Quality assessment and potential health risk of heavy metals in leafy and non-leafy vegetables irrigated with groundwater and municipal-waste-dominated stream in the Western Region, Ghana

Assessing the Health Risk and Trophic Transfer of Lead and Cadmium in Dairy Farming Systems in the Mantaro Catchment, Central Andes of Peru

This study investigated lead (Pb) and cadmium (Cd) transfer in three dairy farming areas in the Mantaro river headwaters in the central Peruvian Andes and at varying distances from the mining complex at La Oroya. At each of these sites, the transfer of trace metals from the soil to raw milk was estimated, and a hazard assessment for lead and cadmium was carried out in scenarios of minimum, average, and maximum milk consumption in a Peruvian population aged 2-85. Pb and Cd were quantified by flame atomic absorption spectrometry. Significantly, the concentrations of lead and cadmium were found to exceed the maximum limits recommended by the World Health Organization, with a positive geospatial trend correlated with the distance from mining activity. Both Pb and Cd were found to be transferred through the soil-pasture-milk pathway, with the primary source of Cd being phosphate-based fertilizers used in pasture improvement. Pb was found to be the most significant contributor to the Hazard Index (HI) with those under 19 years of age and over 60 recording an HI of >1, with infants being the most vulnerable group due to their greater milk consumption in relation to their body weight. A marginal increase in contamination was observed in the dry season, indicating the need for studies to be expanded over several annual cycles.

Persistent organic pollutants and heavy metals in Ghanaian environment: a systematic review of food safety implications

Advances in industrial and technological innovations have led to significant socio-economic benefits, but with overwhelming negative impacts on the environment. These impacts include the infiltration of organic contaminants into soil, water, and air, posing a threat to the environment and public health. Polybrominated diphenyl ethers (PBDEs), heavy metals, and polycyclic aromatic hydrocarbons (PAHs) are increasingly released as waste, endangering the environment. In countries like Ghana, where regulations are weakly enforced, industrial waste is released uncontrollably, posing threats to public health, environmental integrity, and food systems. This study systematically evaluated existing literature on PBDEs, heavy metals, PAHs, and organic contaminant exposure in Ghana and proposes a roadmap for achieving food safety and protecting the environment and human health. The research identified high mobility of specific heavy metals and risks associated with PBDEs and PAHs in sediments, dumpsites, and various food items. Unregulated dumping of electronic waste with PBDEs raised environmental concerns. An integrated approach is needed to address the multifaceted impact of organic pollutants on public health and ecosystems. Urgent implementation of effective environmental management strategies and regulatory measures is crucial. The study proposed short- to mid-term priorities emphasising the need to foster collaboration and implementing global measures. The mid- to long-term strategy includes a national information surveillance system, local monitoring capacity development, and integrating land contamination controls with food safety legislation. These measures would mitigate risks, ensure sustainable practices, and improve overall food safety management in Ghana, serving as a model for regions facing similar challenges with diverse pollutants.

Metal distribution and human health risk assessment in legumes crops (chickpea, lentils and peas) from Belesa districts, Ethiopia

Accumulation of heavy metals in food is a major concern for humans' health. This study was aimed at determining the levels of Cu, Fe, Mn, Ni and Zn in chickpea, lentil and pea samples and evaluating the health risk for consumers. The concentrations (in mg/kg) of Cu, Fe, Mn, Zn, and Ni were varied from 23.6-48, 67.7-132.3, 15-26.5, 37.6-68.2, and 25.5-33.3 in chickpea, 39.8-80.5, 116.1-180.5, 12.1-21.6, 36.4-57.2, and 25.4-34.1 for lentil and 32-64.2, 51.6-100.0, 6.3-15, 25.3-42.5, and 25.5-48.5 for peas, respectively. Pearson correlation verified that strong positive correlations were observed between Cu and Zn in lentils, Ni and Mn, Fe with Cu and Mn in peas. Target hazard quotients (THQ) except Ni in all samples, Cu in lentil and pea were < 1 and the hazard index (HI) values of all heavy metals were greater than 1, thus an appropriate strategy is required to reduce exposure to heavy metals.

Assessment of heavy metals accumulation by vegetables irrigated with different stages of textile wastewater for evaluation of food and health risk

Wastewater irrigation for vegetable cultivation is greatly concerned about the presence of toxic metals in irrigated soil and vegetables which causes possible threats to human health. This study aimed to ascertain the accumulation of heavy metals (HMs) in edible parts of vegetables irrigated with different stages of textile dyeing wastewater (TDW). Bio-concentration factor (BCF), Estimated daily intake (EDI), and target hazard quotient (THQ) were computed to estimate human health risks and speculate the hazard index (HI) of adults and children with the consumption of HMs contaminated vegetables at recommended doses. Five vegetables (red amaranth, Indian spinach, cauliflower, tomato, and radish) in a pot experiment were irrigated with groundwater (T1) and seven stages of TDW (T2∼T8) following a randomized complete block design (RCBD) with three replications. Among the TDW stages, T8, T7, T4, and T5 exhibited elevated BCF, EDI, THQ, and HI due to a rising trend in the accumulation of Pb, Cd, Cr, and Ni heavy metals in the edible portion of the red amaranth, followed by radish, Indian spinach, cauliflower, and tomato. The general patterns of heavy metal (HM) accumulation, regarded as vital nutrients for plants, were detected in the following sequence: Zn > Mn/Cu > Fe. Conversely, toxic metals were found to be Cd/Cr > Ni > Pb, regardless of the type of vegetables. Principal Component Analysis (PCA) identified T8, T7, and T4 of TDW as the primary contributors to the accumulation of heavy metals in the vegetables examined. Furthermore, the analysis of the heavy metals revealed that the BCF, THQ, and HI values for all studied metals were below 1, except for Pb. This suggests that the present consumption rates of different leafy and non-leafy vegetables, whether consumed individually or together, provide a low risk in terms of heavy metal exposure. Nevertheless, the consumption of T8, T7, and T4 irrigated vegetables, specifically Indian spinach alone or in combination with red amaranth and radish, by both adults and children, at the recommended rate, was found to pose potential health risks. On the other hand, T2, T3, and T6 irrigated vegetables were deemed safe for consumption. These findings indicated that the practice of irrigating the vegetables with T8, T7, and T4 stages of TDW has resulted in a significant buildup of heavy metals in the soils and edible parts of vegetables which are posing health risks to adults and children. Hence, it is imperative to discharge the T8, T7, and T4 stages of TDW after ETP to prevent the contamination of vegetables and mitigate potential health risks.

A review of heavy metal risks around e-waste sites and comparable municipal dumpsites in major African cities: Recommendations and future perspectives

In Africa, the effects of informal e-waste recycling on the environment are escalating. It is regularly transported from developed to developing nations, where it is disassembled informally in search of precious metals, thus increasing human exposure to harmful compounds. Africa has a serious problem with e-waste, as there are significant facilities in Ghana and Nigeria where imported e-waste is unsafely dismantled. however, because they are in high demand and less expensive than new ones, old electronic and electrical items are imported in large quantities, just like in many developing nations. After that, these objects are frequently scavenged to recover important metals through heating, burning, incubation in acids, and other techniques. Serious health hazards are associated with these activities for workers and individuals close to recycling plants. At e-waste sites in Africa, there have been documented instances of elevated concentrations of hazardous elements, persistent organic pollutants, and heavy metals in dust, soils, and vegetation, including plants consumed as food. Individuals who handle and dispose of e-waste are exposed to highly hazardous chemical substances. This paper examines heavy metal risks around e-waste sites and comparable municipal dumpsites in major African cities. Elevated concentrations of these heavy metals metal in downstream aquatic and marine habitats have resulted in additional environmental impacts. These effects have been associated with unfavourable outcomes in marine ecosystems, such as reduced fish stocks characterized by smaller sizes, increased susceptibility to illness, and decreased population densities. The evidence from the examined studies shows how much e-waste affects human health and the environment in Africa. Sub-Saharan African nations require a regulatory framework that includes specialized laws, facilities, and procedures for the safe recycling and disposal of e-waste.

Ecological and health risk assessment of heavy metals in agricultural soils from northern China

Soil pollution by heavy metals can cause continuing damage to ecosystems and the human body. In this study, we collected nine fresh topsoil samples and 18 maize samples (including nine leaf samples and nine corn samples) from agricultural soils in the Baiyin mining areas. The results showed that the order of heavy metal concentrations (mg/kg) in agricultural soils was as follows: Zn (377.40) > Pb (125.06) > Cu (75.06) > Ni (28.29) > Cd (5.46) > Hg (0.37). Cd, Cu, Zn, and Pb exceeded the Chinese risk limit for agricultural soil pollution. The average the pollution load index (4.39) was greater than 3, indicating a heavy contamination level. The element that contributed the most to contamination and high ecological risk in soil was Cd. Principal component analysis (PCA) and Pearson's correlation analysis indicated that the sources of Ni, Cd, Cu, and Zn in the soil were primarily mixed, involving both industrial and agricultural activities, whereas the sources of Hg and Pb included both industrial and transportation activities. Adults and children are not likely to experience non-carcinogenic impacts from the soil in this region. Nonetheless, it was important to be aware of the elevated cancer risk presented by Cd, Pb, and especially Ni. The exceedance rates of Cd and Pb in corn were 66.67% and 33.3%, respectively. The results of this research provide data to improve soil protection, human health monitoring, and crop management in the Baiyin district.

Potential toxic elements accumulation in soils and parts of palm (Elaeis guineensis) growing on reclaimed tailings and mined spoils in southwestern Ghana

This study examined the accumulation of potentially toxic elements (PTE) in oil palm (Elaeis guineensis) biomass, fruits, and soils. About 40 soil samples to a depth of 40 cm and 90 palm biomass samples from roots, leaves/stems, and fruits were collected from reclaimed tailings dam and control sites at two mining areas in southwestern Ghana. PTE concentrations and pollution indices were analyzed via various inferential statistics. The PTE (As, Fe, Zn, Mn, and Cu) concentrations in the palm roots were significantly higher (p < 0.001) than in the soil at Ghana Manganese Company (GMC) Ltd, Nsuta except for As which was significantly higher (p < 0.0001) in the fruits than the soil. Soil PTE concentration was however significantly higher (p < 0.0001) than that of the roots, leaves, and fruits at the Bogoso tailings dam. The contamination factors, enrichment factors, geoaccumulation indices, and pollution load index (PLI) of soils at the tailings dam and reclaimed sites were significantly higher than the control sites. The PLI of the reclaimed tailings and control sites at Bogoso were 17.98 ± 0.56 and 6.06 ± 0.58, respectively, implying the soils at Bogoso are severely polluted with As, Fe, Zn, and Mn while those of the GMC are unpolluted. Bioaccumulation factors were significantly higher in roots than in the leaves and fruits (p < 0.0001) and were greater than 2 at GMC. The translocation of Cu and As to the fruits was significantly high on both study locations with TF of As = 9 at GMC. PTE accumulation in the palm biomass reduced soil PTE concentrations, but the soils on these mined spoils were severely polluted. These high As contents, in the fruits, may contaminate the food chain and increase PTE-related health risks among human populations. Therefore, phytoremediation of mine spoils with oil palm should be done with caution. Experimental studies to examine soil amendment effects on PTE accumulation capacity or removal efficacy by the palm plants at various ages are recommended.

Increased health risk assessment in different vegetables grown under untreated sewerage irrigation regime due to higher heavy metals accumulation

Heavy metals are environmental pollutants and carcinogenic for human health if ingested. In developing countries, including Pakistan, untreated sewerage water is one of the major sources of irrigation for vegetable production in the vicinities of urban areas which might be toxic to human health due to heavy metals contamination. The present study was conducted to investigate the uptake of heavy metals by sewage water application and its impact on human health. The experiment consisted of five vegetable crops (Raphanus sativus L, Daucus carota, Brassica rapa, Spinacia oleracea, and Trigonella foenum-graecum L.) and two irrigation sources (clean water irrigation and sewage water irrigation). Each treatment was three time replicated for all five vegetables, and standard agronomic practices were applied. The results demonstrated that shoot and root growth in radish, carrot, turnip, spinach, and fenugreek was enhanced significantly with sewerage water, probably due to enhanced organic matter. However, pithiness was observed in the root of radish under sewerage water treatment. Very high concentrations of Cd, up to 7.08 ppm in turnip roots while up to 5.10 ppm in fenugreek shoot, were observed, and other vegetables also contained higher concentrations of Cd. Zn concentrations in the edible parts of carrot (control (C) = 129.17 ppm, sewerage (S) = 164.10 ppm), radish (C = 173.73 ppm, S = 253.03), turnip (C = 109.77 ppm, S = 149.67 ppm), and fenugreek (C = 131.87 ppm, S = 186.36 ppm) were increased by sewerage water treatment but a decrease in Zn concentration in spinach (C = 262.17 ppm, S = 226.97 ppm) was observed. Fe concentration in edible parts of carrot (C = 888.00 ppm, S = 524.80 ppm), radish (C = 139.69 ppm, S = 123.60 ppm), turnip (C = 195.00 ppm, S = 121.37 ppm), and fenugreek (C = 1054.93 ppm, S = 461.77 ppm) were also decreased by sewerage water treatment while spinach leaves had accumulated higher Fe (C = 1560.33 ppm, S = 1682.67 ppm) in sewerage water treatment. The highest bioaccumulation factor value was 4.17 for Cd in carrots irrigated with sewerage water. The maximum value of bioconcentration factor was 3.11 for Cd in turnip under control, and the highest value of translocation factor was 4.82 in fenugreek irrigated with sewerage water. Daily intake of metals and health risk index (HRI) calculation indicated that HRI for Cd was more than 1, suggesting toxicity in these vegetables while HRI for Fe and Zn is still under safe limit. Correlation analysis among different traits of all vegetables under both treatments revealed valuable information for selecting traits in the next crop breeding programs. It is concluded that untreated sewerage-irrigated vegetables, highly contaminated with Cd, are potentially toxic for human consumption and should be banned in Pakistan. Furthermore, it is suggested that the sewerage water should be treated to eliminate toxic compounds, particularly Cd, before irrigation usage and non-edible/phytoremediation crops might be grown in contaminated soils.

Heavy metal contamination assessment and probabilistic health risks in soil and maize near coal mines

Objective

Coal mining activities have continuously introduced heavy metals into the soil-crop system, causing increasing damage to crops. This study integrated the analysis of the heavy metal contamination status and human health risk in soil and maize near coal mines to help formulate control strategies for soil quality, maize production, and safe consumption.

Method

This study was carried out on maize agricultural land near a coal mining plant. Heavy metal contamination was assessed by the geo-accumulation index (I_geo), enrichment factor (EF), and bioaccumulation factor (BCF). The Monte Carlo simulation was used to estimate the probabilistic health risk of heavy metals exposure in soil and maize. The relationship between the concentration of heavy metal in the soil and that in maize was further visualized by correlation analysis and random forest analysis.

Results

The results revealed that the mean concentrations of soil Ni, Cu, As, Cd, Sn, Zn, Pb, and Hg were all above the local background level. Ni was the most severely polluted heavy metal in maize and had a concentration higher than the risk control standard for corn in China (NY 861-2004). The I_geo values of all heavy metals were low, and EF values showed enrichment in V, Cr, Ti, Ni, and As. The assessment of probabilistic health risk exposed by heavy metals in soil and maize indicated that 1.16 and 1.46% of residents exceeded the carcinogenic risk level due to heavy metal exposure from soil and maize, respectively. Children were the most sensitive to maize and soil heavy metal exposure in the contaminated area. Ingestion of heavy metals was associated with the highest health risk to residents, followed by dermal contact and inhalation. As and Cr in soil and Cr and Ni in maize had the greatest impact on human health risk. Furthermore, maize heavy metals were affected the most by soil Cr, Cd, and V.

Conclusion

These results may provide useful information for human carcinogenic risk associated with soil and maize heavy metal exposure due to coal mining activities.

Geospatial distribution and health risk assessment of groundwater contaminated within the industrial areas: an environmental sustainability perspective

Groundwater is the second largest water source for daily consumption, only next to surface water resources. Groundwater has been extensively investigated for its pollution level in urban areas. The groundwater quality assessments in industrial areas associated with every urban landscape are still lacking. This study was carried out in two industrial areas including Okhla and Mohan cooperative in New Delhi, India. The six groundwater samples were obtained for water quality assessment for 2015 and 2018. The heavy metals investigated in water samples were Cu, As, Pb, Mn, Ni, Zn, Fe, Cr, and Mn. The water quality was assessed in the heavy metals index (MI) and heavy metal pollution index (HPI). From indexing approach, it was observed that pollution levels have increased in year 2018 as compared to the year 2015. MI < 1 for Cu in 2015 and 2018 in both industrial areas. In the case of remaining metals, MI ranged from 2.5 to 8.4. When the HPI indexing approach was adopted, water was unfit for drinking in both industrial areas in 2015 and 2018, with an HPI value > 100. Non-carcinogenic risk assessment (HI) ranged from 1.7 to 1.9 in 2015, increasing from 17.41 to 217 in 2018, indicating high risk in both years. Carcinogenic risk (CR) was within the acceptable range for 48% of each heavy metal analysed sample. When the Carcinogenic risk index was considered (CRI), all samples were beyond the acceptable range, and every person was prone to carcinogenic risk in 2015.

Lead and Cadmium Bioaccumulation in Fresh Cow's Milk in an Intermediate Area of the Central Andes of Peru and Risk to Human Health

The dairy basin of the Mantaro River located in the centre of Peru faces serious anthropogenic disturbances as it receives emissions and discharges from the metallurgical mining activity located in the headwaters of the basin and milk contaminated with lead (Pb) and cadmium (Cd) endangers the environmental and human health, especially children. To measure the concentrations of Pb and Cd in milk and the dangers of their consumption in the Peruvian population, 40 milk samples were collected and quantified by atomic absorption spectrometry. The mean concentration of Pb in milk was 15 ± 2.6 µg/kg, which represented 75% of the Maximum Limit (ML), and that of Cd was 505 ± 123 µg/kg, which exceeded the ML by more than 194 times. The estimated weekly intake of Pb for people aged 2−85 years was below the Provisional Tolerable Weekly Intake (PTWI) references, determining risk coefficients (CRD) < 1. Weekly Cd intake was much higher than the PTWIs and CRDs were between 14 and 34, indicating that consumers would experience carcinogenic health effects, with children being at higher risk than adults, therefore, milk from the area is not safe for consumption. Cd would be transferred mainly through the soil (water)-grass-milk pathway, due to its presence in irrigation water and in fertilizers that contain Cd. The main pathway for Pb entry would be air-soil (water)-milk grass, from the fine particles emitted into the air by the mining-metallurgical activity, developed approximately 90 km from the study area.

E-waste it wisely: lessons from Africa

E-waste is the world’s fastest growing and most valuable domestic waste stream. The increasing production of e-waste is driving elevated levels of export from developed to developing countries. Although countries worldwide are actively recognising the issues around e-waste and introducing policies, legislation or regulations governing e-waste, a large fraction of e-waste, goes undocumented at its end-of-life. Much of the global e-waste is accumulating in open dumpsites in several African countries. Using available data, we calculate the total e-waste in Africa (locally produced plus imported e-waste) for 2019 to be between 5.8 and 3.4 metric tonnes (Mt). This is believed to be an underestimate, large data gaps exist, hindering more precise estimates. The data is further complicated by, sometimes intentional, differences in labelling and reporting between formal and intermittent informal importers. Based on the available data, the main African recipients of e-waste are Nigeria, Ghana, and Tanzania, with Kenya, Senegal and Egypt featuring as countries of concern. The lack of proper waste management in the recipient developing countries, leads to environmental contamination and human exposure. A coordinated, regional and global, approach is needed in tackling e-waste. Regulatory frameworks, together with monitoring and compliance mechanisms need to be developed, financed, and enforced.

Occurrence and health risk assessment of arsenic and heavy metals in groundwater of three industrial areas in Delhi, India

Groundwater is a primary natural water source in the absence of surface water bodies. Groundwater in urban environments experiences unprecedented stress from urban growth, population increase, and industrial activities. This study assessed groundwater quality in terms of arsenic and heavy metal contamination in three industrial areas (Shahdara, Jhilmil, and Patparganj), Delhi, India. The water quality was assessed over a 3-year time interval (i.e., 2015 and 2018). The groundwater constituents investigated were As, Fe, Cr, Cd, Ni, Zn, Mn, Cu, and Pb. Metal index and heavy metal pollution indexes were estimated to assess groundwater pollution. The health risk was evaluated in terms of non-carcinogenic and carcinogenic risk assessment. Patparganj industrial area saw increment in concentration for Cu 0.23 mg/L (2015)-0.85 mg/L (2018), Zn 0.51 mg/L (2015)-7.2 mg/L (2018), Fe 0.32 mg/L (2015)-0.9 mg/L (2018), Cr 0.21 mg/L (2015)-0.26 mg/L (2018), Mn 0.14 mg/L (2015)-0.25 mg/L (2018), Ni 0.04 mg/L (2015)-0.34 mg/L (2018), and As 0.01 mg/L (2015)-0.18 mg/L (2018). Cd and Pb concentrations were observed to decrease by 40-90 % and 85-99% for all the three industrial areas. Metal index and heavy metal index values were found to be >1 for all locations. The risk quotient value > 1 was observed for all locations in the year 2015 but was found to increase further to a range of RQ 10-62 in the year 2018, inferring increased non-carcinogenic risk to consumers. The carcinogenic risk was significant with respect to Fe (0.2-0.7), Zn (0.001-0.007), and As (0.002-0.003) for all locations in the year 2015. This study concludes that groundwater in the three industrial areas is highly polluted and is not fit for human consumption. Further studies are required to explore possible control measures and develop methods to mitigate groundwater pollution, sustainable management, and optimized use to conserve it for future generations.

Heavy metals in soils and edible tissues of Lepidium meyenii (maca) and health risk assessment in areas influenced by mining activity in the Central region of Peru

Heavy metal contamination of soil and agricultural products is an environmental problem, has an adverse effect on the quality of food crops, and is a danger to food security and public health. The concentration of arsenic (As), cadmium (Cd), lead (Pb), iron (Fe) and zinc (Zn) in surface soils and edible hypocotyls tissues of two ecotypes of Lepidium meyenii Walpers (maca) was evaluated in three districts of the Junín province, Peru. In addition, the risk to human health due to exposure to heavy metals from maca consumption was evaluated. Soil samples and maca hypocotyls were collected in areas influenced by mining and metallurgical activity. The mean concentration of Cd (0.32 ± 0.23 mg/kg) and Pb (0.20 ± 0.12 mg/kg) in maca samples exceeded the values established by the Food and Agriculture Organization and the World Health Organization. The bioconcentration factor was less than 1. The estimated daily intake of each metal was below the oral reference dose. The hazard quotient and hazard index were less than 1, it is unlikely to cause non-cancer adverse health outcome. The cancer risk for As and Cd was higher than the tolerable limit (1 × 10-6) in children and adults. In the district of Ondores, the cancer risk for As in children was higher than the acceptable limit (1 × 10-4). Residents of the Ondores district would be more exposed to As and Cd from consumption of maca hypocotyls. It is very important to carry out continuous monitoring of other toxic metals in different ecotypes of maca (red, black, yellow, purple, creamy white, pink) in order to evaluate the variation in the accumulation of heavy metals and the level of toxicity of each metal between ecotypes.

Heavy Metals Presence in the Soil and Their Content in Selected Varieties of Chili Peppers in Slovakia

Capsicum chili peppers are popular vegetables in Slovakia. They provide a supply of health-promoting substances, but contaminated vegetables can pose a serious health risk to the people who consume them. Therefore, the aim of this study was to determine the content of heavy metals (Mn, Zn, Cr, Cu, Ni, Cd, Pb and Hg) in the soil as well as in selected varieties of the genus Capsicum grown in southern Slovakia. The results were compared with the limit values given by the Law no. 220/2004 (valid in the SR) as well as threshold values proposed by the European Commission (EC) (2006). The gained result showed that the total content of Cd (1.64 mg/kg) as well as the available mobile forms of Cd (0.12 mg/kg) and Pb (0.26 mg/kg) was exceeded on the soil on which Capsicum cultivars were grown. The limit values of other monitored heavy metals (Mn, Zn, Cr, Cu, Ni, and Hg) were not exceeded. The studied species of the genus Capsicum did not accumulate monitored heavy metals. It can be stated that consumption of chili peppers does not pose any risk for human health.