Evaluating the health risk of metals (Zn, Cr, Cd, Ni, Pb) in staple foods from Lagos and Ogun States, Southwestern Nigeria

Health risks of metals in soils and staple foods of the subsistence food gardens in the floodplains of Watut River, Papua New Guinea

The health risks associated with the consumption of staples cultivated in the subsistence food gardens along the Watut River were investigated in Papua New Guinea. Twenty soil samples and twenty-nine samples of staple foods (including banana, taro, sweet potato, and Singapore taro) were collected from the food gardens following a three-day dietary recall survey. The concentration of metals (Cr, Cu, Pb, and Ni) was analyzed in the soil and food samples using Inductively Coupled Plasma Optical Emission Spectrophotometer. The descending order of mean metal concentration in the food garden soils is as follows: Cr > Cu > Ni > Pb. The concentration of Pb in all samples and Cr in 97% of staple foods exceeded the FAO/WHO permissible limits. Approximately 87% of adult consumers of bananas (Musa sp) were found to have estimated Cr and Pb ingestion levels exceeding the permissible daily tolerable intake of metals (0.2 and 0.21 mg day-1, respectively). Hazard index values from the staples analysis indicate that the consumption of bananas (9.40) poses the highest risk of non-carcinogenic effects on adults, followed by taro (7.32), sweet potato (6.13), and Singapore taro (4.30). The consumption of taro is dangerous due to cancer risk associated with the intake of excessive Ni (2.88E-02) and Cr (8.82E-03) in adults and children compared to banana, sweet potato, and Singapore taro. Non-carcinogenic hazards of metal ingestion were found to be pronounced in the younger population, while carcinogenic effects were more serious in adults. Urgent measures must be implemented to protect communities, especially children, from the dangerous effects of heavy metal ingestion through staples in the lower Watut region.

Assessment of potentially toxic and mineral elements in paddy soils and their uptake by rice (Oryza sativa L.) with associated health hazards in district Malakand, Pakistan

Rice, a primary food source in many countries of the world accumulate potentially harmful elements which pose a significant health hazard to consumers. The current study aimed to evaluate potentially toxic and mineral elements in both paddy soils and rice grains associated with allied health risks in Malakand, Pakistan. Rice plants with intact root soil were randomly collected from paddy fields and analyzed for mineral and potentially toxic elements (PTEs) through inductively coupled plasma optical emission spectrometry (ICP‒OES). Through deterministic and probabilistic risk assessment models, the daily intake of PTEs with allied health risks from consumption of rice were estimated for children and adults. The results of soil pH (< 8.5) and electrical conductivity (EC > 400 μs/cm), indicated slightly saline nature. The mean phosphorus concentration of 291.50 (mg/kg) in soil samples exceeded FAO/WHO permissible limits. The normalized variation matrix of soil pH with respect to Ni (0.05), Ca (0.05), EC (0.08), and Mg (0.09), indicated significant influence of pH on PTEs mobility. In rice grains, the mean concentrations (mg/kg) of Mg (463.81), Al (70.40), As (1.23), Cr (12.53), Cu (36.07), Fe (144.32), Mn (13.89), and Ni (1.60) exceeded FAO/WHO safety limits. The transfer factor >1 for K, Cu, P and Zn indicated bioavailability and transfer of these elements from soil to rice grains. Monte Carlo simulations of hazard index >1 for Cr, Zn, As, and Cu with certainties of 89.93% and 90.17%, indicated significant noncarcinogenic risks for children and adults from rice consumption. The total carcinogenic risk (TCR) for adults and children exceeded the USEPA acceptable limits of 1×10-6 to 1×10-4, respectively. The sensitivity analysis showed that the ingestion rate was a key risk factor. Arsenic (As) primarily influenced total cancer risk (TCR) in children, while chromium (Cr) significantly impacted adults. Deterministic cancer risk values slightly exceeded probabilistic values due to inherent uncertainties in deterministic analysis. Rice consumption poses health risks, mainly from exposure to Cr, Ni and As in the investigated area.

Chromium contents, distribution and bioaccessibility in cultivated mushrooms from market: Health implications for human consumption

Mushrooms are consumed worldwide as they constitute a part of traditional cuisine culture in many countries. However, chromium (Cr) accumulation in mushrooms may constitute a potential pathway for its chronical exposure to humans. In this work, the Cr contents, distribution and bioaccessibility in 140 cultivated mushrooms from 14 species in 10 top-producing provinces in China were examined. Total Cr contents were 0.09-4.71 mg·kg-1 dw (mean 0.74 mg kg-1), with 59% exceeding the 0.5 mg kg-1standard. Additionally, less Cr was accumulated in the caps than stipes, with Cr ratio in caps/stipes being 0.28-2.6, averaging 0.91. Based on the Solubility Bioaccessibility Research Consortium (SBRC) assay, the mean Cr bioaccessibility in the mushrooms was 24.8% and 50.1% in the gastric phase (GP) and intestinal phase (IP). However, samples from Guizhou show the lowest Cr bioaccessibility at 12.5% in GP and 24.8% in IP. Further, a negative correlation between total Cr contents and Cr bioaccessibility suggests that Cr bioaccessibility is critical for accurate assessment of Cr exposure. In addition, drying mushrooms increased their bioaccessibility in the gastric phase. This study shows a high Cr exceeding rate of cultivated mushrooms, which may indicate a potential exposure risk, with Cr contents and bioaccessibility showing species and regional variation.

Accumulation and risk assessment of heavy metals in rice: a case study for five areas of Guizhou Province, China

In the present study, the concentration and accumulation abilities of five heavy metals (Cd, Hg, As, Pb, Cr) in rice were assessed and their human health risk to local citizens had been evaluated. Soil and rice samples (125 samples) were collected from Guiyang (GY), Qiannan (QN), Bijie (BJ), Tongren (TR), and Zunyi (ZY) in Guizhou Province. Heavy metals were measured by inductively coupled plasma-mass spectrometry (ICP-MS) after microwave digestion. The mean concentrations of Cd, Hg, As, Pb, and Cr were 0.58, 0.65, 12.31, 38.70, and 87.30 mg/kg in soil and were 0.05, 0.005, 0.11, 0.07, and 0.34 mg/kg in rice, respectively. The bioconcentration factors (BCF) decreased with the order Cd > Hg > As > Cr > Pb. Non-carcinogenic risk in this study was evaluated using the method of the hazard quotient (HQ) and hazard index (HI). The mean HQ values for Cd, Hg, Pb, and Cr were all lower than the standard limit (1.0) for children and adults, except As with the mean HQ for children of 2.79. The mean HI values for children and adults were 4.22 and 1.42, which exceeded 1.0. The mean carcinogenic risk (CR) values of As and Pb for children and adults were higher than the upper limit of the acceptable range (1 × 10^-4) established by the United States Environmental Protection Agency (USEPA). In a conclusion, the non-carcinogenic and carcinogenic risks induced by heavy metals for children were higher than that for adults. This study revealed that consumption of rice in study areas may pose potential non-carcinogenic and carcinogenic risks to humans, and As was the largest contributor.

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.

Co-exposure of potentially toxic elements in wheat grains reveals a probabilistic health risk in Southwestern Guizhou, China

Bijie is located at a typical karst landform of Southwestern Guizhou, which presented high geological background values of potentially toxic elements (PTEs). Recently, whether PTE of wheat in Bijie is harmful to human health has aroused people's concern. To this end, the objectives of this study are to determine the concentrations of PTE [chromium (Cr), nickel (Ni), arsenic (As), lead (Pb), cadmium (Cd), and fluorine (F)] in wheat grains, identify contaminant sources, and evaluate the probabilistic risks to human beings. A total of 149 wheat grain samples collected from Bijie in Guizhou were determined using the inductively coupled plasma mass spectrometer (ICP-MS) and fluoride-ion electrode methods. The mean concentrations of Cr, Ni, As, Cd, Pb, and F were 3.250, 0.684, 0.055, 0.149, 0.039, and 4.539 mg/kg, respectively. All investigated PTEs met the standard limits established by the Food and Agriculture Organization except for Cr. For the source identification, Cr and Pb should be originated from industry activities, while Ni, As, and Cd might come from mixed sources, and F was possibly put down to the high geological background value. The non-carcinogenic and carcinogenic health risks were evaluated by the probabilistic approach (Monte Carlo simulation). The mean hazard quotient (HQ) values in the three populations were lower than the safety limit (1.0) with the exception of As (children: 1.03E+00). However, the mean hazard index (HI) values were all higher than 1.0 and followed the order: children (2.57E+00) > adult females (1.29E+00) > adult males (1.12E+00). In addition, the mean carcinogenic risk (CR) values for Cr, As, Pb, and Cd in three populations were all higher than 1E-06, which cannot be negligible. The mean threshold CR (TCR) values were decreased in the order of children (1.32E-02) > adult females (6.61E-03) > adult males (5.81E-03), respectively, all at unacceptable risk levels. Moreover, sensitivity analysis identified concentration factor (C _W ) as the most crucial parameter that affects human health. These findings highlight that co-exposure of PTE in wheat grains revealed a probabilistic human health risk. Corresponding measures should be undertaken for controlling pollution sources and reducing the risks for the local populace.

The Content and Toxicological Risk Assessment of Trace Elemental Impurities (Pb and Cr) in Snacks from Ogun State, Southwestern Nigeria

The monitoring of food contamination by trace elemental impurities (TEIs) are major health challenges in developing countries. The present study evaluated the content and toxicological risk assessment of TEIs in commonly consumed snack/junk foods from Ogun State, Nigeria. TEIs (Pb and Cr) were determined in sixty snack food samples purchased from Ijebu Ode, Ogun State, southwestern Nigeria. The TEIs were analysed in quadruplicates using atomic absorption spectrometry with flame atomization. TEI data were subjected to simple descriptive and inferential statistics. The toxicological risk assessment of TEIs was evaluated for hazard quotient (HQ), hazard index (HI) and cancer risk (CR) using the United States Environmental Protection Agency-Integrated Risk Information System (USEPA-IRIS) model. Data showed the varying Pb levels of 8.22 ± 1.57 mg/kg in sausage to 12.25 ± 4.27 mg/kg in cocoyam chips higher than the permissible limit of the Codex Alimentarius of the Joint World Health Organization and Food and Agriculture Organization. The toxicological risk assessment revealed the HQs greater than 1.0 for Pb and Cr in most snack foods consumed by adults and children, indicating adverse health problems. The CRs of Pb (children) and Cr (adults and children) also breached the acceptable limit of 1.0 × 10^-4, signifying possible lifetime development of cancer. It is therefore necessary to periodically monitor the TEIs in snacks to protect the public health.

The Toxicological Risk Assessment of Trace Elements (Co, Cu, Fe, and Zn) in Snacks from Ijebu Ode, Ogun State, Southwest, Nigeria

Snacks or junk foods are a form of relatively small, packaged, ready-to-eat fast foods, usually taken not as a regular, but as a stopgap. However, contamination of snacks with trace elemental impurities may pose serious health risk to consumers. The main objective of the present study is to assess the toxicological risk of trace elements TEs (Co, Cu, Fe, and Zn) in commonly consumed snack/junk foods from Ijebu Ode, Ogun State, Southwest, Nigeria. A total of sixty snack food samples were purchased and assayed in replicates for Co, Cu, Fe, and Zn using atomic absorption spectrophotometer. Trace elements data were manipulated for simple descriptive and inferential statistics. The toxicological risk of metals was estimated for average daily dose (ADD), hazard quotient (HQ), hazard index (HI), and cancer risk (CR). Results showed Fe as the most abundant TE in the snacks showing insignificant mean concentrations (p > 0.05) varying from 38.10 ± 1.98 mg kg^-1 (potato chip) to 71.25 ± 14.68 mg kg^-1 (cashew nut). Cashew nut had the highest amounts of the TEs. The HQs of Co in all the snacks except corn flakes consumed by children were greater than the threshold limit of 1.0, indicating non-carcinogenic adverse effects. The CRs of Co in all the food samples exceeded the acceptable limit of 1.0 × 10^-4, suggesting possible development of cancer by the consumers. Co is a trace metal of health issues in the snack/junk foods. This study therefore recommends periodic monitoring and toxicological assessment of metals in snacks, especially the raw materials and processing feedstocks.

Snack foods and lead ingestion risks for school aged children: A comparative evaluation of potentially toxic metals and children's exposure response of blood lead, copper and zinc levels

Snack foods are common and highly advertised to children and serve their natural predispositions for sweet and salty tastes. However, the risk issues of low-cost snacks eaten by 0-6 aged children are lack of more concern. To better understand the issue of low-cost snacks this study considered potentially toxic metals (PTMs) impact on children's health risk, measured PTMs in a collection of 570 collected low-cost snacks contributed by 1342 voluntary participants children aged 0-6 years involved in Xi'an city are conducted. Nine priority PTMs and amounts ranked as Mn > Zn > Cu > Cr > Sb > Pb > Ni > Cd > Co. The Estimated Weekly Intake of PTMs in snacks for children accounted for a proportion of the Provisional Tolerance Weekly Intake. Children's daily snack ingestion of Cr, Cd and Pb were especially concerning. It was noted that all PTMs in flour products contribute to the total Target Hazard Quotient (THQ>1) were observed having a non-carcinogenic risk compared to the single metals Cr, Co and Cd with carcinogenic risk. The correlations between Cu, Pb, Zn in low-cost snacks and children's bloods reflected PTMs especially for Pb that transfers into children's bodies mostly through low-cost foodstuffs ingestion. Also, the elevated blood lead levels (BLLs) depended on readily available, low-quality snacks accessible for children. Therefore, multi-initiatives aimed at improving the quality, increasing awareness, and a PTM monitoring program for low-cost snack food market to young children should be undertaken.

Health Risk Assessment of Metals in Selected Drinks from Abeokuta, Southwestern Nigeria

The present study assessed the human health risk of metals in selected drinks from Abeokuta, southwestern Nigeria. Fifteen different brands of drinks (alcoholic, non-alcoholic, herbal and non-herbal) were purchased from notable markets in Abeokuta between June and August, 2018. A total of sixty drink samples were analysed for metals using atomic absorption spectrophotometry. Data were subjected to descriptive and inferential statistics. Human health risks were assessed for cancer risk (CR) and non-carcinogenic indices of hazard quotient (HQ) and hazard index (HI). Results showed acidic medium for most of the samples ranging from 3.12 ± 0.29 to 6.14 ± 0.17. The highest concentrations of Fe (5.53 ± 2.81 mg/L) and Mn (6.63 ± 8.33 mg/L) were found in Kunnu and Zobo, respectively. The HQ and HI values of Cu in bottled water indicated non-carcinogenic adverse effects, while the CR of Co in bottled water and bitters demonstrated carcinogenic effects. Regular monitoring of metals in drinks from the study area is recommended.

Elemental composition of teff (a gluten-free grain), maize and wheat: Staple crops in the Main Ethiopian Rift Valley

Teff, maize, and wheat are the major cereals grown in volcanic ash-rich soils of the Main Ethiopian Rift (MER) Valley. Teff is a gluten-free cereal native to Ethiopia, used for making a local flat bread called injera, and is getting popularity globally due to its nutritional value (gluten-free and high fiber content). Teff can thus be an alternative diet for the treatment of celiac disease, a lifelong intolerance to gluten. This study aims to assess the distribution of toxic and essential elements in these staple cereals using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and compare with mineral composition of wheat, and maize consumed in the Main Ethiopian Rift Valley. We found significantly higher mean concentrations (in mg/kg) of Mg (1400), Ca (1210), Na (33), Fe (159), Mn (71), Sr (5.6), and Cu (4.8) in teff compared to wheat and maize. Maize had the lowest concentrations of these essential elements. Mean concentrations (in μg/kg) of As (24.7) and Pb (70) in teff were relatively higher compared to wheat and maize, which had similar values of As (4.5) and Pb (8.9). Teff and wheat had similar Cd concentrations (in μg/kg) of 4.8 and 5.4 respectively compared to maize (1.5). Cadmium concentrations were below the Codex standard established for Cd in cereal grains (100 μg/kg). Only one teff sample exceeded the Codex standard set for Pb (200 μg/kg) in cereal grains. This study provides information on nutritional values and food safety of maize, wheat, and teff; the latter is becoming an alternative gluten-free diet for celiac patients in countries where wheat is commonly a staple food.

Sentinel species for biomonitoring and biosurveillance of environmental heavy metals in Nigeria

Nigeria receives copious annual precipitation to nourish its forests and agriculture, it has an extensive river drainage system, and it possesses valuable mineral deposits that stimulate both commercial and artisan mining activities. The combination of these features complicates Nigeria's efforts to produce adequate amounts of healthy foods to support its population. Toxic heavy metals like lead, cadmium, and mercury, and toxic metalloids such as arsenic, are also present in its mineral deposits and they migrate gradually into the soil and water of Nigeria by natural means. However, mining activities can liberate higher levels of toxic metals, which adversely affect Nigerian ecosystems and its food chains. Thus, environmental pollution due to anthropogenic activities is a major public health concern in Nigeria. This review covers the importance of native Nigerian and African wild and cultivated plants along with livestock and wild animals as sentinel species to evaluate heavy metals as environmental stressors and the use of sentinel species for food safety monitoring and for predicting potential risks to human health.

Rapid determination of cadmium in rice by portable dielectric barrier discharge-atomic emission spectrometer

In this work, a home-made portable dielectric barrier discharge-atomic emission spectrometer (DBD-AES) was explored to the determination of heavy metal in foodstuffs. A rapid and simple method was developed for Cd determination in rice based on this instrument. Rice was pretreated with diluted acid dissolution without complex operations and apparatus. The detection time by DBD-AES is about 3 min and the total analysis time for rice sample is within 11 min. The effects of some key experiment parameters were investigated. The limit of detection was 11.9 μg kg^-1 for Cd in rice, much lower than the maximum allowable level established by EC (200 μg kg^-1). The practical performance of this method was demonstrated by analyzing real and CRM rice samples. With the portability of DBD-AES, the method is suitable for rapid and in-field analysis of Cd in rice. It will be a useful tool for the routine analysis of rice.