic elements and critical risk sources. The total concentration of eight toxic elements (Se, Cd, Pb, Zn, As, Cu, Ni, and Cr) in Beijing showed a trend of first increasing and then decreasing: full lockdown (322.9 ng m−3) &gt; pre-lockdown (264.2 ng m−3) &gt; partial lockdown (245.3 ng m−3). During the lockdown period, stringent control measures resulted in significant reductions (6−20%) in Zn, Pb, Cd, and Ni levels, while concentrations of Se, As, Cu, and Cr were unexpectedly elevated (14−348%). A total of five sources was identified: traffic emission, coal combustion, dust emission, industrial emission and mixed source of biomass burning and firework combustion. Total carcinogenic risk (TCR) of the selected toxic elements exceeded the US EPA limits for children and adults. As and Cr (IV) were the main contributors to non-carcinogenic and carcinogenic risks, respectively. For source-resolved risks, coal combustion was the main contributor to HI (43%), while industrial emissions were the main cause of TCR (45%). Additionally, increased contributions from coal combustion, biomass burning, and firework combustion during the full lockdown elevated the HI and TCR values.

Determination of Some Heavy Metals in Water and Sediment Samples from Maska Dam, Katsina State, Nigeria

Water and sediment samples collected from Maska dam in dry and wet seasons were analysed for some heavy metals namely, Cd, Cu, Ni and Zn. After sample digestion, micro-wave Plasma atomic absorption spectroscopy (MPAES) was used to determine the concentrations of the metals. The concentrations were analysed statistically using one way analysis of variance (Anova). The levels of metals in water and sediment were compared with local and international regulatory authorities. From the result of analysis, the concentrations of the metals in (mg/L) were as follows: 0.03±0.01 for Cd, 0.186±0.003 for Cu, 0.19±0.005 for Ni and 0.193±0.003 for Zn, 0.027±0.002 for Cd, 0.057±0.002 for Cu, 0.114±0.002 for Ni and 0.141±0.001 for Zn in water samples in dry and wet seasons. Likewise, the concentration of the metals in sediment in dry and wet seasons were, 0.0196±0.002 for Cd, 0.143±0.003 for Cu, 0.166±0.044 for Ni and 0.766±0.044mg/kg for Zn in dry season. Similarly, 0.019±0.001 for Cd, 0.143±0.004 for Cu, 0.160±0.09 for Ni and 0.451±0.003mg/kg for Zn were obtained in wet season. The concentrations of Cu and Zn were below the permissible limits of WHO/SON while Cd and Ni were above the permissible limit of WHO/SON in water samples. However, the concentrations of all the metals were below the permissible limits of NOAA and USEPA. The result of statistical analysis indicated no significant difference at P greater than 0.05 (P&gt;0.05).

Assessment and Evaluation of Atmospheric Trace Metals Pollution in Lapai Metropolis, Niger State Using Foliose Epiphytic Lichen (Parmelia sulcata)

The levels of atmospheric trace metals were determined using foliose epiphytic lichens (Parmelia sulcata) samples collected in eight (8) different locations within the residential areas and two control locations outside the residential area of Lapai town in Lapai local government of Niger State. A stratified random sampling technique was adopted and the analysis of the samples with atomic absorption spectrophotometer (AAS) gives the concentration range of the metals as follows; 1.123-7.837 mg/kg for Fe, 4.579-6.627 mg/kg for Pb, 0.210-2.152 mg/kg for Cr, 0.491-1.171 mg/kg for Ni, 0.018-0.983 mg/kg for Cd, 0.057-1.471 mg/kg Zn, 0.198-1.287 mg/kg for Mn, and 0.098-2.583 mg/kg for Cu but Selenium was not detected in all the samples. The levels of some of these metals were slightly higher compared to recommend USEPA (1993) limits but lower than FEPA (1991) limits. However, the distribution of these metals was not uniform across the samples, though their level was still at the background and very low compared to the reports on similar studies from industrialized areas of South-south and South-west Nigeria and other European countries. The variation in concentration of these metals at P≤0.05 indicates their source is mainly anthropogenic in origin. Epiphytic lichens validate the cost-effectiveness of this method for evaluating, assessing, and identifying depositional sources of the metals in the environment. The study revealed the atmospheric trace metal concentration of the area under study to be at a threshold level and hence the environment is still very safe from atmospheric trace metal pollution.

Integrated GIS-based and water quality index for evaluation of groundwater quality in the coastal slum settlements of Lagos, Nigeria

This study aimed to identify drinking water suitability through a statistical and water quality index (WQI) approach in coastal slum settlements in Lagos, Nigeria. A total of 250 borehole groundwater samples collected for drinking purposes during the wet (125) and dry (125) seasons were analysed for their physical and chemical properties from 2019 to 2020. The physical and chemical characterisation of the region was conducted based on the correlation matrix, scree plot, PCA, Q-mode HCA, and ROC curve to identify the types of weathering, the influence of rock on precipitation and evaporation, and types of reactions that affect groundwater composition. The analytical mean concentration results revealed that SO4, Cl, TH, NO3, TDS, and PO4 surpassed the USEPA and WHO permissible limits in both seasons. The WQI results demonstrate that 7.6% and 6.7% of water samples fall into the excellent category, while 12.4% and 11.5% are moderately tolerable. In contrast, for both seasons, >100% of the samples fell into the unsuitable drinking category across SA1-SA5, SB1-SB5, SC1-SC5, SD1−SD5, and SE1−SE5. Groundwater quality mainly deteriorates due to anthropogenic activities and climatic variability. The spatial variation map indicates that groundwater quality is primarily affected during the wet season and, to a lesser extent, in a few slums during the dry season. Seawater influx in coastline areas has been identified as the main factor threatening the quality and availability of groundwater resources. As a result, the groundwater quality is mostly poor to unsuitable, and this study confirms its unsuitability for drinking. Hence, this study serves as a guide for effective action in sustainable groundwater management.

Distribution, Levels, Potential Sources and Human Health Risk Assessment of Trace Metals in Atmospheric Particulate Matter in Ogbia communities of Bayelsa State, Niger Delta, Nigeria

The occurrence of toxic metals in atmospheric particulate matter is of high risk to human health. Hence, the objective of this paper was to evaluate the distribution, concentrations, potential sources and human health risk assessment of trace metals in atmospheric particulate matter in Ogbia communities of Bayelsa State, Niger Delta, Nigeria. Samples of atmospheric particulate matter were digested using a mixture of acids, and quantification of trace metals was achieved using atomic absorption spectrophotometry (Model: Buck 230 ATS). The concentration (µg m-3) of trace metals in atmospheric particulate matter ranged as follows: Pb (&lt;0.010 - 0.060), Cd (&lt;0.010 - 0.880), Ni (&lt;0.010 - 0.028), Cu (&lt;0.010 - 0.046), Zn (&lt;0.010 - 0.028), and Co (&lt;0.010 - 0.021). Except nickel (Ni) and cadmium (Cd), other metal concentrations were below the US EPA limits. Principal component analysis indicated a common source of the studied metals and two major factors (gas flaring and uncontrollable fossil fuel combustion) were identified; while non-carcinogenic risk due to inhalation indicated negligible health risk. Therefore, hazardous effects due to inhalation of trace metals in atmospheric particulate matter in the study area is minimal.

Radon Levels and Risk Assessment due to its Ingestion and Inhalation from Groundwater of Lapai, North-Central Nigeria

Radon exposure through ingestion or inhalation from groundwater can be a significant public health concern due to its carcinogenic effects. This study assessed the health risks of radon exposure from groundwater in Lapai, Nigeria, using a Rad7 detector to measure radon concentration levels. The measured concentrations ranged from 5.36 ± 0.22 BqL-1 to 0.52 ± 0.06 BqL-1 with an average value of 2.82 ± 0.14 BqL-1. The annual effect dose due to ingestion of Radon obtained varies in the range of 2.76 to 28.34 μSva-1, 1.02 to 10.43 μSva-1, and 1.33 to 13.69 μSva-1 for infants, children, and adults, respectively. While the effective dose per year from inhalation of Radon released from water by adults has values in the range of 1.31 to 13.50 μSva-1. Radon levels were within permissible limits of UNSCEAR and USEPA, and the annual effective doses from inhalation and ingestion were within WHO's safe range. Nonetheless, monitoring is advised, especially during the rainy season when contamination levels may increase.

Evaluation of environmental radioactive contamination of radon gas in Karrada homes in Baghdad Governorate, Iraq

The analysis addressed the study of radon contamination collection in dwellings located at Karada, Baghdad. The outcomes revealed that the concentration of radon varied from 17.324 to 45.00 Bq/m3 with an average value of 26.8432 ± 2.216 Bq/m3. AED results were observed to vary from 0.001 mSv/year to 0.847 mSv/year having an average value of 0.2352 ± 0.0647 mSv/year, where potential alpha energy concentrations ranged from 0.26 mWL to 0.93 mWL with a mean value of 0.4179 ±0.057 mWL and radon daughter exposure ranged from 0.13 mWLM/Y to 0.44 mWLM/Y having a mean value of 0.4943 ± 0.111 mWLM/Y.Based on our findings we can conclude that, as anticipated, most indoor values are well below the US EPA limit of 148 Bq/m3

Human health risk assessment of trace elements in commonly consumed herbs in Ibadan, Nigeria

Elemental contamination of medicinal herbs is a major barrier to its general use. This study assessed the concentrations and health risks of Manganese, Iron, Copper, Zinc, Chromium, Cadmium, Cobalt, Nickel, Lead and Selenium via consumption of commonly sold medicinal herbs in Ibadan, Nigeria. Exactly 180 medicinal herb samples, purchased from 10 markets across Ibadan, were digested using aqua-regia. Quantification via Inductively Coupled Plasma-Optical Emission Spectrometry (ICP–OES) was done and validated via recovery (99.6–101%) and linearity (R2 > 0.999) procedures. The health risk associated with the consumption of medicinal herbs was estimated as Chronic Daily Intake (CDI), Hazard Quotient (HQ), Hazard Index (HI) and Target Carcinogenic Risk (TCR). The concentrations (mg kg-1) of Iron, Manganese, Copper, Zinc, Chromium, Selenium and Cobalt ranged from 65.4 to 369, 32.7–184, 17.0–96.0, 36.1–203, 5.41–30.5, 0.028–0.159 and 0.675–3.81 respectively. The average concentrations of Iron, Copper, Zinc and Chromium exceeded the WHO permissible limits. Although some elemental HQ values <1, all medicinal herbs had HI values > 1. Likewise, TCR values exceeded the 1 × 10–4 USEPA limit for cancer suggesting that consumption of these medicinal herbs is not safe for both adults and children.

Bioaccumulation of Potentially Toxic Elements in Tilia tomentosa Moench Trees from Urban Parks and Potential Health Risks from Using Leaves and Flowers for Medicinal Purposes

Potentially toxic element (PTE) contamination in medicinal plants, particularly those growing in urban environments, can cause human health issues. Therefore, this study evaluated trace element accumulation and translocation patterns (As, Cr, Cu, Ni, Pb, Sr, and Zn) in the aboveground tissue of common Tilia tomentosa Moench, often used as a medicinal plant, sampled in Belgrade’s urban parks (Zemunski Park, Park Blok 63, and Park Topčider). Our results indicated that this species exhibits the ability to accumulate and translocate PTEs, particularly Cu, in its aboveground parts. It was found that the levels of Cu and Sr in flowers were within the toxic range for plants, indicating a potential risk in using T. tomentosa flowers from Park Topčider for medicinal purposes. The maximum Estimated Daily Intake of Ni from the consumption of leaves and flowers of plants growing in two parks (Zemunski Park and Park Topčider) exceeded the corresponding Provisional Tolerable Daily Intake. Additionally, the Carcinogenic Risk calculated for Cr present in flowers was above the USEPA limit (3.021 × 10−3), indicating possible adverse effects on human health and a carcinogenic risk from ingesting tea prepared from T. tomentosa flowers from Park Topčider. Our research underlines how crucial it is to cautiously use medicinal tree species growing in urban parks in residential areas.

Statistical Analysis and Health Risk Assessment: Vegetables Irrigated with Wastewater in Kirri Shamozai, Pakistan.

One of the primary environmental routes through which humans are exposed to metals and may be exposed to health risks is the food chain's contamination with heavy metals. The study observed the risks posed by contaminants in vegetables produced in soil that received wastewater irrigation, as well as their origins and the human health impacts. Eight harmful metals (Cu, Fe, Zn, Mn, Pb, Cd, Ni, and Cr) were tested for concentration levels in water, soil, and vegetable samples using analytical techniques and an atomic absorption spectrophotometer. The present study investigated the potential health implications associated with the consumption of vegetables irrigated using wastewater containing heavy metals. The results indicated a notable accumulation of heavy metals in plant and soil samples obtained from Kirri Shamozai, Pakistan. In comparison to vegetables cultivated in soil irrigated with fresh water, the concentration levels of heavy metals in vegetables grown on soil irrigated with untreated wastewater were considerably higher at (P ≤ 0.001) and above the World Health Organization (WHO) recommended limits. The results showed that heavy metals had significantly accumulated in the soil and had permeated into the crops. Heavy metal concentrations in vegetables cultivated on land irrigated with wastewater were more significant than those grown on land irrigated with freshwater. They exceeded US EPA and World Health Organization (WHO) limits. PCA results for Pb, Cu, and Cr are the main issues impacting water quality and health hazards. The PCA results show that the soil has an extensive loading of heavy metals Cd, Ni, and Mn.

A Comparative Study of Heavy Metal Pollution in Ambient Air and the Health Risks Assessment in Industrial, Urban and Semi-Urban Areas of West Bengal, India: An Evaluation of Carcinogenic, Non-Carcinogenic, and Additional Lifetime Cancer Cases

Air pollution is an immense problem due to its detrimental health effects on human populations. This study investigates the distribution of particle-bound heavy metals and associated health risks in three diverse areas (Durgapur as an industrial complex, Kolkata as an urban area, and Bolpur as a semi-urban region) in West Bengal, India. Twenty-one (84 samples) sampling sites were chosen, covering industrial, traffic, residential, and sensitive zones. The respirable suspended particulate matter (RSPM) samples were collected using a portable Mini-Vol Tactical Air Sampler, and heavy metal concentrations (Cd, Cr, Mn, Ni, Pb, and As) were analyzed using ICP-OES. The non-carcinogenic and carcinogenic health risks were assessed using exposure concentration (EC), hazard quotient (HQ), hazard index (HI), and additional lifetime cancer cases. The results highlight variations in heavy metal concentrations across the regions, with industrial areas exhibiting higher levels. Principal component analysis (PCA) unveiled distinct metal co-variation patterns, reflecting sources such as industrial emissions, traffic, and natural contributors. The sum of non-carcinogenic risks (HI) of all heavy metals exceeded the US EPA’s risk limit (HI&lt;1) in both Kolkata and Durgapur, except for Bolpur. Similarly, the sum of cancer risk in three distinct areas exceeded the USEPA limits (1.00E-06). The Monte Carlo simulation revealed the 5th and 95th percentile range of cancer risk was 9.12E-06 to 1.12E-05 in Bolpur, 3.72E-05 to 4.49E-05 in Durgapur and 2.13E-05 to 2.57E-05 in Kolkata. Kolkata had the highest additional lifetime cancer cases compared to Bolpur and Durgapur. This study provides information on the complex connections between heavy metal pollution and possible health risks in industrial, urban, and semi-urban regions.

Potential of the Bioaugmentation Method to Enhance the Remediation Process in the Solidification/Stabilization Method

In the published literature, Stabilization/Solidification (S/S) method was excellent in remediating heavy metals, whereas bioremediation was excellent in remediating organic contaminants. However, tremendous papers onlyfocus on specific contaminants, while the polluted environment is not due to specific contaminants. In this paper, both methods were combined and targeted to remediate both group contaminants, namely organic contaminants and heavy metals. The study focused on the effect of the bioaugmentation method on S/S method with the use of Portland cement as a binder in the S/S method. Sphingobacterium spiritivorum(bacteria) and Aspergillus brasiliensis(fungi) as degrading agents in the bioaugmentation method. The S/S matrices were tested for leaching behaviour which is the concentration of Chemical Oxygen Demand (COD) and heavy metals after 14 and 28 days of hydration. Bacteria augmentation showed a better COD removal compared to without augmentation (S/S method only). Bacteria augmentation also shows better removal compared to fungi augmentation for both hydration days. In addition, by using the S/S method only, COD concentration was increased from 14 to 28 days. For heavy metals, chromium shows a positive result; bacteria augmentation shows the lowest concentration after 14 and 28 days of hydration. While other metals, S/S method only shows the lower concentration compared to samples that augment with bacteria and fungi. Nonetheless, the concentrations of heavy metals in all samples did not exceed the USEPA limit. Therefore, this study contributed to the possibility of combining the S/S and bioaugmentation methods by adding degrading agents to remediate contaminants in the sludge, especially for sludge that containshigh organic contaminants.

Levels of heavy metals in water and Nile tilapia fish (&lt;i&gt;Oreochromis niloticus&lt;/i&gt;) of Eleyele Lake in Ibadan, Nigeria

Surface waters are susceptible to hazardous pollution which may migrate with devastating health challenges through the food chain to humans. This study evaluates the levels of heavy metals in water and Nile tilapia of Lake Eleyele. The physicochemical properties of water samples were determined using standardized methods, while heavy metals in both water and fish samples were determined using atomic absorption spectrophotometer (AAS). Water pH, electrical conductivity, total dissolved solids, total suspended solids, and dissolved oxygen were within WHO and USEPA limits for potable water. Cu (0.028 – 0.112 mgL-1), Pb (0.002 – 0.009 mgL-1), and Zn (1.46 – 3.79 mgL-1) were below the maximum permissible limits by both WHO and USEPA, while cadmium, chromium, and nickel were not detected in the water samples. Cu (2.56 -3.54 mg/kg), Zn (22.93 – 32.13 mg/kg), and Ni (0.39 – 0.48 mg/kg), are within acceptable levels, while Cd and Cr were also not detected in the fish samples. However, Pb (1.71 – 2.30 mg/kg) was higher in the fish samples than the threshold limit (0.3 mg/kg) by FAO and WHO. In accordance, Pb with bioconcentration factor (BCF: 402) was more highly bio-accumulated in the fishes than Cu (BCF: 54.4) and Ni (BCF: 10.97). The results recommend the river water for utility purposes but raised concerns about the consumption of Nile tilapia fishes in the lake.