Heavy Metal Concentrations Research Articles

Content of Selected Harmful Metals (Zn, Pb, Cd) and Polycyclic Aromatic Hydrocarbons (PAHs) in Honeys from Apiaries Located in Urbanized Areas.

The chemical composition of honey, and therefore its quality and properties, is influenced by many factors, including its botanical origin and the harvesting conditions-the location of the apiary, access to melliferous plants, the proximity of industrial infrastructure and communication routes, etc. This quality may be reduced by undesirable, toxic compounds that penetrate honey from a contaminated environment, such as heavy metals and residues from other environmental pollutants. Therefore, the aim of our research was to assess the quality of honeys from urbanized areas-in particular, to assess contamination with heavy metals and persistent organic pollutants (PAHs). In total, 35 samples from six different apiaries located in urbanized areas were examined. The content of heavy metals (Cd, Pb, Zn) was determined by atomic absorption spectrophotometry (AAS), and the content of total PAHs as the sum of the concentrations of the compounds benzo(a)anthracene, chrysene, benzo(b)fluoranthene and benzo(a)pyrene was determined by high-performance liquid chromatography with fluorescence detection (HPLC-FLD). The average zinc content ranged from about 2 to 4.5 mg/kg, the average lead content ranged from 3.5 µg/kg to 388 µg/kg and the average cadmium content ranged from 0.5 to 14 µg/kg. It was found that all honeys contained certain amounts of harmful metals, and only lead exceeded the permissible limits. None of the samples tested contained sum content of PAHs exceeding 10 µg/kg of honey. Contrary to our expectations, the results obtained indicate that honeys from urbanized areas do not contain these harmful substances. In general, the presence of harmful metals does not, however, reduce honey's quality or its health value.

Effects of Tin Mining on Water Sources in Mwerasandu Tin Mine, Ntungamo District, Uganda

Tin mining is a widespread economic activity across various regions worldwide. Understanding the consequences of such operations is crucial for sustainable water management and environmental conservation. The current study aimed at determining the concentrations tin, lead and mercury in the water sources of Nyakahiimbura Stream in Mwerasandu, and assessed the physico-chemical properties including pH, turbidity, and chemical oxygen demand (COD) of the water from the Nyamuhimbura stream, Ntungamo district. Water samples from three locations, that is; the upstream, impact area and downstream of the Nyakahiimbura water stream were collected during the dry and wet seasons of the year 2024. The samples collected were analyzed for the physico-chemical properties in the laboratory while the Inductively Coupled Plasma-Optical Emission Spectrometry (ICP – OES) was used to determine the concentration of heavy metals in the water samples. The pH, COD values obtained were within the acceptable effluent standards while the turbidity values at the upstream and downstream of the dry season and downstream during the wet season were above the acceptable effluent Standards. The tin concentration was high in the dry season (0.09mg/L) as compared to concentration (0.118mg/L) in the wet season. Lead concentration was the same (0.015mg/L) in both seasons. The concentrations of the heavy metals showed some variations in both dry and wet seasons in the upstream, impacted area and the downstream of the study area as compared to the values of the effluent standards. The study recommends that alternative sources of water for domestic use should be sought of. Also, the government officials especially from the Ministry of Health should carry out awareness campaigns to members of the community about the health risks associated with the uptake of the contaminated waters for domestic purposes. Constructed wetlands should be in place around the mining sites to act as filters for the dangerous metals before the water enters the surrounding environment.

Assessment of the Quality of Borehole Water Collected Around Unlined Solid Waste Dumpsites within Awka Metropolis

Groundwater is an important natural resource that is essential to man and other living things. However, it can become polluted resulting from natural and anthropogenic conditions. The quality of selected groundwater samples collected from boreholes around abandoned and active dumpsites in Awka metropolis, Nigeria between January and March 2023, was assessed using water quality index (WQI) method. The samples were analyzed for their physico-chemical properties and some selected heavy metals using atomic absorption spectroscopy. The results of the physico-chemical analysis showed that the mean pH ranged from 5.75 – 6.71 in January as compared to 5.92 – 6.98 in February and 5.94 – 6.84 in March indicating slight acidity. Calcium and magnesium content ranged from 8 – 20mg/l of Ca2+ and 96 – 314 mg/l of Mg2+ ion. The concentration of heavy metals in the samples were all seen to be within the standard limits for potable water (Fe (0.057 – 2.384 ppm), Cu(0.00 – 0.185 ppm) except for mercury, lead and cadmium(Hg (0.00 – 0.248 ppm), Pb (0.00 – 0.051 ppm), Cd (0.006 – 0.39 ppm) for the month of February whereas heavy metal concentration for the month of March ranged from Fe (1.432 – 2.908 ppm), Cu (0.00 – 0.008 ppm), Hg (0.00 – 0.016 ppm), Pb (0.00 – 0.003 ppm), Cd (0.00 – 0.01ppm). Pollution Index of the sampled borehole water from the different locations shows that some were potable and can be consumed without treatment. The study shows that solid wastes contribute to the level of contamination caused by Heavy metals and some physico-chemical parameters in groundwater matrix.

Production of Autoclaved Cementitious Composites Using Recycled Waste Glass

ABSTRACTOne of the major negative environmental implications of economic growth and the advancement of information technology is the large quantity of electronic waste dumped in landfills. Cathode ray tubes (CRTs) from outdated televisions and computer monitors are a significant source of electrical waste. The CRT funnel primarily consists of silica, significant alkalis (Na2O‐K2O), and heavy metals like barium‐strontium, along with a substantial lead (Pb) content that may contaminate the soil. Owing to its heavy metal content, CRT is considered hazardous waste, and regulations require its glass to be recycled or repurposed instead of landfill disposal. The low pozzolanic activity of CRT silica suggests that its high content, when paired with an optimized particle size and specific curing conditions, can enhance the mechanical properties of cement‐based products. Hydrothermal treatment has been found to speed up both the hydration of ordinary Portland cement (OPC) and the pozzolanic reactions. Since the main objective was to safely recycle large amounts of CRT, three mixes were proposed with 10%, 20%, and 30% OPC + 90%, 80%, and 70% CRT, respectively, and the effect of hydrothermal curing conditions on mechanical properties and durability of these blends was investigated. CRT‐70, a blend containing 70% CRT glass waste, showed enhanced strength due to the formation of zeolitic phases and calcium silicate hydrate (CSH). These phases also provided CRT‐70 with notable fire resistance, ensuring its structural stability under elevated temperatures. These results demonstrate the possibility of production of precast building products via high‐volume recycling of hazardous CRT waste.

Potential of Selected Species of Spiraea L. for Phytoremediation of Heavy Metals from Soils of Urban Areas

Four taxa of Spiraea were selected for this study: S. × cinerea Zabel ‘Grefsheim’, S. nipponica Maxim. ‘Snowmound’, S. splendens É. N. Baumann ex K. Koch and S. × vanhouttei (Briot) Carrière growing for a minimum of 5 years along heavily trafficked traffic routes. This study included the genus Spiraea due to its popularity in horticultural practice (commercial availability, widespread in urban environments). In addition, the use of ornamental shrubs for phytoremediation in urban green spaces effectively combines the aesthetic needs of residents with those of caring for the urban environment. This study was conducted in Poznań (population 550,000, the fifth largest city in Poland). Soils and foliage were examined in spring and autumn. Soil pH and specific electrolytic conductivity (EC) were determined. The content of micronutrients (Cu, Fe, Mn, Ni, Zn) and toxic heavy metals (Cd, Cr, Pb) in soil dry matter and leaves was determined. The uptake capacity of bioavailable forms of heavy metals by Spiraea from the soil was analyzed by determining the bioconcentration factor (BCF). It was found that the studied taxa meet the basic requirements for plants used for soil phytoremediation processes, especially for chromium phytoextraction. The degree of salinity of the tested soils did not pose a threat to the shrubs growing there, and most of the sites, despite the alkaline reaction, are suitable for their cultivation. S. × cinerea and S. × vanhouttei have BCFs for lead <1. The remaining taxa are characterized by strong concentrations of all analyzed elements. A particularly high BCF, above 10, was recorded for chromium and high for manganese and nickel.

Ozonation combined to BAC filtration for secondary effluent treatment containing moderate concentration of heavy metals

The treatment of industrial and urban effluents is a recognized strategy for environmental preservation, which brings benefits not only to fauna and flora but also to human health. In this paper, the combination effect of ozonation (O3) and biological activated carbon (BAC) filtration treatments on the inorganic contaminants removal, disinfection, and mitigation of toxicity in secondary effluent from wastewater treatment plants (WWTP) were evaluated. Disinfection efficiency was evaluated using total coliforms and Escherichia coli inactivation, and toxicity was investigated by Eruca sativa germination, Artemia salina larvae and Daphnia similis. The O3-BAC system was efficient to remove metals, disinfect the samples and reduce toxicity. The combined treatment reduced 99.9 % of the assessed metal concentration and ≥ 96 % on samples enriched with 2x the concentration allowed by Brazilian legislation. O3-BAC also demonstrated superior bactericidal performance compared to BAC and O3 alone, exhibiting a 5-log reduction within 24 h against total coliforms and 4-log reduction in E. coli, whereas BAC and O3 achieved ≤ 3-log inactivation. Regarding toxicity, the bioassays demonstrated that the combined treatment effect improved the relative germination of E. sativa (∼97 %), and the relative root elongation showed no differences compared to the control group (∼100 %). Similar behavior was also observed in the analysis with wheat and radish seeds, with no differences noted between the treated samples and the positive control. In relation to A. salina, no toxic results were observed even at high metals concentration. Additionally, BAC treatment reduced D. similis immobilization from 97 ± 6 % to a level with no observed effect. The observed synergy suggests that the O3-BAC combination may address a variety of pollutants and improve treatment efficacy.

Exploring the traits and possible ecological risks of heavy metals in biochars derived from rice husk and sugar beet pulp.

This research investigated the properties and potential environmental hazards associated with biochars derived from rice husk (RH) and sugar beet pulp (SBP), both of which are rich in heavy metals (HMs). The results indicated that the concentration of various HM fractions is significantly affected by the type of feedstock and the pyrolysis temperature. Specifically, the total concentrations of HMs in biochars produced at 600°C were found to be 10-140% higher than those in the original biomasses, a phenomenon attributed to the precipitation of HMs. Cd was a notable exception, exhibiting a reduction of 3-7% in the resultant biochars when compared to biomass, likely attributable to its volatilization. The results also revealed that the F1 + F2 fraction of HMs were largely transformed into F3 + F4 fraction during combustion, indicating that pyrolysis may reduce the ecotoxicity of HMs present in contaminated biomass. However, the process did not effectively diminish the F1 and F2 fractions of Cr and Cd. Elevated pyrolysis temperature significantly enhanced the reduction of HMs phytoavailability. Specifically, the phytoavailability of HMs in biochars produced at 600°C exhibited a decrease ranging from 10 to 92% when compared to the original biomass. Conversely, an unexpected rise in the phytoavailable fractions of Cr and Cd was noted in both RH and SBP biochars as the pyrolytic temperature increased, which correspondingly raised the potential ecological risk index (PERI). All materials analyzed exhibited a very high risk level, with PERI values exceeding 800, primarily due to the significant toxicity of Cd. Excluding Cd from consideration, the biomasses and their resultant biochars displayed PERI values ranging from 7 to 13. It is important to acknowledge that pyrolysis may not effectively diminish the environmental toxicity associated with HMs present in contaminated biomass, thereby limiting its safe application.

Assessment of radioactive nuclides and heavy metals in soil and drink water in Lahij city, Yemen

This study was conducted in Lahij city, Yemen, to evaluate the concentrations and potential health risks of natural radioactive nuclides and heavy metals in soil and drinking water. A total of 21 soil samples and 17 water samples were collected from various locations. A high-purity germanium gamma detector HPGe was used to measure the concentrations of 40K, 232Th, and 226Ra in all samples, along with the concentrations of heavy metals. In soil samples, the average concentrations of 40K, 232Th, and 226Ra were 731.5, 30.7, and 28.16 Bq kg−1, respectively. While some samples showed higher than permissible levels for 226Ra and 232Th, the overall average remained within acceptable limits. However, 40K levels were almost twice the recommended global limits. In water samples, the average concentrations of these nuclides were 5.38, 0.73, and 0.66 Bq L−1, all within the global safety limits. Radiological risk assessments for soil indicated an average radium equivalent activity (Raeq) of 124.4 Bq kg−1, absorbed dose rate in air of 59.9 nGy h−1, annual effective dose rate of 0.07 mSv y−1, outdoor excess lifetime cancer risk (ELCR) of 0.26 × 10−3, and annual gonad equivalent dose (AGED) of 336.6 mSv y−1. Risk indices, including the activity concentration index (Iγ), external hazard index (Hex), and internal hazard index (Hin), averaged 0.48, 0.34, and 0.41, respectively, all below global limits except for AGED, which slightly exceeded the recommended level. For drinking water, the total ingestion dose was calculated for different age groups. The average doses for infants, children, and adults were 0.15, 0.27, and 0.19 mSv y−1, respectively. The doses for children and adults exceeded the permissible limits, while those for infants were within safe levels. Heavy metal concentrations were measured in all samples, and the Hazard Quotient (HQ) was calculated. In soil samples, HQ values for all metals >1, indicating potential health risks. In water samples, HQ values were also >1 for all metals except vanadium (V) and iron (Fe). To reduce the dangers associated with radioactive nuclides and heavy metals, regular monitoring and cleanup are crucial, and further research is needed to understand contamination sources and long-term health impacts.

The Presence of Heavy Metals in Drinking Water and Its Possible Impact on the Development of Type 1 Diabetes in Children

This study aimed to determine the relationship between the concentration of heavy metals in drinking water and the number of type 1 diabetes mellitus (T1DM) cases in two regions of Poland. The number of births in 2015-16 in Pomeranian Voivodeship was 50,461, while the number of new T1DM cases was 219. In Lublin Voivodeship, the number of births in the same period reached 39,381, and the number of new T1DM cases was 221. The incidence of T1DM, calculated per 100 live births, amounted to 0.43 and 0.56 in Pomeranian and Lublin. The statistical analysis of collected data proved that the number of new T1DM cases in Pomeranian Voivodeship is correlated to the concentrations of selenium (Se; p < 0.0001), lead (Pb; p < 0.00001), cadmium (Cd; p < 0.00001), zinc (Zn; p < 0.00001) and arsenic (As; p = 0.00001). In the case of Lublin Voivodeship, the number of new T1DM cases was correlated to the concentrations of Se (p = 0.0000001), Pb (p < 0.000001), Cd (p = 0.0000001) and Zn (p < 0.00001) in drinking water. No correlation was found between the number of new T1DM cases and arsenic concentration in the drinking water samples from Lublin Voivodeship. The results indicated that environmental exposure to specific heavy metals may contribute to the risk of T1DM, underscoring the need for stringent environmental controls and public health policies to mitigate these risks.

Nymphaea lotus Distribution in Oguta Lake: Implications for Heavy Metal Pollution in Surface Water and Sediments

Water quality is increasingly deteriorating and has affected lakes, which are important sources of freshwater. Heavy metals are of great concern because they are mostly toxic and resistant to decomposition. Aquatic macrophytes serve as stable biological filters that purify water bodies by accumulating dissolved metals and toxins in their tissues. Given their ability to trap various toxic heavy metals, the macrophyte Nymphaea lotus, which is observed on the surface waters of Oguta Lake, was studied to estimate the concentrations of six heavy metals in the water, sediment, and macrophytes. This was achieved by studying the spatial and temporal distribution of Nymphaea lotus in the lake and analysing the concentrations of heavy metals in the surface water, macrophytes, and sediment samples. Descriptive statistics, exploratory data analysis, and correlation analysis were used to analyse data obtained. Results revealed that the population of Nymphaea lotus declines over time from June to November in all regions. Upstream had the highest concentration of macrophytes (64%), while the downstream area has the lowest (2%). The heavy metal concentrations in the three samples ranges from 0.16 mg/kg to 2.96 mg/kg in sediments and Nymphaea lotus, and from 0.16 mg/L to 2.16 mg/L in water, with lead showing the highest concentration across all sample type. This highlights heavy metal contamination in the lake. The sparsely populated Nymphaea lotus exhibits selective bioaccumulation of lead, mercury, and zinc, while it seems to exclude or inefficiently absorb arsenic and chromium. Correlation analysis suggests a close interdependence between the concentrations of metals in sediments, water, and macrophytes, with sediments playing a key role in both water contamination and macrophyte metal absorption. Corrective and preventive measures should be taken to restore the lake.

Assessment of heavy metal contamination in groundwater of rural areas of Kurdistan Province Iran: A comprehensive study

This study focuses on the contamination of groundwater by heavy metals (HMs) in the Kurdistan Province of Iran, an area heavily reliant on these water resources, especially in rural regions. This research aimed to quantify the concentrations of 20 HMs in groundwater sources and assess the associated health risks, including both carcinogenic and non-carcinogenic effects, for different age groups. The study was conducted in 2024. We collected 155 groundwater samples from water resources of the villages in Kurdistan Province, west of Iran. The study encompassed comprehensive sampling of groundwater from various wells and springs throughout the province, which was subsequently subjected to thorough laboratory analysis utilizing Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) for the quantification of heavy metal (HM) concentrations. The highest concentrations of As, Co, Cu, and Mo were 7.90, 0.22, 2.48, and 1.68 μg/l, respectively. It was related to the cities of Qorveh, Sanandaj, Baneh, and Qorveh respectively. A Health Risk Assessment (HRA) was performed, indicating that, while the concentrations of most HMs were within the thresholds established by national and international standards, certain metals, such as arsenic and lithium, presented notable non-carcinogenic risks, especially to children. These metals were responsible for over 48 % of the cumulative hazard index (HI) across all ten cities evaluated. Furthermore, the HI for the adult demographic exceeded 1.0 (specifically 1.23) exclusively in Qorwe city. The study also identified a high carcinogenic risk associated with lead across the province, which has a carcinogenic risk of 7.3 × 10−03 in 10 studied cities, which is more than the guideline value of 10−04. The findings underscore the urgent need for continuous monitoring and the implementation of preventive measures to safeguard public health. The results provide crucial insights for policymakers and health authorities, facilitating informed decisions to mitigate the health risks posed by HM contamination in the region's groundwater.

Geospatial clustering of auto-antibodies against apolipoprotein A-1, heavy metals, cardiovascular and liver diseases in the general population

Abstract Aims Heavy metals (HM) are combustion-related environmental factors predisposing to cardiovascular (CVD), autoimmune and liver diseases, even below regulatory concentrations. Pro-atherogenic and pro-steatotic auto-antibodies against apolipoprotein A1 (AAA1) are prevalent in the general population for unclear reasons. We explored a putative interplay between HM exposure, AAA1, CVD risk factors and a non-alcoholic fatty liver disease (NAFLD) risk score, using a geospatial clustering approach at the general population level. Methods Getis-Ord, Moran I2 clustering and geographically weighted regression (GWR) geosptatial analyses were carried out on 6361 individuals recruited in the CoLaus/PsyCoLaus general population cohort. Geospatial dependences between serum AAA1, urinary HM (cadmium, arsenic, cobalt) concentrations, SCORE2 CVD risk, and fatty liver index (FLI) were assessed. Results Cadmium and cobalt were found to be associated with higher SCORE2 risk (p<0.04). AAA1 were associated with higher cadmium, cobalt, and cigarette consumption, independently of SCORE2 (p<0.04). AAA1 hotspots overlapped significantly with those of cadmium and FLI, independently of SCORE2. According to GWR, correlations between cadmium and AAA1 were the highest in railways proximity regions, increasing up to 10-fold compared to global associations. AAA1 were not associated with other HM. Conclusions These geospatial footprints highlight independent associations between Cadmium, AAA1, and NAFLD risk score in the general population. We hypothesize that environmental cadmium exposure may facilitate the occurrence of AAA1 in humans. Ongoing experimental studies will confirm/refute a possible causal link. Whether AAA1 could represent an early biological signature of cadmium exposure and subsequent health hazards remains to be shown.

Environmental Impact of Automobile Wastes on Surface Water Quality in Ebonyi State, Southeast Nigeria

ABSTRACTThe negative impact of operations in informal auto mechanic workshops is a major public health concern, and its effect on surface water pollution cannot be overlooked. This current work evaluates the environmental impact of automobile waste on surface water quality in Ebonyi State, Southeast Nigeria. A total of 108 surface water samples were taken in 2022 and 2023 from Abakaliki, Onueke, and Afikpo streams, and WHO as controls using standard analytical methods. Data sets were analyzed using Fisher's Significance Least Difference (F‐LSD) at the 0.05 probability level. The study showed that surface water appearance was slightly brown, and the observed upstream is acidic in nature, the midstream is alkaline, and the downstream is natural. Water samples from Abakaliki, Onueke, and Afikpo streams were observed to be hard since their concentration levels were above the WHO standard. Furthermore, the high concentrations of heavy metals (Pb and Mn) as well as the oil and grease content indicate that the surface water in the area of study is polluted and its overall quality is degraded. The study therefore concluded that automobile waste had a negative influence on the surface water quality in the study area. Based on these new findings, it is recommended that automobile waste be properly treated and disposed of to avoid their adverse effects on surface water quality. In addition, given the uncontrolled development of these informal auto workshops across the nation in recent years, there is a need for the execution of environmental standards connected to automobile service activities.

Determination of heavy metals and health risk assessment in drinking water in Bukayriyah City, Saudi Arabia

Abstract Heavy metal levels, including arsenic, lead, cadmium, mercury, chromium, and nickel, were analyzed in 124 samples of tap and filtered water obtained from Bukayriyah city, Saudi Arabia, using inductively coupled plasma mass spectrometry. Additionally, measurements of total dissolved solids, conductivity, and pH were also performed. The study also evaluated the potential non-cancer and cancer risks (CRs) associated with the ingestion of these heavy metals for both children and adults. The results indicated that the average concentrations of heavy metals in both tap and filtered water were found to be below the recommended limits set by the World Health Organization and the Gulf Standard Organization. To assess the non-carcinogenic risks, the chronic daily intake (CDI), hazard quotient (HQ), and hazard index were calculated for analyzed metals present in both tap and filtered water. In both the children and adult populations, the CDI indices for heavy metals in tap and filtered water followed the order of Cr > Hg > Ni > Pb > As > Cd. However, it is worth noting that the CDI values for tap water were higher than those for filtered water for both children and adults. The descending order of HQ values is as follows: Hg > Cr > As > Cd > Pb > Ni. This indicates that the HQ values for all metals are below the acceptable limit of 1. These findings confirm that the exposure to the examined metals from both tap and filtered water in Bukayriyah City is within safe limits and poses no non-carcinogenic risks. To assess the carcinogenic risks, the incremental lifetime cancer risk (ILCR) and total carcinogenic risk (TCR) were calculated. The order of ILCR values for both children and adults in tap and filtered water is as follows: Ni > Cr > Cd > As > Pb. All ILCR values were below the acceptable limit of 10−6 to 10−4. However, TCR values exceeded this threshold range only for children exposed to tap water, with a value of 1.43 × 10−4. Thus, children exposed to tap water have a potential risk of developing carcinogenic diseases.

A field study of the molecular response of brown macroalgae to heavy metal exposure: An (epi)genetic approach

Our understanding of the relative contribution of genetic and epigenetic mechanisms to organismal response to stress is largely biased towards specific taxonomic groups (e.g. seed plants) and environmental stresses (e.g. drought and salinity). In previous work, we found intraspecific differences in heavy metal (HM) uptake capacity in the brown macroalgae Fucus vesiculosus. The molecular mechanisms underlying these differences, however, remained unknown. Here, we evaluated the concentrations of HMs, and characterized the genetic (single nucleotide polymorphisms) and epigenetic (cytosine DNA methylation) variability in reciprocal transplants of F. vesiculosus between two polluted and two unpolluted sites on the NW Spanish coast after 90 days. Genetic and epigenetic differentiation did not explain the phenotypic differentiation observed, possibly due to the combined effect of multiple environmental factors acting on the algae in their natural habitats. Nonetheless, we provide further evidence of intraspecific genetic differentiation in F. vesiculosus at short spatial scales, as well as first evidence of population-specific epigenetic changes in brown macroalgae in response to changes in environmental conditions (i.e. transplantation ex situ). We propose that both genetic and, to some extent, epigenetic mechanisms might impinge upon the adaptive potential of this species to environmental change, but this needs to be further addressed.

A Comparative Study of the Effects of Dumpsites on Groundwater Quality in Uyo Metropolis of Akwa Ibom State

The study was conducted to compare the effects of dumpsites on groundwater quality in Uyo Metropolis of Akwa Ibom State. It aimed at examining the effect of dumpsites from physicochemical and heavy metal content of borehole water and determining the water quality rating of boreholes in the study areas. Three (3) dumpsites, namely Uyo Village Road Dumpsite (UVD), Atiku Road Dumpsite (ARD) and Ediene Uyo Dumpsite (EUD) were used for the study. The triangular sampling method was used to select three boreholes in each dumpsite area, giving a total of thirty-six (36) samples on replication for the three dumpsites and control. The water samples were collected in well-labeled pretreated 1-litre plastic bottles and were immediately transported to the laboratory for analysis. Data obtained were analyzed using descriptive statistics and means of significant parameters were separated using the Duncan multiple range test at 5% level of probability. The result showed that mean pH was 7.49 in control, significantly lower than 8.22–8.66 in the study areas. Electrical conductivity was 245.33–580.67 μs/cm with 335.00 μs/cm as control. Mean temperatures were 28.53–28.67 oC and 28.0 oC for control. Also, values obtained for turbidity were 3.47–4.21 and 3.47 in control. DO in control borehole water was 3.07 mg/l while that of dumpsites was 3.18–3.37 mg/l. The calculated water indices were 1871.92, 33492.86 and 32288.10 for UVD, ARD and EUD respectively. The findings revealed that mean values in water quality parameters like Magnesium, Dissolved Oxygen, Lead, Cadmium, Nickel and Zinc were above the permissible limit of the World Health Organization for drinking water, indicating higher evidence of groundwater pollution in the study area. The study generally showed that borehole water samples from the three dumpsites were unsuitable for drinking. Public awareness among borehole owners and users within the dumpsite environment on ground water contamination by dumpsites was recommended among others in the study area and the water should be treated before human consumption.

Assessment of Heavy Metals in Tea Plantation Soil and Their Uptake by Tieguanyin Tea Leaves and Potential Health Risk Assessment in Anxi County in Southeast China

Evaluating heavy metal pollution in tea plantation soil and conducting potential health risk assessments are crucial for ensuring the safety of tea consumers. However, soil heavy metal pollution levels and dietary exposure risk remain poorly understood, and there is no consensus on how soil physicochemical properties affect heavy metal concentrations. In this study, seventy-three soil samples and corresponding tea leaves from main tea-producing regions in Anxi County were analyzed for arsenic (As), chromium (Cr), lead (Pb) and copper (Cu) concentrations. The results showed that mean concentrations of As, Cr, Cu and Pb in the soil did not exceed respective risk screening values in China (GB 15618-2018). The concentrations of As, Cr, Cu and Pb in the tea leaves were within limiting values of the Chinese National Food Safety Standard, and the bioaccumulation factor of heavy metals in descending order was Cu > Pb > As > Cr. The hazard index values of heavy metals indicated no potential human health risk. Soil pH, EAl, EA and AP were the main controlling factors for heavy metal in soil and tea leaves. Cu and Pb concentrations in tea leaves were positively correlated with soil Cu and Pb concentrations. These results provide a scientific basis for effective monitoring and management in tea plantations and for controlling potential risks in tea leaves.

Monitoring of urinary nickel and chromium in metal industries workers in Alborz, Iran

Heavy metal contamination from occupational sources is a cause for concern due to its potential accumulation in the environment and the body of living organisms, which leads to long-term toxic effects. There is limited evidence on the concentration of heavy metals in the body fluids of welding workers. This study aimed to measure the concentration of nickel (Ni) and chromium (Cr) as two main toxic heavy metals in the urine samples of welders and determine the potential relationship of various environmental factors on their concentration levels. This study was conducted in Iran in 2022–2023. Eighty-five urine samples were collected from the studied welding workers. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to measure the concentration of Ni and Cr. Data related to socio-demographic characteristics (education level, income, work experience, age, and body mass index (BMI)), lifestyle profile (consumption of seafood and canned food, smoking, physical activity), type of ventilation and preventive devices at work, and suffering from underlying diseases (cardiovascular and high blood pressure) were collected using valid questionnaires. Ni and Cr were present in 100% of urine samples with mean concentrations of (1.09 ± 0.294) and (11.45 ± 16.751) µg/g creatinine, respectively. A significant correlation was observed between the mean concentration of Ni and Cr with the level of education, income, work experience, age, consumption of seafood and canned food, smoking, type of ventilation and preventive devices, and underlying diseases (p-value < 0.05). Also, there was no significant difference between Ni concentration and physical activity and Cr concentration with BMI. Lifestyle determinants and not using preventive devices are important predictors of urinary heavy metals in welding workers. Therefore, more research is required to determine the adverse effects of long-term exposure to these heavy metals.

Analysis and quantification of selected heavy metals and paraphenylenediamine in commercially available herbal black hair dyes in Sri Lanka

Currently, the use of henna-based herbal black hair dyes is widespread in the community. However, it is important to note that these dyes cannot be classified as completely natural due to the addition of various ingredients to enhance their effectiveness. Most black hair dyes use paraphenylenediamine (PPD) to get a black hue, however, PPD is widely recognized as a contact sensitizer. The toxicity of heavy metals is also prevalent in the cosmetics sector. These metallic elements can permeate the skin and provide widespread exposure throughout the body. Hair dye requires an alkaline pH value because of reactions that occur during the dyeing process, which is incompatible with scalp pH. The varying concentrations of these chemicals and their frequency of usage can result in diverse health issues. The present research implemented High-Performance Liquid Chromatography and Atomic Absorption Spectrometry to quantify the concentrations of PPD and heavy metals (Pb, Cd, and Fe) in seven frequently used brands in Sri Lanka. The lead content in the examined samples exhibited variability, ranging from 0.04 ± 0.01 ppm to 0.28 ± 0.14 ppm. However, all the samples remained below the allowed level of 2 ppm according to the BVL standard. Regarding Cd, certain examined materials surpassed the acceptable thresholds, while others did not and varied between 0 ppm and 2.33 ± 1.92 ppm. Iron was found at a significantly higher concentration compared to the other two heavy metals. A significant quantity of PPD was detected, exceeding the allowable threshold of 6 % according to the European Union legislation. All the samples that were analyzed had a pH value within the alkaline range. The study indicates that herbal dyes generated from natural materials may contain harmful compounds, such as a high concentration of PPD in herbal black hair color potentially inducing sensitization.

Evaluation of Environmental Risk from Heavy Metals in Sediments in Port Areas

This research aims to evaluate the concentration and distribution of heavy metals in sediment in the Port area of ​​PT Pelindo Dumai Branch, which is one of the main ports in Riau Province, Indonesia. Heavy metals such as cadmium, copper, lead, mercury and zinc are known to have significant toxic effects on maritime ecosystems and can accumulate in the food chain, potentially endangering aquatic life and human health. The research methodology involves taking sediment samples from various points around the port area, which are then analyzed using spectroscopic techniques to determine heavy metal concentrations. The results showed that the concentration of heavy metals in sediments varied, with zinc having the highest concentration (average 0.019724 mg/L), followed by copper, lead, cadmium, and mercury. This variation indicates the existence of diverse sources of pollution and uneven distribution in the port area. Although cadmium and mercury concentrations are relatively low, they still raise concerns due to their high toxicity and potential accumulation in the food chain. These results emphasize the need for more intensive environmental monitoring and targeted risk management to reduce the negative impacts of heavy metals on maritime ecosystems and human health. This research provides an important scientific basis for mitigation efforts in port areas, which are crucial to ensuring the sustainability of ecosystems and the well-being of communities that depend on marine resources.