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The members of this panel were asked to assess Richard Stewart's contributions to administrative law, but my knowledge of that field is too fragmentary to capture the totality of his sweeping impact. I will instead focus on only a minor part of it, but in a way that, I hope, sheds light on why his overall impact has been so great. That minor part is his effect on one lesser scholar, me. Showing why he had such a huge impact on my work over the decades will suggest why he has enriched the work of so many around him and has thereby improved the law. [ABSTRACT FROM AUTHOR]

Importance: Childhood lead exposure has been linked to disrupted brain development, but long-term consequences for structural brain integrity are unknown.Objective: To test the hypothesis that childhood lead exposure is associated with magnetic resonance imaging (MRI) measurements of lower structural integrity of the brain in midlife.Design, Setting, and Participants: The Dunedin Study followed a population-representative 1972-1973 birth cohort in New Zealand (N = 564 analytic sample) to age 45 years (until April 2019).Exposures: Childhood blood lead levels measured at age 11 years.Main Outcomes and Measures: Structural brain integrity at age 45 years assessed via MRI (primary outcomes): gray matter (cortical thickness, surface area, hippocampal volume), white matter (white matter hyperintensities, fractional anisotropy [theoretical range, 0 {diffusion is perfectly isotropic} to 100 {diffusion is perfectly anisotropic}]), and the Brain Age Gap Estimation (BrainAGE), a composite index of the gap between chronological age and a machine learning algorithm-estimated brain age (0 indicates a brain age equivalent to chronological age; positive and negative values represent an older and younger brain age, respectively). Cognitive function at age 45 years was assessed objectively via the Wechsler Adult Intelligence Scale IV (IQ range, 40-160, standardized to a mean of 100 [SD, 15]) and subjectively via informant and self-reports (z-score units; scale mean, 0 [SD, 1]).Results: Of 1037 original participants, 997 were alive at age 45 years, of whom 564 (57%) had received lead testing at age 11 years (302 [54%] male) (median follow-up, 34 [interquartile range, 33.7-34.7] years). Mean blood lead level at age 11 years was 10.99 (SD, 4.63) μg/dL. After adjusting for covariates, each 5-μg/dL higher childhood blood lead level was significantly associated with 1.19-cm2 smaller cortical surface area (95% CI, -2.35 to -0.02 cm2; P = .05), 0.10-cm3 smaller hippocampal volume (95% CI, -0.17 to -0.03 cm3; P = .006), lower global fractional anisotropy (b = -0.12; 95% CI, -0.24 to -0.01; P = .04), and a BrainAGE index 0.77 years older (95% CI, 0.02-1.51 years; P = .05) at age 45 years. There were no statistically significant associations between blood lead level and log-transformed white matter hyperintensity volume (b = 0.05 log mm3; 95% CI, -0.02 to 0.13 log mm3; P = .17) or mean cortical thickness (b = -0.004 mm; 95% CI, -0.012 to 0.004 mm; P = .39). Each 5-μg/dL higher childhood blood lead level was significantly associated with a 2.07-point lower IQ score at age 45 years (95% CI, -3.39 to -0.74; P = .002) and a 0.12-point higher score on informant-rated cognitive problems (95% CI, 0.01-0.23; P = .03). There was no statistically significant association between childhood blood lead levels and self-reported cognitive problems (b = -0.02 points; 95% CI, -0.10 to 0.07; P = .68).Conclusions and Relevance: In this longitudinal cohort study with a median 34-year follow-up, higher childhood blood lead level was associated with differences in some MRI measures of brain structure that suggested lower structural brain integrity in midlife. Because of the large number of statistical comparisons, some findings may represent type I error. [ABSTRACT FROM AUTHOR]

Lead exposure is known to affect the pituitary-thyroid axis. Likewise, ascorbic acid (AA) has a protective action against lead poisoning.We examine the protective role of AA in lead-induced damage to the thyroid gland. The Wistar rats were divided into three groups: control that received 0.2% AA in drinking water throughout the experiment (15 days), intoxicated with lead acetate (20 mg/kg) intraperitoneally every 48 h for 15 days, and the experimental group treated with lead acetate and 0.2% AA in drinking water throughout the experiment. Plasma thyroid-stimulating hormone, triiodothyronine, thyroxine, and lead were determined. The thyroid gland was weighed, then epithelial cell height and nuclear volume were measured on histological slides. The results show that AA reduced the thyroid atrophy caused by lead acetate, as well as the loss of weight of the gland. In addition, it prevented the decrease of the hormone triiodothyronine, although the thyroxine hormone remained lower than the control values and the thyroid-stimulating hormone remains high. Our results indicated that AA could play a protective role in lead poisoning in the thyroid gland. [ABSTRACT FROM AUTHOR]

The unfavorable ecological state of the environment at present is as a result of man-made human activity. Among the main pollutants of the habitat at present time is recognized the lead, which has a polytropic effect on the organism. With the help of morphometric and statistical methods, the viability has been explored of red blood cells and amniotic fluid cells of control and experimental animals which are subjected to lead acetate toxicity. To identify the belonging of amniotic fluid cells to stem cells (SC), we carried out their cultivation in the special environment «Amniokar» of the company LLC PanEco Company, Russia. Studies have been carried out using an Axio Imager.M2 digital microscope (ZEISS, Japan) and a Countess ™ automatic cell counter (Invitrogen, USA). The effect of lead acetate led to the formation of aggregates of erythrocytes of blood of the type of «coin columns», to decrease in the concentration of living erythrocytes and their viability. The study of amniotic fluid under intoxication conditions has showed that only the squamous epithelium cells remained in the suspension which has been obtained as a result of centrifugation kept squamous cells only. Lead acetate leads to a decrease in the number of viable red blood cells in the blood, as well as to an increase in their aggregation properties. [ABSTRACT FROM AUTHOR]

This study was designed to measure the concentration of some Trace metals ( Copper, Lead, Cobalt & Zinc ) in the blood of its effect upon antioxidant enzymes ( Super oxide dismutase Enzyme and Glutathione ) parameters of cleaner workers in hospitals, have chosen three hospitals (Al- Hussein teaching hospital, Bant Al-Huda hospital and Al-Haboubi hospital ) in Al-Nasiriyah city (Center of Thi-Qar province southern of Iraq). The current study included 100 blood samples have collected randomly, 75 of it were taken from a group of cleaner workers at three hospitals. They aged from 20 to 55 years (them duration work was 1-33 years) and 25 samples of non- working as a control group, each sample of blood separate the serum for the purpose of divided into two parts, the first part to estimate of SOD enzyme & Glutathione, second part measuring the concentration of trace metals (lead, copper, Cobalt Zinc). Glutathione concentrations in age ≥ 20 years ranged less than from age 1-9 year group for SOD enzyme concentrations in age ≥ 20 years ranged less than from age 1-9 year group. increased significantly in hospitals workers within 1-9-year, with significant differences compared to other study groups. Also, the current study showed that the smoker workers were exposed to high concentrations of studied trace elements, but they had low concentrations of glutathione and SOD. However, the control group exposed to less concentrations of studied elements and they had high concentrations of enzymes. [ABSTRACT FROM AUTHOR]

Background: Pediatric lead exposure in the United States (U.S.) remains a preventable public health crisis. Shareable electronic clinical decision support (CDS) could improve lead screening and management. However, discrepancies between federal, state and local recommendations could present significant challenges for implementation.Methods: We identified publically available guidance on lead screening and management. We extracted definitions for elevated lead and recommendations for screening, follow-up, reporting, and management. We compared thresholds and level of obligation for management actions. Finally, we assessed the feasibility of development of shareable CDS.Results: We identified 54 guidance sources. States offered different definitions of elevated lead, and recommendations for screening, reporting, follow-up and management. Only 37 of 48 states providing guidance used the Center for Disease Control (CDC) definition for elevated lead. There were 17 distinct management actions. Guidance sources indicated an average of 5.5 management actions, but offered different criteria and levels of obligation for these actions. Despite differences, the recommendations were well-structured, actionable, and encodable, indicating shareable CDS is feasible.Conclusion: Current variability across guidance poses challenges for clinicians. Developing shareable CDS is feasible and could improve pediatric lead screening and management. Shareable CDS would need to account for local variability in guidance. [ABSTRACT FROM AUTHOR]

Lead (Pb) is one of the important heavy metals responsible for human health deterioration. The Delhi NCR host a number of companies related to mining, mineral, engineering, machines, construction, etc. The presence of industries exposes the residents to the harsh chemicals. Lead is excreted in the water sources by the Industries in the Delhi NCR region. The lead from the Industries reaches the human body via the water cycle. The present study attempts to assess the health risk from the presence of lead in the population of Delhi NCR associated with age, gender, residential area, and disease In Delhl-NCR using GTA-Atomlc Absorption Spectroscopy. Correlations were found between the lead concentration In blood and water. The lead concentration In blood and lead concentration In water also showed correlations with the region from which the samples were taken. [ABSTRACT FROM AUTHOR]

An extensive validation of a rapid and direct sampling method was done for estimation of lead content in whole blood using graphite tube atomizer atomic absorption spectroscopy without pre-digestion. The sequence of sample introduction and amount of addition of a mixed matrix modifier solution is conceded here. The current method is optimized and rigorously validated within the commonly disseminated lead toxicity range on whole blood samples without a tedious step of sample preparation and/or digestion. Multivariate optimization and validation were used to establish the optimal conditions of the graphite tube atomizer and matrix modifier solution for blood lead detection. No significant differences were found between the results obtained using the proposed method and the optimized mixed matrix modifier solution for the lead analyte estimation in whole blood matrix. [ABSTRACT FROM AUTHOR]

• Fluticasone propionate and triamcinolone acetonide led to physiological effects. • Glucocorticoids altered expression of target genes encoding important pathways. • Glucocorticoid mixtures were additive. • Mixture activity supports the concentration addition concept. • Additive action of glucocorticoids may have adverse consequences. Many synthetic glucocorticoids from medical applications occur in the aquatic environment. Whether they pose a risk for fish health is poorly known. Here we investigate effects of glucocorticoids fluticasone propionate (FLU) and triamcinolone acetonide (TRI) as single steroids and as ternary mixtures with clobetasol propionate (CLO) in zebrafish embryos. Exposure to FLU and TRI in a range of concentrations between 0.099 and 120.08 μg/L led to concentration-related decrease in muscle contractions and increase in heart rate at 0.98 and 1.05 μg/L, respectively, and higher. Genes encoding for proteins related to glucose metabolism (g6pca , pepck1), immune system regulation (fkb p5 , irg1l, socs3 , gilz) and matrix metalloproteinases mmp-9 and mmp-13 showed expressional alterations, as well as genes encoding for the progestin receptor (pgr) and corticosteroid dehydrogenase (hsd11b2). FLU accelerated hatching and led to embryotoxicity (immobilization and edema). Ternary mixtures (FLU + TRI + CLO) induced the same physiological and toxicological effects at concentrations of individual glucocorticoids of 11.1–16.37 μg/L and higher. Heart rate was increased in the mixture at concentrations as low as 0.0885−0.11 μg/L of each steroid. Glucocorticoids in mixtures showed additive activity; the fold-changes of transcripts of 19 target genes were additive. Together, our data show that glucocorticoids act additively and their joint activity may be of concern for developing fish in contaminated environments. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study was to determine the effect of exposure to lead contaminants on the psychiatric disorders and quality of life in employees of various occupations in Sanandaj city, Iran, where there is lead in the workplace. Method: The present study was a descriptive-analytical study done on employees of different occupations (including: non-exposed people, gas station, welding and painting) in Sanandaj, Iran. 64 people were considered as the non-exposed group, and 124 were selected as the exposed group.To obtain blood sample from the employees, about 7 ml of the blood of each person in the heparin tubes was collected by a sterile disposable syringe, and then, transferred to the laboratory. Blood lead levels were measured by the atomic absorption spectrophotometer apparatus AA6800. A psychiatric disorders' questionnaire (-90Checklist Symptom 90-Scl) was used to assess the psychiatric disorders. The questionnaire contained 90 questions for evaluating the mental symptoms, and the results were reported by the interviewee. In this study, a 36-item quality of life questionnaire (SF-36) with a total of 36 questions in 8 health domains including physical function, physical role, physical pain, general health, energy and vitality, social functioning, emotional-mental problems and mental health was used. After collecting the data, the obtained information was entered to the SPSS software version 20. Results: The age range of the subjects was between 25 and 50 years old. All the subjects were male, and 43% of the exposed group and 37% of the non-exposed group had higher education than diploma. The highest blood lead level was observed for welding staff with an average of 63.3500 µg/dl, and the lowest blood lead level belonged to the subjects without exposure to lead with an average of 14.7500 µg/dl. Moreover, the highest level of quality of life and the lowest levelsof psychiatric disorders were found in non-exposed people, and the lowest level of quality of life and the highest psychiatric disorders were in welding staff. Conclusion: Regarding the problems associated with the exposure to lead, reducing blood lead levels by decreasing the amount of lead in chemicals should be used in various industries, as well as the use of personal protective equipments such as chemical masks are necessary. [ABSTRACT FROM AUTHOR]

Lead (Pb) is one of the most abundant toxic metals in the environment that can cause a variety of harmful effects. During embryonic development of vertebrates, somites are temporary organs that give rise to skeletal muscle, cartilage, tendon, endothelial cells, and dermis. In this study, we investigated the effects of lead on the development of somites and their derivatives in chick embryos under in vitro conditions. For this propose, fertilized eggs of Gallus gallus domesticus were incubated until they reached the stage of 15–20 somites. The somites and notochord were isolated and treated with different concentrations of lead acetate (500, 1000, 2000, and 4000 ng ml−1) for 72 h. Our results indicated that high concentrations of lead reduced the nucleus diameter, reduced the synthesis of collagen, inhibited the formation of the cartilage matrix in somite cells, and disturbed the formation and order of myotubes. In conclusion, the results of the current study for the first time indicated the disturbing effects of lead on the development of somites in the chick embryo. Our results revealed that lead disturbed the development of somites in the chick embryo, which suggested that at high concentrations it can cause a serious mortal danger to life. [ABSTRACT FROM AUTHOR]

Abstract Background Lead exposure represents a significant human health concern that often occurs with little warning to the consumer. Water lead levels can be mitigated by point-of-use (POU) devices such as reverse osmosis, distillation, or activated carbon with lead reduction media. Objectives This study assessed a partial cost-benefit of residential installation of POU devices to reduce lead concentrations in drinking water and examined the economic impact at the community level based on exposures reported in Flint, Michigan. Methods We calculated the individual consumer breakeven point for each lead abatement option by subtracting the lifetime cost of device installation and maintenance from the lifetime cost of lead exposure through its impact on intelligence (IQ) and lifetime earnings. This approach was then extrapolated to the community level based on reported lead exposures in Flint, Michigan. Results Based on operating POU device costs, lead absorption from water, and economic losses associated with reduced IQ, initial water lead levels associated with consumer breakeven points for reverse osmosis (7.31 µg/L), activated carbon (3.73 µg/L), and distillation (12.0 µg/L) were calculated. For example, an individual consuming water with 25 µg/L of lead, similar to the 90th percentile of concentrations measured in Flint, Michigan, would have an expected blood lead level of 1.25 µg/dL, a corresponding loss of 0.641 IQ points, and a lifetime economic earnings loss of $14,284. Over 70 years of continued use, activated carbon with lead reduction media is the least expensive device to maintain and operate as compared to reverse osmosis and distillation. Conclusions Infrastructure failures related to drinking water are unpredictable and exposure to contaminates can have significant economic ramifications. POU devices represent a cost-effective option to reduce the impact of lead exposure, particularly when water lead concentrations exceed regulated levels. Highlights • Reverse osmosis, activated carbon, and distillation effective for lead removal. • Point-of-use devices can be cost effective for lead removal over a lifetime. • Lead exposure from drinking water decreases IQ and lifetime earnings. [ABSTRACT FROM AUTHOR]

Abstract Sertoli cells (SCs) provide lactate as an energy substrate to develop germ cells during spermatogenesis. Lead (Pb) and cadmium (Cd) can induce SC toxicity. However, the mechanisms remain unclear. This study aimed to investigate the molecular mechanisms by which Pb and Cd alter lactate transport and production by SCs. Mouse SC line (15P-1 cells) were cultured in the absence and presence of lead acetate (PbAc, 1, 10, 20 and 30 μM) or cadmium chloride (CdCl 2 , 0.5, 5, 10 and 15 μM) for 24 h. The results showed that PbAc exposure significantly decreased lactate dehydrogenase (LDH) activity and mRNA level, intracellular and extracellular lactate, and MCT4 and CD147 protein levels but increased MCT4 and CD147 mRNA levels. However, PbAc did not alter the glucose uptake, glucose transporters 1 (GLUT1) and 3 (GLUT3) mRNA expression of SCs. Thus, PbAc mainly decreased lactate production by inhibiting LDH activity. In CdCl 2 -treated SCs, intracellular lactate content increased but extracellular lactate content decreased significantly, P <.05. The glucose uptake, LDH activity, and mRNA expression of GLUT1, GLUT3 and LDH, all significantly increased. But the mRNA and protein levels of MCT4 and CD147 significantly decreased. Moreover, the fluorescence intensity of co-localizations of the MCT4–CD147 complex dose-dependently decreased in the cell membrane. Thus, CdCl 2 may reduce lactate export by suppressing MCT4 and CD147 expression. These results suggest that PbAc and CdCl 2 disrupt lactate production and transport in mouse SCs by disturbing glycolysis or inhibiting MCT4–CD147 transporter expression and co-localizations. Highlights • Male infertility caused by lead or cadmium was explored from the perspective of lactate transport in Sertoli cells. • Lead and cadmium reduced extracellular lactate content of in vitro cultured Sertoli cells. • Protein expression levels of transporter MCT4 and CD147 declined. • Lead mainly reduced lactate production by inhibiting LDH activity. • Cadmium reduced lactate export by suppressing MCT4 and CD147 expressions. [ABSTRACT FROM AUTHOR]

The article discusses the lead hazard control programs at the U.S. Department of Housing and Urban Development (HUD) aimed at making homes safer for children and families to live in. Topics covered include lead exposure of children through lead-based paint in the home, cost benefits of removing lead paint hazards in older homes of children from low-income families, and role of the Residential Lead-Based Paint Hazard Reduction Act of 1992 in addressing the lead-based paint problem.

Graphical abstract Highlights • Lead exposure is a possible risk factor for sensory integration dysfunction. • The SPM-HKC was used to compare frequency of behavioral dissonance-related behaviors. • Elevated lead exposure is associated with an increased sensory integration score. • Serum cortisol concentration is negatively associated with blood lead levels. • Cortisol may be involved in touch-related sensory integration difficulties. Abstract Exposure to lead is associated with adverse effects on neurodevelopment. However, studies of the effects of lead on sensory integration are few. The purpose of this research is to investigate the effect of lead exposure on child sensory integration by correlating the blood lead levels of children with sensory processing measures. A total of 574 children, from 3 to 6 years of age, 358 from an electronic waste (e-waste) recycling town named Guiyu, and 216 from Haojiang, a nearby town with no e-waste recycling activity, were recruited in this study. The median blood lead level in Guiyu children was 4.88 μg/dL, higher than the 3.47 μg/dL blood lead level in Haojiang children (P < 0.001). 47.2% of Guiyu children had blood lead levels exceeding 5 μg/dL. The median concentration of serum cortisol, an HPA-axis biomarker, in Guiyu children was significantly lower than in Haojiang, and was negatively correlated with blood lead levels. All subscale scores and the total score of the Sensory Processing Measure (Hong Kong Chinese version, SPM-HKC) in Guiyu children were higher than Haojiang children, indicating greater difficulties, especially for touch, body awareness, balance and motion, and total sensory systems. Sensory processing scores were positively correlated with blood lead, except for touch, which was negatively correlated with serum cortisol levels. Simultaneously, all subscale scores and the total SPM-HKC scores for children with high blood lead levels (blood lead > 5 μg/dL) were higher than those in the low blood lead level group (blood lead < 5 μg/dL), especially for hearing, touch, body awareness, balance and motion, and total sensory systems. Our findings suggest that lead exposure in e-waste recycling areas may result in a decrease in serum cortisol levels and an increase in child sensory integration difficulties. Cortisol may be involved in touch-related sensory integration difficulties. [ABSTRACT FROM AUTHOR]

Lead is one of the most dangerous xenobiotic elements. It is actively accumulated not only in the environment, the distribution of lead in the water-soil-plant-animal-man chain directly depends on the initial content of elements in the geochemical province and is directly related to the health of the population. [1]. This paper presents the results of a study of the biotoxicity of lead cations in the structure of salts with different anionic components in relation to bacteria of the genus Bacillus, which are part of the probiotic preparations. These microorganisms are representatives of the soil microflora and are transitory to the organism of animals and humans. When conducting research, methods such as the agar wells were used, which not only visually but also qualitatively evaluate the effect of metal cations on the growth of the microorganisms studied, the colorimetric method was used to assess the effect of the element under study on the growth of the microorganism population, and the atomic absorption method made it possible to study accumulating characteristics of the studied bacteria. As a result of research, it has been established that lead acetate has a more pronounced toxic effect on the microorganisms under study. It should be noted that lead, which is present in the medium in high concentrations, does not have an inhibitory effect on bacterial strains; we associate this with the detoxification mechanisms of bacteria. The accumulating ability of microorganisms of the Bacillus genus of lead cations from nutrient substrates 24 hours after their cultivation in the presence of this element has high sorption characteristics with a percentage of its accumulation of more than 50%, the most active lead accumulates B. subtilis 534 with 66.3%, and the minimum values were recorded in B. amyloliquefaciens 10642 and amounted to 53.2%. [ABSTRACT FROM AUTHOR]

Highlights • Lead is a risk factor for neurodegenerative disorders involving the dopaminergic and noradrenergic systems. • Pb toxicity alters dopaminergic, noradrenergic systems and locomotor behavior. • Pb could be involved in the neuro-physiopathology of Parkinson disease. • Crocus sativus repairs the Pb neurotoxicity of dopaminergic, noradrenergic systems and locomotor behavior. Abstract Lead (Pb) is a metal element released into the atmosphere and a major source of environmental contamination. The accumulation and concentration of this metal in a food web may lead to the intoxication of the body, more precisely, the nervous system (NS). In addition, Pb-exposure can cause structural and functional disruption of the NS. Studies have shown that Pb-exposure could be a risk factor in the development of Parkinson's disease (PD). The latter is related to dopaminergic deficiency that may be triggered by genetic and environmental factors such as Pb intoxication. In this study, we have evaluated, in one hand, the neurotoxic effect of Pb (25 mg / kg B.W i.p) for three consecutive days on dopaminergic system and locomotor performance in Merione shawi. In the other hand, the possible restorative potential of C. sativus (CS) (50 mg / kg BW) by oral gavage. The immunohistochemical approach has revealed that Pb-intoxicated Meriones show a significant increase of Tyrosine Hydroxylase (TH) levels within the Substantia Nigra compacta (SNc), Ventral Tegmental Area (VTA), Locus Coeruleus (LC), Dorsal Striatum (DS) and Medial Forebrain Bundle (MFB), unlike the control meriones, a group intoxicated and treated with Crocus sativus hydroethanolic extract (CSHEE) and treated group by CSHEE. Treatment with CSHEE, has shown a real potential to prevent all Pb-induced damages. In fact, restores the TH levels by 92%, 90%, 88%, 90% and 93% in SNc, VTA, LC, DS and MFB respectively, similarly, locomotor activity dysfunction in Pb-intoxicaed meriones was reinstated by 90%. In this study, we have revealed a new pharmacological potential of Crocus sativus that can be used as a neuroprotective product for neurodegenerative disorders, especially, which implying dopaminergic and noradrenergic injuries, like PD, trigged by heavy metals. [ABSTRACT FROM AUTHOR]

Abstract Impact of co-exposures to toxic metals cadmium, lead, and mercury along with perfluoroalkyl substances on the healthy kidney function was evaluated among US adults aged > = 20 years by analyzing data (N = 7857) from National Health and Nutrition Examination Survey for 2003–2014. Perfluoroalkyl substances selected for analysis were: perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), and perfluorononanoic acid (PFNA). High levels of exposures to Cd, Pb, total Hg, and PFAS were said to occur if their observed levels in blood/serum were greater than 75th percentiles. A healthy kidney function was defined if estimated glomerular filtration rate was found to be > = 60 mL/min/1.73 m2 and urine albumin creatinine ratio was ≤ 30 mg/g creatinine. Adjusted odds of a healthy kidney function due to co-exposures to high levels of Cd along with high levels of PFOA, PFOS, and PFNA were found to be 0.713, 0.576, and 0.640 respectively. Adjusted odds of a healthy kidney function due to co-exposures to high levels of Pb along with high levels of PFOA, and PFNA were found to be 0.657, and 0.671 respectively. Co-exposures to high levels of Hg as measured by the total mercury in blood was not found to affect the odds of a healthy kidney function. Highlights • Odds of a healthy kidney with co-exposures to Cd and PFAS varied from 0.58 to 0.71. • Odds of a healthy kidney with co-exposures to Pb and PFAS varied from 0.66 to 0.77. • Co-exposure to Hg with PFAS did not affect the odds of a healthy kidney function. [ABSTRACT FROM AUTHOR]

Highlights • Temporal changes in metal concentrations of Xanthoria parietina thalli were examined. • A pronounced upward trend in Pb concentration over time was observed. • Vegetative parts of the thallus and apothecia differ in element accumulation levels. • Definition of part of thallus designated for elemental analysis is highly desirable. • Certain anatomical characteristics are correlated with concentrations of trace metals. Abstract Certain lichens are widely used in air pollution biomonitoring because the contents of various elements in their thalli accurately reflect the chemical composition of the air. Temporal changes in selected concentrations of trace metals in vegetative and generative parts of Xanthoria parietina thalli exposed to urban-related pollution were analysed and the relationship between anatomical organisation and element accumulation identified. The lichen material included thalli relocated to an urban area of Cracow (southern Poland) along with their host trees, which had previously been cultivated at a site characterised by a lower level of air pollution. The thalli were sampled immediately and 1, 3, 6, and 12 months after planting trees. Concentrations of Zn, Pb, Cd, Cu, Ni, and Cr, as measured by means of flame atomic absorption spectrometry (FAAS), and various anatomical characteristics were determined in vegetative thalli and the corresponding apothecia. Accumulation of Pb over time demonstrated a pronounced upward trend; calculated exposed-to-control (EC) ratios indicate 'severe accumulation' of this element. Diverse levels of accumulation in different parts of thalli – higher, in the cases of Pb, Cd, Cu, Ni, Cr, and lower, in the case of Zn, in vegetative parts compared to apothecia – were observed. Thus sampling uniformity is highly desirable in air biomonitoring studies, along with a determination of which part of the thallus is to be designated for elemental analysis. The results also showed that certain anatomical characteristics are correlated with concentrations of metal elements in the thallus. [ABSTRACT FROM AUTHOR]

Although rates of violent crime have been on the decline in the United States for the past two decades, young people—and particularly young men—continue to commit and fall victim to alarmingly high rates of violence. Effective prevention requires data on what the determinants of violence are and when in the life course they emerge. The goal of this review was to identify early‐in‐life risk factors for violence and to describe (a) who is most affected and (b) effect mechanisms. I focus on abuse and neglect and exposure to lead as risk factors for violence that disproportionately affect young children and that are likely to have causal effects on development. I conclude with future directions for research and intervention. [ABSTRACT FROM AUTHOR]

Though the adverse consequences of lead exposure in children have been well known for over a century, the recent Flint water crisis has drawn renewed attention to the impacts of lead exposure on human health and development. This study considers connections to educational outcomes, asking whether population-level lead exposure in early childhood influences later academic achievement and racial achievement gaps. It assesses the effectiveness of recent local- and state-level lead hazard control programs in mitigating exposure and uses this source of exogenous variation in early childhood exposure across birth cohorts to draw inferences about the long-term effects of lead on mean student test scores. Our findings indicate that lead hazard control grants reduced lead poisoning incidents by over 70% of the baseline prevalence. And each one percentage point reduction in lead poisoning in early childhood translated to a growth of 0.04 standard deviations in student math test scores and 0.08 standard deviations in student reading scores. This same reduction in lead poisoning narrowed both the white-Hispanic math achievement gap and white-Hispanic reading achievement gap by 0.06 standard deviations, implying important downstream consequences for economic inequality. [ABSTRACT FROM AUTHOR]

Previous studies have reported that exposure to lead and cadmium can damage the inner ear receptor, which perceives high-frequency sounds. However, few studies have used the pure-tone average (PTA), including high-frequency ranges, for the estimation of hearing loss caused by lead and cadmium exposure. We estimated hearing loss using the PTA test, in low-frequency, speech frequency, and high-frequency ranges and compared the differences in the results using 3 PTA calculation methods. We analyzed the data of 2,387 participants, between the ages of 19 and 85 years, that were obtained from the Korea National Health and Nutrition Examination Survey (KNHANES) of 2010-2012. A dose-response relationship between hearing loss and heavy metal exposure was observed in the high-frequency method after adjustment for confounding factors. When using the high-frequency PTA, it was found that doubling of the levels of lead and cadmium in the blood was associated with a 1.88- (95% CI 1.11-3.17) and 1.89-fold (95% CI 1.02-3.50) increase in the OR for hearing loss. In the case of the low-frequency and speech frequency PTA, however, there were no significant relationships between hearing loss and the concentrations of lead and cadmium in the blood. The outcomes of the present study suggest that the estimation of hearing loss caused by environmental exposure to lead and cadmium is affected by the frequencies used in the PTA calculation. [ABSTRACT FROM AUTHOR]

Highlights • Pb exposure significantly upregulated Dmt1 mRNA expression (a divalent metal transporter) in differentiated mouse osteoblasts. • Pb is evidenced to co localize with calcium and phosphate in intracellular calcified vesicles, which is a part of mineralization mechanism. • Pb co-localized with calcium phosphate in all stage of mineralization. • Different mineral morphologies contain unequally Pb content, as Pb deposits in globular shaped minerals more than in needle shaped minerals. Abstract The present study investigated the effect of lead (Pb) on bone ultrastructure and chemistry using an in vitro bone model. MC3T3-E1 preosteoblasts were differentiated and treated with lead acetate at 0.4, 2, 10, and 50 μM. No abnormalities in either cell growth or bone nodule formation were observed with the treated dose of lead acetate. However, Pb treatments could significantly increase Pb accumulation in differentiated osteoblast cultures and upregulate expression of Divalent metal transporter 1 (Dmt1) in a dose dependent manner. Pb treatments also altered the expression of osteogenic genes, including secreted phosphoprotein 1, osteocalcin, type I collagen, and osteoprotegerin. Moreover, in mineralized osteoblast cultures, Pb was found to be mainly deposited as Pb salts and oxides, respectively. Ultrastructure analysis revealed Pb localizing with calcium and phosphorus in the mineralized matrix. In mineralizing osteoblast cells, Pb was found in the intracellular calcified vesicles which is one of the bone mineralization mechanisms. Pb was also present in mineral deposits with various shapes and sizes, such as small and large globular or needle-like mineral deposits representing early to mature stages of mineral deposits. Furthermore, Pb was found more in the globular deposits than the needle shaped mineral crystals. Taken together, our observations revealed how Pb incorporates into bone tissue, and showed a close association with bone apatite. [ABSTRACT FROM AUTHOR]

Abstract Human exposure to lead (Pb) is a growing global public health concern. Elevated blood lead is thought to cause the mental retardation of >0.6 million children globally each year, and has recently been attributed to ~18% of all-cause mortality in the US. Due to the severe health risk, the international community, led by the United Nations Environment Programme (UNEP) and the World Health Organization (WHO), is actively supporting the global phase-out of lead-based paint by 2020. However, there are many significant hurdles on the way to achieving this goal. In light of the importance of the lead-based paint issue, and the urgency of achieving the 2020 phase-out goal, this review provides critical insights from the existing scientific literature on lead-based paint, and offers a comprehensive perspective on the overall issue. The global production and international trade of lead-based paints across Asia, Africa, Latin America, and Europe are critically discussed – revealing that lead-based paints are still widely used in many low and middle-income developing countries, and that the production and trade of lead-based paint is still wide-spread globally. In India, as well as many south-east Asian, African, Latin American and European countries, lead concentrations in paints often exceed 10,000 mg/kg. This will certainly pose a serious global threat to public health from surfaces painted with these products for many decades to come. The sources and pathways of exposure are further described to shed light on the associated health risk and socioeconomic costs. Finally, the review offers an overview of the potential intervention and abatement strategies for lead-based paints. In particular, it was found that there is a general lack of consensus on the definition of lead based paint; and, strengthening regulatory oversight, public awareness, and industry acceptance are vital in combating the global issue of lead based paint. Highlights • A summary of the global production and international trade of lead-based paints. • Production and consumption of leaded paint is still growing in developing countries. • A description of sources and pathways of lead paint exposure and associated risks. • An overview of potential intervention and abatement strategies for lead paint. • Greater regulatory oversight, public awareness, and industry acceptance is needed. [ABSTRACT FROM AUTHOR]

Risk assessment indices such as risk assessment code (RAC), potential ecological risk index (PERI), geoaccumulation index (Igeo), contamination factor (CF) and enrichment factor (EF) provide a good measure of environmental risk posed by Pb accumulated in shooting range soils as opposed to total Pb concentration. For this reason, the S/P Pistol shooting range, even though accumulated lower concentration of Pb (685±218 mg/kg), exhibited 'very high risk' to the environment with RAC value of 77 exceeding the 51 set guideline value for 'very high risk' with a significant margin compared to MAT R2 (20888±5419 mg/kg) at RAC value of 48 and highest total Pb concentration. This implies that mobility and bioavailability of Pb at S/P Pistol shooting range will be higher posing a greater risk to biota even though contamination from Pb is low. Best shooting range management practices and low cost remedial actions such as phytoremediation and chemical immobilization should be carried out as soon as possible to minimize the bioavailability and mobility of Pb in the studied shooting ranges. [ABSTRACT FROM AUTHOR]

Mobilization of lead from retained bullets may lead to elevated lead levels in game tissue with consequences for consumers. We investigated lead mobilization in 2 white-tailed deer (Odocoileus virginianus) carrying retained lead ammunition from previous gunshot wounds. Lead concentrations in muscle tissue of deer with retained lead bullets were in the same range as control deer. In contrast, 1 deer had higher bone lead levels than controls, suggesting mobilization occurred. Our results suggest that lead mobilization to meat from retained lead bullets does not appear to pose a consumption risk for those consuming meat that is physically distant from lead particles embedded within the carcass. [ABSTRACT FROM AUTHOR]

Exposure to heavy metals may lead to hearing impairment. However, experimental studies have not explored this issue with and without noise exposure in mature animals with environmentally relevant doses. The aim of this study was to investigate ototoxicity produced by lead (Pb) and cadmium (Cd) and noise, singly and in combination, in the adult CBA/CaJ mouse. Metals were delivered via drinking water (0.03 mM, 1 mM, and 3 mM Pb; or 30, 100, and 300 μM Cd) for 12 weeks, resulting in environmentally- and occupationally relevant mean (± standard deviations) blood levels of Pb (2.89 ± 0.44, 38.5 ± 4.9, and 60.1 ± 6.6 μg/dl, respectively) and Cd (1.3 ± 0.23, 6.37 ± 0.87, 27.2 ± 4.1 μg/L, respectively). Metal treatment was also combined with a noise exposure consisting of a 105 dB broadband (2-20 kHz) stimulus for 2 hr or a sham exposure. Auditory performance was determined by comparing auditory brainstem responses (ABR) and distortion product otoacoustic emissions (DPOAE) at baseline and after 11 weeks of metal treatment. Metal-exposed animals did not develop significant auditory deficits and did not exhibit morphological damage to cochlear hair cells. In contrast, noise-exposed animals, including those exposed to combinations of metals and noise, demonstrated significant hair cell loss, reduced DPOAE amplitudes, and ABR threshold shifts of 42.2 ± 13 dB at 32 kHz (105 dB noise alone). No significant potentiation or synergistic effects were found in groups exposed to multiple agents. This study establishes a highly reproducible adult mouse model that may be used to evaluate a variety of environmental exposure mixtures. [ABSTRACT FROM AUTHOR]

Abstract Background High blood pressure (BP) in childhood is frequently renal in origin and a risk factor for adult hypertension and cardiovascular disease. Shorter gestations are a known risk factor for increased BP in adults and children, due in part to a nephron deficit in children born preterm. As nephrogenesis is incomplete until 36 weeks gestation, prenatal lead exposure occurring during a susceptible period of renal development may contribute to programming for later life renal disease. The relationship between shorter gestation and children's BP has not yet been explored to identify i) critical windows using nonlinear piecewise models or ii) combined with other early life risk factors such as prenatal lead exposure. Objectives (1) To evaluate the nonlinear relationship between lower gestational age and childhood BP measured at 4–6 years of age, and (2) to investigate modification by prenatal lead exposure. Methods In a prospective longitudinal birth cohort, we assessed 565 children between 4 and 6 years of age (mean: 4.8 years) in the PROGRESS cohort in Mexico City, Mexico. Gestational age at delivery was calculated using maternal report of last menstrual period (LMP) and confirmed with Capurro physical examination at birth. We measured pregnant women's blood lead levels (BLLs) in the second trimester via inductively coupled plasma-mass spectrometry and children's BP using an automated device. We performed both linear and nonlinear piecewise regression analyses to examine associations of gestational age with children's BP adjusting for children's age, sex, height, prenatal exposure to smoke, and maternal socioeconomic status. We stratified to assess modification by prenatal lead exposure, and used a data-adaptive approach to identify a lead cutpoint. Results Maternal second trimester BLLs ranged from 0.7 to 17.8 μg/dL with 112 (20%) women above the CDC guideline level of 5 μg/dL. In adjusted linear regression models, a one week reduction in gestational age was associated with a 0.5 mm Hg (95%CI: 0.2, 0.8) increase in SBP and a 0.4 mm Hg (95%CI 0.1, 0.6) increase in DBP. Our nonlinear models suggested evidence for different magnitude estimates on either side of an estimated join-point at 35.9 weeks' gestation, but did not reach statistical significance. However, when stratified by prenatal lead exposure, we identified a cutpoint lead level of concern of 2.5 μg/dL that suggested an interaction between gestational age and blood lead. Specifically, for BLLs ≥ 2.5 μg/dL, SBP was 1.6 (95%CI: 0.3, 2.9) mm Hg higher per each week reduction in gestational age among children born before 37.0 weeks; and among children born after 37.0 weeks, this relationship was attenuated yet remained significant [β: 0.9, 95%CI (0.2, 1.6)]. At BLLs below 2.5 μg/dL, there was no appreciable association between lower gestational age and SBP. Conclusions Our findings suggest that shorter gestation combined with higher prenatal lead exposure contributes to a higher risk of increased SBP at 4–6 years of age, particularly among infants born <37 weeks gestation. Our results underscore the importance of preventing prenatal lead exposure - even levels as low as 2.5 μg/dL - especially among pregnant women at risk for preterm birth. Given that high BP in childhood is a risk factor for adult hypertension and cardiovascular disease later in life, these results may have implications that extend across the life span. Highlights • Shorter gestations combined with higher prenatal lead exposure contribute to higher 4-yr blood pressure. • Associations are particularly notable among infants born <37 weeks' gestation. • We identify a blood lead level of 2.5 μg/dL that may have implications for renal health. • We utilize nonlinear modeling to identify critical windows of susceptibility. [ABSTRACT FROM AUTHOR]

Abstract Lead (Pb) pollution has been considered as a major threat for human health due to induction of inflammatory cascades in various tissues. The aim of present review is to summarize the literature on the effects of lead exposure on respiratory, neurologic, digestive, cardiovascular and urinary disorders and the role of inflammation as an underlying mechanism for these effects. Various databases such as ISI Web of Knowledge, Medline, PubMed, Scopus, Google Scholar and Iran Medex, were searched from 1970 to November 2017 to gather the required articles using appropriate keywords such as lead, respiratory disorders, neurologic disorders, digestive disorders, cardiovascular disorders, urinary disorders and inflammation. Disorders of various body systems and the role of inflammation due to lead exposure has been proven by various studies. These studies indicate that lead exposure may cause respiratory, neurologic, digestive, cardiovascular and urinary diseases. The results were also indicated the increased inflammatory cells and mediators due to lead exposure including cytokines and chemokines due to lead exposure which suggested to be the cause various organ disorders. [ABSTRACT FROM AUTHOR]

Metal pollution can drastically decrease the diversity of species of many groups of terrestrial invertebrates. Well-performed reclamation may prevent the loss of species diversity. In this study, we used multivariable statistical methods to describe the species diversity of carabids and ants originating from two zinc-lead mine tailing ponds under different degrees of reclamation practices. Although the species diversity of carabids and ants in both study sites and in both seasons was relatively high, the investigated communities were dominated by one numerous species. Discriminant analysis indicated that the difference between study sites is due to the high number of carabid species found in the comprehensively reclaimed site and the high abundance of several species of ants found in the partially reclaimed site. The most striking difference in species composition between the study sites was the contribution of forest species. The comprehensively reclaimed site maintains more species of forest carabids but fewer forest species of ants in comparison to the partially reclaimed one. [ABSTRACT FROM AUTHOR]

Background: We developed a systematic, data‐driven approach to estimate metrics of occupational exposure to lead to aid in epidemiologic analyses in a case‐control study of kidney cancer. Methods: Probability of exposure to ten lead sources was assigned using decision rules developed from an extensive literature review and expert judgement. For jobs with >50% probability of exposure, we assigned source‐specific frequency based on subjects' self‐reported task frequencies or means of subjects' job‐groups and source‐specific intensity estimates of blood lead (μg/dL). Results: In our study, 18.7% of employed person‐years were associated with high (≥80%) probability of exposure to any lead source. The most common medium (>50%) or high probability source of lead exposure was leaded gasoline (2.5% and 11.5% of employed person‐years, respectively). The median blood lead attributed to occupational exposure was 3.1 μg/dL. Conclusions: These rules can aid in future studies after population‐specific adaption for geographic differences and different exposure scenarios. [ABSTRACT FROM AUTHOR]

Lead wheel weights (LWWs) have been banned in Europe, and some US States, but they continue to dominate the market in Canada. Exposure to lead is associated with numerous health impacts and can result in multiple and irreversible health problems which include cognitive impairment when exposure occurs during early development. Such impacts incur high individual and social costs. The purpose of this study was to assess the costs and public health benefits of a Risk Management Strategy (RMS) that would result from a LWW phase-out in Canada and compare this to a Business-As-Usual (BAU) scenario. The contribution of LWWs to lead concentrations in media including roadway soil/dust, ambient and indoor air, and indoor dust were estimated. The Integrated Exposure Uptake Biokinetic Model for Lead in Children (IEUBK) was used to develop estimates for the blood lead levels (BLLs) in children (μg/dL) associated with the BAU and the RMS. The BLLs estimated via the IEUBK model were then used to assess the IQ decrements associated with the BAU that would be avoided under the RMS. The subsequent overall societal benefits in terms of increased lifetime earning potential and reduced crime rate, were then estimated and compared to industry and government costs. LWWs form 72% of the Canadian wheel weight market and >1500 tonnes of lead as new LWWs attached to vehicles enters Canadian society annually. We estimate that 110–131 tonnes of lead in detached WWs are abraded on roadways in Canada each year. A LWW phase-out was predicted to result in a drop in pre-school BLLs of up to 0.4 μg/dL. The estimated net benefits associated with the RMS based on cognitive decrements avoided and hence increased lifetime earning potential (increased productivity) and reduced crime are expected to be: C$248 million (8% discount rate) to C$1.2 billion (3% discount rate) per year. [ABSTRACT FROM AUTHOR]

Exposure to low levels of lead in children can cause cognitive deficits (reduced IQ) and behavioral changes such as reduced attention span and increased antisocial behavior. There are no mandatory limits on lead in paint in Israel, with the exception of paints used on toys and children's furniture. However, paints in playgrounds and public areas may be a source of exposure to lead in young children. In this study, we quantified lead concentrations in painted surfaces in public playgrounds and public areas, and in spray paints in Israel, using X-ray fluorescence (XRF). Lead was detected in 43/48 (90%) of surfaces; concentrations exceeded the US regulatory limit for lead in paint (90 ppm) in 4/5 (80%) of tested surfaces on wooden picnic tables and benches, and 22/25 (88%) of surfaces in playgrounds. In 15 surfaces, lead concentrations were 10–700 times higher than the US limit. Out of 11 spray paints sampled, three (27%) had concentrations above the US standard for residential paints. In order to prevent exposure of the general public to lead in playgrounds and public areas and in spray paints, we recommend an integrated approach, including regulatory restrictions (mandatory lead limit of 90 ppm in all paints except labeled industrial paints); awareness raising in the public and in national agencies and local authorities responsible for maintenance in playgrounds, schools and public areas; and encouragement of voluntary measures by industry to prevent sale of industrial paints for use in areas accessible to the public. [ABSTRACT FROM AUTHOR]

Highlights • Higher level of fetal aluminum was found in CHDs group compared to in controls. • Oxidative stress level was relation with the concentration of Pb and Al. • Imbalance of oxidative stress may bring about the occurrence of CHD. Abstract Objectives This study aimed to analyze the association between fetal lead or aluminum exposure and congenital heart disease (CHD) occurrence as well as to explore the mechanism of oxidative stress in heart development. Methods Lead and aluminum concentrations were measured by ICP-MS in umbilical serum. The oxidative stress statuses were analyzed by measuring SOD, GPx and MDA with colorimetric assays. Results Higher concentrations of Al were seen in the CHD groups compared to the controls. The risk of CHD occurrence increased markedly in the highly elevated Al group (aOR 2.08, 95%CI 1.11–3.88). With increasing Al and Pb levels, the activity of SOD decreased, and the level of MDA increased. Significantly decreased activity of SOD and GPx were found in the CHD groups (P < 0.05). Conclusion Fetal aluminum exposure may contribute to CHD occurrence. Oxidative stress was related to the concentration of Pb and Al, which may be involved in the occurrence of CHD. [ABSTRACT FROM AUTHOR]

Managing lead in the complex plumbing systems of school buildings can be a challenge, but proper guidance, careful planning, and collaboration increase the likelihood of achieving this worthy goal. [ABSTRACT FROM AUTHOR]

The effects caused by exposure to lead (Pb) are still considered as a relevant health risk despite public policies aimed to restricting the use of this element. The toxicity limit in the blood (10 μg/dL, established by the Center for Disease Control and Prevention) has been insufficient to prevent adverse effects and even lower values have been related to neurobehavioral dysfunctions in children. Currently, there is not a safe limit of exposure to Pb. A large body of evidence points to environmental pollutant exposure as the cause of predisposition to violent behavior, among others. Considering the evidence by our group and others, we propose that Pb exposure induces alterations in the brain vasculature, specifically in nitric oxide synthases (NOS), affecting in turn the serotonergic system and leading to heightened aggressive behavior in the exposed individuals. This review article describes the consequences of Pb exposure on the nitrergic and serotonergic systems as well as its relationship with aggressive behavior. In addition, it summarizes the available therapy to prevent damage in gestation and among infants. [ABSTRACT FROM AUTHOR]

Homeostatic synaptic plasticity (HSP) helps to stabilize the neuronal network activity, which is essential for optimal information coding. Synaptic scaling is a form of homeostatic plasticity that stabilizes neuronal firing in response to activity blockade. Lead (Pb) is a ubiquitous environmental neuro-toxicant and can impair the input-specific Hebbian type synaptic plasticity, but whether Pb exerts effects in HSP remains unknown. We previously reported that blocking L-type calcium channel induces synaptic scaling, which stimulates the synthesis of all-trans retinoic acid (RA) and the expression of GluA2-lacking α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor. Given Pb is a potent blocker of calcium channel, we hypothesized Pb may participate in synaptic scaling accompanied by RA synthesis and AMPA receptor trafficking. In this study, cultured hippocampal neurons were treated with Pb (1 μM 5 min, 15 min, 4 h, 24 h, and 10 μM 24 h) alone or in combination with tetrodotoxin (TTX, 1 μM, 24 h). The results showed that Pb alone, either at 1 μM or 10 μM, cannot induce synaptic scaling. But Pb participated in synaptic scaling when concurrent with TTX (10 μM Pb + 1 μM TTX, 24 h). Further results showed that surface heteromeric GluA1 and GluA2 AMPA receptors were increased in TTX+ Pb-induced synaptic scaling. In addition, RA was proved not to participate in TTX+ Pb-mediated synaptic scaling. Taken together, our work supported that TTX+ Pb could induce synaptic scaling and enhance synaptic accumulation of AMPAR GluA1 and GluA2 during synaptic up scaling. Our study would help for elucidation of the Pb-induced neuronal network instability mechanism. [ABSTRACT FROM AUTHOR]

Aims: Most plants produce a root tip extracellular matrix that includes viable border cell populations programmed to disperse into soil. Like neutrophils, border cells export structures that trap pathogens and prevent root tip infection. Border cells also trap metals. The goal of this study was to determine if border cells trap Pb.Methods: Border cell responses to Pb were observed microscopically. Border cell impact on Pb-induced injury to roots was assessed using root growth assays. Pb removal from solution was measured using inductively coupled plasma mass spectrometry (ICP-MS). Speciation of Pb associated with border cells was evaluated by synchrotron X-ray absorption spectroscopy (XAS).Results: Increased border cell trap size and number occurred within minutes in response to Pb but not silicon (Si). Transient immersion of root tips into Pb after border cells were removed resulted in growth inhibition. Immersion of root tips and border cells into Pb solution resulted in significant removal of Pb. Si levels in the presence of root tips remained unchanged. The Pb speciation, measured with Pb LIII XAS, altered when reacted with border cells, indicating that direct binding by extracellular traps occurred.Conclusions: Border cells can trap Pb and prevent damage to the root tip. [ABSTRACT FROM AUTHOR]

Abstract Background. The lead (Pb) exposure crisis in Flint, Michigan has passed from well-publicized event to a footnote, while its biological and social impact will linger for lifetimes. Interest in the "water crisis" has dropped to pre-event levels, which is neither appropriate nor safe. Flint's exposure was severe, but it was not unique. Problematic Pb levels have also been found in schools and daycares in 42 states in the USA. The enormity of Pb exposure via municipal water systems requires multiple responses. Herein, we focus on addressing a possible answer to long-term sequelae of Pb exposure. We propose "4R's" (remediation, renovation, reallocation, and research) against the Pb crisis that goes beyond a short-term fix. Remediation for affected individuals must continue to provide clean water and deal with both short and long-term effects of Pb exposure. Renovation of current water delivery systems, at both system-wide and individual site levels, is necessary. Reallocation of resources is needed to ensure these two responses occur and to get communities ready for potential sequelae of Pb exposure. Finally, properly focused research can track exposed individuals and illuminate latent (presumably epigenetic) results of Pb exposure and inform further resource reallocation. Conclusion. Motivation to act by not only the general public but also by scientific and medical leaders must be maintained beyond initial news cycle spikes and an annual follow-up story. Environmental impact of Pb contamination of drinking water goes beyond one exposure incident in an impoverished and forgotten Michigan city. Population effects must be addressed long-term and nationwide. [ABSTRACT FROM AUTHOR]

The identification of body fluids at a crime scene is an important aspect of forensic casework analysis, being a source for investigative leads and contributing to case evidence. Yet, current methods for the forensic identification of body fluids suffer from several limitations, ranging from poor sensitivity and specificity, to sample destruction and interference with subsequent DNA analysis. Moreover, current identification assays target only one body fluid at the time. Besides being inefficient in terms of time, money and sample consumption, poor identification methods can also negatively influence the outcome of a (court) case. In this study, eleven potential protein biomarkers and antibodies were selected and assessed on their suitability for serving as identification markers, as a first step towards the development of a new multiplex protein-based body fluid identification assay relying on antigen-antibody interactions. Performing antibody-based dot blot assays, the specificity of the biomarkers for their target body fluids was evaluated, and biomarker detection was studied in diluted, mixed, aged and simulated casework samples. Hereby, nine out of eleven markers were identified as promising biomarkers to identify blood, semen, saliva, urine and sweat. With the identification of these targets and detection antibodies, a major step forward has been taken towards the development of a highly sensitive and specific, fast and non-labour-intensive protein-based body fluid identification assay, suitable for on-site analysis and able to test for multiple body fluids in a single reaction. [ABSTRACT FROM AUTHOR]

Heavy metals are well known as environmental pollutants with hazardous impacts on human and animal health because of their wide industrial usage. In the present study, the role of Spirulina platensis in reversing the oxidative stress-mediated brain injury elicited by lead acetate exposure was evaluated. In order to accomplish this aim, rats were orally administered with 300 mg/kg bw Spirulina for 15 d, before and simultaneously with an intraperitoneal injection of 50 mg/kg bw lead acetate [6 injections through the two weeks]. As a result, the co-administration of Spirulina with lead acetate reversed the most impaired open field behavioral indices; however, this did not happen for swimming performance, inclined plane, and grip strength tests. In addition, it was observed that Spirulina diminished the lead content that accumulated in both the blood and the brain tissue of the exposed rats, and reduced the elevated levels of oxidative damage indices, and brain proinflammatory markers. Also, because of the Spirulina administration, the levels of the depleted biomarkers of antioxidant status and interleukin–10 in the lead-exposed rats were improved. Moreover, Spirulina protected the brain tissue (cerebrum and cerebellum) against the changes elicited by lead exposure, and also decreased the reactivity of HSP70 and Caspase–3 in both cerebrum and cerebellum tissues. Collectively, our findings demonstrate that Spirulina has a potential use as a food supplement in the regions highly polluted with heavy metals. [ABSTRACT FROM AUTHOR]

The present study was designed to evaluate soluble receptors as potential targets for lead (Pb). Analyses included the serum levels of soluble Vascular Endothelial Growth Factor Receptors 2 (sVEGFR-2), soluble Epidermal Growth Factor Receptor (sEGFR), soluble Human Epidermal Growth Factor 2 (sHER-2/neu), and soluble Interleukin 6 Receptors (sIL-6R) in the groups of chronically and subchronically occupationally exposed workers. The first group consisted of 56 male workers chronically exposed to Pb. The second group (control) comprised 24 male administrative workers. The third group included 36 male workers exposed to Pb for 40 + 3 days. Examined subjects were employed in the Pb-zinc works to perform periodic maintenance of blast furnaces and production lines. The serum levels of sHER-2/neu and sIL-6R were significantly lower in the group of workers chronically exposed to Pb compared to control values by 45% (p < 0.05) and 44% (p < 0.05), respectively. The values of sVEGFR-2 and sEGFR decreased after a subchronic exposure to Pb compared to baseline by 14% (p < 0.05) and 21% (p < 0.05), respectively. At the same time, the levels of sIL-6R also decreased by 14% (p < 0.05). Results of the present study indicated that both chronic and subchronic occupational Pb exposures resulted in decreased levels of several soluble receptors (sVEGFR-2, sEGFR, sHER-2/neu, and sIL-6R), probably due to Pb-induced modulations of the transcription factors and metalloprotease activities, that are necessary for soluble receptor synthesis. [ABSTRACT FROM AUTHOR]

Background Lead and mercury are freely transferred across the placenta, while cadmium tends to accumulate in the placenta. Each contributes to adverse neurological outcomes for the child. Although prenatal heavy metal exposure has been linked with an array of neurodevelopmental outcomes in childhood, its association with the development of motor skills in children has not been robustly studied. Aims/objective The aim of the present study was to investigate the association between prenatal exposure to lead, cadmium and mercury, measured as maternal blood concentrations during pregnancy, and motor skills, measured as subtests of the Movement Assessment Battery for Children (Movement ABC) at age 7 years in a large sample of mother–child pairs enrolled in a UK observational birth cohort study (Avon Longitudinal Study of Parents and Children, ALSPAC). Methods Whole blood samples from pregnant women enrolled in ALSPAC were analysed for lead, cadmium and mercury. In a complete case analysis (n = 1558), associations between prenatal blood concentrations and child motor skills assessed by Movement ABC subtests of manual dexterity, ball skills and balance at 7 years were examined in adjusted regression models. Associations with probable developmental coordination disorder (DCD) were also investigated. Results The mean prenatal blood levels were: lead 3.66 ± 1.55 μg/dl; cadmium 0.45 ± 0.54 μg/l; mercury 2.23 ± 1.14 μg/l. There was no evidence for any adverse associations of prenatal lead, cadmium or mercury exposure with motor skills measured at age 7 years with Movement ABC subtests in adjusted regression models. Further, there were no associations with probable DCD. Conclusions There was no evidence to support a role of prenatal exposure to heavy metals at these levels on motor skills in the child at age 7 years measured using the Movement ABC. Early identification of symptoms of motor skills impairment is important, however, to enable investigation, assessment and treatment. [ABSTRACT FROM AUTHOR]

Lead (Pb) is one of the most prevalent toxic, nonessential heavy metals that can contaminate food and water. In this study, effects of chronic exposure to low concentrations of Pb on metabolism and gut microbiota were evaluated in mice. It was observed that exposure of mice to 0.1 mg/L Pb, supplied via drinking water, for 15 weeks increased hepatic TG and TCH levels. The levels of some key genes related to lipid metabolism in the liver increased significantly in Pb-treated mice. For the gut microbiota, at the phylum level, the relative abundance of Firmicutes and Bacteroidetes changed obviously in the feces and the cecal contents of mice exposed to 0.1 mg/L Pb for 15 weeks. In addition, 16 s rRNA gene sequencing further discovered that Pb exposure affected the structure and richness of the gut microbiota. Moreover, a 1 H NMR metabolic analysis unambiguously identified 31 metabolites, and 15 metabolites were noticeably altered in 0.1 mg/L Pb-treated mice. Taken together, the data indicate that chronic Pb exposure induces dysbiosis of the gut microbiota and metabolic disorder in mice. Capsule Chronic Pb exposure induces metabolic disorder, dysbiosis of the gut microbiota and hepatic lipid metabolism disorder in mice. [ABSTRACT FROM AUTHOR]

Summary: Lead (Pb) is a nonthreshold multi‐targeted toxicant that causes alterations in different organs of the body, especially the gonads. This study was aimed to investigate the possible protective effect of thymoquinone (TQ), the major active ingredient of volatile oil of Nigella sativa seeds, against Pb‐induced testicular histological damage. Adult male rats were randomised into four groups as follows: control group received no treatment, Pb group was exposed to 2000 ppm of Pb acetate in drinking water, Pb‐TQ group was cotreated with Pb plus TQ (5 mg/kg/day, per os) and TQ group receiving only TQ. All treatments were applied for five weeks. Results showed that Pb exposure produced morphological changes in the testis, especially degeneration of germinal epithelium, sloughing of germ cells into the lumen of seminiferous tubules and reduction in the number of luminal spermatozoa. Interestingly, coadministration of TQ to the metal‐treated animals prevented the testicular adverse effects. In conclusion, our data indicate for the first time a remarkable protective effect of TQ against Pb‐induced testicular histopathological lesions in rat. On this basis, TQ deserves more consideration and further examination as a potential therapeutic option. [ABSTRACT FROM AUTHOR]

Acquired hearing loss is caused by complex interactions of multiple environmental risk factors, such as elevated levels of lead and noise, which are prevalent in urban communities. This study delineates the mechanism underlying lead-induced auditory dysfunction and its potential interaction with noise exposure. Young-adult C57BL/6 mice were exposed to: 1) control conditions; 2) 2 mM lead acetate in drinking water for 28 days; 3) 90 dB broadband noise 2 h/day for two weeks; and 4) both lead and noise. Blood lead levels were measured by inductively coupled plasma mass spectrometry analysis (ICP-MS) lead-induced cochlear oxidative stress signaling was assessed using targeted gene arrays, and the hearing thresholds were assessed by recording auditory brainstem responses. Chronic lead exposure downregulated cochlear Sod1, Gpx1, and Gstk1, which encode critical antioxidant enzymes, and upregulated ApoE, Hspa1a, Ercc2, Prnp, Ccl5, and Sqstm1, which are indicative of cellular apoptosis. Isolated exposure to lead or noise induced 8–12 dB and 11–25 dB shifts in hearing thresholds, respectively. Combined exposure induced 18–30 dB shifts, which was significantly higher than that observed with isolated exposures. This study suggests that chronic exposure to lead induces cochlear oxidative stress and potentiates noise-induced hearing impairment, possibly through parallel pathways. [ABSTRACT FROM AUTHOR]

Studies about the association between lead exposure and the elevation of blood pressure and risk of hypertension are varied, while available data on blood lead levels (BLL) in workers with lead-exposure are scarce. This research aimed to evaluate associations between BLL and blood pressure in an occupational population-based study in Jiangsu province, China. We enrolled 21,688 workers in this study. Information on socioeconomic and occupational background was obtained with face-to-face interviews. BLL, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured, and hypertension status was confirmed. We found that workers in mini-factories had the highest average BLL (20.3 μg/dL; 95% CI, 19.0–21.6 μg/dL) for overall participants. The employees in private factories had higher BLL (9.6 μg/dL; 95% CI, 9.5–9.8 μg/dL). However, BLL was much lower (4.0 μg/dL; 95%CI, 3.7–4.2 μg/dL) in state-owned factories. Participants working in the electrical machinery and equipment manufacturing industry had higher BLL (9.1 μg/dL; 95% CI, 9.0–9.3μg/dL). Compared to those workers with ≤ 4.6 μg/dL BLL, workers with > 17.5 μg/dL BLL presented 1.34 mmHg and 0.70 mmHg average difference in SBP and DBP, respectively. The adjusted OR for hypertension was 1.11 (95%CI, 1.08–1.15) compared to the workers with > 17.5 μg/dL BLL and to those with ≤ 4.6 μg/dL BLL. In summary, we found that BLL was positively associated with SBP and DBP and with the morbidity of hypertension in occupational populations with a high concentration of lead exposure. It is important to formulate new standards of blood lead levels to screen for elevated lead exposure. In addition, a series of new systems of risk assessment should be established to further reduce and prevent lead exposure. [ABSTRACT FROM AUTHOR]

Most studies examining bald eagle (Haliaeetus leucocephalus) exposure to lead (Pb) have focused on adults that ingested spent Pb ammunition during the fall hunting season, often at clinical or lethal levels. We sampled live bald eagle nestlings along waterbodies to quantify Pb concentrations in 3 national park units and 2 nearby study areas in the western Great Lakes region. We collected 367 bald eagle nestling feather samples over 8 years during spring 2006-2015 and 188 whole blood samples over 4 years during spring 2010-2015. We used Tobit regression models to quantify relationships between Pb concentrations in nestling feathers and blood using study area, year, and nestling attributes as covariates. Pb in nestling feather samples decreased from 2006 to 2015, but there was no trend for Pb in blood samples. Pb concentrations in nestling feather and blood samples were significantly higher in study areas located closer to and within urban areas. Pb in feather and blood samples from the same nestling was positively correlated. Pb in feathers increased with nestling age, but this relationship was not observed for blood. Our results reflect how Pb accumulates in tissues as nestlings grow, with Pb in feathers and blood indexing exposure during feather development and before sampling, respectively. Some nestlings had Pb concentrations in blood that suggested a greater risk to sublethal effects from Pb exposure. Our data provides baselines for Pb concentrations in feathers and blood of nestling bald eagles from a variety of waterbody types spanning remote, lightly populated, and human-dominated landscapes. [ABSTRACT FROM AUTHOR]

For biochemical assay of every enzyme including redox regulatory enzymes, any interfering small molecules (ISM) that may cross react with substrates or indirectly influence the reaction, must be removed. Such ISM(s) if present, need to be either neutralized or filtered out both from the sample or from the reaction mixture. This is a standard protocol adapted worldwide and fundamental rule in biochemistry. Without such approach, results obtained from a study that includes enzymatic assays seem to be inaccurate. Such inaccuracy raises question on the use of such data in future, especially as ecotoxic biomarkers. Tissue specific seasonal variation in natural titre of such ISM(s) in organisms leads to give rise counterfeit results. Such a case is highlighted in this correspondence article in relation to assay of redox regulatory enzymes including superoxide dismutase, catalase, especially the enzymes of glutathione system in presence of glutathione (GSH) in sample. This fact is discussed considering a recent publication doi.org/10.1016/j.ecoenv.2017.03.056 in which the authors have measured glutathione enzymes in tissues without removing GSH, that acts as ISM, from the sample. It is inferred that logical and sound scientific practices need to be followed for measuring biochemical activity of all enzymes in general and enzymes of glutathione system in particular. The main objective of this article was to make an alert in scientific society to avoid such mistakes in future. [ABSTRACT FROM AUTHOR]