A systematic literature review for some toxic metals in widely consumed rice types (domestic and imported) in Iran: Human health risk assessment, uncertainty and sensitivity analysis

Efficient removal of lead and arsenic using macromolecule-carbonized rice husks

The adsorption process using inexpensive adsorbents is one of the methods to remove contaminants from aqueous solutions. Biomass porous carbon based materials are among the most widely used adsorbents in this field. Rice husk is a bio-based adsorbent material for pollutant removal. In this study, the porous carbon material obtained from the rice husk was used for the adsorptive removal of lead (Pb) and arsenic (As) from aqueous solutions. Silica was removed from rice husk structure through the one-step reaction using PTFE. The morphological and crystallographic characteristics of the adsorbent surface were determined by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The removal efficiency was investigated under different conditions of pH (3–9), contact time (3–90min), adsorbent amount (0.5–6 g/l) and initially adsorbed concentration (10–100 μg/l) by changing the parameters in the adsorption reactions. The Response Surface Method (RSM), a Box-Behnken design (BBD), was used to optimize adsorption of Lead and Arsenic by Rice husk. The removal efficiency was finally calculated using analysis of variance. According to the adsorption analysis results, the removal efficiency of Pb and As in aqueous solutions increased (up to 97%, 85% for Lead and Arsenic) under optimum conditions.

A systematic review and meta-analysis of human biomonitoring studies on exposure to environmental pollutants in Iran

Population exposure to environmental contaminants can be precisely observed through human biomonitoring studies. The present study aimed to systematically review all the biomonitoring studies conducted in Iran on some selected carcinogen environmental pollutants. In this systematic review study, 11 carcinogen agents were selected including arsenic, cadmium, chromium, nickel, lindane, benzene, trichloroethylene (TCE), pentachlorophenol (PCP), radon-222, radium-224, - 226, - 228, and tobacco smoke. The Web of Science, PubMed, and Scopus databases were searched for peer-reviewed articles published in English. After several screening steps, data were extracted from the studies. Meta-analyses (a random-effect model using the DerSimonian-Laired method) were performed only for the biomarkers with more than three eligible articles, including cadmium in blood and breast milk, and arsenic in breast milk. Methodological quality of the studies was assessed using the Newcastle-Ottawa Quality Assessment Scale adapted for cross-sectional studies. Of the 610 articles found in the database search, 30 studies were eligible for qualitative review, and 13 were included in the meta-analysis (cadmium in blood (n = 3), cadmium in breast milk (n = 6), and arsenic in breast milk (n = 4)). The overall pooled average concentrations (95% CI) of cadmium in blood, cadmium in breast milk, and arsenic in breast milk were 0.11 (95% CI: 0.08, 0.14), 5.38 (95% CI: 3.60, 6.96), and 1.42 (95% CI: 1.02, 1.81) µg/L, respectively. These values were compared with the biomarker concentrations in other countries and health-based guideline values. This study showed that there is a need for comprehensive action plans to reduce the exposure of general population to these environmental contaminants.

The relationship between rice consumption and glioma: a case-control study in adults

Previous studies have shown the effect of refined grains on various cancers; however, data on the link between rice consumption and brain cancer are scarce. We aimed to investigate the relationship between rice consumption and glioma in Iranian adults. Current hospital-based case–control study was done in Tehran between 2009 and 2011. Cases were individuals with pathologically confirmed glioma in a maximally 1 month of the disease diagnosis (n = 128). Controls were individuals, aged between 20 and 75 years, who were hospitalized or were outpatients referred to other wards of the same hospital (n = 256). Cases and controls were frequently matched in terms of age and gender. Usual dietary intakes of participants, including rice consumption, during the preceding year were examined using a Block-format validated semi-quantitative 126-item food frequency questionnaire. Compared with participants in the lowest tertile of rice consumption (< 181 g/day), those in the highest tertile (≥ 279 g/day) had 2.47 times greater chance for having glioma (OR: 2.47, 95% CI 1.44–4.23). This relationship was also seen when potential confounders including demographic variables, energy and dietary intakes as well as body mass index were taking into account; such that individuals in the top tertile of rice consumption had 2.46 times greater odds of glioma compared with those in the bottom tertile (OR: 2.46, 95% CI 1.01–5.97). We found that rice consumption was positively associated with risk of glioma in adults. Further prospective studies are required to confirm this finding.

Presence of antibacterial substances, nitrofuran metabolites and other chemicals in farmed pangasius and tilapia in Bangladesh: Probabilistic health risk assessment

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ANCs in pangasius and tilapia, fish feed, pond sediments and water were analysed comprehensively.

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Residual ANCs except heavy metals were not found in farmed pangasius and tilapia flesh.

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Residual toxic heavy metals lead and chromium in fish were above the permissible limit.

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Heavy metals sourced primarily from fish feed with secondary sources such as groundwater.

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Lead and chromium concentrations in fish flesh pose potential carcinogenic risks to human health.

Intensive feeding and the use of drugs and other chemicals for enhancing yield characterised commercial pangasius and tilapia aquaculture in Bangladesh. The residual presence of prohibited antibacterial substances, nitrofuran metabolites and other chemicals (ANCs) in fish, and their effect on public health are a concern for consumers. This study collected samples from 15 pangasius and 15 tilapia ponds to assess the contamination of ANCs, including pesticides, dyes and heavy metals in fish flesh, and heavy metals in feed, sediments and water. Antibacterial substances, nitrofuran metabolites and dyes in fish flesh were detected using LC–MS/MS. Organochlorine pesticides and heavy metals were detected applying GC–MS and AAS, respectively. We found very low residue of the most ANCs in pangasius and tilapia flesh, however, both species contained heavy metals, particularly lead (Pb) and chromium (Cr). The level of metal contamination was affected by the age of the pond; the highest concentration of Pb was in pangasius from old ponds (> 10 years), and the highest concentration of Cr was found in pangasius from new ponds (< 10 years), and tilapia from old ponds. The feed sampled in this study, particularly the commercial pellet and farm-made feed, were highly contaminated with heavy metals. Pond water and sediments were contaminated by heavy metals; fish, water and sediment samples from older ponds had higher concentrations of heavy metals. The concentration of these heavy metals in fish flesh above regulatory limits poses potential risks to human health. To ensure the production of safe fish for human consumption, commercial aquaculture in Bangladesh requires a functional regulatory framework.

Phytoavailability and human risk assessment of heavy metals in soils and food crops around Sutlej river, India

We assessed the phytoavailability of heavy metals in wheat and rice grown on soils along flood plains of Sutlej river (India) and its effects on human health. Surface soil samples along with wheat (pre-monsoon season) and rice (post-monsoon season) grain samples were collected during the years 2017 and 2018. Soil samples were analysed for total and DTPA-extractable metals and, wheat and rice grains samples for total metals. There were no significant (p < 0.05) changes in total metal concentration during both the years, but the concentration of DTPA-extractable metals was higher during pre-monsoon than post-monsoon season. The concentration of Pb, Cd, and Co in wheat grains, whereas the concentration of Cr, Co, Pb and Cd in rice grains surpassed their safe limits. Both DTPA-extractable metals (water soluble plus exchangeable) and non-exchangeable fractions explained more than 80% of the variations in metal uptake by plants. The bioaccumulation factor for DTPA-extractable metals (BCF) was above one, but Pollution Load Index for these metals (PLI) was less than one. The carcinogenic risks due to ingestion of wheat and rice grains were higher for Cd. The BAF, PLI and health risks were higher along transboundary of the river. These results suggest that exchangeable and non-exchangeable fractions are contributing towards metals uptake by wheat and rice along flood plain soils of the Sutlej river and the present study may act as a model for carrying out similar studies to find out the risks of heavy metals and it effect on human health in future.

The Concentration and Probabilistic Health Risk of Potentially Toxic Elements (PTEs) in Edible Mushrooms (Wild and Cultivated) Samples Collected from Different Cities of Iran

The present study was devoted to investigate the PTE concentrations including cadmium (Cd), chromium (Cr), copper(Cu), iron (Fe), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), arsenic(As), and zinc (Zn) among six types of edible wild, 23 cultivated mushroom samples collected from Iran's market by the aid of an inductively coupled plasma-optical emission spectrometry (ICP-OES). Also, the related health risk assessment was established by the aid of the Monte Carlo simulation method (MSC). The limit of detection (LOD) and limit of quantification (LOQ) were ranged 0.001-0.048 and 0.003-0.160 ppm, respectively. The concentrations of As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn were determined in the ranges of 0.003-11. 5, 0.0008-5.89, 0.32-26.32, 9.15-110.08, 15.25-751.17, 0.16-2.24, 2.1-60.47, 1.21-24.22, 0.16-8.92, and 37.13-268.11 mg kg^-1, respectively. According to findings, highest mean concentration of Cr in both types of mushrooms (cultivated and wild) was lower than recommended level by Codex Alimentarius/Food and Agriculture Organization/World Health Organization (CODEX/FAO/WHO) while the corresponding values for Hg (0.87 mg kg^-1), As (1.39 mg kg^-1), Ni (10.08 mg kg^-1), Cu (36.65 mg kg^-1), Cr (10.44 mg kg^-1), Cd (0.589 mg kg^-1), Fe (201.04 mg kg^-1), Mn (10.30 mg kg^-1), Zn (2266.43 mg kg^-1), and Pb (3.81 mg kg^-1) were higher than related standard levels. According to the health risk assessment, no concern regarding the non-carcinogenic risk due to the ingestion of PTEs via the consumption of the edible mushrooms, except Hg in wild mushrooms for children, was noted.

Occurrence and risk assessment of emerging contaminants in a water reclamation and ecological reuse project

Water reclamation and ecological reuse is gradually becoming a popular solution to address the high pollutant loads and insufficient ecological flow of many urban rivers. However, emerging contaminants in water reuse system and associated human health and ecological risks need to be assessed. This study determined the occurrence and human health and ecological risk assessments of 35 emerging contaminants during one year, including 5 types of persistent organic pollutants (POPs), 5 pharmaceutical and personal care products (PPCPs), 7 endocrine disrupting chemicals (EDCs) and 18 disinfection by-products (DBPs), in a wastewater treatment plant (WWTP) and receiving rivers, as well as an unimpacted river for comparison. Results showed that most of PPCPs and EDCs, especially antibiotics, triclosan, estrogens and bisphenol A, occurred frequently at relatively high concentrations, and they were removed from 20.5% to 88.7% with a mean of 58.9% via WWTP. The highest potential noncarcinogenic and carcinogenic risks in different reuse scenarios were assessed using maximal detected concentrations, all below the acceptable risk limits, with the highest total combined risk value of 9.21 × 10^-9 and 9.98 × 10^-7, respectively. Ecological risk assessment was conducted using risk quotient (RQ) method and indicated that several PPCPs, EDCs and haloacetonitriles (HANs) pose high risk (RQ > 1) to aquatic ecology in the rivers, with the highest RQ up to 83.8. The study suggested that ecological risks need to be urgently addressed by updating and optimizing the process in WWTPs to strengthen the removal efficiencies of emerging contaminants. The study can serve as a reference for safer water reuse in the future, while further studies could be conducted on the health risk of specific groups of people, exposure parameters in water reuse, as well as more emerging contaminants.

Hazards and risk assessment of heavy metals from consumption of locally manufactured painkiller drugs in Nigeria

In the informal sector of Nigeria's economy, jobs are done manually as against automation resulting in body stress and pain, hence the need for painkiller drugs. Thirty different locally manufactured painkiller drugs, with analgesic, antipyretic and anti-inflammatory effects, were randomly sampled from pharmaceutical shops within Awka in October 2016. The drugs were pulverised, sieved and ashed before digestion using conc aqua regia HCl : HNO3 (3:1), carcinogenic heavy metals (arsenic, cadmium, chromium, mercury, nicked and lead) were assayed using Varian AA240 atomic absorption spectrophotometer (AAS). Risk assessment was carried out using US EPA model. The highest levels of arsenic (0.350 mg/kg) were found in samples with code 01, 03 and 020, cadmium (0.107 mg/kg and 0.144 mg/kg) were in samples code 013 and 028, and samples 03 and 011 had chromium levels as 6.637 mg/kg and 5.298 mg/kg. Highest value of mercury (0.470 mg/kg) was in sample code 01. All the painkiller drugs have nickel in the range of 0.046-0.448 mg/kg while highest values of lead were in sample code 05, 025 and 029 as 2.47 mg/kg, 1.11 mg/kg and 1.16 mg/kg. Non-cancer risk ranged as As (Nd -1.60 × 10-3), Cd (Nd-1.97 × 10-4), Cr (Nd-6.06 × 10-6), Hg (Nd-2.15 × 10-4), Ni (9.93 × 10-6-3.34 × 10-5) and Pb (Nd-4.36 × 10-4) while the cancer risk were As (Nd-1.63 × 10-7), Cd (Nd-4.45 × 10-9), Cr (Nd-1.56 × 10-7), Hg (Nd -1.53 × 10-9), Ni (1.50 × 10-10 -1.46 × 10-9) and Pb (Nd-8.82 × 10-9). The total cancer risk (TCR) and total non-cancer risk (TNCR) for all the heavy metals were in the range of 7.21 × 10-13-1.25 × 10-10 and 1.51 × 10-7-5.56 × 10-5 respectively. The TCR was below 1 × 10-6 -1 × 10-4 range while TNCR for heavy metals was below 1; the values established by US EPA. In conclusion, continuous consumption of locally Nigerian made painkiller drugs may expose the subjects to heavy metal toxicity.

Contamination of staple crops by heavy metals in Sibaté, Colombia

Heavy metal contamination in water resources, soil, and food sources is an issue that compromises food safety in Sibaté, Colombia. In the present study concentration of heavy metals [HMs], such as Cu, As, Pb, Cr, Zn, Co, Cd and Ni, present in vegetables included in the typical Colombian diet were measured. The study was conducted as follows: samples of parsley, artichoke and carrots produced in a location near the Muña dam were collected, where the Bogotá River water is treated for use as a water resource. To determine food safety, national and international [HMs] established limits were compared with quantified [HMs] in samples of different vegetable parts and of the surrounding soil. Fresh samples were separated in their respective parts for cold acid digestion with HCl and HNO₃ (1:1) for 15 days. Heavy metal mean ± standard error (SE) were as follows (mg/kg) As 2.36 ± 0.185, Cd 0.16 ± 0.009, Co 0.43 ± 0.019, Cr 12.1 ± 0.453, Cu 13.1 ± 1.68, Ni 0.00, Pb 7.07 ± 0.482 and Zn 3.976 ± 0.332. Cd, Cr, As, Co and Ni showed high transfer factor in Cynara scolymus. Moreover, high Pb, Cu and Zn transfer factor were present in Petroselinum crispum. Except for Daucus carota roots, there was a high metal transfer specifically in Petroselinum crispum leaves and other different plant parts, with high transfer factor for Cr, As, Co, Pb, Cu and Zn.

The concentration of polycyclic aromatic hydrocarbons (PAHs) in the processed meat samples collected from Iran's market: a probabilistic health risk assessment study

The concentration of PAHs among raw and cooked meat products (sausages and burgers), randomly collected from five regions of Tehran, Iran, was investigated by the aid of a gas chromatography-mass spectrometry (GC-MS), and the risk assessment was conducted. The concentration of 16 types of PAHs in sausage and burger samples was found in the range of 8.08 to 29.55 and 10.18 to 29.85 μg/kg, respectively. The concentrations of some PAHs such as anthracene (A) (14.12 μg/kg) and acenaphthylene (Acl) (13.4 μg/kg) were higher than the European Standard (2 μg/kg). Among the meat products with different meat percentages (50, 70, and 90), the highest level of total PAHs was noted in the product containing 90% meat (19.34 μg/kg), while the highest mean level of PAHs was noted in fried meat products (23.31 μg/kg). A positive and significant correlation between cooking method and brand of product with the concentration of PAHs (p-value < 0.05) was noted. Also, no concern regarding the non-carcinogenic risk due to the ingestion of PAHs via consumption of the meat products was demonstrated by the health risk. However, the carcinogenic risk due to the consumption of sausage and burger was at the tolerable (1E-6 to 1E-4) and considerable (> 1E-4) risk levels, respectively. In this regard, further assessments to control and modify the cooking method among the Iranian population were recommended.

Geographical variation of cadmium in commercial rice brands in Bangladesh: Human health risk assessment

Food, including rice, is the major source of toxic element cadmium (Cd) for human exposure. Globally, many populations rely on the consumption of significant amounts of rice as a staple food. Using dietary intake and concentration of Cd, this study determines the risk posed to both adults and children due to Cd exposure from consumption of rice sold in Bangladeshi markets. Polished rice samples (n = 144) were collected from the markets of 16 districts of Bangladesh to determine the distribution, regional variability and associated health risk from Cd. The mean and median concentrations of Cd in rice were 44 μg/kg and 34 μg/kg, respectively, ranging between 1 and 180 μg/kg, dry weight. The Cd concentrations of the rice samples did not exceed the safe limit of EU/CODEX but 9% exceeded the safe limit of FSANZ (Food standards Australia New Zealand) values. Results indicated that there were significant variations of Cd among (33%) and within (67%) the districts. Some rice brands such as Najirshail, Katarivogh and Chinigura had Cd levels of 81, 70 and 68 μg/kg, respectively. Cadmium ingested on a daily basis ranged between 0.09 and 0.58 μg/kg body weight (bw) with the incremental lifetime cancer risk (ILCR) for individuals varying between 1.35 × 10^-3 and 8.7 × 10^-3 in different districts. The age groups (2-5 yrs) and (6-10 yrs) experienced higher risks than others and both males and females were found to be susceptible from Cd exposure of rice.

Levels and human health risk assessments of heavy metals in fish tissue obtained from the agricultural heritage rice-fish-farming system in China

China began to practice Rice-fish-farming system (RFFS) 1700 years ago. Nowadays, the widely spread of metals could be potential threats to the quality of RFFS fish. In this study, Pb, Cd, Hg, As and Cr as the top five most toxic heavy metals were determined in six species of RFFS fish meat obtained from 7 provinces in south China. The mean concentrations of metals in RFFS fish followed Pb (36.89 μg/kg) > As (33.36 μg/kg) > Cr (18.54 μg/kg) > Hg (16.35 μg/kg) > Cd (2.01 μg/kg), which were mostly lower in comparison with fish from traditional aquaculture systems raised by fish feeds. Grass carp obtained lower metal concentrations compared with other fishes, possibly indicating the importance of feeding habits of RFFS fish. Concentrations of metals in fish and RFFS sediment were in good correlations, and benthic fish obtained high pollution levels, suggesting the accumulation of metals through the direct contact with sediment. Risks assessments coupled with Monte Carlo simulation indicated the potential non-carcinogenic risks and carcinogenic risks decreased following As > Hg > Cr ≈ Pb > Cd, and As > Cr > Cd > Pb, respectively. These results suggested RFFS is still a successful mode of green agriculture.

Potential sources and health risk assessment of polycyclic aromatic hydrocarbons in street dusts of Karaj urban area, northern Iran

In the present study chemical fingerprinting approach (isomeric ratios), a receptor-oriented model (principal component analysis with multiple linear regression, PCA/MLR) and a probabilistic health risk framework were employed to characterization, source appointment and carcinogenic risk assessment of polycyclic aromatic hydrocarbons (PAHs) in street dusts of Karaj urban area (northern Iran). Thirty street dusts samples were collected from the different functional areas in the city of Karaj and analyzed for PAHs by gas chromatography/mass spectrometry (GS/MS). The results obtained showed that ∑16PAHs concentrations varied widely from 16.2 to 1236.2 with a mean of 624 μg/kg and decreased in the following order of functional areas; traffic> residential > green/park areas. PAHs profile in the majority of dust samples were dominated by 5-6 rings PAHs, accounting for 25%-95% of the total PAHs. Qualitative source apportionment using the molecular isomeric ratios indicated mixed sources of PAHs in street dusts while PCA/MLR receptor model quantitatively identified three major sources with following relative contributions to the total dust PAH burden; 51% for pyrogenic-traffic sources, 32% for traffic-stationary sources and, 16% for petrogenic sources. The results of health risk assessment based on probabilistic model indicated that at the 95% percentiles, total cancer risks for children and adults are 8.43 × 10^-4 and 3.34 × 10^-5, respectively which both are higher than the acceptable baseline (10^-6) indicating potential carcinogenic risk for local residents. It was also revealed that dust ingestion pathway is the most important contributor to the total carcinogenic risks of PAHs for both children and adults although the cancer risk level for adults through dermal and inhalation was 10 times greater than that for children. Based on the sensitivity analysis using the Monte Carlo simulation, benzo[a]pyrene equivalent concentration, exposure duration, dermal exposure area and ingestion rate were found to be the most sensitive exposure parameters which could introduce uncertainties into the cancer risk estimated.

A simple and accurate PCR method for detection of genetically modified rice

BACKGROUND

Legislation regulating for labeling and use of genetically modified (GM) crops are increased considerably worldwide in order to health and safety assurance of consumers. For this purpose, a polymerase chain reaction (PCR) method has been developed for detection of GM rice in people's food diet.

METHODS

In this study, eighty-one non-labeled rice samples were collected randomly from different market sites of Tehran, Iran. In order to analysis, rice genomic DNA was extracted using MBST DNA extraction kit and subsequently, sucrose phosphate synthase (SPS) gene was used to confirm the quality of extracted DNA. Then, cauliflower mosaic virus (CaMV) 35S promoter and Agrobacterium nopaline synthase (NOS) terminator were selected as screening targets for detection of GM rice sequences by PCR.

RESULTS

According to our results, 2 out of 81 (2.4%) samples tested were positive for CaMV 35S promoter while no positive result was detected for NOS terminator.

CONCLUSION

The obtained data indicated that this method is capable to identify the GM rice varieties. Furthermore, it can demonstrate the possibility of the presence of GM rice in Tehran's market, thus putting emphasis on the requirement for developing a precise approach to evaluate this product.