Cumulative rate and distribution of Cd and Pb in the organs of adult male Wistar rats during oral exposure

The degree of accumulation of Cd and Pb in the brains, spleens, lungs, hearts, livers and kidneys of adult Wistar rats was compared both for separate (Cd or Pb) and combined (Cd + Pb) oral exposure. In addition, the metals were administered either with liquids or with solid feed. Rats were exposed to low doses of metals (7 mg Cd and 50 mg Pb/kg feed or L of distilled water) over 6 or 12 weeks. In total the organs of rats accumulated about 0.3–0.5% Cd and 0.4–0.6% Pb supplied with food or drink. The presented studies demonstrated that the distribution of Cd and Pb in the organs is affected by: the type of exposure (separate or combined), the source of metals (feed or drinks) and the duration of exposure. It was found that simultaneous exposure to low doses of Cd and Pb supplied with food is much more hazardous than exposure to such metals supplied with water.     

Safety evaluation of metal exposure from commonly used moisturizing and skin-lightening creams in Nigeria

The concentrations of ten metals (Cd, Pb, Ni, Cr, Cu, Co, Fe, Mn, Zn and Al) were measured in some commonly used moisturizing and skin-lightening creams in Nigeria with a view to providing information on the risk of exposure to metals from the use of these products. The metal concentrations in these products were measured by atomic absorption spectrometry after acid digestion of the samples. The measured concentrations of metals in the skin moisturizing creams ranged from <0.15 to 6.3 μg/g Cd, <0.02 to 17.5 μg/g Cu, 2.25 to 6.25 μg/g Cr, <0.25 to 124.3 μg/g Al, 0.2 to 7.3 μg/g Pb, <0.03 to 10.7 μg/g Ni, 17.3 to 372.0 μg/g Zn, <0.02 to 1.0 μg/g Co, 17.75 to 28.8 μg/g Mn, <0.1 to 89.8 μg/g Fe while the concentrations of metals in the skin-lightening products ranged from <0.15 to 16.5 μg/g Cd, <0.02 to 10.0 μg/g Cu, 4.25 to 8.0 μg/g Cr, <0.25 to 128.0 μg/g Al, 0.5 to 4.5 μg/g Pb, <0.03 to 1.65 μg/g Ni, 24.7 to 267.5 μg/g Zn, <0.02 to 2.5 μg/g for Co, 19.3 to 31.8 μg/g Mn, 9.5 to 211.63 μg/g Fe. In a significant number (>93%) of the samples investigated the concentrations of Pb, Cd, Ni and Co were below the specified limit, or the maximal limit for impurities in colour additives in cosmetics for external use. However, Cr was found at concentrations above the allergenic limit of 1 μg/g. The results also showed that skin-lightening creams contained higher concentrations of the studied metals than the moisturizing creams, except for Ni, which indicates that persons who uses skin-lightening creams in preference to moisturizing ones, are exposed to higher concentrations of metals.     

Simultaneous assessment of zinc,cadmium, lead and copper in poultry feeds by differential pulse anodic stripping voltammetry

In the present work four metals (Zn, Cd, Pb and Cu) were determined simultaneously in 28 commercial broiler poultry feeds by differential pulse anodic stripping voltammetry (DPASV) using hanging mercury drop electrode (HMDE). The digestion of poultry feeds was carried out with concentrated nitric acid and hydrogen peroxide (2:1) with the help of microwave heating. Acetate buffer of pH 5 was used as a supporting electrolyte. The limit of detection for Zn, Cd, Pb and Cu was 0.69, 0.35, 0.68 and 0.24 μg/kg, respectively. The amount of Zn, Cd, Pb and Cu in the analyzed poultry feeds was ranged between 54.3–482.2, 3.8–33.6, 23.2–32.6 and 12.3–65.8 mg/kg, respectively. In most of analyzed poultry feed samples, the amount of Cd and Pb was found to be greater than the maximum tolerable level (MTL) which could be harmful for the poultry.     

Toxic trace metals and human oocytes during in vitro fertilization (IVF)

Trace exposures to the toxic metals mercury (Hg), cadmium (Cd) and lead (Pb) may threaten human reproductive health. The aim of this study is to generate biologically-plausible hypotheses concerning associations between Hg, Cd, and Pb and in vitro fertilization (IVF) endpoints. For 15 female IVF patients, a multivariable log-binomial model suggests a 75% reduction in the probability for a retrieved oocyte to be in metaphase-II arrest for each μg/dL increase in blood Pb concentration (relative risk (RR) = 0.25, 95% confidence interval (CI) 0.03–2.50, P = 0.240). For 15 male IVF partners, each μg/L increase in urine Cd concentration is associated with an 81% decrease in the probability for oocyte fertilization (RR = 0.19, 95% CI 0.03–1.35, P = 0.097). Because of the magnitude of the effects, these results warrant a comprehensive study with sufficient statistical power to further evaluate these hypotheses.     

Heavy metal burdens of public primary school children related to playground soils and classroom dusts in Ibadan North-West local government area,Nigeria

Information about heavy metal burden of children in Nigeria related to playground soils and classroom dusts is lacking. Playground soil, classroom dust, blood and spot urine samples (n = 253) were collected from 6 urban and 2 semi-rural public schools in Ibadan North-West, Nigeria. Samples were analysed for Pb, Cu, Zn, Fe and Mn. Mean blood Pb levels in urban area (male, 41.66 ± 8.78 μg/dl vs. female, 40.64 ± 5.46 μg/dl) were twice as high as those in semi-rural area (male, 19.71 ± 3.73 μg/dl vs. female, 20.65 ± 2.26 μg/dl). Concentrations of Pb, Cu, Zn, and Fe in soil and dust samples in the urban schools were between 2- to 4-fold greater than that of semi-rural schools. No correlation was observed between blood and dust metals. A positive correlation (r = 0.168, p = 0.008) was observed between blood Pb and playground soil Pb. Pb burden in the children might be from their schools’ playgrounds and other yet unidentified sources.     

Alteration in bone geometric and mechanical properties,histomorphometrical parameters of trabecular bone,articular cartilage,and growth plate in adolescent rats after chronic co-exposure to cadmium and lead in the case of supplementation with green,black, red and white tea

Adolescent male Wistar rats were used to check whether regular consumption of black, red, white, or green tea would have a protective effect on femur development during 12-week exposure to Cd and Pb (7 mg Cd and 50 mg Pb in 1 kg of the diet). The animals were randomly divided (n = 12) into a positive control (without Cd, Pb and teas), a negative control group (Cd and Pb), and groups supplemented additionally with green (GT), black (BT), red (RT), and white tea (WT). Heavy metals reduced the geometric and densitometric parameters and the total thickness of articular cartilage irrespective of tea administration and influenced mechanical endurance, growth plate thickness, and trabecular histomorphometry depending on the tea type. It is difficult to indicate which tea has the best protective effects on bone and hyaline cartilage against heavy metal action.     

Evaluation of urinary metal concentrations and sperm DNA damage in infertile men from an infertility clinic

This study aimed to examine associations between urinary metal concentrations and sperm DNA damage. Thirteen metals [arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), molybdenum (Mo), mercury (Hg), nickel (Ni), selenium (Se), and zinc (Zn)] were detected in urine samples of 207 infertile men from an infertility clinic using inductively coupled plasma mass spectrometry, and also, sperm DNA damage (tail length, percent DNA tail, and tail distributed moment) were assessed using neutral comet assay. We found that urinary Hg and Ni were associated with increasing trends for tail length (both p for trend < 0.05), and that urinary Mn was associated with increasing trend for tail distributed moment (p for trend = 0.02). These associations did persist even when considering multiple metals. Our results suggest that environmental exposure to Hg, Mn, and Ni may be associated with increased sperm DNA damage.     

Concentrations of arsenic,cadmium and lead in human hair and typical foods in eleven Chinese cities

Concentrations of arsenic (As), cadmium (Cd) and lead (Pb) were determined in 384 human hair samples and 445 purchased food samples from 11 cities in China. The mean concentrations of hair As, Cd and Pb were 0.23, 0.062 and 2.45 mg kg⁻¹, respectively. The As, Cd and Pb concentrations in different foods were lower than the national maximum allowable contaminant levels. By comparison, males had higher hair As concentrations but lower Cd concentrations than females. When the interaction effects of gender and age were considered, males had the higher hair As, Cd and Pb concentrations in the 51–65 year-old age group. Residents of rural areas had higher hair As, Cd and Pb concentrations than people living in urban areas. Further analysis indicates that hair As, Cd and Pb concentrations and their changes with biological and environmental factors cannot be satisfactorily explained by the estimated intakes from purchased food.     

Evaluated the adverse effects of cadmium and aluminum via drinking water to kidney disease patients: Application of a novel solid phase microextraction method

In present study aluminum (Al) and cadmium (Cd) were determined in ground water samples and assesses human health risks associated with elevated concentrations of toxic metals in dissolved form, using a novel solid phase microextraction (SPμE). Ground water sample (n = 200) and biological sample (blood) of patients having chronic kidney disorders (CKD) along with healthy control subjects of same area (southern part of Pakistan) were collected. A simple system, including the micropipette tip packed with modified ionic liquid-activated carbon cloth (IL-ACC) coated with 8-hydroxyqunilone (8-HQ) attached to syringe. The analytes in water and acid digested blood samples were manually drawn for 2–10 cycles (drawing/discharging) at different pH range. The analytes sorbed on coated ACC were then desorbed with 2.0 mol L⁻¹ HNO₃ in ethanol by drawing/discharging cycles for 1–5 times. The concentration of extracted analytes was determined by electrothermal atomic absorption spectrometer. The influence of different variables on the extraction efficiency of Cd and Al, were optimized. The Al and Cd concentrations in groundwater were found to be elevated than recommended limits by the World Health Organization. The urinary N-acetyl-h-glucosaminidase values were significantly higher in CKD patients as compared to refrent subjects (p < 0.001). The significant variation in levels of Cd and Al were observed in blood samples of CKD patients than referents subjects (p < 0.01). The strong positive correlation among Al and Cd levels in groundwater versus blood samples of CKD patients (r = 0.82–0.85) p < 0.01) was observed than those values calculated for referent subjects (r = 0.425–0.536).     

Dyslipdemia induced by chronic low dose co-exposure to lead,cadmium and manganese in rats: the role of oxidative stress

Lead (Pb), cadmium (Cd) and manganese (Mn) have many potential adverse health effects in vitro and in animal models of clinical toxicity. The current study investigated the dyslipidaemic and oxidative stress effects of chronic low-dose oral exposure to Pb, Cd and Mn and the combination (Pb + Cd + Mn) in rats for 15 weeks. Chronic exposure to the metals did not significantly (P > 0.05) alter serum lipid profiles. However, the atherogenic index decreased by 32.2% in the Pb + Cd + Mn group, relative to the control. The triglyceride/high-density lipoprotein cholesterol ratio decreased by 39.4% in the Pb + Cd + Mn group, relative to the control, and elevated by 81.8, 94.8 and 20.8%, relative to the Pb, Cd and Mn groups, respectively. While the serum concentrations of malondialdehyde significantly increased in the Mn and Pb + Cd + Mn groups, that of glutathione peroxidase-1 decreased in the Pb + Cd + Mn group, and metallothionein-1 and zinc concentrations markedly decreased in all the metal treatment groups.The results suggest that long-term exposure of rats to Pb + Cd + Mn may result in hypolipidaemia, mediated via oxidative stress and metal interactions. Individuals who are constantly exposed to environmentally relevant levels of the metals may be at risk of hypolipidaemia.     

Sensitive biomarkers identification for differentiating Cd and Pb induced toxicity on zebrafish embryos

Cadmium (Cd) and lead (Pb) are naturally existing heavy metals that pose significant health risks. The present study aims to identify sensitive biomarkers for differentiating the toxicities induced by Cd and Pb and for providing clues for the early prediction of toxicity and environmental risk assessment. Indicators related to oxidative stress and inflammatory responses in zebrafish treated with Cd and Pb over time (from 24 hpf to 96 hpf) were compared. Furthermore, endpoints such as embryo lethality and teratogenicity were detected. Then, several related genes involved in oxidative stress and inflammatory responses characterizing both Cd and Pb exposure, along with key molecules in the MAPKs pathway, were compared at the mRNA level, allowing the selection of the most sensitive and informative biomarkers. Significant increases in reactive oxygen species (ROS) production were observed in zebrafish exposed to Cd and Pb. Cd and Pb exposure induced developmental toxicity, influencing survival rate, hatching rate, larval growth, and heart rate and causing abnormal embryonic development. Similar trends in SOD1 and SOD2 gene expression were induced by Cd and Pb, while nuclear factor erythroid-2 related factor 2 (Nrf2) gene expression responded differently to each metal. In addition, Cd and Pb induced a delayed activation of the CAT and HO-1 genes, with no apparent change in the 24 hpf and 48 hpf groups. Genes related to immunotoxicity were activated significantly in a time-dependent manner, and these genes exhibited different sensitivities to Cd and Pb. MAPKs pathway genes were also activated in a time-dependent manner, and the expression of these genes showed different effects under Cd and Pb treatment. In summary, the present works have identified some potential sensitive biomarkers. The Nrf2 gene is a potential biomarker to differentiate Pb-induced toxicity from that of Cd, and the IFN-γ gene may be used as a sensitive biomarker for evaluating the risk of Pb contamination. We found that the timeline of MAPKs pathway activation helped to differentiate these two metals toxicities. Furthermore, Pb induced the early activation of ERK2/3 and JNK1, while p38 MAPKs showed delayed activation with no apparent change in the 24 hpf group. Cd induced an early activation of ERK2 and a delayed activation of p38a, p38b, ERK3 and JNK1, indicating that the JNK1 pathway is sensitive to Pb exposure, while the p38 pathway may be susceptible to Cd. This work contributes to sensitive biomarker identification and early environmental risk evaluation for chemicals as well as toxicity prediction.     

Toxicological assessment of combined lead and cadmium: Acute and sub-chronic toxicity study in rats

The exposure to chemical mixtures is a common and important determinant of toxicity and receives concern for their introduction by inhalation and ingestion. However, few in vivo mixture studies have been conducted to understand the health effects of chemical mixtures compared with single chemicals. In this study, the acute and 90 day sub-chronic toxicity tests of combined Pb and Cd were conducted. In the acute toxicity test, the LD₅₀ value of Pb(NO₃)₂ and CdCl₂ mixture by the oral route was 2696.54 mg/kg by Bliss method. The sub-chronic treatment revealed that the low-dose combination of Pb and Cd exposures can significantly change the physiological and biochemical parameters of the blood of Sprague–Dawley (SD) rats with dose–response relationship and causes microcytic hypochromic anemia and the damages of liver and kidney of the SD rats to various degrees. Histopathological exams showed that the target organs of Pb and Cd were testicle, liver, and kidneys. These observations suggest that Pb and Cd are practically additive-toxic for the SD rats in oral acute toxicity studies. The lowest observed adverse-effect level in rats may be lower than a dose of 29.96 mg/(kg bw day) when administered orally for 90 consecutive days.     

Lead,mercury, and cadmium in blood and their relation to diet among Swedish adults

The aim of the present study was to examine the body burden of lead (Pb), mercury (Hg), and cadmium (Cd) in blood among Swedish adults and the association between blood levels, diet and other lifestyle factors.The study was based on a subgroup (n = 273) of the national survey Riksmaten 2010–2011 (4-day food records and questionnaire). Lead, Hg, and Cd were measured in whole blood, and Cd additionally in urine, by mass or fluorescence spectrometry methods.The median values (5–95th percentiles) of the metals in blood were as follows; Pb: 13.4 (5.8–28.6) μg/L, Hg: 1.13 (0.31–3.45) μg/L, and Cd: 0.19 (0.09–1.08) μg/L. All three metals increased with increasing age. Lead levels in blood were positively associated with intakes of game and alcohol, Hg was related to fish intake, and blood Cd related to smoking and low iron stores and to a low meat intake.Body burdens of the studied metals were generally below health based reference values, but several individuals had blood Pb levels above the reference point for possible nephrotoxic and developmental neurotoxic effects. As health effects cannot be excluded, individuals with high Pb exposure should aim at decreasing their body burden, both from food and from other exposure routes.     

Heavy metals in agricultural soils and crops and their health risks in Swat District,northern Pakistan

This study assessed the concentrations of heavy metals such as cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni) and zinc (Zn) in agricultural soils and crops (fruits, grains and vegetable) and their possible human health risk in Swat District, northern Pakistan. Cd concentration was found higher than the limit (0.05 mg/kg) set by world health organization in 95% fruit and 100% vegetable samples. Moreover, the concentrations of Cr, Cu, Mn, Ni and Zn in the soils were shown significant correlations with those in the crops. The metal transfer factor (MTF) was found highest for Cd followed by Cr > Ni > Zn > Cu > Mn, while the health risk assessment revealed that there was no health risk for most of the heavy metals except Cd, which showed a high level of health risk index (HRI ⩾ 10E-1) that would pose a potential health risk to the consumers.     

Investigation of lead contents in lipsticks by solid sampling high resolution continuum source electrothermal atomic absorption spectrometry

In this study, the lead contents of different kinds of lipsticks were determined by solid sampling high resolution continuum source electrothermal atomic absorption spectrometry (SS-HR-CS ET AAS) and the results were compared with those obtained after microwave-assisted acid digestion of the samples. The experimental parameters for solid sampling such as the maximum amount of sample on the platforms of solid autosampler, graphite furnace program were optimized. Samples were directly loaded on the platforms of solid autosampler between 0.25 and 2.0 mg and lead was determined applying 800 °C for pyrolysis and 2100 °C for atomization. Under optimized conditions, interference-free determination could be performed using aqueous standards. The LOD and the characteristic mass were 21.3 and 12.6 pg, respectively. The lead in the same lipstick samples was determined after microwave-assisted acid digestion and compared with those found by solid sampling. Mostly, there was no significant difference between the lead concentrations found by the two techniques. The lead in 25 lipstick samples with different properties were 0.11–4.48 ng mg^?1 which were not significantly different from those (<0.026–7.19 ng mg^?1) reported by FDA for around 400 samples.     

Evaluation of estrogenic activity in animal diets using in vitro assay

A yeast estrogen bioassay (RIKILT REA) was in-house validated for feed on the 5 μg 17β-estradiol-equivalents per kg level according to EC Decision 2002/657/EC. All the performance characteristics met the criteria as defined in the Decision and the REA is able to detect 17β-estradiol in animal feed at a low level of 1.15–2 μg kg⁻¹. Subsequently, the developed and validated procedure was applied to determine the estrogenic activity in 24 feed samples intended for food producing animals, pets and laboratory animals. Two batches of rodent diet Murigran and one dog feed have been presented as a suspect, i.e. gave responses above the determined decision limit (CCα) and detection capability (CCβ). In assessing the performance of the estrogenic activity in these diets evaluated by comparison with the 17β-estradiol calibration curve, 17β-estradiol-equivalence levels of 7.07 μg EEQ kg⁻¹ and 9.54 μg EEQ kg⁻¹ in two batches of rodent diet and 5.3 μg EEQ kg⁻¹ in dog feed have been established. The activities observed in the rodent feed could be explained by chemical analysis, revealing high amounts of genistein, daidzein and trace amounts of zearalenone. In addition, the estrogenic activity in one of rodent feed was above the established CCα, but below the CCβ values established and all other samples showed no estrogenic activity with responses below the CCα value, which corresponds to levels below 2 μg EEQ kg⁻¹.     

Prenatal exposure to lead in relation to risk of preterm low birth weight: A matched case–control study in China

We investigated the association between prenatal exposure to lead (Pb) and the risk of preterm low birth weight (PLBW). Pb concentrations in maternal urine collected at birth from 408 subjects (102 cases and 306 matched controls) were analyzed and adjusted by creatinine. The median Pb concentration in the PLBW cases (10.60 μg Pb/g creatinine) was higher than that of the controls (7.28 μg Pb/g creatinine). An adjusted odds ratio (OR) of 2.96 (95% CI = 1.49–5.87) for PLBW was observed when the highest tertile was compared to the lowest tertile of Pb levels. The association was more pronounced among female infants (adjusted OR = 3.67 for the highest tertile; 95% CI = 1.35–9.93) than male infants (adjusted OR = 1.91 for the highest tertile; 95% CI = 0.74–4.95). Our study suggests that prenatal exposure to levels of Pb encountered today in China is associated with an elevated risk of PLBW.     

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.     

Dietary fumonisin exposure in a rural population of South Africa

A validated culturally specific dietary assessment method was used to determine the habitual maize intakes of black Xhosa-speaking Africans living in the Centane region of the Eastern Cape Province to assess their exposure to the carcinogenic fumonisin mycotoxins. The mean total dry weight maize intakes of home-grown, commercial or combined (both maize sources) were 474, 344, 462 g day^?1, respectively. When considering the total mean levels of fumonisin in home-grown maize (1142 μg kg^?1) and commercial maize (222 μg kg^?1), the probable daily intakes (PDI’s), expressed as μg kg^?1 body weight day^?1 were 12.1 (95%CI: 0.3–4926.5) and 1.3 (95%CI: 1.0–1.8) for men and 6.7 (95%CI: 1.0–457.8) and 1.1 (95%CI: 0.9–1.3) for women, consuming home-grown and commercial maize, respectively. Based on the different maize-based beer drinking frequencies the PDI’s varied between 6.9 and 12.0 μg kg^?1/drinking event. Depending on the maize intake patterns an exposure “window” exists where fumonisin exposure is below the recommended group provisional maximum tolerable daily intake (PMTDI) for fumonisins of 2 μg kg^?1 bw day^?1. The assessment of fumonisin exposure and development of preventative strategies depend, not only the accurate determination of total fumonisin levels in maize, but also on the distinct dietary patterns of a specific population.     

Development and validation of an HPLC–UV method for the quantification of carbamazepine in rabbit plasma

An isocratic simple rapid assay has been developed and validated for the determination of carbamazepine (CBZ) in both solution form and rabbit plasma using propylparaben as an internal standard. The assay was performed using a μ-Bondapak C₁₈ (150 mm × 4.6 mm i.d) with a mobile phase consisting of methanol and water (50:50), the flow rate was 1 ml/min and UV detection at 285 nm. The method was found to be specific for CBZ, no interfering peaks were observed with an overall analytical run time of 15 min. Accuracy reported as % recovery were found to be 98.37–100.45% and 97.53–103.58% for inter-day and intra-day accuracies, respectively. Inter-day precision (reproducibility) was found to be 0.53–2.75% RSD, while intra-day precision (repeatability) was found to be 1.06–3.7% RSD for the samples studied. The calibration curve was found to be linear with the equation y = 0.2847x + 0.0138, with a correlation coefficient of 0.9999 (R²) over a concentration range of 0.5–40 μg/ml. The limit of quantitation was the lowest concentration. The method is simple and rapid and does not require any preliminary treatment of the sample. The method was fully validated.