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

Rice (Oryza sativa) is the second cereal consumed in Iran. Many studies have been carried out in Iran about the contamination of rice by environmental pollutants such as heavy metals. The aim of present study was:

??to systematically review about Arsenic (As), Chromium (Cr), Lead (Pb), Cadmium (Cd) and Nickel (Ni) concentrations in cultivated rice in Iran and;

??to estimate the non-carcinogenic risk for age and sex groups.

We applied the target hazard quotient (THQ) and total target hazard quotient (TTHQ) to evaluation of the non-carcinogenic risk. International and Iranian databases were searched from January 2008 to October 2016. Data obtained from 27 articles showed that minimum and maximum concentrations of heavy metals were As (0.05?±?0.09?μg/g dry weight) and Ni (0.83?±?0.04?μg/g dry weight), respectively. The rank order of heavy metals based on THQ was As?>?Cr?>?Pb?>?Cd?>?Ni. Also the rank order of consumers rice based on TTHQ were rural females (0.49)?>?urban females (0.461)?>?rural males (0.455)?>?urban males (0.41). Minimum and maximum of TTHQ was related to 35–44 and 15–24 years age groups both males and females, respectively. Since THQ and TTHQ were either lower than 1 value, therefore, consumers were not exposed to carcinogenic risk by consumption of rice cultivated in Iran.     

Assessment of heavy metal content in refined and unrefined salts obtained from Urmia,Iran

A heavy metal is any relatively dense metal that may be potentially toxic in a variety of foods. Heavy metals pollute and contaminate foods. These metals are usually toxic to human body. Heavy metals are the most important toxic metals which may cause health risks following the consumption of contaminated foods. The edible salt (NaCl) is a substance that has been used as a food additive since ancient times. Twenty samples of refined and unrefined edible salts produced in Iran were analyzed using flame atomic absorption spectrometry (FAAS) method for the presence of toxic heavy metals. The precision of the analysis was assured through the repeated analysis of the samples. The mean (±standard deviation) concentrations of toxic metals in dried samples of rock salt were as follows: Ni (1.870?±?0.850), Cd (0.328?±?0.143), Mn (0.184?±?0.230) and Co (3.124?±?0.880) mg/kg and in dry weights of samples obtained from Urmia market: Ni (1.982?±?0.021), Cd (2.461?±?0.036), Mn (0.192?±?0.028) and Co (8.450?±?0.025) mg/kg. There was a significant difference between the toxic metal concentrations and their guideline values. Therefore, it was important to assess the public health risks posed by the presence of toxic contaminants.     

Non-carcinogenic risk assessment induced by heavy metals content of the bottled water in Iran

Recently, the exposure to heavy metals from bottled waters raised huge concerns. In this context, for the first time the risk of non-carcinogenic exposure by the heavy metals in Iranian drinking water was assessed. Therefore, by using the obtained data in our previous published study, the target hazard quotient (THQ) and total target hazard quotient (TTHQ) by considering to the sexuality of consumers were calculated. THQ in females were determined as significantly higher (p??Pb?>?Hg?>?Cd?>?Cu, respectively. The minimum and maximum of THQ for the males were observed in age groups of?+65 and 1–3?years, respectively. The minimum and maximum of THQ for females were noted in age groups of 11–14 and 1–3?years, respectively. Since TTHQ for all ages were less than 1 (p?相似文献   

Risk assessment of heavy metals in honey consumed in Zhejiang province,southeastern China

The levels of copper (Cu), zinc (Zn), cadmium (Cd), lead (Pb), arsenic (As), and mercury (Hg) in eight types of honey collected in China were determined. The average concentrations of the six heavy metals in the honey samples were 46.18, 1329.5, 1.34, 33.98, 13.44, and 1.65 μg kg⁻¹, respectively. All these values were below the maximum allowable contaminant levels in foods (GB2762-2005) and honey (GB14963-2011) in China. The hazard quotients of individual heavy metals and the hazard index of all six heavy metals were far below one, indicating no chronic-toxic risk from these metals for the inhabitants of Zhejiang under the current consumption rates of honey. However, the carcinogenic risk of As for the female inhabitants in Zhejiang exceeded the acceptable level of 10⁻⁴. Therefore, As is the most concerning heavy metal in honey.     

原子吸收法测定丹参中Pb、Cd两种重金属的含量

目的考察石墨原子吸收法测定丹参中铅、镉重金属含量的可行性。方法建立原子吸收法测定丹参中Pb、Cd两种重金属的含量,Cd的灰化温度为950℃,原子化温度1600℃,Pb的灰化温度为800℃,原子化温度1700℃,将丹参药材经微波消解处理后,采用上述方法 3批次样品中铅、镉含量。结果经方法学检查,Cd、Pb均符合相关标准,Pb在0.0~50.0μg/L浓度范围内,与吸光度呈良好线性相关,相应回归方程是:y=235.5A1-254.3(r=0.9995),Cd在0.0~5.0μg/L浓度范围内,与吸光度呈良好线性相关,相应回归方程是:y=432.1A2-53.4(r=0.9996),所测各批次丹参药材的铅、镉重金属含量均合格。结论采用原子吸收光谱法测定丹参药材Cd、Pb重金属含量,操作快捷、方法可靠、精密度和稳定性高,可用于丹参重金属测定。     

Effects of selected heavy metals (Pb, Cu, Ni, and Cd) in the aquatic medium on the restoration potential and accumulation in the stem cuttings of the terrestrial plant, Talinum triangulare Linn

The heavy metal (Cu, Pb, Ni, and Cd) accumulation capacity of the stem cuttings of the terrestrial, ornamental plant, Talinum triangulare was assessed in hydroponic medium. The stem cuttings of T. triangulare, grew well in distilled water regenerating roots and aerial parts. On exposure to various concentrations of Cu, Pb, Ni, and Cd, a concentration dependent decrease was observed in the number of leaves produced and roots regenerated and an increase in the number of days required for the initiation of roots. The number of leaves produced showed an increasing trend in almost all treatment concentrations of Cu, Pb, Ni, and Cd with an increase in the duration of experiment, whereas, with an increase in the treatment concentration of metals a significant (P < 0.05) decrease was observed in the number of leaves produced. The number of days required for root initiation in metal solutions, however, increased with increasing concentration of Cu, Pb, Ni, and Cd. The root development was completely arrested from 10 mg l⁻¹ of Ni and 4 mg l⁻¹ of Cd. Compared to the control, a significant decrease was recorded in the number of roots produced in all treatment concentrations of Cu, Pb, Ni, and Cd. Pink colouration of metal solution consequent to leaching of plant pigment from T. triangulare was observed which was not persistent and disappeared after a few days. Decaying of stem was observed when exposed to Ni and Cd but not to Cu and Pb. Although, copper accumulation by T. triangulare at treatment concentration of 15 and 20 mg l⁻¹ exceeded 1,000 mg kg⁻¹ dry matter, necessary pot culture experiment is required before “T. triangulare” can be definitely classified as a Cu hyperaccumulator.     

Heavy metals (Ni, Cr, Cu) in the Karoon waterway river, Iran

Environmental pollution is a world-wide problem, heavy metals belonging to the most important pollutants. The progress of industries has led to increased emission of pollutants into ecosystems. Karoon is the biggest and only navigable river in the South of Iran. Along the Karoon industrial units such as piping, steel, paint making, agriculture, paper mill, fish cultivation, abbottiors, electroplating industries drain their wastewater into the river. In this study, the concentrations of heavy metals (Ni, Cr, Cu) in the Karoon river have been determined. Samples were collected from 16 stations along the river, in winter and spring 1996. Heavy metal concentrations were measured by graphite furnace atomic absorption spectrometry. The minimal and maximal concentrations of these metals in winter were 69.3-110.7, 1.7-118.3, and 5.5-70.3 microg/l, for Ni, Cr, and Cu, respectively. The minimal and maximal concentrations of these metals in spring were 41.0-60.7, 0.7-19.8, and 0.5-28.7 microg/l, for Ni, Cr, and Cu, respectively. The results show that the pollution has increased along the river, down to the estuary at the Persian Gulf.     

Determination of Pb (Lead), Cd (Cadmium), Cr (Chromium), Cu (Copper), and Ni (Nickel) in Chinese tea with high-resolution continuum source graphite furnace atomic absorption spectrometry

The contents of lead, cadmium, chromium, copper, and nickel were determined in 25 tea samples from China, including green, yellow, white, oolong, black, Pu’er, and jasmine tea products, using high-resolution continuum source graphite furnace atomic absorption spectrometry. The methods used for sample preparation, digestion, and quantificational analysis were established, generating satisfactory analytical precisions (represented by relative standard deviations ranging from 0.6% to 2.5%) and recoveries (98.91–101.32%). The lead contents in tea leaves were 0.48–10.57 mg/kg, and 80% of these values were below the maximum values stated by the guidelines in China. The contents of cadmium and chromium ranged from 0.01 mg/kg to 0.39 mg/kg and from 0.27 mg/kg to 2.45 mg/kg, respectively, remaining in compliance with the limits stipulated by China’s Ministry of Agriculture. The copper contents were 7.73–63.71 mg/kg; only 64% of these values complied with the standards stipulated by the Ministry of Agriculture. The nickel contents ranged from 2.70 mg/kg to 13.41 mg/kg. Consequently, more attention must be paid to the risks of heavy metal contamination in tea. The quantitative method established in this work lays a foundation for preventing heavy metal toxicity in human from drinking tea and will help establish regulations to control the contents of heavy metals in tea.     

Alterations of lipid synthesis in the normal and dysmyelinating trembler mouse sciatic nerve by heavy metals (Hg, Pb, Mn, Cu, Ni)

Lipid synthesis from 14C-labeled acetate was dramatically reduced by inorganic mercury in the mouse sciatic nerve in vitro (IC50 was 10 microM). The dysmyelinating trembler mutant was less affected (IC50 was 40 microM). Under the same conditions, lipid synthesis was less inhibited by inorganic lead but was increased 3 times by manganese, copper and nickel at less than 2 mM. Although the synthesis of all lipids is dramatically reduced by inorganic mercury, their relative proportions vary in the presence of this metal:cholesterol synthesis was inhibited most strongly, phosphatidylcholine synthesis was also reduced, whereas synthesis of other lipids was relatively unchanged (phosphatidylserine, phosphatidyl inositol, sphingomyelin, cholesterol esters, cerebrosides). Incorporation of [14C]acetate into free fatty acids was enhanced by a factor of 4 in the presence of inorganic mercury.     

A review of heavy metals in rice (Oryza sativa) of Iran

With attention to high public concern to dietary intakes of heavy metals from various foods and rice as one of the main food of the people in the Iran, the aim of this study was to survey heavy metals in rice samples of Iran. Based on obtained results, among the metals in some Iranian cultivated rice samples, cadmium (Cd), arsenic (As) and lead (Pb) concentrations were higher than national standard of Iran. But, totally in Iran, average weekly intake for Cd, As, Pb, cobalt (Co), nickel (Ni) and chromium (Cr) were lower than the maximum weekly intake recommended by WHO/FAO. However, the average weekly intake amount for Hg from rice in Iran is higher than the maximum weekly intake recommended by WHO/FAO.     

Response patterns of biomarkers in omnivorous and carnivorous fish species exposed to multicomponent metal (Cd,Cr, Cu,Ni, Pb and Zn) mixture. Part III

Ecotoxicology - Toxicity to fish of multicomponent metal mixtures at maximum-permissible-concentrations (MPC: Cd—0.005, Cr—0.01, Cu—0.01, Ni—0.01, Pb—0.005 and...     

Differential effect of N-acetylcysteine on excretion of the metals Hg,Cd, Pb and Au

Male Wistar rats were subacutely treated with sublethal doses of HgCl₂, CdCl₂, Pb(NO₃)₂, or Na-aurothiomalate. The metal preparations contained trace doses of radioactive nuclide. Based on the doses given and on the radioactivity excretion in urine and faeces the body burden was determined. After the metal treatment periods, some of the animals received N-acetylcysteine (up to 100 mg/kg daily, on 6 consecutive days, i.p.), and the effect of this potential chelator on metal excretion was monitored. The excretion of Hg (after dosing with HgCl₂) was not influenced by N-acetylcysteine. The elimination of Cd in urine (after dosing with CdCl₂) was increased by a factor of four. Also, the elimination of Pb [after dosing with Pb(NO₃)₂] was gradually increased (in faeces and urine) by increasing doses of N-acetylcysteine. After dosing with Na-aurothiomalate, the excretion of Au in urine was increased to about 30%. The data suggest some activity of N-acetylcysteine in facilitating excretion of Pb, Cd or Au, but not of Hg.This is an abridged report on the research conducted. The full material is available from the authors on request     

Occurrence of toxic metals (Hg,Cd and Pb) in fresh and canned tuna: Public health implications

Hg, Pb and Cd levels in fresh and canned tuna were determined and assessed by comparing element levels in these samples with maximum permissible limits set by European legislation. The estimated weekly intakes by human consuming both fresh and canned tuna were also evaluated for possible consumer health risks. Among tested metals, Hg had the highest concentrations, followed by Pb and Cd either in fresh tuna or canned tuna. None of the tested samples surpassed the European regulatory limits fixed for Cd and Pb, whereas 8.9% of the tuna cans and 20% of fresh tuna samples exceeded standard for Hg. The size of tuna was a determining factor of Hg burden. A high intake of Hg surpassing the toxicological reference value established by WHO, was associated with consumption of larger size tuna specimens. Also canned tuna consumption with Hg concentrations higher than 1 μg kg⁻¹, strongly increased the consumer exposure. In contrast, Cd and Pb weekly intakes through consumption either of fresh tuna or canned tuna did not exceed the toxicological reference values established by WHO, and consequently there was no human health risk. A continuous surveillance system of Hg content in these fishery products is crucial for consumer protection.     

Comparative evaluation of the cytotoxicity sensitivity of six fish cell lines to four heavy metals in vitro.

To establish the potential use of cell cultures as a simple and sensitive biological tool to detect environmental pollutants, six cell lines established from several fish species including GCF (grass carp fins), CIK (Ctenopharyngodon idellus kidney), EPC (epithelioma papulosum cyprini), CCO (channel catfish ovary), BB (brown bullhead caudal trunk) and FHM (fathead minnow muscle) were tested and compared for their cytotoxic sensitivity to four heavy metals: cadmium (Cd), chromium (Cr), zinc (Zn), and copper (Cu). Following a 24-h exposure to these metal salts at selected concentrations, test cells were characterized by morphology, viability and proliferation. Our results indicate that all these metal salts are cytotoxic to these fish cell lines, but at varied levels. Calculated inhibitory concentration (IC(50)) values revealed that the cytotoxicity of Cr and Cd was significantly more pronounced than that of the other two metal salts. Comparative analysis of these fish cell lines showed that C. idellus kidney (CIK) cells are the most sensitive cell line to copper, epithelioma papulosum cyprini (EPC) cells are more sensitive than other cells to Cr and Zn, while channel catfish ovary (CCO) cell line is the most sensitive one to Cd. In conclusion, CIK, EPC and CCO could potentially be sensitive bio-indicators for the initial monitoring and assessment of acute cytotoxicity of heavy metals in the aquatic environment.     

Potential human health risks from metals (Hg, Cd, and Pb) and polychlorinated biphenyls (PCBs) via seafood consumption: Estimation of target hazard quotients (THQs) and toxic equivalents (TEQs)

Edible marine species (fish, cephalopod molluscs, crustaceans) from the Adriatic Sea were analyzed for content in heavy metals (Hg, Cd and Pb) and polychlorinated biphenyls (PCBs). Health risks to human via dietary intake of seafood were assessed by the target hazard quotients (THQs) and the toxic equivalent factors (TEFs). Mercury maximum concentrations corresponded to fish (0.07-1.56 microg g(-1)w.w.), followed by cephalopod molluscs (0.10-0.55 microg g(-1)w.w.), and crustaceans (0.27-0.33 microg g(-1)w.w.). Cadmium levels in cephalopods (0.18-0.59 microg g(-1)w.w.) were higher than those in fish (0.01-0.05 microg g(-1)w.w.) and crustaceans (0.02-0.04 microg g(-1)w.w.), while for Pb the concentrations were generally low (fish: ND-1.18 microg g(-1)w.w., cephalopods: ND-0.17 microg g(-1)w.w., crustaceans: ND-0.03 microg g(-1)w.w.). For PCBs, concentrations in fish, cephalopods and crustaceans ranged between 141 and 3,406 ng g(-1)l.w., 190 and 542 ng g(-1)l.w., and 202 and 429 ng g(-1)l.w., respectively. Cd and Pb THQ values as well as estimates of PCB TEQ exposure indicated the absence of health risks through consumption of the various seafood. In contrast, mercury TEQs values due to consumption of certain fish species (albacore, rosefish and thornback ray) indicated that human health risk might be of concern.     

Biotransformation of polychlorinated biphenyls (PCBs) and bioformation of hydroxylated PCBs in fish

Hydroxylated PCBs (OH-PCBs) are a class of organic contaminants that have been found recently in the plasma of Great Lakes fish, the source of which is either bioformation from PCBs or accumulation from the environment. To address the potential for fish to biotransform PCBs and bioform OH-PCBs juvenile rainbow trout (Oncorhynchus mykiss; approximately 80 g) were exposed to dietary concentrations of an environmentally relevant mixture of PCBs. Eight OH-PCBs were found in the plasma of rainbow trout after 30 days of exposure to the PCBs, the relative pattern of which was similar to those observed in wild lake trout (Salvelinus namaycush) from Lake Ontario. Hydroxylated-PCBs were not found (detection limit 0.02 pg/g) in the food or control (not PCB-exposed) fish. A curvilinear logt(1/2)-logK(ow) relationship for recalcitrant PCBs was found, similar to previously reported relationships, although t(1/2) values were longer and shorter than studies using smaller fish or cooler temperatures, respectively. A number of PCB congeners fell below the logt(1/2)-logK(ow) relationship providing the first estimates of non-chiral PCB biotransformation rates in fish. Enantioselective degradation of the chiral congeners PCBs 91 and 136, also indicated biotransformation. Biotransformation of PCBs was structure-dependent with greater biotransformation of PCBs with vicinal hydrogen atoms in the meta/para positions, suggesting CYP 2B-like biotransformation. Other chiral congeners with a meta/para substitution pattern showed no enantioselective degradation but were biotransformed based on the logt(1/2)-logK(ow) relationship. The results of this study demonstrate that laboratory held rainbow trout can biotransform a number of PCB congeners and that bioformation is likely an important source of OH-PCBs in wild salmonids of the Great Lakes.     

Effects of field contamination by metals (Cd, Cu, Pb, Zn) on biometry and mechanics of echinoderm ossicles

Echinoderms are known to readily incorporate metals in their calcified endoskeleton. It is currently unclear if this has an impact on the skeleton function or if this can be considered as a detoxification mechanism. In the present work, populations of the sea urchin Echinus acutus and the starfish Asterias rubens were studied in stations distributed along a metal contamination gradient in a Norwegian fjord (S?rfjord). Ossicles involved in major mechanical functions - sea urchin spine and starfish ambulacral plate - were analyzed for their metal concentration (Cd, Cu, Pb and Zn) and their biometric and mechanical properties. Starfish plates were more contaminated by Cd, Pb and Zn than sea urchin spines. Cu concentrations were at background levels. In E. acutus, metals principally affected size. In A. rubens, material stiffness and toughness were decreased in the most contaminated station. This reduction is attributed either to the direct incorporation of metals in the calcite lattice and/or to deleterious effects of metals during skeleton ontogenesis. The contrasting incorporation of metals in the skeleton of the two investigated species accounts for the different impact of the metals, including in terms of fitness. The present results clearly indicate that, at least in A. rubens, incorporation of metals in the skeleton cannot be considered as a detoxification mechanism.