Half of US population exposed to adverse lead levels in early childhood.

SignificanceConsiderable effort is expended to protect today's children from lead exposure, but there is little evidence on the harms past lead exposures continue to hold for yesterday's children, who are victims of what we term legacy lead exposures. We estimate that over 170 million Americans alive today were exposed to high-lead levels in early childhood, several million of whom were exposed to five-plus times the current reference level. Our estimates allow future work to plan for the health needs of these Americans and to inform estimation of the true contributions of lead exposure to population health. We estimate population-level effects on IQ loss and find that lead is responsible for the loss of 824,097,690 IQ points as of 2015.

The impact of childhood lead exposure on adult personality: Evidence from the United States, Europe, and a large-scale natural experiment.

Childhood lead exposure has devastating lifelong consequences, as even low-level exposure stunts intelligence and leads to delinquent behavior. However, these consequences may be more extensive than previously thought because childhood lead exposure may adversely affect normal-range personality traits. Personality influences nearly every aspect of human functioning, from well-being to career earnings to longevity, so effects of lead exposure on personality would have far-reaching societal consequences. In a preregistered investigation, we tested this hypothesis by linking historic atmospheric lead data from 269 US counties and 37 European nations to personality questionnaire data from over 1.5 million people who grew up in these areas. Adjusting for age and socioeconomic status, US adults who grew up in counties with higher atmospheric lead levels had less adaptive personality profiles: they were less agreeable and conscientious and, among younger participants, more neurotic. Next, we utilized a natural experiment, the removal of leaded gasoline because of the 1970 Clean Air Act, to test whether lead exposure caused these personality differences. Participants born after atmospheric lead levels began to decline in their county had more mature, psychologically healthy adult personalities (higher agreeableness and conscientiousness and lower neuroticism), but these findings were not discriminable from pure cohort effects. Finally, we replicated associations in Europeans. European participants who spent their childhood in areas with more atmospheric lead were less agreeable and more neurotic in adulthood. Our findings suggest that further reduction of lead exposure is a critical public health issue.

Metal Exposure and Risk of Parkinson Disease: A Systematic Review and Meta-Analysis.

Metal exposure has been suggested as a possible environmental risk factor for Parkinson disease (PD). We searched the PubMed, EMBASE, and Cochrane databases to systematically review the literature on the relationship between metal exposure and PD risk and to examine the overall quality of each study and the exposure assessment method. A total of 83 case-control studies and 5 cohort studies published during the period 1963-July 2021 were included, of which 73 were graded as being of low or moderate overall quality. Investigators in 69 studies adopted self-reported exposure and biomonitoring after disease diagnosis for exposure assessment approaches. The meta-analyses showed that concentrations of copper and iron in serum and concentrations of zinc in either serum or plasma were lower, while concentrations of magnesium in CSF and zinc in hair were higher, among PD cases as compared with controls. Cumulative lead levels in bone were found to be associated with increased risk of PD. We did not find associations between other metals and PD. The current level of evidence for associations between metals and PD risk is limited, as biases from methodological limitations cannot be ruled out. High-quality studies assessing metal levels before disease onset are needed to improve our understanding of the role of metals in the etiology of PD.

Environmental exposure to lead, mercury, and cadmium is not associated with abnormal kidney function in Korean adolescents.

BACKGROUND: We aimed to elucidate the relationship between environmental exposure to lead (Pb), mercury (Hg), and cadmium (Cd) which were measured in blood and the kidney function of adolescents. METHODS: Cross-sectional study was conducted using data from the Korea National Health and Nutrition Examination Survey from 2010 to 2017. Statistical procedures were performed to analyze the Korean population of adolescents aged 12-17 years. Regression analysis was performed, and covariates included age, sex, body mass index, smoking status, and other heavy metal levels. RESULTS: The median blood levels of Pb, Hg, and Cd were 1.165 µg/dL, 1.805 µg/L, and 0.304 µg/L, respectively. Adolescents with Pb levels in the highest quartile (> 1.454 µg/dL) had a 3.35 mL/min/1.73 m2-lower estimated glomerular filtration rate using creatinine (eGFRcr) (95% confidence interval (CI), -6.03 to -0.68 mL/min/1.73 m2) compared to those in the lowest quartile (< 0.856 µg/dL) in the unadjusted model. However, there was no association between the blood Pb level and eGFRcr in the adjusted model. Levels of Hg and Cd were not associated with eGFRcr in either model. High blood levels of all three heavy metals were not associated with the risk of hypertension. CONCLUSIONS: There was no association between increased blood levels of Pb, Hg, and Cd; eGFRcr; and increased risk of hypertension in Korean adolescents who were exposed to relatively low levels of heavy metals.

Factors associated with blood lead levels in children in Shenyang, China: a cross-sectional study.

BACKGROUND: Although blood lead levels (BLLs) in children are gradually decreasing, low-concentration lead exposure can still exert adverse effects. We studied the factors that affect BLLs in children in Shenyang, China. METHODS: We conducted a cross-sectional study by administering structured questionnaires on family demographics and food intake. The concentrations of lead in venous blood were determined by graphite furnace atomic absorption spectrometry. RESULTS: A total of 273 children aged 1-6 years were enrolled. The geometric mean (geometric standard deviation) of BLLs was 24.94 (12.70) µg/L in boys and 23.75 (11.34) µg/L in girls. The prevalence of BLLs of ≥35 µg/L was 22.7% and was mainly observed in children aged under 3 years. Often hand washing before meals was protective against BLLs ≥20 µg/L (adjusted OR: 0.427, 95%CI: 0.238-0.767, p = 0.004). Consumption of puffed grains and eggs had an adjusted OR (95%CI) for BLLs ≥20 µg/L of 1.714 (1.012-2.901) (p = 0.045) and 1.787 (1.000-3.192) (p = 0.050), respectively. CONCLUSIONS: BLLs of children in Shenyang are still higher than in developed countries. Consumption of puffed grains and eggs is associated with higher BLLs. Often hand washing before meals may be protective against high BLLs.

Multibiomarker approach to assess the magnitude of occupational exposure and effects induced by a mixture of metals.

Metals and metalloids including lead (Pb), arsenic (As) and manganese (Mn) can occur as mixtures in occupational contexts, such as mines. These chemicals are all known to be neurotoxic and provoke changes in heme metabolism also known to induce neurotoxicity. The objective of this work was to propose a multi-biomarker (BM) methodology to screen subjects exposed to the mixture of Pb, As and Mn and assess the severity of their exposure/effects, in an individual basis. The urinary levels of the metals, dela-aminolevulinic acid (ALA) and porphyrins were determined in Portuguese miners and in a control group. The combination of Pb and As urinary levels had the highest capability to identify subjects occupationally exposed to this mixture in mines, as evaluated through Receiver Operating Characteristic (ROC) (A = 98.2%; p < 0.05), allowing that 94.2% of 86 studied subjects were properly identified and the generation of an equation indicating the odd of a subject be considered as exposed to the metal mixture. The combination of urinary ALA and porphyrins revealed to be best one to be applied in the assessment of subjects with high, intermediate, and low magnitudes of exposure/effects, with 95.7% of 46 miners classified correctly according to their severity sub-group and allowing to generate equations, which can be applied in new subjects. The proposed methodology showed a satisfactory performance, evaluating in an integrated manner the magnitude of exposure/effects of the exposed workers, may contributing to improve the control of their health.

Low-level Eexposure to lead dust in unusual work schedules and hematologic, renal, and hepatic parameters.

BACKGROUND: Many workers are exposed to lead dust in lead-­zinc mines. Exposure to this heavy toxic metal and its compounds can cause irreversible adverse health effects. OBJECTIVE: To assess possible hematotoxic, nephrotoxic, and hepatotoxic potentials of low levels of lead in a group of mine workers exposed to this heavy metal in an unusual work schedule. METHODS: A total of 73 exposed and 70 non-exposed employees were interviewed. Demographic data, and occupational and medical history of the employees were obtained by questionnaires. Air monitoring was performed to determine the workers' time-weighted average (TWA) exposure to lead dust. The threshold limit value (TLV) for lead was adjusted for unusual work schedules according to the model developed by the University of Montreal and the Institute de Recherche en Sante et en Securite du Travail (IRSST). Blood samples were collected for complete blood count, liver and kidney function tests. Data were analyzed using version 21.0 of the SPSS software. RESULTS: The TWA exposure of workers was 24 µg/m3. On average, the worker's exposure to lead dust did not exceed the 8-h OSHA and ACGIH TLV-TWA of 50 µg/m3. Significant associations were found only between exposure to lead and platelet count, red cell distribution width, total protein, and albumin. CONCLUSIONS: Exposure to low levels of lead dust in unusual work schedules was not associated with overt hematotoxicity, hepatotoxicity or nephrotoxicity. However, mild, sub-clinical, pre-pathologic significant changes were noted in some blood parameters of the exposed employees as compared with their referent counterparts.

Exposure to lead on expression levels of brain immunoglobulins, inflammatory cytokines, and brain-derived neurotropic factor in fetal and postnatal mice with autism-like characteristics.

Autism spectrum disorders (ASD) are neurodevelopmental disorders, and their incidence is increasing worldwide. Increased exposure to environmental metal lead (Pb) has been proposed as a risk factor associated with ASD. In the present study, BTBR T+ tf/J (BTBR) mice with ASD-like behavioral characteristics and control FVB mice were exposed gestationally and/or neonatally to Pb, and compared with highly social FVB mice to investigate neuroimmunological abnormalities. IgG1 and IgG2a levels in fetal brains from BTBR dams exposed to Pb (BTBR-Pb) were significantly higher than those of BTBR-controls (BTBR-C). However, this change did not occur in FVB mice exposed to Pb. The IgG1:IgG2a ratio was higher in both fetal and postnatal brains of BTBR mice compared to FVB animals regardless of Pb exposure. The IL-4:IFN-γ ratio was elevated in BTBR-Pb relative to BTBR-C mice, but this ratio was not markedly affected following Pb exposure in FVB animals. These findings suggest the potential for a Pb-driven predominant TH2-like reactivity profile in brain microenvironment present in BTBR mice. Brain-derived neurotrophic factor was decreased in fetal and postnatal BTBR-Pb brains relative to BTBR-C brains but not in FVB-Pb relative to FVB-C mice. Taken together, data demonstrate that Pb exposure might contribute to developmental brain abnormalities associated with ASD, particularly in individuals with genetic susceptibility to ASD.

Global DNA (LINE-1) methylation is associated with lead exposure and certain job tasks performed by electronic waste workers.

OBJECTIVE: This study assessed the associations between blood and urine levels of toxic metals; cadmium (Cd) and lead (Pb), and methylation levels of the LINE-1 gene among e-waste and control populations in Ghana. METHODS: The study enrolled 100 male e-waste workers and 51 all-male non-e-waste workers or controls. The concentrations of Cd and Pb were measured in blood and urine using inductively coupled plasma mass spectrometry, while LINE1 methylation levels were assessed by pyrosequencing of bisulfite-converted DNA extracted from whole blood. Single and multiple metals linear regression models were used to determine the associations between metals and LINE1 DNA methylation. RESULTS: Blood lead (BPb) and urine lead (UPb) showed higher median concentrations among the e-waste workers than the controls (76.82 µg/L vs 40.25 µg/L, p ≤ 0.001; and 6.89 µg/L vs 3.43 µg/L, p ≤ 0.001, respectively), whereas blood cadmium (BCd) concentration was lower in the e-waste workers compared to the controls (0.59 µg/L vs 0.81 µg/L, respectively, p = 0.003). There was no significant difference in LINE1 methylation between the e-waste and controls (85.16 ± 1.32% vs 85.17 ± 1.11%, p = 0.950). In our single metal linear regression models, BPb was significantly inversely associated with LINE1 methylation in the control group (ßBPb = - 0.027, 95% CI - 0.045, - 0.010, p = 0.003). In addition, a weak association between BPb and LINE1 was observed in the multiple metals analysis in the e-waste worker group (ßBPb = - 0.005, 95% CI - 0.011, 0.000, p = 0.058). CONCLUSION: Continuous Pb exposure may interfere with LINE1 methylation, leading to epigenetic alterations, thus serving as an early epigenetic marker for future adverse health outcomes.

Exceptionally high levels of lead pollution in the Balkans from the Early Bronze Age to the Industrial Revolution.

The Balkans are considered the birthplace of mineral resource exploitation and metalworking in Europe. However, since knowledge of the timing and extent of metallurgy in southeastern Europe is largely constrained by discontinuous archaeological findings, the long-term environmental impact of past mineral resource exploitation is not fully understood. Here, we present a high-resolution and continuous geochemical record from a peat bog in western Serbia, providing a clear indication of the extent and magnitude of environmental pollution in this region, and a context in which to place archaeological findings. We observe initial evidence of anthropogenic lead (Pb) pollution during the earliest part of the Bronze Age [∼3,600 years before Common Era (BCE)], the earliest such evidence documented in European environmental records. A steady, almost linear increase in Pb concentration after 600 BCE, until ∼1,600 CE is observed, documenting the development in both sophistication and extent of southeastern European metallurgical activity throughout Antiquity and the medieval period. This provides an alternative view on the history of mineral exploitation in Europe, with metal-related pollution not ceasing at the fall of the western Roman Empire, as was the case in western Europe. Further comparison with other Pb pollution records indicates the amount of Pb deposited in the Balkans during the medieval period was, if not greater, at least similar to records located close to western European mining regions, suggestive of the key role the Balkans have played in mineral resource exploitation in Europe over the last 5,600 years.

Population-based study of environmental lead exposure and hearing loss: a systematic review and meta-analysis.

OBJECTIVES: Multiple studies suggest that there is an association between environmental lead exposure and hearing loss. However, the results of studies exploring the relationship between lead exposure and the occurrence of hearing loss are inconsistent. To clarify this issue, we conducted a meta-analysis to determine the association between lead exposure and hearing loss. STUDY DESIGN: This study was a meta-analysis. METHODS: A comprehensive literature search was performed using PubMed, Web of Knowledge, Elsevier ScienceDirect, and Springer databases. Eight articles involving 10 studies were included, and a random effect model was used for the meta-analysis. The Agency for Healthcare Research and Quality was used for judging the quality of the articles. RESULTS: Environmental lead exposure was significantly and substantially associated with hearing loss (combined odds ratio [OR] 1.42; 95% confidence interval [CI] 1.22-1.67) with mild heterogeneity (I2 = 47.0%, P = 0.049). Subgroup and sensitivity analyses confirmed the results; however, publication bias was evident. After the 'fill and trim' method, the recalculated OR was 1.36 (95% CI 1.12-1.64). CONCLUSIONS: The results of this study suggest an association between lead exposure and hearing loss. Exposure to a high concentration of lead was positively proportional to the risk of hearing loss. To eliminate the effects of other confounding factors, larger prospective cohort studies are required to further elucidate the relationship between lead exposure and hearing loss.

Prolonged blood coagulation time among occupationally exposed automobile technicians in Abeokuta, Nigeria.

Automobile technicians in resource-poor settings often work in poor environments and are exposed to chemicals that put them at risk of ill health and disease. These chemical exposures could affect blood coagulation, leading to bleeding disorders or thrombosis. The present study is aimed at assessing prothrombin test (PT) and activated partial thromboplastin test (aPTT) values, serum zinc (Zn) and copper (Cu) concentrations, and blood lead level (BLL) among occupationally exposed automobile technicians compared to unexposed controls. A total of 140 consenting participants comprising 70 automobile technicians and 70 unexposed controls were recruited for this case-control study. A 6-mL blood sample was drawn from each participant for estimation of BLL, serum Zn and Cu concentrations, and PT and aPTT values. Blood lead level, and serum Zn and Cu concentrations were determined using atomic absorption spectrophotometry, while PT and aPTT values were determined using Innovin PT and Actin FS Activated PTT reagents on the Sysmex CA-101 coagulation analyser. Data were analysed using t-tests, chi-square tests, and logistic and multiple linear regression analyses with statistical significance set at p < 0.05. The mean BLL, serum Zn concentration, and PT and aPTT values were significantly higher in automobile technicians compared to controls. Binary logistic regression showed that automobile technicians had higher odds of elevated PT value (OR = 21.769; p = 0.000), aPTT value (OR = 1.348; p = 0.018), BLL (OR = 1.261; p = 0.000) and serum Zn concentration (OR = 1.063; p = 0.005) than unexposed controls. Linear regression showed significant positive association of PT value with BLL and with serum Zn concentration. Higher PT and aPTT values reflect prolonged blood coagulation time among automobile technicians, which indicates impairment of extrinsic and intrinsic coagulation pathways associated with work-related exposures.

Melatonin Protects Tobacco Suspension Cells against Pb-Induced Mitochondrial Dysfunction.

Recent studies have shown that melatonin is an important molecule in plant physiology. It seems that the most important is that melatonin effectively eliminates oxidative stress (direct and indirect antioxidant) and switches on different defence strategies (preventive and interventive actions) during environmental stresses. In the presented report, exogenous melatonin potential to protect Nicotiana tabacum L. line Bright Yellow 2 (BY-2) exposed to lead against death was examined. Analyses of cell proliferation and viability, the level of intracellular calcium, changes in mitochondrial membrane potential (ΔΨm) as well as possible translocation of cytochrome c from mitochondria to cytosol and subsequent caspase-like proteolytic activity were conducted. Our results indicate that pretreatment BY-2 with melatonin protected tobacco cells against mitochondrial dysfunction and caspase-like activation caused by lead. The findings suggest the possible role of this indoleamine in the molecular mechanism of mitochondria, safeguarding against potential collapse and cytochrome c release. Thus, it seems that applied melatonin acted as an effective factor, promoting survival and increasing plant tolerance to lead.

Evidences for antioxidant response and biosorption potential of Bacillus simplex strain 115 against lead.

In this study, we investigated effects of lead on growth response and antioxidant defense protection in a new identified strain isolated from a soil, in the rhizosphere of Sainfoin Hedysarum coronarium L. Different concentrations of lead (0, 0.2, 1.5 and 3 g L-1) added to Bacillus simplex strain 115 cultures surprisingly did not inhibit its growth. However, a resulting oxidative stress as attested by overproduction of H2O2 (+ 6.2 fold) and malondialdehyde (+ 2.3 fold) concomitantly to the enhancement of proteins carbonylation (+ 221%) and lipoxygenase activity (+ 59%) was observed in presence of 3 g L-1 of lead. Intrinsic antioxidant defenses were revealed by the coupled up-regulation of catalase (+ 416%) and superoxide dismutase (+ 4 fold) activities, with a more important Fe-SOD increase in comparison to the other isoforms. Bioaccumulation assays showed both intracellular and extracellular lead accumulation. Biosorption was confirmed as a particularly lead resistance mechanism for Bacillus simplex strain 115 as the metal sequestration in cell wall accounted for 88.5% to 98.5% of the total endogenous metal accumulation. Potentiality of this new isolated microorganism as a biotechnological tool for agricultural soil lead bioremediation was thus proposed.

Erythrocyte levels of cadmium and lead and risk of B-cell non-Hodgkin lymphoma and multiple myeloma.

Cadmium and lead are persistent environmental toxins that are known or probable carcinogens, based on evidence for causality for nonhematologic cancers. Associations of these metals with risk of non-Hodgkin lymphoma (NHL) and multiple myeloma (MM) are unknown but biologically plausible. To examine the associations of circulating levels of lead and cadmium exposure with risk of B-cell NHL (B-NHL) and multiple myeloma, we conducted a nested case-control study among 299 incident B-cell NHLs and 76 MM cases within the Cancer Prevention Study-II Nutrition Cohort (CPS-II NC). Each case was incidence-density matched to two eligible controls on age, race, sex and blood draw date. Conditional logistic regression was used to estimate relative risks (RR) and 95% confidence intervals (CI) for lymphoid malignancies overall and stratified by subtype. We observed a significant positive association between high erythrocyte lead concentration and risk of lymphoid malignancies overall (RR = 1.16, 95% CI: 1.02-1.33 per 17.6 µg/L (1 standard deviation [SD])) and follicular lymphoma in particular (RR = 1.80, 95% CI: 1.15-2.80 per SD). In contrast, there was no association between erythrocyte cadmium and risk of B-NHL (RR = 0.89, 95% CI: 0.75-1.06 per 0.37 µg/L [1 SD]), or any B-NHL subtypes; but a strong inverse association with MM risk (RR = 0.59, 95% CI: 0.38-0.89, per SD). Results from our study suggest a positive association between erythrocyte lead level and risk of lymphoid malignancies and a possible inverse association between cadmium and myeloma. Additional research is needed to confirm and further explore these findings.

Transcriptome profiling of Fagopyrum tataricum leaves in response to lead stress.

BACKGROUND: Lead (Pb) pollution is a widespread environmental problem that is harmful to living organisms. Tartary buckwheat (Fagopyrum tataricum), a member of the family Polygonaceae, exhibits short growth cycles and abundant biomass production, could be an ideal plant for phytoremediation due to its high Pb tolerance. Here, we aimed to explore the molecular basis underlying the responses of this plant to Pb stress. RESULTS: In our study, ultrastructural localization assays revealed that Pb ions primarily accumulate in leaf vacuoles. RNA deep sequencing (RNA-Seq) of tartary buckwheat leaves was performed on two Pb-treated samples, named Pb1 (2000 mg/kg Pb (NO3)2) and Pb2 (10,000 mg/kg Pb (NO3)2), and a control (CK). A total of 88,977 assembled unigenes with 125,203,555 bases were obtained. In total, 2400 up-regulated and 3413 down-regulated differentially expressed genes (DEGs) were identified between CK and Pb1, and 2948 up-regulated DEGs and 3834 down-regulated DEGs were generated between CK and Pb2, respectively. Gene Ontology (GO) and pathway enrichment analyses showed that these DEGs were primarily associated with 'cell wall', 'binding', 'transport', and 'lipid and energy' metabolism. The results of quantitative real-time PCR (qRT-PCR) analyses of 15 randomly selected candidate DEGs and 6 regulated genes were consistent with the results of the transcriptome analysis. Heterologous expression assays in the yeast strain Δycf1 indicated that overexpressing CCCH-type zinc finger protein 14 (ZFP14) enhanced sensitivity to Pb2+, while 5 other genes, namely, metal transporter protein C2 (MTPC2), phytochelatin synthetase-like family protein (PCSL), vacuolar cation/proton exchanger 1a (VCE1a), natural resistance-associated macrophage protein 3 (Nramp3), and phytochelatin synthetase (PCS), enhanced the Pb tolerance of the mutant strain. CONCLUSION: Combining our findings with those of previous studies, we generated a schematic model that shows the metabolic processes of tartary buckwheat under Pb stress. This study provides important data for further genomic analyses of the biological and molecular mechanisms of Pb tolerance and accumulation in tartary buckwheat.

Metal-containing Particulate Matter and Associated Reduced Olfactory Identification Ability in Children from an Area of High Atmospheric Exposure in Mexico City.

Air pollution has been linked to poor olfactory function in human adults. Among pollutants, particulate matter (PM) is especially relevant, as it may contain toxic metal ions that can reach the brain via olfactory pathways. Our purpose was to investigate the relation between atmospheric PM and olfactory identification performance in children. Using a validated method, we tested the olfactory identification performance of 120 children, 6-12 years old, from two locations in Mexico City: a focal group (n = 60) from a region with high PM levels and a control group of equal size and similar socioeconomic level from a region with markedly lower PM concentrations. Groups were matched for age and sex. Concentrations of manganese and lead in the hair of participants were determined as biomarkers of exposure. Daily outdoor PM levels were obtained from official records, and indoor PM levels were measured in the children's classrooms. Official records confirmed higher levels of outdoor PM in the focal region during the days of testing. We also found higher classroom PM concentrations at the focal site. Children from the focal site had on average significantly lower olfactory identification scores than controls, and hair analysis showed significantly higher levels of manganese for the focal children but no difference in lead. Children appear to be vulnerable to the effects of air pollution on olfactory identification performance, and metal-containing particles likely play a role in this. Olfactory tests provide a sensitive, noninvasive means to assess central nervous function in populations facing poor air quality.

Perspectives from the Society for Pediatric Research: contaminants of water and children's health: Can we do better?

Children are uniquely susceptible to the health consequences of water contamination. In this review, we summarize the existing, robust literature supporting the importance of examining specific water contaminants (i.e., lead, pesticides, nitrates, arsenic, perchlorate) and the routes of contamination in the United States and globally. We also discuss the health effects of exposure to contaminated water and significant disparities related to access to clean water. Lastly, we offer strategies for prevention and intervention-including those focused on the individual patient level-and review the current US policy framework pertaining to regulation of these toxicants. IMPACT: A key message in this article is that exposure to water contaminants have serious and long-lasting consequences on children's health. This review summarizes current existing literature and adds policy recommendations supporting clean water for children. Information from this review has two potential impacts: Guide health professionals in screening and/or treating children's health problems resulting from water contaminant exposure. Guide policy makers in using evidence-based approaches to improve water quality and clean water access.

Mercury, lead, and cadmium exposure via red blood cell transfusions in preterm infants.

BACKGROUND: Mercury, lead, and cadmium are developmental neurotoxicants. We predict that preterm newborns requiring packed red blood cell (PRBC) transfusions may be exposed to neurotoxic doses. We explored the relationship between donor concentration, number of donors, number of transfusions and mercury, lead and cadmium exposure. METHODS: Single-donor PRBCs were analyzed for mercury, lead and cadmium concentration. Dose per transfusion was calculated and compared to intravenous reference doses (IVRfDs). Linear regression analyses were performed to correlate donor and infant exposure. RESULTS: Thirty-six infants received 268 transfusions from 94 donors. Number of donors and transfusions were significantly correlated with birthweight and gestational age. All three metals were detected in ≥95% of donor PRBCs. Number of donors was significantly associated with cumulative dose, and there was a significant correlation between mercury and lead doses/transfusion. IVRfDs were exceeded for mercury and lead in 8.6% and 38% of transfusions, respectively. None exceeded the IVRfD for cadmium. For lead, infants exposed to three donors had more transfusions exceeding IVRfD than those exposed to 1-2 donors. CONCLUSIONS: Preterm infants are exposed to heavy metals via transfusions. Doses exceeded the IVRfDs for mercury and lead. Cadmium did not pose a risk. Prescreening donor blood could reduce exposure risk.

Pb exposure triggers MAPK-dependent inflammation by activating oxidative stress and miRNA-155 expression in carp head kidney.

Lead (Pb) is a toxic heavy metal and an aquatic pollutant. Various amounts of heavy metals are released into the environment through industrial discharge, causing excessive contamination of aquatic ecosystems. The head kidney is a unique immune organ of the bony fish and plays an important role in the metabolism of heavy metals. Studies of toxic Pb exposure that have investigated the head kidney of carp are limited. This study was carried out to explore the potential immunotoxicity effects of Pb and the specific related mechanisms in the carp head kidney. Pb poisoning was shown to induce the production of reactive oxygen species (ROS) and increase the expression levels of phosphorylated proteins related to the MAPK pathway, including p38, extracellular signal-regulated protein kinase (ERK), and c-Jun N-terminal kinase (JNK). We also found that microRNA-155 played a key role in regulating the production of inflammatory factors TNF-α, IL-1ß, and IL-6, and the pre-miRNA-155 inhibitor reversed the Pb-induced inflammation. In conclusion, these in vitro and in vivo findings suggest that oxidative stress and the MAPKs are involved in the Pb-induced inflammasome response, and the production of microRNA-155 aggravated the occurrence of inflammation in carp head kidney.