Effect of heavy metal exposure on blood haemoglobin concentration and methemoglobin percentage in Lumbricus terrestris

The earthworm haemoglobin (Hb) is a large extracellular hemoprotein flowing in a closed circulatory system. In spite of the fundamental role of this respiratory pigment in earthworm physiology, little is known about its sensitivity to environmental pollutants. The aim of the present work was to investigate the possible effect of heavy metal (cadmium, copper, mercury) exposure on Hb concentration and oxidation state (methemoglobin formation) in the earthworm Lumbricus terrestris. In addition, the tissue concentration of metallothioneins, a well-known biomarker of heavy metal exposure, was determined as an indicator of metal uptake. The animals were exposed to increasing concentrations of Cd, Cu and Hg utilizing the standard acute toxicity test, “Filter paper test” for 48 h. Exposure to heavy metals (10⁻⁵–10⁻³ M for Cd, 10⁻⁴–10⁻³ M for Hg, and 10⁻⁴–10⁻² M for Cu) was found to increase haemoglobin concentration in L. terrestris, although the magnitude of such an increase was dependent on the metal. In addition, metal exposure led to the formation of methemoglobin. Compared to other known biological responses to heavy metals, such as metallothionein induction, methemoglobin increase showed a higher sensitivity and a higher percentage variation in exposed organisms, showing to be a possible suitable biomarker of exposure/effect to be included in a multi biomarker strategy in earthworm in soil monitoring assessment.     

Genetics analysis of haptoglobin gene in Fujian Han nationality

To study the genetic features (characteristics) of haptoglobin gene, four different age groups of Fujian Han people were investigated. The phenotypes of the haptoglobin of four different groups were analyzed by using polyacrylamide gel electrophoresis. The frequency of HP ¹ in the population of Fujian Han nationality accounted for 0.340, among which children, youths, middle aged and elder groups were 0.307, 0.338, 0.363 and 0.383, respectively. The Hp^0–0 phenotype frequency was 0.026 in which the four age groups accounted for 0.032, 0.046, 0.014 and 0.014, respectively. The frequency of Hp ¹ gene is rising with increasing age. The frequency of Hp^0–0 phenotype is highest in the middle aged group and then tends to drop with increasing age. __________ Translated from Journal of Fujian Medical University, 2007, 41(5): 452–453 [译自: 福建医科大学学报]     

Mycorrhizal fungi and ectomycorrhiza associated bacteria isolated from an industrial desert soil protect pine seedlings against Cd(II) impact

Effects of mycorrhization with Amanita rubescens or Hebeloma sinapizans and dual inoculation with the fungi and ectomycorrhiza associated bacteria (EMAB) Pseudomonas putida or Bacillus cereus on seedling growth and accumulation of Cd(II) in Pinus sylvestris were studied. Both fungal and bacterial species were isolated from roots of pines growing in an industrial area polluted with high concentrations of heavy metals. During mycorrhization, A. rubescens colonized higher number of pine seedlings than H. sinapizans, especially when EMAB were co-inoculated. In addition, the seedling biometric characteristics (i.e. root and shoot lengths and biomass) were stimulated by treatment with the fungal species alone and dual inoculation with the fungi and EMAB. Amanita rubescens was more efficient in this stimulation than H. sinapizans. The increased growth of pine seedlings was especially seen for co-inoculation with P. putida. Furthermore, elevated accumulation of Cd(II), ranging from 56 μg g⁻¹ to 72 μg g⁻¹ dry weight, in underground parts of the inoculated seedlings was found. The seedlings treated with A. rubescens accumulated higher concentrations of the metal than those inoculated with H. sinapizans. Additional treatment of pine seedlings with P. putida resulted in the higher accumulation of Cd(II) in the roots as compared with those inoculated with B. cereus. The results suggest that the growth of pine seedlings in Cd(II)-polluted soil may depend on fungal species forming ectomycorrhizae, species-specific co-inoculation with EMAB and specificity of fungal-EMAB interactions.     

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.     

Study on the action of resistin-induced human umbilical vein endothelial cell dysfunction

The aim of this paper was to investigate the effects of resistin on human umbilical vein endothelial cells (HUVECs), and to explore its role and mechanism of action in atherosclerosis. HUVECs were incubated with recombinant human resistin (0, 50, 100 ng/mL) for 24 h. ICAM-1, VCAM-1 and reactive oxygen species (ROS) were assayed by flow cytometer. ET-1, eNOS and iNOS mRNA expression were measured by semi-quantitative RT-PCR. Incubation of HUVECs with resistin resulted in an increase in ICAM-1 expression and ET-1 mRNA expression. However, resistin had no effect on VCAM-1 expression and ROS release. eNOS and iNOS mRNA expression were not altered by resistin stimulation. Adipokine resistin exerted a direct effect in promoting HUVEC dysfunction by promoting ICAM-1 and ET-1 expression. These data suggest that adipocyte-endothelium cross-talk might play an important role in the pathogenesis of cardiovascular disease in diabetes mellitus. Translated from Journal of Sun Yat-Sen University (Medical Sciences), 2006, 27(3): 258–261 [译自: 中山大学学报 (医学科学版)]     

Association study on GNB3 gene polymorphism with essential hypertension in Xinjiang Uygur group

The relationship between the tenth exon C825T of G-protein β3 subunit (GNB₃) genetic polymorphism and hypertension in the Uygur population of China was investigated. A nested case-control study (n = 738) was carried out. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was used to genotype GNB₃ C825T polymorphism in 354 hypertensive (HT) and 384 normotensive (NT) Uygur subjects. The distributions of GNB₃ C825T genotypes were CC (27.2%), TT (42.9%), and CT (29.9%) in the hypertensive subjects and CC (27.7%), TT (42.4%), CT (29.9%) in the normotensive subjects. There were no significant differences in the genotype distributions between the two groups (χ ² = 0.0262 P = 0.99). The T allele was 51.4% in hypertensive subjects and 51.2% in normotensive subjects, which, between the two groups, was not a significant difference (χ ² = 0.0016 P = 0.97). Further analysis shows that there is no association between C825T genotypes and age, body mass index (BMI), Glucose (GLU), Triglyceride (TG), Cholesterol (CHO), systolic blood pressure (SBP) and diastolic blood pressure (DBP). No evidence was found to suggest an association between GNB₃ C825T polymorphism and hypertension in the Uygur population of China. Translated from Journal of Fudan University (Medical Sciences), 2006, 33(4): 433–436 [译自: 复旦大学学报 (医学版)]     

Effects of podocin transfection on CD2AP distribution in HEK293 cells

The aim of this paper is to construct a podocin fluorescence expression vector and observe the effects of podocin transfection on CD2AP distribution in HEK293 cells. The pGEMT-easy vector containing the full-length cDNA encoding human podocin was cloned and digested with BamHI and XhoI. The digested full-length podocin was subcloned into pEGFP-C2. The constructed plasmids were transfected into HEK293 cells and its effects on CD2AP distribution were observed by immunofluorescence. The pEGFP-NPHS2 expression vector was successfully constructed and podocin exclusively located on the HEK293 cell membrane. After podocin transfection, CD2AP redistributed from the perinucleus to the cytoplasm in HEK293 cells. It can be concluded that podocin can recruit CD2AP to redistribute from the perinucleus to the cytoplasm in HEK293 cells. __________ Translated from Journal of Nanjing Medical University (Natural Science), 2007, 27(6): 527–529, 533 [译自: 南京医科大学学报(自然科学版)]     

Suitability of <Emphasis Type="Italic">Daphnia similis</Emphasis> as an alternative organism in ecotoxicological tests: implications for metal toxicity

The acute toxicity of metals to Daphnia similis was determined and compared to other daphnid species to evaluate the suitability of this organism in ecotoxicology bioassays. To verify the performance D. similis in toxicity tests, we also investigated the effect of Pseudokirchneriella subcapitata at 1 × 10⁵ and 1 × 10⁶ cells ml⁻¹ on Cd and Cr acute toxicity to the cladoceran. Daphnid neonates were exposed to a range of chromium and cadmium concentrations in the absence and presence of the algal cells. Metal speciation calculations using MINEQL⁺ showed that total dissolved metal concentrations in zooplankton culture corresponded to 96.2% free Cd and 100% free Cr concentrations. Initial total dissolved metal concentrations were used for 48 h-LC₅₀ determination. LC₅₀ for D. similis was 5.15 × 10⁻⁷ mol l⁻¹ dissolved Cd without algal cells, whereas with 1 × 10⁵ cells ml⁻¹, it was significantly higher (7.15 × 10⁻⁷ mol l⁻¹ dissolved Cd). For Cr, the 48 h-LC₅₀ value of 9.17 × 10⁻⁷ mol l⁻¹ obtained for the cladoceran in tests with 1 × 10⁶ cells ml⁻¹ of P. subcapitata was also significantly higher than that obtained in tests without algal cells (5.28 × 10⁻⁷ mol l⁻¹ dissolved Cr). The presence of algal cells reduced the toxicity of metals to D. similis, as observed in other studies that investigated the effects of food on metal toxicity to standard cladocerans. Comparing our results to those of literature, we observed that D. similis is as sensitive to metals as other standardized Daphnia species and may serve as a potential test species in ecotoxicological evaluations.     

Heavy metal bioaccumulation in different fish species in the coast of the Persian Gulf,Iran

This study project aimed to determine the concentrations of five heavy metals (Al, As, Cd, Hg and Pb) in different fish species in the coast of the Persian Gulf in Iran. Ninety samples divided to three types’ fish including Rastrelliger kanagurta, Tenualosa ilisha and Scomberomorus commerson. The investigation performed by ICP-OES technique. The estimated daily intake of heavy metals compared with allowable daily intake of these. Also, the means compared with the allowable limit regulated by national Iranian standards. Results showed that the heavy metal contamination of these was in the standard limit, except Pb in R. kanagurta (43.33%), T. ilisha (23.33%) and S. commerson (13.3%) had greater than European Union limit (300?μg L^?1). Therefore, monitoring of the heavy metals contents, specially Pb is very important yet because of the presence of these in soils due to increase of industrial activity and use pesticides and fertilizers.     

Health risk assessment of heavy metals in the water environment of Zhalong Wetland,China

Concentrations of the Cu, Cd, Cr, As, Zn and Ni in water samples from 272 sampling stations in the water environment of Zhalong Wetland, China were studied. Health risk assessment associated with six heavy metals and metalloid was conducted using health risk assessment model from United States Environmental Protection Agency. It can be concluded that the mean concentrations of Cu, Ni, Zn, As, Cd and Cu were 0.19, 0.45, 0.52, 4.9, 0.12 and 0.24 μg L^?1, respectively. The carcinogenic risk of Cr, As and Cd in the discharged area, experimental area, buffer area and core area were lower than the maximum allowance risk level recommended by International Commission on Radiological Protection (ICRP 5.0 × 10^?5 a^?1). The non-carcinogenic risks (Cu, Zn, Ni) was also lower than the maximum allowance levels recommended by ICRP. Though it was lower than the level, it was very approaching to maximum acceptable risk level, need to draw attention to the relevant departments.     

Acute combined exposure to heavy metals (Zn,Cd) blocks memory formation in a freshwater snail

The effect of heavy metals on species survival is well documented; however, sublethal effects on behaviour and physiology are receiving growing attention. Measurements of changes in activity and respiration are more sensitive to pollutants, and therefore a better early indicator of potentially harmful ecological impacts. We assessed the effect of acute exposure (48 h) to two heavy metals at concentrations below those allowable in municipal drinking water (Zn: 1,100 μg/l; Cd: 3 μg/l) on locomotion and respiration using the freshwater snail, Lymnaea stagnalis. In addition we used a novel assessment method, testing the ability of the snail to form memory in the presence of heavy metals in both intact snails, and also snails that had the osphradial nerve severed which connects a chemosensory organ, the osphradium, to the central nervous system. Aerial respiration and locomotion remained unchanged by acute exposure to heavy metals. There was also no effect on memory formation of these metals when administered alone. However, when snails were exposed to these metals in combination memory formation was blocked. Severing the osphradial nerve prevented the memory blocking effect of Zn and Cd, indicating that the snails are sensing these metals in their environment via the osphradium and responding to them as a stressor. Therefore, assessing the ability of this species to form memory is a more sensitive measure of heavy metal pollution than measures of activity, and indicates that the snails’ ability to demonstrate behavioural plasticity may be compromised by the presence of these pollutants.     

Toxicity of lead, cadmium and mercury on embryogenesis, survival, growth and metamorphosis of Meretrix meretrix larvae

In order to assess the toxicity of heavy metals on the early development of Meretrix meretrix, the effects of mercury (Hg), cadmium (Cd) and lead (Pb) on embryogenesis, survival, growth and metamorphosis of larvae were investigated. The EC₅₀ for embryogenesis was 5.4 μg l⁻¹ for Hg, 1014 μg l⁻¹ for Cd and 297 μg l⁻¹ for Pb, respectively. The 96 h LC₅₀ for D-shaped larvae was 14.0 μg l⁻¹ for Hg, 68 μg l⁻¹ for Cd and 353 μg l⁻¹ for Pb, respectively. Growth was significantly retarded at 18.5 μg l⁻¹ (0.1 μM) for Hg, 104 μg l⁻¹ (1 μM) for Cd and 197 μg l⁻¹ (1 μM) for Pb, respectively. The EC₅₀ for metamorphosis, similar to 48 h LC₅₀, was higher than 96 h LC₅₀. Our results indicate that the early development of M. meretrix is highly sensitive to heavy metals and can be used as a test organism for ecotoxicology bioassays in temperate and subtropical regions.     

Potential risk assessment of trace metals accumulation in food,water and edible tissue of rainbow trout (Oncorhynchus mykiss) farmed in Haraz River,northern Iran

This study focuses on the extent of Zn, Cu, Ni, Cd and Pb bioaccumulation in water, fish feed and the muscles of 40 rainbow trout (Oncorhynchus mykiss) from four farmsalong Haraz River, Mazandaran Province, north of Iran. The dependence of bioaccumulation with food chain and environmental heavy metals concentration was specifically addressed. The potential human health risks due to consumption of rainbow trout have been assessed by estimated daily intake (EDI) and target hazard quotient (THQ) of aforementioned metals. The detected concentration ranges of the elements in the muscles, reported as μg.g^?1?dry weight, were as following: Zn (13.92–15.92), Cu (0.54–0.74), Ni (0.12–0.26), Cd (0.008–0.01) and Pb (0.25–0.57). The rank order of the levels of the heavy metals was: in edible tissue Zn?>?Cu?>?Pb?>?Ni?>?Cd; in water Pb?>?Zn?>?Cu?>?Ni?>?Cd; in fish feed Pb?>?Zn?>?Ni?>?Cu?>?Cd. In general, the concentrations of all target metals were positively correlated with fish feed contents, whereas negative correlations were observed between the metal concentrations and water. Risk assessments suggested that there isn’t potential ecological and human health risk.     

Changes in antioxidant activity,total phenolic and abscisic acid constituents in the aquatic plants <Emphasis Type="Italic">Myriophyllum spicatum</Emphasis> L. and <Emphasis Type="Italic">Myriophyllum triphyllum</Emphasis> Orchard exposed to cadmium

Changes in antioxidant activity, total phenolic and abscisic acid (ABA) constituents of Myriophyllum spicatum L. and Myriophyllum triphyllum Orchard, cadmium (Cd) aqueous macrophytes, were investigated exposed to 0, 2, 4, 6, 8, 16 mg l^-1 Cd concentrations. M. triphyllum exhibited strong antioxidant activity but not M. spicatum before and after exposure. Free radical scavenging activity of M. triphyllum was significantly affected from the Cd concentrations and a significant increase was observed at 6 mgl^-1 Cd concentration. Total phenolic constituent and ABA concentration of M. triphyllum is higher than that of M. spicatum with or without heavy metal exposure (P < 0.05). While total phenolic constituents of both species were not significantly affected from Cd concentrations except for 6 mgl^-1 Cd concentration ABA contents did. ABA content of M. triphyllum increased from 1.81 ± 0.10 μg g^-1 (control) to 5.13 ± 0.15 μg g^-1 at 16 mg l^-1 Cd concentration and increase was from 0.59 ± 0.08 μg g^-1 (control) to 2.05 ± 0.10 μg g^-1 for M. spicatum at the same Cd concentration. Both species accumulated ABA indicating submerge plants can also accumulate ABA and its concentration increase with increasing Cd concentration. Such studies as this one may be important for evaluation of the metabolic variations of toxic metal tolerant macrophytes that grown in polluted aqueous ecosystem.     

Heavy metal (Pb,Cu, Zn,and Cd) concentrations in the water and muscle of common carp (Cyprinus carpio) fish and associated non-carcinogenic risk assessment: Alagol wetland in the Golestan,Iran

Short- and long-term exposure to heavy metals can be dangerous for human health. One of the main routes of exposure to heavy metals is intake of seafood such as fish. In this study, lead (Pb), copper (Cu), zinc (Zn), and cadmium (Cd) concentration in the water and muscle of C. Carpio fish was measured and non-carcinogenic risk of these heavy metals was estimated. The mean (range) concentrations of Cu, Zn, Pb, and Cd were 7.92?±?7.99 (1.22–39.43?mg/kg), 120.90?±?106.25 (1.15–477?mg/kg), 5.84?±?5.22 (ND-21.86?mg/kg), and 0.027?±?0.043 (ND-0.14). Except Cd, the concentrations of Cu, Zn, and Pb were significantly more than Food and Agricultural Organization United Nations (FAOUN) maximum guidelines (p??Cu?>?Pb?>?Cd in the water and muscle tissue of C. carpio fish. Lowest and highest target hazard quotient (THQ) for adults was related to Cd (0.005) and Pb (0.252) and for children, Cd (0.003) and Pb (0.168), respectively. The rank order of THQ for adults and children are Pb?>?Zn?>?Cu?>?Cd. Since THQ and hazard index (HI) for both adults and children were significantly lower than 1 (p?C. Carpio fish consumption.     

Changes of phenotype and function of human CD4+CD25-T cells induced by transfection of Foxp3

The aim of this paper is to explore the effects of transfection of Foxp3 gene on the phenotype and function of naive CD4⁺ T cells. The pMSCV-Foxp3 retroviral vector encoding Foxp3 gene was transduced into the PT67 packaging cell line. Virus-containing supernatant was applied to differentiate CD4⁺CD25⁻ T cells. The resulting cells were sorted with flow cytometry. The expressions of CD25, CD127, CTLA-4 and the proliferation of transfected T cells were examined. The effect of transfected CD4⁺ T cells on the proliferation and cytokine production of CD4⁺CD25⁻ T cells was examined. Foxp3-gene transfected CD4⁺ T cells could express Foxp3 and transfection of Foxp3 gene up-regulated the expressions of CD25 and CTLA-4, but down-regulated CD127 expression. After transfection, the proliferation of CD4⁺ T cells was eliminated. Transfected T cells inhibited the proliferation of CD4⁺CD25⁻ T cells. CD4⁺CD25⁻ T cells acquired a regulatory phenotype and function after it was transduced with the Foxp3 gene. This suggested a key role of Foxp3 in the generation of CD4⁺CD25⁺ regulatory T cells. __________ Translated from Acta Academiae Medicinae Militaris Tertiae, 2008, 30(3): 186–188 [译自: 第三军医大学学报]     

Monitoring air pollution at Mohammedia (Morocco): Pb,Cd and Zn in the blood of pigeons (<Emphasis Type="Italic">Columba livia</Emphasis>)

The concentrations of Pb, Cd and Zn were investigated in the blood of pigeons (Columba livia) in order to assess the degree of pollution by heavy metal. For this, wild city pigeons were caught at four different locations in Mohammedia classified according to their industrial activity and road traffic density. Significant difference in heavy metal concentrations were observed between sites studied, the highest lead and cadmium levels were found in industrial area and center town, while the highest zinc level was found in the less contaminated area. These results indicate that the industrial activities and the road traffic are the most important source of pollution.     

Effect of Feixian Recipe on laminin, collagen I and III in rats with pulmonary fibrosis induced by bleomycin

The aim of this paper is to observe the effect of the Feixian Recipe on pulmonary fibrosis in rats. A rat model with pulmonary fibrosis was established by intratracheal injection of bleomycin. On days 14, 28 and 45, the contents of laminin, collagen I and collagen III in lung tissue homogenate in the model group, the sham operated group, the Feixian group and the prednisone group were measured. The contents of laminin and collagen I and III were decreased significantly by the Feixian Recipe. Feixian Recipe has a significant therapeutic effect on bleomycin-induced pulmonary fibrosis in rats. __________ Translated from Journal of Beijing University of Traditional Chinese Medicine, 2007, 30(9): 608–610 [译自: 北京中医药大学学报]     

Antioxidant responses and metal accumulation in tissues of Nile tilapia Oreochromis niloticus under Zn,Cd and Zn + Cd exposures

We investigated the effects of Zn, Cd and a Zn + Cd mixture on antioxidant parameters and metal accumulation in Oreochromis niloticus. Fish were exposed to 0.5 and 5.0 mg l^?1 Zn, 0.1 and 1.0 mg l^?1 Cd, and 0.5 mg l^?1 Zn + 0.1 mg l^?1 Cd and 5.0 mg l^?1 Zn + 1.0 mg l^?1 Cd mixtures for 7 and 28 days to determine Zn and Cd accumulation, reduced glutathione (GSH) level and glucose‐6‐phosphate dehydrogenase (G6PD) activity in gill and liver. There was increasing accumulation of the metals in the tissues with increasing concentrations of metals in the exposure medium and with increasing duration of exposure (except at the lower concentration of Zn). Concentration of metals in the tissues of fish exposed to the Zn + Cd combination were significantly lower than in fish exposed to the single metal. The highest metal accumulation was observed in the liver. Exposure to the heavy metals affected the antioxidant parameters in the tissues, with both GSH level and G6PD activity in the gill and liver being increased under Zn, Cd and Zn + Cd exposures, especially in their higher concentrations. These increases in the antioxidant responses were higher with the Cd alone, and in combination with Zn, than with Zn alone. Furthermore, GSH level and G6PD activity increased with increasing exposure period only for Cd alone, and in Cd combination with Zn. The results indicate that O. niloticus resisted oxidative stress induced by heavy metal exposure by antioxidant mechanisms. Copyright © 2008 John Wiley & Sons, Ltd.     

Study of heavy metal levels in indoor dust and their health risk assessment in children of Ahvaz city,Iran

The concentration of heavy metals in household dust and their health risks on children living in different areas of Ahvaz city was investigated during November 2013 to October 2014 in Iran. Totally, 108 dust samples were taken from their houses in three different areas including S₁ (industrial), S₂ (heavy traffic) and S₃ (residential zone far away from industrial and traffic emission sources). The samples were analyzed for eight selected heavy metals (Cr, Ni, Cu, Mn, Pb, Zn, Co and Cd) using an inductively coupled plasma optical emission spectroscopy (ICP-OES, Spectro Arcos Model, Germany). Exposure and risk assessment of these metals were estimated using USEPA’s exposure parameters. Results showed that the mean values of all heavy metals in tempered months were significantly higher than the other months (p?<?0.05). Cancer risk and non-carcinogenic risk (hazard index) of Ni, Cr, Cd and Pb from indoor dust exposure were estimated for children via three exposure pathways (ingestion, inhalation and dermal contact). The non-cancer risks to children in all samples were lower than acceptable level of 1, while the potential cancer risks from Ni intake in S₁ and S₂ were 1.57E???06 and 1.19E???06, respectively, and for Cr in S₁ and S₂, it was 1.43E???06 and 1.15E???06, respectively, which these values were slightly higher than the acceptable level (1?×?10^?6). In conclusion, household dust of Ahvaz city would probably have a significant potential to cause cancer in most exposed children.