Blood Pb Concentrations Research Articles

Longitudinally monitored lifetime changes in blood heavy metal concentrations and their health effects in urban birds

Urban heavy metal pollution can impair the health of humans and other organisms inhabiting cities. While birds are suggested as one of the appropriate bioindicators for essential and non-essential trace element monitoring, the process of particular elements' accumulation in blood and its possible adverse health effects during ageing of individuals remain unexplored. We have investigated lifetime changes in blood lead (Pb), cadmium (Cd), arsenic (As) and zinc (Zn) concentrations and searched for links to health-related traits in sub-urban free-living great tit (Parus major) population monitored over a long period of time. The blood As concentrations were under the limit of detection in most samples. The blood Pb levels showed a non-linear relationship to individuals age, where the highest Pb concentrations were measured in nestlings and in a very small group of highly senescent birds (over 7 years old), while no clear trend was observed for the majority of the adult age stages. No age-related patterns were found for blood Cd or Zn concentrations. The positive relationship between date of capture and blood Cd and Zn levels may reflect seasonal changes in diet composition. We did not reveal any anaemia-like conditions (decreased total erythrocyte count or increased immature erythrocyte count) in relation to blood heavy metal concentrations in the investigated birds. Total leukocyte counts, heterophil/lymphocyte (H/L) ratio and total heterophil and lymphocyte counts increased with increasing Pb, Cd and Zn concentrations in blood. This study demonstrates the suitability of avian blood for actual heavy metal spatial and temporal biomonitoring even in situations when the precise age of the individuals remains unknown.

Occupational exposure of lead and cadmium on adolescent and adult workers of battery recycling and welding workshops: Adverse impact on health

The occupational exposure of toxic metals is an important concern, because of its potential accumulation in living organisms, leading to long term toxic effects. The occupational and environmental contacts of toxic metals, cadmium (Cd) and lead (Pb) have been evaluated by determination of them in biological samples (blood and scalp hair) of adolescent and adults, workers of battery recycling and welding workshops. The age matched adolescent and adult residing in nonindustrial areas were also selected, termed as referent/control subjects. The blood and scalp hair samples of workers and controls were analyzed for Cd and Pb using graphite furnace atomic absorption spectrometry previously decomposed the matrices using acid mixture. The biochemical parameters of workers of both age groups were also evaluated. The average concentrations of Cd and Pb in blood and scalp hair samples of adolescent workers were three fold higher as compared with control subjects. The drinking water in containers of both workshops contained Pb and Cd in two to four and five to thirteen folds, respectively, higher than recommended permissible limits of WHO. The significant correlations between the blood lead levels and hemoglobin (%) in adolescent (r = −0.78). The positive correlation was observed among incidence of blood pressure with Pb and Cd concentrations in biological samples of workers (adults) (r = 0.65 to 0.83). These findings suggest that occupational exposure of toxic metals might be created adverse impacts on workers due to ill management of workshops.

Oral Supplementation of Lead-Intolerant Intestinal Microbes Protects Against Lead (Pb) Toxicity in Mice.

Oral exposure to the heavy metal lead (Pb) causes various dysfunctions in animals. However, the influence of gut bacteria on Pb absorption, bioaccumulation, and excretion is largely unknown. In this study, we use a mouse model to investigate the relationship between gut microbiota, Pb-intolerant intestinal microbes and Pb toxicity. First, mice were treated with a broad-spectrum antibiotic cocktail to deplete their gut microbiota, and were then acutely and orally exposed to Pb at 1304 mg/kg for 3 days. Compared to the control mice, antibiotic-treated mice had increased Pb concentrations in the blood and primary organs and decreased Pb fecal concentrations, suggesting that gut microbiota limited the Pb burden that developed from acute oral Pb exposure. Next, three Pb-intolerant gut microbes, Akkermansia muciniphila, Faecalibacterium prausnitzii, and Oscillibacter ruminantium, were orally administered to mice, and their effects against Pb toxicity were evaluated. F. prausnitzii treatment significantly promoted the fecal Pb excretion and reduced Pb concentrations in blood (from 152.70 ± 25.62 μg/dL to 92.20 ± 24.33 μg/dL) and primary tissues. Supplementation with O. ruminantium significantly decreased Pb concentrations in blood (from 152.70 ± 25.62 μg/dL to 104.60 ± 29.85 μg/dL) and kidney (from 7.30 ± 1.08 μg/g to 5.64 ± 0.79 μg/g). Treatment with F. prausnitzii and O. ruminantium also upregulated tight junction (TJ) protein expression and the production of short-chain fatty acids by colonic microbiota, and showed protective effects against liver and kidney toxicity. These results indicate the potential for reducing Pb toxicity by the modulation of gut microbiota.

Factors associated with lead (Pb) exposure on dogs around a Pb mining area, Kabwe, Zambia

Lead (Pb)-poisoning is a serious public health concern and dogs have been useful as a sentinel-animal for Pb exposure of humans. In the present study, the blood Pb concentrations (BLC), isotope ratios (208 Pb/206 Pb and 207 Pb/206 Pb), and biochemistry of 120 domestically owned dogs living around a Pb mining area, in Kabwe, Zambia were analyzed to determine factors associated with Pb exposure. The overall mean value of Pb in dog blood in the present study was 271.6 μg/L. The BLC in the dogs from sites near the mine were significantly higher than those in the dogs from a site 4 km from the mine (352.9 ± 205.1 μg/L versus 28.0 ± 13.9 μg/L). BLC significantly decreased with both increasing age of the dogs and distance from the mine. The Pb isotope ratios in the dog that resided near the mine showed values similar to those reported at the galena mine in Kabwe, which is considered to be the source of Pb exposure. In contrast to the high metal exposure that was determined in these dogs, the mean values of most analyzed parameters in the blood biochemical analysis were surprisingly within or close to the standard reference values. Moreover, none of the dogs showed overt signs of Pb-poisoning or other clinical symptoms. The results of analysis of Pb exposure of the dogs obtained in the present study, which are similar to the previously reported results in human in this location, suggest that dogs could be useful as a sentinel animal for Pb exposure of humans in Kabwe.

Influential Factors on Blood Pb and Hg Concentrations in Koreans over 50 Years Old: Data Analysis of the 1st (2009-2011) and 2nd (2012-2014) KoNEHS

Objective: Elderly people are particularly vulnerable to environmental pollutants due to the effects of aging. Pb and Hg are heavy metals that can cause elevated environmental pollution and harm humans. With this study, we aimed at collecting Pb and Hg blood concentrations in Koreans over 50 years old in the general population and comparing different factors that might affect these concentrations. Methods: For this study, we selected a total of 6,681 adults who participated in the 1st and 2nd stage (during 2009-2011 and 2012-2014, respectively) of the Korean National Environmental Health Survey (KoNEHS). Results: The proportion of women over 65 years old slightly increased from the 1st to 2nd the stage; meanwhile, the Pb and Hg blood concentrations increased and remained stable, respectively. Heavy metals blood concentrations were relatively high compared to those registered in other countries. During the 1st stage, Pb concentration was related to gender (i.e., higher concentrations in males), drinking habits, residential areas (i.e., higher concentrations in the presence of air pollution monitoring stations), and smoking. During the 2nd stage, we did not consider the residential area but the residential type (i.e., higher concentrations living in the detached house). Influential factors affecting Hg concentration during the 1st stage were gender (i.e., higher concentrations in males), fish intake (i.e., daily or weekly), age (i.e., between 50-64 years), seafood consumption during the week (i.e., yes). During the 2nd stage, the body mass index (BMI) (i.e., eventual obesity) was also considered. Conclusion: The concentration of heavy metals in the blood of adult Koreans was estimated to be higher than in other countries. Hence, exposure levels should be reduced by continuous monitoring and the identification of pollution sources. The outcomes of the present research will ultimately contribute to the prevention of heavy metals exposure, while considering the elderly population characteristics.

A comparison of blood and toenails as biomarkers of children’s exposure to lead and their correlation with cognitive function

This study sought to compare lead (Pb) concentrations in toenails and blood and to investigate the association of each biomarker with children’s cognitive function. Toenails and whole blood samples were collected from 224 twelve-year-old children, and their full-scale intelligence quotient (FSIQ) was assessed using the Wechsler Intelligence Scale for Children–4th edition. Inductively coupled plasma-mass spectrometry was used to determine blood (BPb) and toenail (TPb) Pb concentrations. Log BPb and Log TPb were significantly correlated (r2 = 0.49, p < 0.001). In unadjusted analyses, both log-transformed BPb and TPb were significantly associated with decreased FSIQ, but BPb accounted for approximately quadruple the FSIQ scores’ variability than log-transformed TPb (model R2 = 0.12 and R2 = 0.03, respectively). After adjusting for neighborhood deprivation, caregiver intelligence (assessed with the Wechsler Abbreviated Scale of Intelligence–2nd edition), and child BMI, BPb remained significantly associated with decreased FSIQ, while TPb did not (p = 0.16). These results suggest that while concentrations of Pb in blood and toenails are correlated, TPb does not predict cognitive outcomes at these exposure levels. With caution and in conjunction with BPb, TPb may be used as a population-based biomarker of Pb exposure.

The effect of heavy metal contamination on humans and animals in the vicinity of a zinc smelting facility.

A diagnosis of heavy metal poisoning in sheep living on pastures in the vicinity of a smelting facility in the Wumeng mountain area of China was based on laboratory tests and clinical symptoms. Furthermore, heavy metal contamination in the food chain was found to have a deleterious effect on the health of local residents. The levels of copper(Cu), zinc(Zn), cadmium (Cd), and lead (Pb) in irrigation water, soil, forages, and animal tissues were measured in samples taken from the vicinity of a smelting facility and control samples. Heavy metal contents in food (corn, rice, and wheat), as well as in human tissues (blood and hair) obtained from local residents were also determined. Hematological values were also determined in human and animal samples. The content of Cu, Zn, Cd, and Pb in irrigation water, soils, and forages were markedly higher in affected areas than in samples from healthy pastures. Concentrations of Cd and Pb were 177.82 and 16.61 times greater in forages than controls, respectively, and 68.71 and 15.66 times greater in soils than controls, respectively. The heavy metal content in food (corn, rice, and wheat) from affected areas was markedly higher than in the control samples. Cd and Pb content in the tissues of affected sheep were markedly higher than in control animals (P < 0.01), while concentrations of Cd and Pb in blood and hair samples from local residents were markedly higher than in control samples (P < 0.01). The occurrence of anemia in affected humans and animals followed a hypochromic and microcytic pattern. The intake of Cd and Pb was estimated according to herbage ingestion rates. It was found that the levels of Cd and Pb which accumulated in sheep through the ingestion of vegetation growing in the sites closest to the smelter were approximately 3.36 and 38.47 mg/kg body wt./day, respectively. Such levels surpassed the fatal dosages for sheep of 1.13 mg Cd/kg body wt/day and 4.42 mg Pb/kg body wt./day. The serum total antioxidant capacity in affected humans and animals was significantly lower than in the controls (P < 0.01). Serum protein parameters in affected humans and animals were significantly reduced (P < 0.01); therefore, it was concluded that heavy metal contamination caused harm to sheep, and also posed a significant risk to humans living in the vicinity of the zinc smelting facility.

Trace elements and ALAD gene polymorphisms in general population from three uranium legacy sites – A case study in Kyrgyzstan

At three uranium (U) legacy sites in Kyrgyzstan, namely, Kadji Sai, Mailuu-Suu and Sumsar, an initial human bio-monitoring programme was introduced as a complementary activity to environmental impact studies in these areas. The aim was to assess trace element (TE) contents in blood and genetic susceptibility for Pb as one of the contaminants.The programme included the determination of 9 TE in blood samples from 123 residents living permanently in this environment. The analyses included U and the potentially toxic TE, lead (Pb), cadmium, mercury (Hg), and arsenic (As), together with essential elements iron (Fe), copper, selenium (Se) and manganese (Mn). TE were analysed by inductively coupled plasma mass spectrometry (ICPMS) and genetic background effect by three single nucleotide polymorphisms (SNPs) of delta-aminolevulinic acid dehydratase (ALAD; rs1805313, rs818708, rs1800435) genotyped by quantitative polymerase chain reaction (qPCR).The obtained results were generally similar to literature reference values obtained from the U non-exposed environments. However, some significant findings indicated elevated levels of certain contaminants typical of the studied environment (U, Pb). Several essential (Se, Mn) and toxic TE (Pb, Hg, As, U) in blood showed statistically significant differences among the studied areas. All areas showed diminished Fe blood levels. Altogether, this indicated specific and different environmental conditions at three industrial legacy sites for U milling and processing along with the accompanying chemical (pollutant) elements. Blood U concentrations were slightly higher at Mailuu-Suu, known for elevated technogenic and naturally occurring U. At Sumsar, the distribution of elevated blood Pb concentrations indicated an airborne source of pollution that was different from the anticipated aqueous exposure pathway. Pb blood variability was found associated with ALAD polymorphisms (SNPs rs1805313, rs1800435).Results are confirming that human data will be a useful and scientifically important additional tool for environmental impact assessment studies at industrial legacy sites in Kyrgyzstan.

Dynamics of Lead Bioavailability and Speciation in Indoor Dust and X-ray Spectroscopic Investigation of the Link between Ingestion and Inhalation Pathways.

Lead (Pb) exposure from household dust is a major childhood health concern because of its adverse impact on cognitive development. This study investigated the absorption kinetics of Pb from indoor dust following a single dose instillation into C57BL/6 mice. Blood Pb concentration (PbB) was assessed over 24 h, and the dynamics of particles in the lung and gastro-intestinal (GI) tract were visualized using X-ray fluorescence (XRF) microscopy. The influence of mineralogy on Pb absorption and particle retention was investigated using X-ray absorption near-edge structure spectroscopy. A rapid rise in PbB was observed between 0.25 and 4 h after instillation, peaking at 8 h and slowly declining during a period of 24 h. Following clearance from the lungs, Pb particles were detected in the stomach and small intestine at 4 and 8 h, respectively. Analysis of Pb mineralogy in the residual particles in tissues at 8 h showed that mineral-sorbed Pb and Pb-phosphates dominated the lung, while organic-bound Pb and galena were the main phases in the small intestines. This is the first study to visualize Pb dynamics in the lung and GI tract using XRF microscopy and link the inhalation and ingestion pathways for metal exposure assessment from dust.

Analysis of disease profile, and medical burden by lead exposure from hospital information systems in China

BackgroundThough lead (Pb)-gasoline has been banned for decades in China, Pb continues to be a vital risk factor for various diseases. Traditional studies, without large sample size, were unable to identify explicitly the associations among Pb, its disease profile, and the related medical burden. This study was designed to investigate: 1) current status of blood Pb levels; 2) Pb-associated disease profile, medical burden, as well as impact factors.MethodsResearch subjects were patients who visited military hospitals and were required to test their blood Pb levels by doctors between 2013 and 2017. The large sample size and area coverage may, to a large extent, reveal the characteristics of Pb exposure in the whole Chinese population. Information of patients’ electronic medical records was extracted using Structured Query Language (SQL) in Oracle database. The spatial, temporal, and population distribution of their blood Pb levels were tested, to illustrate the association of Pb exposure with diseases’ profile, and medical burden. Non-parametric tests were applied to compare the differences of Pb levels among various groups.ResultsThe blood Pb concentration showed a positively skewed distribution by Kolmogorov-Smirnov test (D = 0.147, p < 0.01). The blood Pb concentration of Chinese patients was 28.36 μg/L, with the lowest blood Pb levels, 4.71 μg/L, found in patients from Guangxi Zhuang Autonomous Region, and the highest, 50 μg/L, in Yunnan province. Han Chinese patients’ Pb levels were significantly lower than other minorities groups (z-score = − 38.54, p < 0.01). Average medical cost for Pb poisoning was about 6888 CNY for Chinese patients. Pb levels of patients with malignant neoplasm of lung, 45.34 μg/L, were far higher than malignant neoplasm of other respiratory, and intrathoracic organs, 24.00 μg/L (z-score = − 2.79, p < 0.01).ConclusionsThis study reported current status of blood Pb levels for patients who once visited military hospitals, partially representing the whole Chinese population. The result shows that Pb poisoning is still imposing marked economic burdens on patients under Pb exposure. Association of Pb with lung cancer may open up new areas for Pb-induced toxicology. The research strategy may advance toxicological studies in the aspect of medical data mining.

Association between early lead exposure and externalizing behaviors in adolescence: A developmental cascade

BackgroundLead (Pb) exposure is associated with adverse neurological development. Most notably, it has been observed through externalizing behavior symptoms, as observed among Inuit children from northern Québec. Evidence for a persistent neurological impact of early Pb exposure later in life is however scarce. Pb exposure may initiate a developmental cascade that increases the risk of long-term behavior problems. ObjectivesTesting for direct associations between childhood Pb concentrations and adolescent externalizing symptoms and substance use, as well as indirect associations through childhood behavior assessments. MethodsThe study sample is a longitudinal cohort of Inuit children (n = 212) followed since birth. Blood Pb concentrations were measured during childhood (median age = 11.4 years) and adolescence (median age = 18.5 years). Externalizing/inattentive behavior were teacher-assessed through the Teacher Report Form and the Disruptive Behavior Disorders Rating Scale for children. At the adolescence follow-up, behavior problems were self-reported by filling Achenbach's Youth Self-Report, the Barkley Adult ADHD-IV Rating Scale, and the Diagnostics Interview Schedule for Children. Adolescent substance use was also self-assessed through the DEP-ADO. Direct and indirect associations of child Pb concentrations with adolescent outcomes were tested through mediation models. ResultsChild blood Pb concentrations were not directly associated with any adolescent outcomes. On the contrary, childhood Pb exposure was indirectly associated, through childhood externalizing behavior assessments, with adolescent externalizing behaviors, binge drinking, and cannabis use. These indirect associations held after controlling for adolescents’ concurrent Pb blood concentrations. DiscussionOur results highlight the indirect but lasting effects of child Pb exposure on adolescent behavior problems, and the importance of childhood externalizing behavior in this relationship. Adverse early-life environment put children on a riskier developmental trajectory, increasing their likelihood of lifelong psychological, social and health problems.

In Vitro, in Vivo, and Spectroscopic Assessment of Lead Exposure Reduction via Ingestion and Inhalation Pathways Using Phosphate and Iron Amendments.

This study compared lead (Pb) immobilization efficacies in mining/smelting impacted soil using phosphate and iron amendments via ingestion and inhalation pathways using in vitro and in vivo assays, in conjunction with investigating the dynamics of dust particles in the lungs and gastro-intestinal tract via X-ray fluorescence (XRF) microscopy. Phosphate amendments [phosphoric acid (PA), hydroxyapatite, monoammonium phosphate (MAP), triple super phosphate (TSP), and bone meal biochar] and hematite were applied at a molar ratio of Pb:Fe/P = 1:5. Pb phosphate formation was investigated in the soil/post-in vitro bioaccessibility (IVBA) residuals and in mouse lung via extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structures (XANES) spectroscopy, respectively. EXAFS analysis revealed that anglesite was the dominant phase in the ingestible (<250 μm) and inhalable (<10 μm) particle fractions. Pb IVBA was significantly reduced (p < 0.05) by phosphate amendments in the <250 μm fraction (solubility bioaccessibility research consortium assay) and by PA, MAP, and TSP in the <10 μm fraction (inhalation-ingestion bioaccessibility assay). A 21.1% reduction in Pb RBA (<250 μm fraction) and 56.4% reduction in blood Pb concentration (<10 μm fraction) were observed via the ingestion and inhalation pathways, respectively. XRF microscopy detected Pb in the stomach within 4 h, presumably via mucociliary clearance.

Low concentrations of lead decrease the sperm fertilization ability by altering the acrosome reaction in mice

Lead (Pb) exposure at high concentrations is associated with poor sperm quality, acrosome alterations, and low fertilization rate. Sperm capacitation and the acrosome reaction (AR) are required for successful fertilization. Actin polymerization is crucial for correct capacitation, and small GTPases, such as RhoA, Rac1, and Cdc42, are involved. This study aimed to evaluate the effects of Pb on sperm fertilization ability, capacitation, AR, and the mechanisms involved in mice exposed to low Pb concentrations. CD1 mice were exposed to 0.01% Pb2+ for 45 days through their drinking water and their spermatozoa were collected from the cauda epididymis-vas deferens to evaluate the following: AR (oAR: initial, sAR: spontaneous, and iAR: induced) using the PNA-FITC assay, sperm capacitation (P-Tyr levels), actin polymerization (phalloidin-TRITC), MDA production (stress oxidative marker), the RhoA, Rac1, and Cdc42 protein levels, and the in vitro fertilization (IVF). After the treatment, the blood Pb (PbB) concentration was 9.4 ± 1.6 μg/dL. Abnormal sperm morphology and the oAR increased (8 and 19%, respectively), whereas the iAR decreased (15%) after a calcium ionophore challenge, and the actin polymerization decreased in the sperm heads (59%) and tails (42%). Rac1 was the only Rho protein to significantly decrease (33%). Spermatozoa from the Pb-treated mice showed a significant reduction in the fertilization rate (19%). Our data suggest that Pb exposure at environmental concentrations (PbB < 10 μg/dL) decreases the acrosome function and affects the sperm fertilization ability; this is probably a consequence of the low Rac1 levels, which did not allow adequate actin polymerization to occur.

Plasma concentration of cadmium, lead and chromium in smokers and nonsmokers in Tripoli, Libya: A comparative study

Tobacco products are known to contain some heavy metals that pose threats to smokers. In order to assess the role of smoking habits in increasing the plasma concentration of cadmium (Cd), chromium (Cr) and lead (Pb), a comparative study between male smokers and nonsmokers was carried out in Tripoli, Libya. Graphite furnace atomic absorption spectrometry (GFAAS) was used to determine the concentration of Cd, Cr and Pb in plasma blood of 25 male nonsmokers representing control group, and of 75 male smokers divided equally into three subgroups, which were: cigarette smokers group, waterpipe group and snuff inhalers group. According to 2-sample test, the means (or the medinas) of Cd, Cr and Pb plasma concentrations were significantly higher in smokers group compared to the nonsmokers group, and as the one-way analysis of Variance (ANOVA) test revealed, the means of Cd, Cr and Pb plasma concentrations were significantly higher in waterpipe group compared to the other two smokers’ groups. In conclusion, smoking increased the plasma concentration of Cd, Cr and Pb, and smoking waterpipe is considered to elevate the plasma concentration of those three metals more than the other two smoking habits, thus it is more dangerous on smokers’ lives.

Relationship between Pb relative bioavailability and bioaccessibility in phosphate amended soil: Uncertainty associated with predicting Pb immobilization efficacy using in vitro assays

In this study, an in vitro in vivo correlation (IVIVC) between Pb in vitro bioaccessibility (IVBA) and relative bioavailability (RBA) was explored to determine whether the efficacy of Pb immobilization in phosphate amended soils could be predicted using an in vitro approach. Mining/smelting impacted soil from Broken Hill, Australia (582–3536 mg/kg of Pb in the <250 μm soil particle fraction) was amended with Phosphoric Acid (PA), Mono Ammonium Phosphate (MAP) or Triple Super Phosphate (TSP) at Pb:P molar ratios of 1:1–1:5. Pb speciation in pre- and post-treated soil was assessed using X-ray Absorption Spectroscopy (XAS), Pb IVBA was measured using the Solubility Bioaccessibility Research Consortium (SBRC) assay (gastric and intestinal phases), and Pb RBA was determined in mice using blood Pb concentration as the bioavailability endpoint. XAS analysis revealed a 3.75–6.00 fold increase in the weighted % of Pb phosphates in soil containing >1000 mg/kg Pb while treatment effect ratios of 0.89–0.99 (SBRC-G), 0.09–0.71 (SBRC-I) and 0.27–0.80 (RBA) were observed in PA amended soil (Pb:P = 1:5). Although significant (p < 0.05) correlation were obtained between Pb RBA and IVBA (%) determined using SBRC-G (r = 0.64) and SBRC-I (r = 0.67), the strengths of the relationships were weak (r2 = 0.41–0.45). This research highlights the complexities associated with the prediction of Pb RBA in phosphate amended soil.

Elevated Serum Pb, Ni, Cd, and Cr Levels and DNA Damage in Exfoliated Buccal Cells of Teenage Scavengers at a Major Electronic Waste Dumpsite in Lagos, Nigeria.

This study investigated the levels of Pb, Ni, Cd, and Cr in the blood, and DNA damage in exfoliated buccal cavity of scavenging teenagers at Alaba International electronic market, Nigeria. One hundred and ninety-nine blood samples were collected from scavenging teenagers in Alaba International market (n = 95) and the control group (n = 104). Blood Pb, Ni, Cd, and Cr concentrations were analyzed using graphite furnace atomic absorption spectrometry. Genotoxicity assessment was through exfoliated buccal cell micronucleus assay, while questionnaire was used to collect data on factors that can contribute to the blood heavy metal levels. The blood Pb of scavenging teenagers from Alaba International market varied from 2.84 to 189.44μg/L compared to the control group with a range of 0.01 to 4.21μg/L. The blood Cd (range = 0.38-12.35μg/L), Cr (range = 0.20-19.03μg/L), and Ni (range = 0.24-21.01μg/L) were higher significantly in the Alaba group compared to the control group (Cd: range = 0.00-0.96μg/L; Cr: range = 0.01-0.72μg/L; and Ni: range = 0.00-0.28μg/L). Frequencies of micronucleus, karyolysis, and pycnosis in the exfoliated buccal cells in Alaba group also increased significantly compared with the control group. Spearman correlation analyses indicated a positive correlation between the blood Pb, Ni, Cd, and Cr and induced micronucleus in the buccal exfoliated cells. Furthermore, data showed a positive correlation between Pb, Ni, Cd, and Cr and the duration of scavenging of the teenagers. However, a negative correlation was observed between educational status and Pb, Ni, Cd, and Cr. E-waste indiscriminate disposal and primitive recycling processes may be responsible for the high blood heavy metal levels, and consequently an increased DNA damage in exfoliated buccal cells in scavenging teenagers at Alaba International market. Graphical Abstract.

Tools for non-invasive sampling of metal accumulation and its effects in Mediterranean pond turtle populations inhabiting mining areas

Among reptiles, freshwater turtle species have high potential for metal accumulation because of their long lifespan or their aquatic and terrestrial habits. In order to monitor metal bioaccumulation, determine potential toxic effects, and investigate tools for non-invasive metal sampling in reptiles, we studied lead (Pb) and mercury (Hg) accumulation in Mediterranean pond turtles (Mauremys leprosa) inhabiting two former mining areas, one of them with high environmental concentrations of Pb (Sierra Madrona-Alcudia Valley district) and the other one with high environmental concentrations of Hg (Almadén district). Individuals from the Pb mining area showed mean blood concentrations (i.e. 5.59 μg Pb/g dry weight, d.w.) that were higher than those measured in other populations. Blood Hg concentrations were highest (8.83 μg Hg/g d.w.) in the site close to the former Hg mines, whereas blood Hg concentrations in terrapins from another site of Almadén district, located ∼28 km downstream, were not different from locations at the non-mining area. Animals from the Pb-contaminated site showed evidence of oxidative stress, whereas those from the Hg-contaminated site showed increased activity of the antioxidant enzyme glutathione peroxidase, as well as reduced circulating levels of the main endogenous antioxidant peptide, glutathione. Concentrations measured in feces and carapace scutes were useful indicators to monitor blood concentrations of Pb, but not of Hg. Our results provide evidence of the usefulness of freshwater turtles as sentinels of chronic metal pollution, and validate non-invasive tools to advance Pb monitoring in reptiles.

Cadmium, lead and mercury in Norwegian obese patients before and 12 months after bariatric surgery

PurposePrevious studies have suggested a role for the toxic elements lead (Pb), mercury (Hg) and cadmium (Cd) in the development of insulin resistance and hypertension. Increased blood Pb levels have been reported after bariatric surgery and weight loss. As about 80% of patients undergoing bariatric surgery are women, most of them of childbearing age, there are concerns regarding fetal exposure to toxic trace elements. We measured whole blood Hg, Pb and Cd concentrations in morbidly obese patients before and 12 months after Roux-en-Y gastric bypass (RYGB). Patients and methodsForty-six patients eligible for bariatric surgery were recruited at Innlandet Hospital Trust, Norway (2012–2014). The majority were women and 54% were of reproductive age. Whole blood samples were collected prior to and 12 months after surgery. Trace element concentrations were measured using mass spectrometry (HR-ICP-MS). ResultsMedian whole blood Pb concentrations increased by 73% during the 12 months study period while Hg and Cd decreased by 31% and 27%, respectively. We found a negative correlation between Pb levels before surgery and BMI (p = 0.02). Before surgery patients with hypertension had significantly higher median whole blood Hg levels compared to patients with normal blood pressure (p < 0.001). ConclusionOne year after bariatric surgery, the median whole blood Pb concentration was increased, while Hg and Cd concentrations were decreased. The majority of bariatric surgery patients are women of reproductive age and weight loss is associated with improved fertility. As even low dose Pb exposure during fetal life is associated with negative effects on the central nervous system, the observed increase in whole blood Pb after weight loss causes concern. Further studies are needed to elucidate these observations.

Fatty acid levels alterations in THP-1 macrophages cultured with lead (Pb)

ObjectiveAs cardiovascular events are one of the main causes of death in developed countries, each factor potentially increasing the risk of cardiovascular disease deserves special attention. One such factor is the potentially atherogenic effect of lead (Pb) on lipid metabolism, and is significant in view of the still considerable Pb environmental pollution and the non-degradability of Pb compounds. MethodsAnalysis of saturated fatty acids (SFA) (caprylic acid (C8:0), decanoic acid (C10:0), lauric acid (C12:0), tridecanoic acid (C13:0), myristic acid (C14:0), pentadecanoic acid (C15:0), palmitic acid (C16:0), heptadecanoic acid (C17:0), stearic acid (C18:0), and behenic acid (C22:0)), monounsaturated fatty acid (MUFA) (palmitoleic acid (C16:1), oleic acid (18:1w9), trans-vaccenic acid (C18:1 trans11)), and polyunsaturated fatty acid (PUFA) (linoleic acid (C18:2n6), gamma-linolenic acid (C18:3n6), arachidonic acid (C20:4n6)), was conducted by gas chromatography. Analysis of stearoyl-CoA desaturase (SCD), fatty acid desaturase 1 (FADS1) and fatty acid desaturase 2 (FADS2) expression was performed using qRT-PCR. Oxidative stress intensity (malondialdehyde - MDA concentration) was measured using spectrophotometric method. Intracellular generation of reactive oxygen species (ROS) in macrophages was visualized by fluorescence microscopy and quantitatively measured by plate reader. ResultsPb caused quantitative alterations in FAs profile in macrophages; the effect was Pb-concentration dependent and selective (i.e. concerned only selected FAs). In general, the effect of Pb was biphasic, with Pb levels of 1.25 μg/dL and 2.5 μg/dL being stimulatory, and 10 μg/dL being inhibitory on concentrations of selected FAs. The most potent Pb concentration, resulting in increase in levels of 9 FAs, was 2.5 μg/dL, the Pb-level corresponding to the mean blood Pb concentrations of people living in urban areas not contaminated by Pb. Pb was found to exert similar, biphasic effect on the expression of FADS1. However, Pb decreased, in a concentration-dependent manner, the expression of SCD and FADS2. Pb significantly increased MDA and ROS concentration in macrophages. ConclusionEnvironmental Pb exposure might be a risk factor resulting in alterations in FAs levels, oxidative stress and increased MDA concentration in macrophages, which might lead to the formation of foam cells and to inflammatory reactions.

Association between maternal blood cadmium and lead concentrations and gestational diabetes mellitus in the Japan Environment and Children's Study.

To examine the association between elevated blood cadmium (Cd) and lead (Pb) concentrations and increased risk of gestational diabetes mellitus (GDM). This cross-sectional study included pregnant women (n = 16,955) enrolled in the Japan Environment and Children's Study. Concentrations of Cd and Pb in blood samples collected at 22-28weeks' gestation were measured by inductively coupled plasma mass spectrometry. GDM was diagnosed according to the 2011 Japan Society of Obstetrics and Gynecology and Japan Association of Obstetricians and Gynecologists criteria. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression analysis. Blood Cd and Pb concentrations were slightly higher among women with GDM than among those without GDM; however, these differences were not statistically significant. Elevated blood Cd and Pb concentrations were not associated with increased GDM risk in the nulliparous group (Cd OR 0.76; 95% CI 0.28-2.08 for high vs low category; Pb OR 2.51; 95% CI 0.72-8.72) or the parous group (Cd OR 0.64; 95% CI 0.29-1.44; Pb OR 0.31; 95% CI 0.04-2.29). This study demonstrates that Cd and Pb exposure, in the range of blood levels observed, has no significant relationship with the development of GDM. Further prospective studies would be valuable to confirm these findings.