Heavy Metal Pollution Index Research Articles

Analysis of Heavy Metals in Water and Wastewater

The primary focus of the study is to assess the presence and concentration of heavy metals in the water and evaluate its suitability for drinking purposes. Given that a significant portion of the local population depends on groundwater for their daily needs, the study is critical in understanding the potential health risks associated with consuming contaminated water. The study begins with a comprehensive survey to gauge the extent of water usage among the local population and their perceptions of water quality. Results from the survey reveal that nearly half of the households in the region are not connected to a formal drinking water network, relying instead on wells and springs. While the majority of respondents perceive the water quality as good, the analytical findings suggest otherwise. Groundwater samples were collected from twelve wells and three springs across the region. These samples were subjected to rigorous analysis using inductively coupled plasma-atomic emission spectrometry (ICP-AES) to detect the concentration of various heavy metals, including aluminum, silver, iron, cadmium, arsenic, chromium, cobalt, zinc, lead, and copper. The results indicate that many of these metals are present in concentrations that exceed the World Health Organization's recommended limits for safe drinking water. Iron, in particular, was found at high levels in all sampled locations, raising significant concerns. The study also employs the Heavy Metal Pollution Index (HPI) to provide a more comprehensive assessment of water quality. The HPI values calculated for the sampled water sources reveal that a majority of the wells and all of the springs have levels of heavy metal contamination that render the water non-potable. This finding is particularly alarming given the region's dependence on water, especially during periods of drought when alternative water sources are scarce.

Evaluation of contaminated groundwater for excessive heavy metal presence and its further assessment of the potential risk to public health.

Water plays a significant role in human life. However, the contamination of groundwater by heavy metals (HMs) has profound implications for public health. Industrialization, urbanization, and agricultural activities are turning out to be major causes for the increasing concentration of HMs in rapidly industrializing areas like Rohtak district, Haryana, India. The current study aimed at evaluating and predicting the health hazards associated with the radical rise of HMs in the groundwater of Rohtak district. For this purpose, 45 seasonal-based groundwater samples were collected from five blocks in Rohtak district, namely Kalanaur, Meham, Lakhan Majra, Rohtak City, and Sampla, both during pre- and post-monsoon seasons. Besides physicochemical analysis, these groundwater samples were analyzed for the contamination of HMs. The findings revealed that groundwater samples were relatively more contaminated during the post-monsoon period rather than pre-monsoon. The water quality index (WQI), devised to classify water quality into specific classes, depicted the Kalanaur region as "very poor." Another index named the HM pollution index (HPI) denoted the levels of HMs and categorized Kalanaur as most deteriorated, followed by Meham, Lakhan Majra, Sampla, and Rohtak City. Additionally, principal component analysis (PCA) was employed that showed a significant variation in the distribution pattern of HMs, with the major load being attributed to PC1 and PC2 for both seasons. Pearson's correlation analysis indicated a significant association of pH (R2 = 0.917) with HMs (specifically for Cd and Cr). In terms of health risk assessment, carcinogenic human health risk due to Pb and Cr was found to be higher in children than adults. Non-carcinogenic risk, indicative of harmful human health effects, apart from cancer, was calculated in terms of hazard quotient (HQ) and hazard index (HI). Results of the same, designated "children" as a vulnerable category compared with "adults," especially in the Kalanaur, Sampla, and Rohtak City blocks of the study area. The results thus reiterated that Kalanaur is the most contaminated block among the five blocks chosen and should be given urgent attention. The study holds importance as it provides a framework regarding the methodology that should be adapted for the evaluation, management, and protection of groundwater at a regional level, which could further be replicated by environmentalists and hydrogeologists across the world. PRACTITIONER POINTS: Water logging is one of the most common problems in Kalanaur block of Rohtak district, responsible for causing groundwater pollution. Cadmium and lead pollution was prevalent in Rohtak due to electroplating industries, paint industry, automobile sector, and industrial discharge. Bioremediation is one of the suitable techniques that can be used for the treatment of groundwater that involves the use of microorganisms. Efficient use of groundwater resources is necessary for sustainable development.

Ecological and Health Risk Assessment of Heavy Metals in Groundwater within an Agricultural Ecosystem Using GIS and Multivariate Statistical Analysis (MSA): A Case Study of the Mnasra Region, Gharb Plain, Morocco

Assessing groundwater quality is essential for ensuring the sustainability of agriculture and ecosystems. This study evaluates groundwater contamination by heavy metals (HMs) using GIS approaches, multivariate statistical analysis (MSA), pollution indices (heavy metal pollution index (HPI), metal index (MI), degree of contamination (Cd), ecological risk index (ERI), and pollution index (PI)), and human health risk assessment (HHRA). The results revealed significant variations in heavy metal concentrations across the study area, with the highest concentrations found in the southern and southeastern parts, characterized by intense agricultural activities and uncontrolled landfills. Statistical analyses indicated both natural and anthropogenic sources of contamination. Pollution indices showed medium to high water pollution levels, with HPI values ranging from 20.23 to 128.60, MI values from 3.34 to 12.17, and Cd values from 2.90 to 11.73, indicating varying degrees of contamination. ERI values suggested a low ecological risk across all samples. However, health risk assessments highlighted significant non-carcinogenic and carcinogenic risks, particularly for children, with TCR values for some heavy metals like Ni and Cr exceeding safe limits, indicating potential health hazards. The findings provide a valuable framework for policymakers to develop targeted strategies for mitigating groundwater contamination and ensuring sustainable water quality management.

Pollution index and distribution characteristics of soil heavy metals among four distinct land use patterns of Taojia River Basin in China

The accumulation of heavy metals (HMs) in soil has become a pressing global concern due to their persistent and non-degradable nature, resulting in the accumulation of toxic levels in the environment. In recent years, human activities have significantly altered land use patterns, leading to a marked increase in soil HM levels and subsequent land degradation. This research focused on four distinct land use patterns (vegetable fields (VGF), woodland (WDL), cultivated land (CVL), and wasteland (WSL)) commonly found in the Taojia River Basin, Hunan, China, which is facing severe HM pollution. Soil samples were collected from three different depths (0–10 cm, 10–20 cm, and 20–30 cm) to investigate HM distribution and intensity (cadmium (Cd), lead (Pb), copper (Cu), nickel (Ni), and zinc (Zn)), comprehensive soil pollution index, and their relationship with soil microbial and enzymatic activities. The results revealed that the Cd content exceeded the national standard for soil environmental quality, whereas concentrations of other HMs did not exceed the national standard across the four land use patterns. Most soil HMs were concentrated in the surface layer, with Cu, Pb, and Zn concentrations gradually decreasing with increasing soil depth. Conversely, Ni and Cd concentrations tended to increase with greater soil depth. There were significant positive correlations among HMs, indicating homogeneity among them. The pollution index across the HMs ranked as Cd > Ni > Zn > Cu and Pb, with land uses following the order of VGF (2.70) > CVL (2.12) > WSL (1.72) > WDL (1.63). Soil microbial and enzymatic activity was not the primary factor influencing HM concentration. The specific impacts of land use changes on soil HMs depend on management practices, local conditions, and the distribution characteristics of the HMs involved.

Assessment of heavy metal diffusion rates from river Yamuna and its effect on the surrounding geology: An experimental and theoretical study

The present study for the first time quantitatively investigates the acute pollution of the Yamuna River, focusing on the diffusion of heavy metals from industrial effluents into groundwater, surrounding soils, and crops, and its subsequent impact on human health. Owing to the unplanned discharge of the untreated effluents, the river exhibits heavy metal concentrations exceeding Indian standards. Utilizing 1-D diffusion transport models, Heavy metal pollution indices (HPI), and transfer factor (TF) for two different locations, it was understood that diffusion is a dominant mechanism that allows the heavy metals from the river to pollute the surrounding geology. The HPI in the groundwater was more than 200 at the studied locations indicating severe contamination of the groundwater, moreover, the TF of the crops through the soil was more than unity for various heavy metals present, viz., Cr, Cu, Zn, Cd, and Hg. The estimated apparent diffusion coefficient (Da) was also found to be very high for these metals that lay in the range of 4.8 × 10−10 – 9.9 × 10−10 m2/s. The time necessary to migrate from the river to the crops was the least for Hg. The suitability of the crops for ingestion post-diffusion was further assessed by estimating the Daily Intake of Metals (DIM). The DIM reveals that the crops are highly unsuitable for children and adults as the values exceed the standard limits. Such a high migration rate of heavy metals from the river to the surrounding geology needs attenuation at the source to restrict migration. The evaluated apparent Da and migration times of heavy metals would provide critical insights for designing effective barrier systems to mitigate contamination.

Heavy metal's pollution health risk assessment and source appraisal of groundwater and surface water in Irob catchment, Tigray, Northern Ethiopia

Contamination of water resources by heavy metals causes health problems for humans. This study attempts to investigate the heavy metal contamination levels, health risks and sources of appraisal of groundwater and surface water in the mountain-bounded catchment and low-grade basement rock-dominated area of ​​the Irob, Tigray. Eighteen grab water samples (13 borehole water, 2 spring water and 3 surface water) were collected and analyzed for pH, electrical conductivity, total dissolved solids and heavy metals using standard procedures. The findings were contrasted with those of the standards set by the World Health Organization and the United States Environmental Protection Agency. Integrated techniques, including indexed and statistical methods, were used to determine the contamination levels of metals, risks to human health and sources. The result shows that the pH value, electrical conductivity and total dissolved solids fluctuated between 7.4 and 7.9, 516 and 2410 µs/cm and 396.7 mg/l and 1719 mg/l, respectively. The findings indicate that 94.4% of the water samples had levels of contamination above the critical limit for all three indices: the heavy metal evaluation index (HEI), the degree of contamination (cd) and the heavy metal pollution index. The hazard index of metals for adults and children was greater than 1. 88.9% of the water samples showed a cancer risk value above the recommended value (CR > 1 × 10–4) for Cd and Cr for both adults and children. Multivariate statistical analyses indicate that weathering of bedrocks and partly anthropogenic influences are responsible for the metal contamination. The study concludes that some water samples sources are unfit for human consumption that can pose health risks over time. Therefore, it is recommended to treat contaminated water sources to protect and sustain public health.

Unveiling the Dynamics and Sustainability of the Nubian Aquifer System in El-Marashda, Egypt Through Geophysical, and Hydrogeochemical Investigations

AbstractThis research investigates the geophysical, hydrogeochemical, and geological characteristics of the Nubian Aquifer System in the El-Marashda area, located beneath the Eastern Sahara Desert in northeastern Africa. The primary objective is identifying the aquifer geometry, assessing groundwater quality, and evaluating environmental pollution levels. A Magnetotelluric survey was employed to examine the subsurface geological composition and electrical resistivity characteristics of the aquifer system. The study revealed a freshwater-saturated Nubian Sandstone layer at depths between 986 and 1009 m with resistivity values of 101 to 182 Ohm.m, indicating a substantial and potentially sustainable groundwater resource. Overlying limestone and Marly Limestone layers influence the aquifer’s permeability and storage capacity. The chemical analysis of water from three wells showed suitability for drinking and irrigation, with no sodium and magnesium levels hazards. The Heavy Metal Pollution Index (HPI) and Heavy Metal Evaluation Index (HEI) indicated low to medium contamination, posing potential environmental health risks. Human health risk assessments using USEPA methodology found acceptable non-carcinogenic risks, with Hazard Quotients (HQs) for heavy metals below 1 and a negligible Hazard Index (HI). The comprehensive investigation underscores the potential for sustainable groundwater utilization in El-Marashda. It highlights the aquifer’s suitability for irrigation, with low contamination levels and minimal health risks. These findings provide a foundation for informed and sustainable water resource management, environmental protection, and resilient infrastructure development in the region. The methodologies and results align with global standards, demonstrating their applicability in globally diverse geological contexts. This research contributes valuable baseline data for future studies and monitoring efforts, whether at local or global sites, emphasizing the importance of continued investigation to ensure sustainable groundwater management.

Distribution Characteristics and Ecological Risk Assessment of Heavy Metals in Roadside Soil of Important National Highways on the Qinghai-Xizang Plateau

To clarify the impact of transportation on the sensitive and fragile ecosystems of the Qinghai Tibet Plateau and major ecological safety barrier functions, soil samples within 0-25 m on the roadside were collected from sections of national highways such as G214, G213, G345, G109, G316, and G317, and the contents of six heavy metals were analyzed. Then, the degree of heavy metal pollution and the risk of ecological hazards were evaluated using the single-factor pollution index method （Pi）, Nemero comprehensive index method （PN）, and potential ecological risk index method （RI）. The results showed that the heavy metal contents of As, Cd, Hg, Ni, Pb, and Zn in the soil of important transportation national roads on the Qinghai Tibet Plateau ranged from 5.65 to 176.00, 0.04 to 0.27, 0.01 to 0.14, 9.52 to 113.00, 9.16 to 54.50, and 24.70 to 109.00 mg·kg-1, respectively, showing high variability. In some sections of the soil, the values of the elements As, Cd, and Hg were higher than the local soil background values. The single-factor pollution index of heavy metals in roadside soil was Pi （As） > Pi （Hg） > Pi（Cd） > Pi （Pb） > Pi （Ni） > Pi （Zn）. The Nemero comprehensive pollution index ranged from 0.41 to 9.20, with an average value of 1.53, indicating clean and mild pollution. Some areas showed a moderate or severe pollution. The average potential ecological risk index of the research section was 106.2, and the soil was generally in a state of no pollution and light pollution. Only two road sections had soil heavy metal enrichment reaching moderate and strong ecological hazards. The comprehensive potential risk of the G213a road section indicated moderate to severe ecological risk, mainly contributed by Hg, As, and Cd. The comprehensive pollution risk of the G317 road section indicated mild to moderate ecological risk, mainly contributed by Hg and Cd. The heavy metal content in the soil of the Qinghai Tibet Plateau road area was not significantly correlated with the roadside distance and soil depth but was significantly positively correlated with the annual average temperature （P < 0.05）. In all, there was a trend of heavy metal input into the soil environment in areas with intense human activities and high traffic flow during road construction on the Qinghai Tibet Plateau.

Advanced approach combines integrated weight water quality index and potential toxic elements for environmental and health risk assessment supported by simulation technique in Oued Souf, Algeria

The current research study evaluated the health and environmental risks issues associated with potentially toxic elements (PTEs) in the complex terminal aquifer located in the Algerian desert. The methods used included principal component and cluster (dendrogram) analysis to estimate source of ions and contamination. Various indices such as the Heavy Metal Pollution Index (HPI), Metal Index, hazard quotient, hazard index (HI), and cancer risk (CR) were applied to assess both environmental and human health risks. Furthermore, the Monte Carlo method was applied for probabilistic assessment of carcinogenic and non-carcinogenic risks through oral and dermal exposure routes in both adults and children. The results revealed that approximately 16% of the samples fell within the low pollution category (HPI < 100), indicating relatively lower levels of heavy metal contamination. However, the remaining 84% of the samples exhibited high pollution levels, indicating a significant presence of heavy metal pollutants in the northeastern part of the investigated area. The calculated average risk index (RI) for the collected samples was 18.99, with a range from 0.03 to 103.21. This indicates that a large portion, 82% of the samples, could cause low ecological risk (RI < 30), whereas the remaining 18% indicate a significant environmental pollution risk. The HI for oral ingestion showed that adults had HI values ranging from 0.231 to 1.54, while children exhibited higher values, ranging from 0.884 to 5.9 (Fig. 5a). For dermal exposure, HI values in adults ranged from 2.71E−07 to 8.74E−06 and in children, from 2.18E−06 to 7.03E−05. These findings highlight the potential non-carcinogenic risks associated with oral exposure to PTEs and underscore the increased vulnerability of children to metals such as Fe, Mn, Pb, and Cr. Most samples showed CR exceeding 1 × 10−4 for chromium (Cr) and lead (Pb), indicating a significant vulnerability to carcinogenic effects in both children and adults.

A probabilistic risk assessment of heavy metal in water and sediment: An industrially affected urban river in Bangladesh.

Human welfare and biodiversity are at risk due to the deterioration of water and sediment quality. Particularly, in last few decades, global water and sediment quality degraded due to the rapid industrialization and urbanization. This study aimed to determine the concentration of nine heavy metals and metalloid (Pb, Cr, Cd, Hg, As, Mn, Ni, Cu, and Zn) and assess the ecological risks using different pollution indices (e.g., heavy metal pollution index [HPI], Nemerow pollution index [NI], geo-accumulation index [Igeo], contamination factor [CF], degree of contamination [CD] and pollution load index [PLI], ecological risk index [ERI]) in water and sediment of the Shitalakshya River, an industrially affected urban river of Bangladesh. For the first time, 20 water and sediment samples were collected across a wider geographical area of the Shitalakshya River during both monsoon and dry seasons and analyzed using the atomic absorption spectrometer. Average concentrations of heavy metals and metalloid in water were within the Bangladesh standard except for Cr (51.69 ppb) and Mn (228.20 ppb) during monsoon season, portraying potential ecological and human health risks. Besides, average concentration of Mn (549.75 and 370.93 ppb), Ni (549.75 and 370.93 ppb), and Cu (45.34 and 36.09 ppb) in sediment during both seasons were above international standard, implying risk to aquatic sediment biota. The average HPI values indicated moderate to high contamination, whereas the NI values implied polluted water in monsoon season with severe pollution in port area of the river. Similarly, Igeo, CF, CD, and PLI elucidated different levels of contamination in the sediment, particularly during dry season. The ERI values also referred moderate ecological risk in the sediment during dry season. Overall, our findings highlight the alarming level of heavy metal pollution in the Shitalakshya River, necessitating immediate action to protect the aquatic environment, sediment biota, and human health. PRACTITIONER POINTS: This study determined the concentration of heavy metals and metalloid in water and sediment of the Shitalakshya River, Bangladesh. The study revealed that the average concentration of Cr and Mn in water exceeded national standard, whereas Mn, Ni, and Cu in sediment exceeded international limit. Potential ecological risk of heavy metals was also assessed using different pollution indices. Calculated pollution indices indicated different degree of pollution, implying critical ecological condition due to heavy metal pollution in aquatic environment and sediment biota.

Evaluation of ground water quality using heavy metal pollution indices and estimation of health risk

ABSTRACT This paper presents the monitoring of heavy metals, including cadmium (Cd), chromium (Cr), lead (Pb), copper (Cu), and zinc (Zn), in the groundwater of the Byrnihat Industrial Area and Guwahati City, which is located in close proximity to the Byrnihat Industrial Area. A total of 20 water samples were collected at distances approximately 1–2 km apart from each other. The pH and the TDS of the collected samples were analysed immediately after collecting samples using a digital pH and TDS meters. The collected samples were analysed using a Flame type Atomic Absorption Spectrophotometer. The highest observed values of Cd, Cr, Pb, Cu and Zn in mg/L were recorded to be 0.0526, 0.1438, 0.5175, 0.1060 and 0.0925, respectively. The average values of Cd, Cr, Pb, Cu and Zn were 0.0246 ± 0.0168 mg/L, 0.0282 ± 0.0421 mg/L, 0.4805 ± 0.0206 mg/L, 0.0653 ± 0.0276 mg/L, and 0.0642 ± 0.0098 mg/L, respectively. Cd and Pb concentrations were above the guideline values set by Bureau of Indian Standards (BIS) and the World Health Organisation (WHO) [WHO recommended values, Cd: 0.003 mg/L, Pb: 0.01 mg/L]. Though the average concentration of Cr was below the allowable limit, five samples within the Byrnihat industrial area were found to be above the limit. High values of pollution indices was observed for all the samples. The cumulative hazard index (HI) values for adults and children were found to be 8.56 and 9.37, respectively. The total cancer risk (TCR) was observed to be 7.87E-03 for adults and 8.54E-03 for children. The result obtained from the present investigation show significant contamination of ground water by heavy metals, particularly Pb, Cd, and Cr concentrations. The observed high values of hazard index and cancer risks indicate significant health risks, necessitating the need for immediate regulatory action.

Exploration of trace elements in groundwater and associated human health risk in Chattogram City of Bangladesh

The study aimed to evaluate trace metals in the groundwater of Chattogram City located on the southeastern coast of Bangladesh and assess their potential health risks. Given the city's unique characteristics as both a coastal and industrial hub in Bangladesh, a knowledge gap persists particularly in the assessment of trace metals. A random sampling technique was applied to collect one hundred and seventeen groundwater samples from different wards of the city to analyze some trace metals (Cr, Cd, Fe, Cu, Mn, Pb, and Zn) and the quality of the collected water samples was evaluated using different indices, such as Heavy Metal Evaluation Index (HEI), Groundwater Quality Index (GWQI), Heavy Metal Pollution Index (HPI), and Degree of Contamination (Cd). The average concentration of all the studied metals except Fe, Mn, and Cd satisfied the Bangladesh drinking water standards. The Fe, Mn, and Cd content were observed higher in shallow wells (depth 10–150 ft) followed by intermediate (151–300 ft) and deep wells (>300 ft). However, the Cr, Cu, and Zn content did not significantly change with aquifer depth. The spatial distribution map showed that the highest values of Mn and Cu were observed in the west-northern region of the city. Metal As was only found in shallow and intermediate aquifers. The HEI suggested that about 9 % of samples fall into the higher degree of pollution category similar to the GWQI, while 37 % and 42 % of samples exhibited a higher degree of pollution in the case of HPI and Cd, respectively. The positive correlations and loadings found in the statistical analysis indicated that Fe, Mn, and Cu originated from the same sources. A variety of industrial activities might be ascribed to this type of pollution. However, an average Hazard Quotient (HQ) through ingestion was found to be greater than 1 for Cd, and the Carcinogenic Risk (CR) values for children were identified as two-fold higher than that of adults. Raising social awareness, avoiding the usage of groundwater without proper treatment, and strict regulations and monitoring by the concerned authority are recommended in the study.

Comprehensive Assessment of the Relationship between Metal Contamination Distribution and Human Health Risk: Case Study of Groundwater in Marituba Landfill, Pará, Brazil

Effective management of urban solid waste in the Metropolitan Region of Belém, State of Pará, Brazil is essential for conserving ecosystems and public health in eight cities, emphasizing the municipality of Marituba. Considering the vulnerability of underground water resources in Marituba to pollution due to the possible impact of leachate percolation from the landfill, this study evaluates the quality of groundwater captured in tubular wells from different adjacent locations potentially used for human consumption. For this purpose, the systematic methodologies of the groundwater quality index and human health risk assessment analysis: non-carcinogenic and carcinogenic risk to human health were used based on chronic daily intake of heavy metals by consumption and dermal adsorption of groundwater, measured through risk quotients, risk index, and incremental lifetime cancer risk. To evaluate the interrelationships of pollutants, analysis of variance, hierarchical cluster analysis, and principal component analysis were used based on the spatio-temporal quantification of pH, temperature, electrical conductivity, As, Al, Ba, Co, Cd, Cu, Cr, Fe, Hg, Ni, Pb, Sb, Se, U, and Zn. Residents of the study area are not at potential risk, as the results demonstrate that groundwater is within the potability standards of Brazilian legislation, except for aluminum concentrations, which ranged from 53.12 to 378.01 μg L−1 and 3.82 to 339.5 μg L−1 in the dry and rainy seasons, respectively, exceeding the established limit of 200.0 μg L−1. The quality index for groundwater and the heavy metal pollution index demonstrated that groundwater has good drinking quality with low metal contamination. The risk was considered low at all sampling sites in the non-carcinogenic risk assessment. Principal component analysis indicated that the sources of metal pollution are natural origins and anthropogeny. In this sense, they become worried because aluminum is a recognized neurotoxicant that can interfere with the central nervous system’s critical physiological and biochemical processes. Furthermore, despite complying with potability standards, trace concentrations of highly toxic metals such as As, Pb, Cd, and Ni may indicate initial contamination by landfill leachate.

Evaluation of Water Quality Indexes and Heavy Metal Pollution Indexes of Different Industrial Effluents and Karnaphuli River Water in Chattogram, Bangladesh

ABSTRACTThe study evaluated the water quality index (WQI) and heavy metal pollution index (HPI) of different industrial effluent and surface water from various sites of the Karnaphuli River, based on the weighted arithmetic index method. The samples were collected from 20 different industries, including textile dyeing, textile washing, oil processing, chemicals, and tannery, and 17 stations of the Karnaphuli River, from the Kalurghat Bridge to the estuary where the river meets with the Bay of Bengal. This study was carried out in the dry season of the 2021–2022 fiscal year. Six physicochemical parameters, namely pH, biochemical oxygen demand, chemical oxygen demand, total dissolved solids, electrical conductivity, and hardness, were taken for the determination of the WQI, and concentration of heavy metals (Pb, Fe, Cd, Cu, Cr, Mn, and Ni) were considered for the calculation of the HPI. Both indexes were calculated against the Bangladesh Standard (denoted by subscript a) and WHO standards (denoted by subscript b). The water quality indexes WQIa and WQIb for industrial effluent ranged from 11.66 to 176.77 and 44.45 to 9703.99, respectively. Samples namely TD‐5, TD‐7, TD‐8, TD‐9, TD‐10, OS‐1, and C‐1 showed excessively high WQI value. On the other hand, the HPIa and HPIb of industrial effluent varied from 43.6 to 167,785.3 and 0.34 to 18,412.3, respectively. Furthermore, oil processing and chemical effluents showed noticeably higher HPI values than other industrial samples. Both WQI and HPI values indicated a serious pollution load in most experimental samples. No river water sample showed a WQI value below 100, denoting it was unfit for consumption. The water quality indexes WQIa and WQIb for river water samples ranged from 1275.40 to 29,405.77 and 131.20 to 5860.99, respectively. According to the Bangladesh Standard, the river water samples were moderately to highly polluted by metal. The highest HPI value for the river water sample was 7965, denoting extreme metal pollution. The investigation revealed that most industrial effluents and Karnaphuli River water samples contained significant pollution load. Therefore, effective measures must be adopted immediately for future sustainability to cope with this contamination. The results emphasize the immediate requirement for strict regulations and advanced water treatment technologies to reduce contamination risks in the Karnaphuli River. Prompt action by authorities is essential to safeguard the river, prevent ongoing ecological damage, and address metal accumulation in fish affecting the food chain. Public awareness and legislative measures are vital for ecosystem preservation.

A comprehensive evaluation of the contamination scenario and water quality in the gas fields of north-east region, Bangladesh

Gas fields generate a significant volume of produced water, disposed in the vicinity of gas fields in Bangladesh after processing. It may have a variety of effects on ecology and the environment. This study was conducted to assess the contamination scenario and quality of produced and discharged water from gas fields in northeastern Bangladesh. The physicochemical analyses for this study were performed using standard procedures. Based on the outcomes of the analyzed samples, the current research employs a variety of indexing and statistical approaches to investigate the overall status of the studied water. The physiochemical analysis revealed high electrical conductivity (EC), total dissolved solid (TDS), salinity, and Na contents in both produced and discharged water. No severe cases have been identified, certain metals, such as Fe, Ni, and Cd, have been detected at levels high enough to impact specific index values in some cases. The results of the weighted contamination index (WCI) indicated mild to considerable pollution in the gas field region. The average score of potential ecological risk (PER) reflects minimal ecological risk. The heavy metal toxicity load (HTML) reveals negligible metal pollution in the studied water. The agricultural risk indices displayed increased sodium concentrations and EC, resulting in salinity and sodium risks. The magnesium absorption ratio is within the allowable range. In addition, the average heavy metal pollution index (HMPI) value demonstrates that the produced and discharged water is unsuitable for drinking. The entropy-based water quality index (EWQI) is below the threshold limit (<100) for all samples, indicating satisfactory water quality. This study is an early effort to evaluate the quality of wastewater produced and discharged from gas fields in Bangladesh. The findings of this research will provide valuable insights for future researchers and regulators in effectively managing and mitigating pollution from wastewater.

Assessing microbiological and heavy metal pollution in surface waters associated with potential human health risk assessment at fish ingestion exposure

Fish represent a significant source of nutrients but also cause negative health effects due to their bioaccumulation capacity for pollutants. The aim of this study was to examine the transfer of metals from the water of several rivers (Somes, Tisa, Sasar, Lapus, Lăpusel) to fish (Caras sp) tissue (subcutaneous fat, muscles, liver, intestines, kidneys, gills, brain, and eyes) and to identify and assess the carcinogenic and non-carcinogenic health risks of Arsenic (As), Cadmium (Cd), Nickel (Ni), Manganese (Mn), Cooper (Cu), Lead (Pb), Chromium (Cr) and Zinc (Zn) through the ingestion of fish (muscles and subcutaneous fat tissues). The obtained results indicated that a diet consisting of fish is particularly vulnerable, particularly in children compared to adults. The risk assessment results were below the threshold limit, although the fish samples contained heavy metals, with values exceeding the permitted limits of Fe (4.41–1604 mg/kg), Cr (727–4155 µg/kg), Zn (4.72–147 mg/kg), and Ni (333–2194 µg/kg). The studied surface waters are characterized by low and high degrees of pollution with heavy metals, as indicated by the heavy metal pollution index scores (HPI: 12.4–86.4) and the heavy metal evaluation index scores (HEI: 1.06–17.6). The considerable pollution levels are attributed to the high Mn content (0.61–49.7 µg/kg), which exceeded the limit up to fifty times. A consistent set of physico-chemical analysis (pH, electrical conductivity, total hardness, turbidity, chloride, sulphate, nitrate, nitrite, ammonium, Ca, Mg, Na, K) was analysed in water samples as well. Considering the water quality index scores (WQI: 16.0–25.2), the surface waters exhibited good quality. Microbiological results indicated the presence of Listeria monocytogenes and atypical colonies of coagulase-positive staphylococcus in fish. In contrast, the surface waters from which fish samples were collected were positive for Escherichia coli, and coliform bacteria intestinal Enterococci. Based on the study’s results, it is recommended to exercise caution in the case of children related to the consumption of fish and using the waters for drinking purposes. This study provides important data of considerable novelty to the riparian population, researchers, and even policy makers on the quality status and potential levels of contamination of river waters, fish and the bioaccumulation of heavy metals in fish that may cause adverse effects on human health if consumed, and similarly the heavy metal pollution degree of waters and the non-carcinogenic risk of heavy metals through ingestion and skin absorption of water in children and adults (the study area is a significant source of fisheries).

Distribution and Comprehensive Risk Evaluation of Cr, Cd, Fe, Zn, and Pb from Al Lith Coastal Seawater, Saudi Arabia

Seawater contamination is a global challenge due to its hazardous effects on marine organisms and human health. Twenty-three surface seawater samples were collected from the Al Lith intertidal area along the Saudi Red Sea coast to evaluate the ecological risks and document the potential sources of Cr, Cd, Fe, Zn, and Pb. Contamination factor (CF), contamination degree (Cd), water quality index (WQI), and heavy metal pollution index (HPI), as well as multivariate tools were applied. The average concentrations of HMs (μg/L) had the following order: Zn (6.616) &gt; Pb (0.284) &gt; Cd and Cr (0.268) &gt; Fe (0.197). CF results showed moderate contamination of seawater with Cd and low contamination of Cr, Fe, Zn, and Pb. However, 26.09% of the samples showed considerable contamination with Cd. Average Cd values revealed low contamination with HMs, while 17.39% of the samples showed moderate contamination. HPI average values indicated medium pollution of Al Lith seawater, while 13 samples reported high pollution. The higher HPI values were reported in samples characterized by higher concentrations of HMs, particularly Cd and Zn. Correlation matrix and principal component analysis suggested anthropogenic sources for Pb and Zn, mostly from industrial and agricultural effluents, landfilling, and domestic wastewater, apart from their natural sources.

Assessing drinking water quality based on water quality indices, human health risk, and burden of disease attributable to heavy metals in rural communities of Yazd County, Iran, 2015–2021

The water quality indices, health risk, and burden of disease attributable to heavy metals in rural communities of Yazd County, Iran during 2015–2021 were studied. The drinking water quality index (DWQI) based on 27 parameters (including heavy metals) and heavy metal pollution index (HPI) were used for assessing drinking water quality. The health risk and burden of disease from heavy metals in drinking water were estimated in terms of hazard quotient (HQ), hazard index (HI), incremental lifetime cancer risk (ILCR), and disability-adjusted life year (DALY). Based on the DWQI scores by community, the drinking water quality in rural communities of Yazd County was characterized as good for 61 %, fair for 25 %, marginal for 2 %, and poor for 12 %. The distribution of the rural communities into the HPI categories was as follows: 43 % for excellent, 36 % for good, 14 % for poor, and 7 % for unsuitable. In about 20 % of the rural communities, the average HI level of heavy metals was higher than the boundary limit of one. The highest average HQ level at the county level was related to arsenic (As) to be 0.44. In all the communities, the total ILCR values of the heavy metals were in the category of significant increased cancer risk (10−6 to 10−4). At the county level, As and cadmium (Cd) exhibited the two highest cancer risk levels to be 1.96 × 10−4 and 1.87 × 10−4 for ILCR, respectively. The DALY rate (per 100,000 people) induced by exposure to the heavy metals via drinking water was 13.9, which was considered relatively high as compared to that of other drinking water pollutants obtained in the previous studies. The drinking water quality improvement through decreasing Cd and As levels below the standard values can drastically reduce the attributable burden of disease and promote the public health in the rural communities.

TINGKAT PENCEMARAN LOGAM Cd, Fe, Cr DAN Cu AIR SUMUR GALI DI Eks-TPA TALANG GULO KOTA JAMBI

Former solid waste disposal at Talang Gulo TPA Jambi City implements a waste management system using a controlled landfill. Leachate and rainwater absorb into the soil and accumulate to become polluted groundwater. Furthermore, the polluted water flows into the dug well water and can reduce the quality of the dug well water. The aim of this study is to determine the heavy metal pollution index of residents' dug well water and the influence of the distance between the ex-TPA and dug well water. This research method is purposive sampling based on the distance of heavy metal sample points, namely 70 m, 230 m and 300 m. Sample analysis used an Atomic Absorption Spectrophometer (AAS) in the laboratory. The results were classed and indexed (C/P), the groundwater was very lightly contaminated with Cd (&lt;0.1), heavily contaminated with Fe (0.51-0.75), very lightly contaminated with Cr (&lt;0.1), and moderately contaminated with Cu (0.26-0.50). Based on the R value of the four metals, it shows that there was a very high influence between the distance between the well water sample and the former solid waste disposal leachate product.

Heavy Metal Risk Assessment from Agriculture in Shallow Tropical Karst Lake, Gunungsewu Karst Area, Java Island, Indonesia

This research investigates the heavy metal pollution in karst lakes, crucial for fisheries, agriculture, and domestic activities. Target metals include Pb, Cd, Cr, Fe, Zn, and Cu. Objectives comprise assessing pollution levels via the Heavy Metal Pollution Index (HPI) and conducting an ecological risk assessment, incorporating the Enrichment Factor, Geoaccumulation Index, and Ecological Risk Index. The Pearson’s correlation and cluster analysis were performed to analyze the connection between samples. Results reveal strong correlations between metals in soil and sediment, such as Pb in soil correlating with Cu in sediment (r = 0.88), Zn in soil with Cu in sediment (r = 0.75), and Zn in soil with Pb in sediment (r = 0.81). Kedokan Lake emerges as the most representative observation (distance 13.1), while Kepleng Lake is the least representative (distance 535). Cluster analysis identifies two distinct clusters: Cluster 1 encompasses Ngrejek Lake, Kedokan Lake, Sodong Lake, Kanigoro Lake, and Ngampelombo Lake. HPI calculations reveal varying contamination levels in lake water and underground river samples within the Bribin Underground River Catchment Area. Notably, one location in Kedokan Lake is categorized as contaminated (HPI value of 188.05). Mean Enrichment Factor values range from no enrichment factor (&lt;1) to low enrichment factor (1–3). Geoaccumulation Index (Igeo) indicates an overall unpolluted classification (Igeo&lt;0) across all sampling sites. These findings underscore the nuanced pollution status in the studied area, emphasizing the importance of continued monitoring and intervention to ensure the sustainability of karst lakes in the face of heavy metal contamination.