Heavy metals (As, Cr, Pb, Cd and Ni) concentrations in rice (Oryza sativa) from Iran and associated risk assessment: a systematic review

Content and dietary exposure of cadmium among residents in Northeast China: a case study based on the 5th China Total Diet Study

Cadmium (Cd), one of the harmful heavy metals, and its accumulation or pollution might cause itai-itai disease. In this study, we investigated the dietary exposure of Cd among residents in Northeast China (including Heilongjiang, Jilin, and Liaoning provinces) and also compared the health risks in adult males in terms of dietary intake. Cd contents in 12 categories of foods were derived from original data from the 5th China Total Diet Study (TDS). The following results were obtained in this study: (i) dietary exposure levels of Cd at the margin of safety (MOS) were 4.55, 1.82, and 2.85 in Heilongjiang, Jilin, and Liaoning provinces, respectively; (ii) the primary dietary sources of Cd included cereals, legumes, potatoes, meat, aquatic products, and vegetables; (iii) Cd contents in the same food category from different regions were not significantly different from the limit of China's National Standards (LCNSs); (iv) dietary exposure of Cd would not have a detrimental effect on the health of residents in Northeast China; (v) we recommend the government to take precedence of the supervision and spot-checking of cereals, legume-nuts, potatoes, meat, aquatic products, vegetables, and alcoholic beverages because of the higher dietary consumption than others; (vi) 99.99% of the Cd content in cereals, legumes, vegetables, meat, and aquatic products sold in Northeast China was less than the LCNSs at the present situation; and (vii) the harmful effects of Cd to human beings are associated with the Cd content in foods and the consumption of such foods.

Cadmium, mercury, and selenium in muscle of the scalloped hammerhead Sphyrna lewini from the tropical Eastern Pacific: Variation with age, molar ratios and human health risk

With the aim of assessing health risk to shark consumers, cadmium, mercury, and selenium were measured in muscle of Sphyrna lewini from four coastal states (Baja California Sur, Sinaloa, Nayarit, and Colima) in western Mexico. According to length of specimens, three age modes were found: juveniles and neonates (the majority of the individuals), preadults and adults. Average concentrations (μg g^-1 dry weight) in all the studied individuals followed the order cadmium (0.06), selenium (0.94), and mercury (1.56). The mean concentrations of cadmium and mercury increased significantly (p < 0.001) with mean length of specimens. Overall, hazard quotient and hazard index values were below one so there is no health risk to consumers. According to molar ratios of Hg and Se in the edible portion (muscle) of sharks, and depending on the areas of collection, individuals from Baja California Sur might not be beneficial to consumers.

The bioavailability and contribution of the newly deposited heavy metals (copper and lead) from atmosphere to rice (Oryza sativa L.)

Despite the global importance of atmospheric heavy metal input into agricultural soils, research has primarily focused on the amount of the depositions with limited attention given to the risk of the newly deposited heavy metals. To understand the remobilization of the newly deposited copper (Cu) and lead (Pb) from the atmosphere and explore the metals' mobility and bioavailability to rice (Oryza sativa L.), a soil transplant experiment was conducted in three areas along a gradient of atmospheric depositions. Approximately 61% of the Cu and 76% of the Pb depositions tended to be present in potentially mobile fractions. The soil retention of newly deposited Cu and Pb presented as higher mobile fractions than these in the original soil. The newly deposited Cu and Pb in soils only accounted for 0.34-8.7% and 0.07-0.29% of the total soil Cu and Pb pools, but they contributed 30-84% and 6-41% in rice tissues, respectively. A major implication of these findings is that once the heavy metal is deposited, it may be reactivated in soils and transported to aerial parts or foliar uptake into plant tissues, emphasizing the important role of the newly deposited Cu and Pb in contributing to the edible parts of crops.

Assessment of human health risk based on characteristics of potential toxic elements (PTEs) contents in foods sold in Beijing, China

Metals are generally classified into essential metals groups. Essential metals include copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn), and nonessential metals include cadmium (Cd) and lead (Pb) etc. However, excessive intake of metals even essential metals would have detrimental effect on the body. In this study, seven potential toxic elements (PTEs) (i.e., Cd, Cr, Cu, Fe, Mn, Pb and Zn) and their distribution characteristics in the foods were analyzed as well as the combination of correlation analysis, factor analysis and cluster analysis were constructed. Meanwhile, combined with the dietary consumption data from the Fifth China Total Diet Study (FCTDS), the dietary exposure of PTEs were analyzed and a consequent safety risk assessment was conducted. The main results are as follows: (1) PTE contents in simply-processed samples were found to be lower than those in the highly-processed samples. (2) The average daily intake of the PTEs were about 12.26 (Cd), 153.17 (Cr), 25.16 (Pb) μg/d, 1.90 (Cu), 20.19 (Fe), 7.12 (Mn) and 12.69 (Zn) mg/d, respectively. (3) The total target hazard quotient (TTHQ) was 2.88, which was lower than 10. Therefore, the long-term consumption of these foods combined with the current dietary structure would not have a detrimental effect on the health of residents in Beijing.

Bioaccumulation of heavy metals in some commercially important fishes from a tropical river estuary suggests higher potential health risk in children than adults

The Karnaphuli River estuary, located in southeast coast of Bangladesh, is largely exposed to heavy metal contamination as it receives a huge amount of untreated industrial effluents from the Chottagram City. This study aimed to assess the concentrations of five heavy metals (As, Pb, Cd, Cr and Cu) and their bioaccumulation status in six commercially important fishes, and also to evaluate the potential human health risk for local consumers. The hierarchy of the measured concentration level (mg/kg) of the metals was as follows: Pb (13.88) > Cu (12.10) > As (4.89) > Cr (3.36) > Cd (0.39). The Fulton's condition factor denoted that fishes were in better 'condition' and most of the species were in positive allometric growth. The bioaccumulation factors (BAFs) of the contaminants observed in the species were in the following orders: Cu (1971.42) > As (1042.93) > Pb (913.66) > Cr (864.99) > Cd (252.03), and among the specimens, demersal fish, Apocryptes bato appeared to be the most bioaccumulative organism. Estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI) and carcinogenic risk (CR) assessed for potential human health risk implications suggest that the values were within the acceptable threshold for both adults and children. However, calculated CR values indicated that both age groups were not far from the risk, and HI values demonstrated that children were nearly 6 times more susceptible to non-carcinogenic and carcinogenic health effects than adults.

Pollution and Health Risk Assessment of Carcinogenic Elements As, Cd, and Cr in Multiple Media—A Case of a Sustainable Farming Area in China

The high concentrations of trace elements in the environment, especially the carcinogenic elements Cr, Cd, and As, in populated areas can lead to an increased non-carcinogenic risk and carcinogenic risk in humans via the effective exposure pathways (inhalation and dermal contact). In this study, the concentrations of the trace elements Cd, Cr, and As in four media were comprehensively evaluated by collecting samples from atmospheric precipitates (A), wheat (W), soil (S), and groundwater (G) in the agricultural plain. This study not only considers the health risk level, but also focuses on the relationship between soil properties and the soil–wheat system. First, according to the results of the analysis, the concentration of carcinogenic elements in atmospheric precipitates was higher than that in other media. The sequence follows the order A > S > W > G. Moreover, the input flux of A was at a relatively higher level (determined via an input flux calculation) than other farming areas. Second, the pollution of Cr, Cd, and As in A and S were analyzed using the geoaccumulation method, and the level of Cd reached mild to moderate pollution. In addition, it was found that the bioaccumulation factors (BAFs) of Cd were much higher than those of As and Cr in the soil–wheat system. Furthermore, it was found that the negative relationship between BAFs and pH, CEC (cation exchange capacity), Corg (soil organic carbon), and clay was significant. Lastly, the hazard quotient (HQ) of the non-carcinogenic risk and carcinogenic risk (CR) of the three elements in multiple media were calculated using the health risk model. The HQ results showed that the total non-carcinogenic risk index (HI) of Cd, As, and Cr in the multiple-media did not exceed the risk limit (1.00), and there was no significant risk to the locally exposed population. However, the total carcinogenic risk index (TCR) indicated that the risk index of Cr, As and Cd in multiple media exceeded the safety index range (≈10−6–10−4), and the three elements posed a significant carcinogenic risk to local residents via the main pathways. In terms of individual elements, the risk of cancer was highest via the ingestion of the carcinogenic element Cd in G and W.

Bioaccumulation and heavy metal concentration in tissues of some commercial fishes from the Meghna River Estuary in Bangladesh and human health implications

Despite the beneficial aspect of aquatic food's consumption, bioaccumulation of toxic metals in fish can enhance the health risk for the consumers. Heavy metals were measured from editable tissues of some commercial fish species like Latis calcarifer, Silonia silondia, Clupisoma garua, Planiliza subviridis, Otolithoides pama, Tenulosa ilisa, Rhinomugil corsula, and Aila coila in the Meghna river estuary in Noakhali district. Heavy metals such as As, Pb, Cd, Cu, and Cr were detected by ICP-MS, which were significantly different (p ≤ 0.01), and the hierarchy of all mean concentrations were: Cu (5.14 mg/kg) > Pb (3.79 mg/kg) > As (1.08 mg/kg) > Cr (0.78 mg/kg) > Cd (0.12 mg/kg). The mean concentration of Cu (6.62 mg/kg) imparted to the maximum level in L. calcarifer, which slightly exceeded the Bangladesh food safety guideline. The mean BAFs of the contaminants were found as: Pb (1042.29) > Cr (1036.47) > As (934.84) > Cd (832.77) > Cu (772). Further, L. calcarifer, S. silondia, C. garua, and P. subviridis showed the bioaccumulative status. To assess the health risk effects, estimated daily intake (EDI), target hazard quotient (THQ) and carcinogenic risk (CR) were conducted. THQs for both adult and children consumers were <1, indicating that, consumers would not experience the non-carcinogenic health effects. Although children were more susceptible than adults, CR for all the consumers was found in the acceptable range (10^-6 to 10^-4).

Carcinogenic and Non-carcinogenic Risk Assessment of Heavy Metals in Groundwater Wells in Neyshabur Plain, Iran

The present work reports the As, Cr, Cu, Pb, Zn, and Fe concentrations of drinking water samples in Neyshabur Plain, Iran. This study aimed also to ascertain the potential consumers' health risk of heavy metal intake. Heavy metal concentrations were analyzed by inductively coupled plasma optical emission spectrometry. The highest and lowest average values in the analyzed water samples were observed for Fe (9.78 ± 5.61 μg/L) and As (1.30 ± 2.99 μg/L), respectively. These values were well below the limits recommended by the World Health Organization and the Iranian national standard. Heavy metal pollution index and heavy metal evaluation index were used to evaluate drinking water quality. The risk index was calculated by chronic daily intake and hazard quotient according to the United States Environmental Protection Agency approach. Heavy metal pollution index in all the samples was less than 100, indicating that it is a low-level heavy metal. The total risk of all heavy metals in the urban environment varied from 40.164 × 10^-7 to 174.8 × 10^-7. In this research, the maximum average of risk belonged to lead and copper with the respective values of 60.10 × 10^-7and 33.99 × 10^-7 from the selected wells. However, considering the toxic effect of some elements, including Pb and As, in the chronic exposure of consumers, we suggest a continuous evaluation and monitoring of drinking water resources.

Concentration and Prevalence of Aflatoxin M1 in Human Breast Milk in Iran: Systematic Review, Meta-Analysis, and Carcinogenic Risk Assessment: A Review

This meta-analysis was designed to review the published reports regarding the concentration and/or prevalence of aflatoxin M₁ (AFM₁) in human breast milk in Iran. The carcinogenic risk for Iranian infants consuming this milk was estimated with the hazard index. The PubMed and Scopus databases and the Scientific Information Database were screened for relevant studies between 1995 and 2017, and 11 of the 112 collected studies were included in the systematic review and meta-analysis. The mean (95% confidence interval) concentration of AFM₁ was 5.85 ng/L (4.54 to 7.15 ng/L), which was lower than the European Union standard (25 ng/L). The mean prevalence of AFM₁ in breast milk in Iran was 42% (11 to 77%). The estimated daily intakes for male and female infants were 0.02 to 5.57 ng/kg and 0.02 to 3.68 ng/kg of body weight per day, respectively. The rank order of estimated daily intake for both male and female infants according to age was 1 week > 1 month > 6 months > 12 months. The hazard index for all age groups of infants in all provinces in Iran was less than 1. Therefore, infants in Iran were not considered at carcinogenic risk from AFM₁ in human breast milk.

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

In present study we aimed to investigate the literature in the form of systematic review to determinate the concentrations of some toxic metals (arsenic, lead, and cadmium) in widely consumed rice brands in Iran and their related health risks. International and Iranian national databases were searched carefully with appropriate keywords for papers on toxic metal contamination of rice from Agust-2000 to Agust-2018. Initially, 560 articles were found, of which only the 50 papers fit the inclusion criteria and were selected for further analysis. The Monte Carlo Simulation was applied to generate missing data (mean, standard deviation, data distribution and sample size) of toxic metal concentration in some papers. Then, statistical analysis, health risk assessment, and uncertainty and sensitivity analysis were performed. The results indicated that approximately 88% of rice consumed in Iran (including Iranian, Pakistani and Indian rice) do not meet the national standard and WHO/FAO guideline requirements and their related health risks are unacceptable. The risks of arsenic and lead in Indian rice and cadmium in Iranian rice were considerably higher than others. In conclusion, according to our findings, In conclusion, it is necessary to prevent toxic metals contamination of rice by modifying cultivation patterns and, also, prevent low-quality rice brands to be imported.

Investigation of twelve trace elements in herbal tea commercialized in Brazil

In this study twelve trace elements were investigated in herbal tea commercialized in Brazil. Boldo, Chamomile, Mate and Peppermint tea samples were acquired in Brazil local markets and both herbs and their infusions were evaluated. Trace elements were classified in two groups: poorly (Al, As, Ba, Cd, Cr, Fe, Pb and Se) and moderately (Cu, Mn, Ni and Zn) extractable. This patterned showed that even levels above threshold established by Brazilian and MERCOSUR regulations were observed in herbal tea (Cd and Pb in 89% and 78% of mate and peppermint tea samples, respectively), their infusions did not presented toxic levels. The estimative of exposure and dietary intake revealed important values for a daily consumption of a single cup of herbal infusion and an unique composition was also verified for herbal tea samples: although age and origin was unavailable, multivariate analysis classified the samples in four distinct groups.

Effects of biochar on growth, and heavy metals accumulation of moso bamboo (Phyllostachy pubescens), soil physical properties, and heavy metals solubility in soil

Pot experiment was conducted to investigate the effects of wood biochar (5%), bamboo biochar (5%), rice straw biochar (5%) and Chinese walnut shell biochar (5%) on growth, accumulation of heavy metals in moso bamboo, soil physical properties, and solubility of heavy metals in soil. The results revealed that dry weight of moso bamboo was significantly increased in treatments of wood biochar (5%), rice straw biochar (5%) and Chinese walnut shell biochar (5%) except bamboo biochar (5%). Application of straw biochar (5%) was most effective in enhancing plants biomass, with increase of 157%, 113% and 111% in leaves, roots and stems of moso bamboo. All treatments of biochar have significantly improved soil electrical conductivity with maximum increase of 360% compared to CK. In case of heavy metals accumulation, application of 5% bamboo biochar, straw biochar and Chinese walnut shell biochar has reduced Cu uptake in roots by 15%, 35% and 26%, respectively. The biochars have significantly reduced solubility of soil heavy metals with maximum reduction of 58.91 mg kg^-1 and 10.59 mg kg^-1 of Cu and Pb with application of rice straw biochar. It is concluded that dry weight of moso bamboo was significantly enhanced by all treatments of biochar except bamboo biochar.

Contamination and Prevalence of Histamine in Canned Tuna from Iran: A Systematic Review, Meta-Analysis, and Health Risk Assessment

Histamine is one of the most important health issues associated with consumption of canned tuna because of possible allergic and anaphylactic reactions in consumers. Although the concentrations of histamine in tuna in Iran have been investigated in several studies, definitive conclusions are elusive. This study was undertaken as a systematic review and meta-analysis of the concentration and prevalence of histamine in Iranian canned tuna, and the related health risk was assessed. An extensive search of articles in the databases Scopus, PubMed, and Scientific Information Database resulted in 11 articles and a total of 693 samples for inclusion in this review. The minimum and maximum concentrations of histamine were determined as 8.59 ± 14.24 and 160.52 ± 87.59 mg kg⁻¹, respectively. The mean concentration was calculated as 77.86 mg kg⁻¹ (95% confidence interval [CI], 47.51 to 108.21 mg kg⁻¹), which was lower than the 200 mg kg⁻¹ recommended limit by the U.S. Food and Drug Administration (FDA). The mean prevalence of histamine was 9.19% (95%; CI, 6.88 to 11.5%). The 95% value of the target hazard quotient for adult consumers was calculated as 0.10. In all studies performed in Iran, the concentration of histamine in canned tuna was lower than FDA standard. Health risk assessment indicated low histamine risk (target hazard quotient < 1) for adults in Iran from consumption of canned tuna.

The concentration of heavy metals in noodle samples from Iran's market: probabilistic health risk assessment

In the current study, the concentration of heavy metals including lead (Pb), chromium (Cr), cadmium (Cd), and aluminum (Al) in commonly instant noodles consumed in Iran (either imported from other countries or produced in Iran) was investigated by acid digestion method followed by an inductively coupled plasma optical emission spectrometry system (ICP-OES). Also, the associated non-carcinogenic risk due to ingestion of heavy metals for adults and children was estimated by calculating percentile 95% target hazard quotient (THQ) in the Monte Carlo simulation (MCS) method. The average concentrations of Pb, Cr, Cd, and Al in Iranian instant noodle samples were measured as 1.21 ± 0.81, 0.08 ± 0.10, 0.03 ± 0.06, and 9.15 ± 4.82 (mg/kg) and in imported instant noodle samples were 1.00 ± 0.61, 0.07 ± 0.07, 0.04 ± 0.03, and 15.90 ± 0.93 (mg/kg), respectively. A significant difference (p value < 0.05) in the mean concentration of Pb, Cr, Cd, and Al of Iranian instant noodle and imported instant noodle samples was observed. Also, the concentration of Pb, Cr, Cd, and Al in all brands of instant noodle (0.025 mg/kg, 0.050 mg/kg, 0.003 mg/kg, and 0.237 mg/kg, respectively) surpassed the WHO-permitted limits for Pb, Cr, Cd, and Al. Percentile 95% of THQ of Pb, Cr, Cd, and Al for the adult consumers was calculated as 0.012, 0.000007, 0.010, and 1.789; while in the case of children, percentile 95% of THQ of Pb, Cr, Cd, and Al was defined as 0.044, 0.00023, 0.035, and 6.167, respectively. Health risk assessment indicated that both adults and children are at considerable non-carcinogenic health risk for Al (THQ > 1). Therefore, approaching the required strategies in order to reduce the concentration of heavy metals particularly Al in the instant noodle is recommended.

Probabilistic risk assessment (Monte Carlo simulation method) of Pb and Cd in the onion bulb (Allium cepa) and soil of Iran

Recently, the exposure to heavy metals through the consumption of vegetables has become a global concern. In this regard, the current study was aimed to measure the concentrations of lead (Pb) and cadmium (Cd) in the collected onion bulb samples as well as the surrounded soil using a flame atomic absorption spectrometer (FAAS). Additionally, the target hazard quotient (THQ) for males and females in all age groups of consumers were estimated by using Monte Carlo Simulation (MCS) method. Furthermore, the soil threshold values (STVs) were evaluated to investigate the heavy metal contents in the soil based on the established standard limits. In this context, 45 onion bulbs (HashtBandi region, 25 and Ravang region, 20) and 41 soil (HashtBandi region, 21 and Ravang region, 20) samples were collected (March-May of 2016). The average concentrations of Pb in the onions from HashtBandi and Ravang regions were determined as 0.0052 ± 0.0011 and 0.0061 ± 0.0022 mg/kg, and for Cd were 0.0095 ± 0.0024 and 0.0011 ± 0.0035 mg/kg, respectively. The average concentration of Pb in the soil from HashtBandi and Ravang regions were measured as 3.99 ± 3.77 and 2.03 ± 0.69 mg/kg, and for Cd, the corresponding values were determined as 2.21 ± 3.17 and 2.22 ± 0.92 mg/kg, respectively. The average concentration of Pb and Cd in both investigated onion bulb and soil were lower than Iranian national (onion bulb: Pb = 0.1 mg/kg, Cd = 0.05 mg/kg) and FAO/WHO (onion bulb: Pb = 0.3 mg/kg, Cd = 0.1 mg/kg; soil: Pb = 50 mg/kg, Cd = 0.3 mg/kg) standard limits. Moreover, the THQ and total target hazard quotient (TTHQ) for males and females in all age groups were less than 1 value. Therefore, no risk of the exposure to Pb and Cd as result of onion bulb consumption was reported. STVs for Pb and Cd in the HashtBandi region were calculated as 3.99 and 2.21 mg/kg, and Ravang as 2.03 and 2.22 mg/kg, respectively. Due to the higher calculated STVs for Cd while compared with the established standard limit for the soil, the further revisions regarding the heavy metal standard limits in the soil were recommended.

Polycyclic aromatic hydrocarbons (PAHs) content of edible vegetable oils in Iran: A risk assessment study

Totally forty samples (23 brands) of different types of edible oils including frying oil (n = 14), blended oil (n = 13), sunflower oil (n = 6), corn oil (n = 5) and canola oil (n = 2) from Iran's market were analyzed for PAHs content by a High-performance liquid chromatography coupled with fluorescence detector. Also, the Health risk assessment in the adults and children consumers were estimated by the calculating margin of exposure (MOE) and the incremental lifetime cancer risk (ILCR) in the Monte Carlo Simulation (MCS) method. Approximately all of the samples contained different amounts of PAHs, while concentrations of BaP, PAH 4, PAH 8 and PAH 13 were reported as 0.90-11.33, 3.51-84.03, 7.41-117.12 and 129.28-19.54 μg/kg, respectively. Light polycyclic aromatic hydrocarbons corresponded to 65% of total PAHs while the remaining 35% belonged to heavy polycyclic aromatic hydrocarbons. Based on BaP content, 12 samples were above the standard limits (2 μg/kg) which set by the Standard Organization of Iran and the European Union, whereas 15 samples exceeded maximum limit 10 μg/kg set for PAH 4 established by EU. Percentile 95% of MOE in the adults due to ingestion of sunflower, corn, frying and blended oils were determined as 4.10E+5; 4.05E+5; , 2.17E+5, 2.33E+5, respectively and in the children due to ingestion of sunflower oil, corn oil, frying oil and blended oil were calculated as 5.38E+4, 4.49E+4, 2.86E+4, 3.37E+4. Regarding the percentile of 95% ILCR in the adults due to ingestion of sunflower oil, corn oil, frying oil and blended oil were reported as 4.5E-6, 4.17E-6l, 5.20E-6, 4.93E-6 and also this value in the children in the same rank order of products can be summarized as 3.43E-5, 3.94 E-5, 3.17E-5, 3.76E-5. The rank order of edible oils investigated based on MOE was sunflower oil > corn oil > blended oil > frying oil; and based on ILCR, frying oil > blended oil > sunflower oil > corn oil. The health risk assessment according to MCS method indicated that adults and children are not at considerable health risk; MOE ≥ 1E+4 and ILCR < 1E-4).

Metal concentrations in fillet and gill of parrotfish (Scarus ghobban) from the Persian Gulf and implications for human health

Despite the benefits of seafood's consumption, the bioaccumulation of metals in fish can endanger consumers' health. This study analyzed lead (Pb), mercury (Hg), Arsenic (As), and Cadmium (Cd) concentrations in fillet and gill of parrotfish (Scarus ghobban) using flame atomic adsorption spectroscopy (FAAS). The potential non-carcinogenic and carcinogenic health risks due to consumption of Scarus ghobban fillet were assessed by estimating average target hazard quotient (THQ) and total target hazard quotient (TTHQ) and Incremental Lifetime Cancer Risk cancer risk (ILCR) of the analyzed metals. This study indicated that Cd, Pb, As and Hg concentrations were significantly (p < 0.05) lower than Food and Agriculture Organization (FAO) and national standard limits. The meal concentrations (μg/kg dry weight) in both fillet and gill were ranked as follows Pb > Cd > As > Hg. THQ and TTHQ were lower than 1 for adults and children, indicating that consumers were not at considerable non-carcinogenic risk. However, ILCR value for As was greater than 10^-4, indicating that consumers are at carcinogenic risk. Overall, this research highlighted that although the consumption of parrotfish from the Persian Gulf does not pose non-carcinogenic health risks, carcinogenic risks derived from toxic As can be detrimental for local consumers.

Carcinogenic and non-carcinogenic health risks of metal(oid)s in tap water from Ilam city, Iran

One of the most important pathways for exposure to metals is drinking water ingestion. Chronic or acute exposure to metals can endanger the health of the exposed population, and hence, estimation of human health risks is crucial. In the current study for the first time, the concentrations of Mercury (Hg), Arsenic (As), Zinc (Zn), Lead (Pb) and Cobalt (Co) in 120 collected tap water samples (2015, July-November) from Ilam city, Iran were investigated using flame atomic absorption spectrophotometer. Also, the metal-induced carcinogenic and non-carcinogenic risks for consumers exposed to tap drinking water were calculated. The average (range) concentrations of Hg, Zn, As, Pb and Co were defined as 0.40 ± 0.10 μg/L (ND-0.9 μg/L), 5014 ± 5707 μg/L (2900.00-5668.33 μg/L), 21.008 ± 2.876 μg/L (3.5-62 μg/L), 30.38 ± 5.56 μg/L (6-87 μg/L), and 11.34 ± 1.61 μg/L (0.1-50 μg/L), respectively. Average concentrations of all examined metals were significantly higher than WHO and national standard recommended limits. The ranking order of metals concentrations in the tap drinking water was Zn > Pb > As > Co > Hg. Except for Hg and Co, at least one age group consumers were at considerable non-carcinogenic risks induced by Zn, As and Pb [Target Hazard Quotient (THQ > 1)]. The rank order of age groups consumers based on THQ and Incremental lifetime cancer risk (ILCR) was <1 years >1-9 years > 20 + years > 10-19 years. The calculated ILCR for As in all age groups were higher than 10^-3 value. All age groups of consumers in Ilam city, especially infants (<1 years) and children (1-10 years), are at considerable non-carcinogenic and carcinogenesis risk.

Concentrations of arsenic and lead in rice (Oryza sativa L.) in Iran: A systematic review and carcinogenic risk assessment

Exposure to heavy metals such as arsenic (As), lead (Pb), and cadmium (Cd) in either the short or the long term can cause cancers in humans. Dietary intake and consumption of rice (Oryza sativa L.) is increasing in Iran, and several studies on the concentration of heavy metals in rice have been carried out in this country in recent years. In this perspective, the main objective of the present study was to investigate, even via a meta-analysis of the existing literature, the presence of As and Pb in rice from many geographical areas in Iran, as well as to estimate the carcinogenic risk of these heavy metals in rice consumers. The results of the present ten years-spanning systematic review indicate that 21 reports, collecting a total of 2088 samples, were performed between 2008 and October 2017. The minimum and maximum concentration of As was observed in the Golestan area (0.01 ± 0.01 mg/kg d.w) and the Gillan region (3 mg/kg d.w); and Pb in the Shahrekord (0.07 ± 0.02 mg/kg d.w) and Mazandaran (35 mg/kg d.w). The meta-analysis of data showed that pooled concentration of As in the rice was 0.04 (95%CI: 0.02-0.06 mg/kg d.w), which resulted lower than the National Standard (NS) limits. However, the pooled concentration of Pb in the rice was 0.38 (95%CI: 0.25-0.5 mg/kg d.w), i.e., higher than NS limits. The heterogeneity was significant between As (I² = 63%, P value = .003) and Pb (I² = 96%, P value < .001) studies. The carcinogenic risk assessment showed that minimum and maximum incremental lifetime cancer risk (ILCR) of As was in the 45-54 (4.53 × 10^-2) and 15-24 (5.50 × 10^-2) year age groups consumers; and Pb, 45-54 (2.442 × 10^-3) and 15-24 (2.96 × 10^-3), respectively. The overall carcinogenesis risk of As (4.864 × 10^-2) was 18.5 times higher than Pb (2.623 × 10^-3). All age groups consumers of rice content of As and Pb are at considerable carcinogenesis risk (ILCR > 10^-3). Therefore a decreased level of heavy metals in rice cultivation should be encouraged and performed in next planning.