Increase In Blood Lead Concentration Research Articles

Association between toxic metals, vitamin D and preterm birth in the Maternal-Infant research on environmental chemicals study.

Toxic metals, like lead, are risk factors for preterm birth (PTB), but few studies have examined low levels found in most Canadians. Vitamin D, which may have antioxidant activity, protects against PTB. In this study, we investigated the impact of toxic metals (lead, mercury, cadmium and arsenic) on PTB and examined if maternal plasma vitamin D concentrations modify these associations. We investigated whether concentrations of metals in whole blood measured in early and late pregnancy were associated with PTB (<37 weeks) and spontaneous PTB in 1851 live births from the Maternal-Infant Research on Environmental Chemicals Study using discrete time survival analysis. We also investigated whether the risk of PTB was modified by first-trimester plasma 25-hydroxyvitamin D (25OHD) concentrations. Of 1851 live births, 6.1% (n= 113) were PTBs and 4.9% (n= 89) were spontaneous PTB. A 1μg/dL increase in blood lead concentrations during pregnancy was associated with an increased risk of PTB (relative risk [RR] 1.48, 95% confidence interval [CI] 1.00, 2.20) and spontaneous PTB (RR 1.71, 95% CI 1.13, 2.60). The risk was higher in women with insufficient vitamin D concentrations (25OHD <50 nmol/L) for both PTB (RR 2.42, 95% CI 1.01, 5.79) and spontaneous PTB (RR 3.04, 95% CI 1.15, 8.04). However, an interaction on the additive scale was not present. Arsenic was associated with a higher risk of PTB (RR 1.10, 95% CI 1.02, 1.19) and spontaneous PTB (RR 1.11, 95% CI 1.03, 1.20) per 1μg/L. Gestational exposure to low levels of lead and arsenic may increase the risk of PTB and spontaneous PTB; individuals with insufficient vitamin D may be more susceptible to the adverse effects of lead. Given our relatively small number of cases, we encourage testing of this hypothesis in other cohorts, especially those with vitamin D-deficient populations.

Long-termindoor gunshot exposure of special police forces induces bronchitic reactions and elevated blood lead levels-The Berlin shooting range study.

Gunshot emissions contain toxic elements that can harm those frequently exposed, such as police officers. Several years ago, police indoor firing ranges were closed by the Berlin municipality in response to police officer health complaints, and an investigation was launched into the possible respiratory health risks of frequent gunshot emission exposure. We, therefore, conducted an exploratory cross-sectional study to investigate clinical and functional parameters of respiratory health as well as the burden of trace elements in policemen with long-term high exposure to indoor gunshot emissions, compared to low-exposure and control groups. We conducted lung function tests and collected blood and urine samples from Berlin police officers and government employees who were divided into three subject groups based on exposure to gunshot emissions: high exposure (n=53), low exposure (n=94) and no exposure (n=76). Lung function was examined using body plethysmography. Blood and urine samples were tested via inductively coupled plasma mass spectrometry for the presence of common gunshot powder elements (antimony, lead and manganese). Exposure and symptoms were assessed using records as well as questionnaires. Higher exposure was associated with more respiratory symptoms during gun shooting practice (64% vs. 21%, P<0.001) compared to the low-exposure group. Headache, cough, discoloured mucous and shortness of breath were also more common as were some other symptoms. The cough symptomatology of the high-exposure group also persisted significantly longer (median: 0.67 vs. 0.01days, range: 0 to 5days, P=0.029) compared to the low-exposure group. They also showed a lower forced expiratory volume in 1s/forced vital capacity quotient (Tiffeneau index), P=0.018 between the three groups and P=0.005 for the high-exposure group, a possible marker of early, subclinical bronchial obstruction. We observed increased blood lead concentrations depending on subject's age (+1.2% per year, 95% confidence interval: 0.5-1.9%, P<0.001) and cumulative gunshot exposure (+0.34% per 100000 shots, 0.02-0.66%, P=0.037). These first results suggest that long-term exposure to indoor gunshot emissions induces bronchitic reactions due to repeated irritation of the airways. Higher levels of exposure lead to more negatively impacted lung function and higher blood lead levels with the possible reason that more frequent exposure may mean shorter regeneration phases for the respiratory mucous membrane. We recommend a reduction of exposure to gunshot emissions in order to decrease symptoms and avoid any-even small-deterioration in spirometry.

Relationship between Postural Stability, Lead Content, and Selected Parameters of Oxidative Stress.

This study attempts to determine whether the increased blood lead concentration affects the posturographic test and to determine the relationship between the parameters of posture stability and selected parameters of oxidative stress. The study population consisted of 268 male employees and was divided into two equal subgroups, depending on the lead content in the blood. A posturographic examination was performed. Concentrations of lead, cadmium, zinc protoporphyrin, selected essential elements, and selected markers of oxidative stress in the blood were tested. Higher blood lead concentrations positively affected the values of the sway results: the field and the mean velocity of the center of the feet pressure in posturography. The absolute value of the proprioception ratio was similar in both subgroups. The content of malondialdehyde shows a statistically significantly higher value in a subgroup with high blood lead concentration and exhibits significant correlations only with some of the posturography parameters. The lipofuscin content in erythrocytes correlates with the results of the posturography test. Zinc protoporphyrin, total oxidant status, total antioxidant capacity, selected minerals, and metals did not correlate with the results of the posturography test. In conclusion, posturographic results correlate only with selected markers of oxidative stress, so it can be assumed that the effect on the body balance is only partial.

The association between metals, vitamin D and preterm birth in the MIREC Cohort Study

BACKGROUND Toxic metals, like lead, are risk factors for preterm birth (PTB), but few studies have explored this association at the low levels currently found in the Canadian population. Conversely, studies suggest that vitamin D may have antioxidant activity and protect against PTB. In this study, we sought to investigate associations between toxic metals (lead, mercury, cadmium and arsenic) and PTB, and to determine if maternal plasma vitamin D concentrations modify these associations. METHODS We investigated whether metals in whole blood measured in early and late pregnancy were associated with PTB (&amp;#x3c;37 weeks) and spontaneous PTB (a subset of PTBs with spontaneous labour) in 1,851 pregnancies resulting in live births from the Maternal-Infant Research on Environmental Chemicals Study (MIREC) using discrete time survival analysis. In addition, we investigated whether the risk of PTB was modified by plasma 25OHD concentration measured in the 1st trimester. RESULTS Six percent (n=117) of live births in the MIREC study were PTBs; 4% (n=89) were spontaneous PTBs. A 1 &amp;#x3bc;g/dL increase in blood lead concentrations during pregnancy was associated with increased risk of PTB (OR=1.5, 95% CI: 1.0, 2.3) and spontaneous PTB (OR=1.7, 95% CI: 1.1, 2.8). In stratified analysis, the risk of PTB (OR=2.7, 95% CI: 1.0, 7.2) and spontaneous PTB (OR=3.4, 95% CI: 1.1, 10.8) was higher in women with insufficient vitamin D concentrations (25OHD &amp;#x3c;50 nmol/L). However, a statistical interaction was not seen. Arsenic was associated with a higher risk of PTB (OR=1.1, 95% CI: 1.0, 1.2) and spontaneous PTB (OR=1.1, 95% CI: 1.0, 1.2) per µg/L, but these associations were not modified by vitamin D. CONCLUSIONS Low levels of lead and arsenic may increase the risk of PTB and spontaneous PTB; the association with lead was stronger in participants with insufficient plasma vitamin D. Replication of these findings is warranted.

Histoarchitectural Changes in the Liver Following Lactational Lead Intoxication in Sprague Dawley Rats

The present experiment was designed to study the histoarchitectural changes in the liver following lactational lead (Pb) intoxication in rats. A total of 12 adult female and 4 male rats were used in the experiment and 32 offspring for the analysis of lactational lead intoxication. The offspring were divided into four groups. Groups B, C and D were administered 10 mg/dL, 30 mg/dL and 70 mg/dL of lead acetate respectively, via drinking water for 21 days through the lactating mothers while group A was control. The livers of the pups were observed using histological methods. One-way ANOVA was used to analyze data, followed by Tukey post hoc test for multiple comparisons. The results from the analysis showed that the total body weight, body length and liver weights were only slightly altered in the Pb intoxicated groups. Using relative liver weights alone revealed some form of hepatomegaly among the experimental groups. The results revealed a dose-dependent increase in blood lead concentration. Histopathological evidences revealed moderate to severe histoarchitectural distortions along Pb concentration gradient. Lactational lead intoxication portends dose dependent histopathological changes in the liver of SD rats.

Association of blood lead level with cognition impairment among elderly aged 65 years and older in 9 longevity areas of China

Objective: To investigate the association between blood lead concentrations and cognition impairment among Chinese older adults aged 65 or over. Method: Data was collected in 9 longevity areas from Heathy Aging and Biomarkers Cohort Study between 2017 and 2018. This study included 1 684 elderly aged 65 years and older. Information about demographic characteristics, socioeconomic factors, health status and cognitive function score of respondents were collected by questionnaire survey and physical examination. Venous blood of the subjects was collected to detect the blood lead concentration. Subjects were stratified into four groups (Q1-Q4) by quartile of blood lead concentration. Multivariate logistic regression model was used to analyze the association between blood lead concentration and cognitive impairment. The linear or non-linear association between blood lead concentration and cognitive impairment were described by restrictive cubic splines (RCS). Results: Among the 1 684 respondents, 843 (50.1%) were female and 191 (11.3%) suffered from cognition impairment. After adjusting for confounding factors, the OR value and 95%CI of cognition impairment was 1.05 (1.01-1.10) for every 10 μg/L increase in blood lead concentration in elderly; Compared with the elderly in Q1, the elderly with higher blood lead concentration had an increased risk of cognitive impairment. The OR value and 95%CI of Q2, Q3 and Q4 groups were 1.19 (0.69-2.05), 1.45 (0.84-2.51) and 1.92 (1.13-3.27), respectively. Conclusion: Higher blood lead concentration is associated with cognitive impairment among the elderly aged 65 years and older in 9 longevity areas in China.

Comparison of blood lead concentrations in patients with acute ischemic stroke and healthy subjects

Background and ObjectivesStroke is the main cause of mortality and long-term disability in the general population. With the increased application of metals in industries and human environment, lead has become a health hazard. In this study, we aimed to evaluate the relationship between the blood concentration of lead and the incidence of acute stroke. Materials and MethodsWe performed this study during 2016−17 at Vali-e-Asr Hospital in Birjand, Iran, among 80 ischemic stroke patients visiting the hospital and 80 healthy gender- and age-matched controls. Blood lead concentration (BLC) was measured using graphite furnace atomic absorption spectrometry. ResultsBLC medians in the case and control groups were 20.65 [5.37−34.87] μg/dL and 2.65 [1.75−13.85] μg/dL, respectively (p < 0.05). The case group had significantly lower mean levels of HDL and phosphors, whereas the mean levels of white blood cells and uric acid were higher in this group. After adjusting for lipid profile and fasting blood sugar, multiple logistic regression indicated that the serum levels of uric acid and BLC were significant for predicting ischemic stroke. It is estimated that the odds ratio of ischemic stroke increases by 1.04 per 1 μg/dl increase in BLC. ConclusionThis study showed that lead can be a risk factor for ischemic stroke. Since it does not have any beneficial effects on the health of individuals, screening serum concentrations of lead can be considered as a preventive strategy for those at risk of stroke.

Lead concentrations in blood from incubating common eiders (Somateria mollissima) in the Baltic Sea

Here we investigate if lead may be a contributing factor to the observed population decline in a Baltic colony of incubating eiders (Somateria mollissima). Body mass and blood samples were obtained from 50 incubating female eiders at the Baltic breeding colony on Christiansø during spring 2017 (n = 27) and 2018 (n = 23). All the females were sampled twice during early (day 4) and late (day 24) incubation. The full blood was analysed for lead to investigate if the concentrations exceeded toxic thresholds or changed over the incubation period due to remobilisation from bones and liver tissue. Body mass, hatch date and number of chicks were also analysed with respect to lead concentrations. The body mass (mean ± SD g) increased significantly in the order: day 24 in 2018 (1561 ± 154 g) < day 24 in 2017 (1618 ± 156 g) < day 4 in 2018 (2183 ± 140 g) < day 4 in 2017 (2359 ± 167 g) (all p < 0.001). The lead concentrations increased significantly in the opposite order i.e. day 4 in 2017 (41.7 ± 67.1 μg/L) < day 24 in 2017 (55.4 ± 66.8 μg/L) < day 4 in 2018 (177 ± 196 μg/L) < day 24 in 2018 (258 ± 243) (all p < 0.001). From day 4 to 24, the eider females had a 1.33-fold increase in blood lead concentrations in 2017 and a 1.46-fold increase in 2018. Three of the birds (13%) sampled in 2018 had lead concentrations that exceeded concentrations of clinical poisoning (500 μg/L) and eleven (48%) had concentrations that exceeded the threshold for subclinical poisoning (200 μg/L). In 2017, none of the birds exceeded the high toxic threshold of clinical poisoning while only one (4%) exceeded the lower threshold for subclinical poisoning. Three of the birds (6%) sampled in 2018 had lead concentrations that exceeded those of clinical poisoning while 12 birds (24%) resampled in both years exceeded the threshold for subclinical poisoning. In addition, lead concentrations and body mass on day 4 affected hatch date positively in 2018 (both p < 0.03) but not in 2017. These results show that bioavailable lead in bone and liver tissue pose a threat to the health of about 25% of the incubating eiders sampled. This is particularly critical because eiders are largely capital breeding which means that incubating eiders are in an energetically stressed state. The origin of lead in incubating eiders in the Christiansø colony is unknown and it remains an urgent priority to establish the source, prevalence and mechanism for uptake. The increase in lead from day 4 to day 24 is due to bone and liver remobilization; however, the additional lead source(s) on the breeding grounds needs to be identified. Continued investigations should determine the origin, uptake mechanisms and degree of exposure to lead for individual birds. Such research should include necropsies, x-ray, lead isotope and stable C and N isotope analyses to find the lead sources(s) in the course of the annual cycle and how it may affect the population dynamics of the Christiansø colony which reflects the ecology of the Baltic eiders being suitable for biomonitoring the overall flyway.

Environmental lead exposure aggravates the progression of Alzheimer's disease in mice by targeting on blood brain barrier

Alzheimer's disease (AD) is a neurodegenerative disease that can be induced by heavy metals such as lead. However, there is limited information on the role of blood-brain barrier (BBB) in lead induced AD-like pathology. This study investigates the potential mechanism of lead exposure aggravating the progression of Alzheimer’s disease in mice through the BBB. 200 mg/L and 500 mg/L lead acetate were given to C57BL/6J and APP/PS1 mice through drinking water from a week before mating, until the offspring were 7-months-old. 8 female juvenile mice in each group were selected for this investigation. Lead exposure increased blood lead concentration which revealed the internal exposure level, accelerated Aβ1-42 deposition in APP/PS1 mouse cortexes and abnormal change in Zonula Occludin-1 (ZO-1) and Claudin-5 protein. It also increased the expression of p-tau in both the C57BL/6J and APP/PS1 mice, and decreased mRNA and protein expression in low-density lipoprotein receptor (LRP-1). Additionally, it increased the mRNA and protein expression of amyloid beta precursor protein (APP) and beta secretase 1 (BACE-1). The activated astrocytes increased in the brains of APP/PS1 mice, and coalesced around the Aβ1-42 deposition after lead exposure. The main vessels in deutocerebrum were attached with Aβ1-42 deposition. These results offer insight into the mechanism of preventing lead induced AD through cerebrovascular pathways.

Blood Lead Concentration and Prescription Medication Use Among US Children and Adolescents

TPS 636: Metals and health 2, Johan Friso Foyer, Floor 1, August 28, 2019, 3:00 PM - 4:30 PM Background: Lead is a toxicant to many organ systems, and it is especially harmful to children during developmental stages. Prescription medication use prevalence in children and adolescent indicates shifting disease burdens, as well as over-prescription of inappropriate or ineffective treatments. There may be relationships between environmental pollutants and prescription medication but it has not been explored. Methods: We used serial cross-sectional data of children and adolescents aged 1 to 19 years in the US National Health and Nutrition Examination Survey (NHANES), from 1999 to 2014. A total of 17 categories of prescription medications commonly used by children and adolescents were involved. We used multivariate linear and logistic regression to explore the relationship of blood lead concentration (independent variable) and prescription medication use (dependent variable), adjusted for age, gender, race, income, education, insurance and health condition. Results: In this serial cross-sectional study that included 24412 subjects, the mean blood lead concentration decreased from 1.61 µg/dL to 0.76 µg/dL. Blood lead concentration was not correlated with overall use of prescription medications in the last 30 days. Each µg/dL increase in blood lead concentration was associated with lower odds ratio of asthma medications (OR=0.88, 95%CI: 0.82 to 0.94) (p<0.005) and higher odds ratio of antibiotics amoxicillin/clavulanate (OR=1.10, 95%CI: 1.05 to 1.14) (p<0.005). Higher blood lead level was also associated with more use of overall antibiotics, narcotic-containing analgesics and ADHD medications (amphetamines), and less use of tetracyclines, antidiabetic agents, antipsychotics, contraceptives, proton pump inhibitors and dermatological agents (p<0.05). Conclusions: Blood lead concentration is related to prescription medication usage use among children and adolescents in the US.

Risk Assessment of Lead Exposure from Cervid Meat in Norwegian Consumers and in Hunting Dogs

Risk Assessment of Lead Exposure from Cervid Meat in Norwegian Consumers and in Hunting Dogs

Reduced regional volumes associated with total psychopathy scores in an adult population with childhood lead exposure

Childhood lead exposure has been correlated to acts of delinquency and criminal behavior; however, little research has been conducted to examine its potential long term influence on behavioral factors such as personality, specifically psychopathic personality. Neuroimaging studies have demonstrated that the effects of childhood lead exposure persist into adulthood, with structural abnormalities found in gray and white matter regions involved in behavioral decision making. The current study examined whether measurements of adult psychopathy were associated with neuroanatomical differences in structural brain volumes for a longitudinal cohort with measured childhood lead exposure. We hypothesized that increased total psychopathy scores and increased blood lead concentration at 78 months of age (PbB78) would be inversely associated with volumetric measures of gray and white matter brain structures responsible for executive and emotional processing. Analyses did not display a direct effect between total psychopathy score and gray matter volume; however, reduced white matter volume in the cerebellum and brain stem in relation to increased total psychopathy scores was observed. An interaction between sex and total psychopathy score was also detected. Females displayed increased gray matter volume in the frontal, temporal, and parietal lobes associated with increased total psychopathy score, but did not display any white matter volume differences. Males primarily displayed reductions in frontal gray and white matter brain volume in relation to increased total psychopathy scores. Additionally, reduced gray and white matter volume was associated with increased blood lead levels in the frontal lobes; reduced white matter volume was also observed in the parietal and temporal lobes. Females demonstrated gray and white matter volume loss associated with increased PbB78 values in the right temporal lobe, as well as reduced gray matter volume in the frontal lobe. Males displayed reduced white matter volumes associated with increased PbB78 values in the frontal, temporal, and parietal lobes. Comparison of the two primary models revealed a volumetric decrease in the white matter of the left prefrontal cortex associated with increased total psychopathy scores and increased blood lead concentration in males. The results of this study suggested that increased psychopathy scores in this cohort may be attributable to the neuroanatomical abnormalities observed and that childhood lead exposure may be influential to these outcomes.

Haematological and antioxidant enzyme response to Lead toxicity in male Wistar rats

The study evaluated the haematological and some antioxidant enzymes response to lead toxicity in male Wistar rats. Twenty male Wistar rats were divided into four groups viz., A, B, C and D. Group A served as the control while groups B, C and D were treated with 200, 300 and 400 ppm of lead (Pb) as lead acetate, respectively. Doses were orally administered in divided doses by intubation to ensure that each rat had the specified doses, after which they have access to water and feed. At the end of two weeks of treatment, blood samples were collected via the median canthus into heparinised tubes for blood lead determination and haematological analysis after which the remaining blood was centrifuged to obtain the plasma for determination of malonydialdehyde, catalase, superoxide dismutase and peroxidase levels. There was a significant increase in blood lead concentrations ranging from 2.15±0.10 µg/dl to 9.21±0.05 µg/dl which was dose dependent while decreases in packed cell volume and the red blood cell counts ranging from 32-53% and 15-52%,respectively. At the highest dose of 400 ppm of lead there was significant decrease in the neutrophils and lymphocytes. There was significant (P<0.05) dose dependent increases in malondialdehyde while the activities of catalase, peroxidase and superoxide dismutase were significantly (P<0.05) reduced. In conclusion, lead disrupts the haematological system leading to generation of free radicals that overwhelm the antioxidant enzymes thus leading to oxidative stress.

The Effects of Earphone Use and Environmental Lead Exposure on Hearing Loss in the Korean Population: Data Analysis of the Korea National Health and Nutrition Examination Survey (KNHANES), 2010-2013.

BackgroundAlthough previous studies have reported that frequent earphone use and lead exposure are risk factors for hearing loss, most of these studies were limited to small populations or animal experiments. Several studies that presented the joint effect of combined exposure of noise and heavy metal on hearing loss were also mainly conducted on occupational workers exposed to high concentration.ObjectivesWe investigated both the individual and joint effects of earphone use and environmental lead exposure on hearing loss in the Korean general population.MethodsWe analyzed data from 7,596 Koreans provided by the Korea National Health and Nutrition Examination Survey (KNHANES) during the period 2010–2013. The pure-tone average (PTA) of hearing thresholds at 2, 3, and 4 kHz frequencies was computed, and hearing loss was defined as a PTA ≥ 25 dB in one or both ears.ResultsA dose-response relationship in hearing loss with earphone use time and blood lead level is observed after adjustment for confounding factors. With a 1-hour increase in earphone use time and 1 μg/dL increase in blood lead concentration, the odds of hearing loss increased by 1.19 and 1.43 times, respectively. For hearing loss, the additive and multiplicative effect of earphone use and blood lead level were not statistically significant.ConclusionsEarphone use and environmental lead exposure have an individual effect on hearing loss in the general population. However, the estimated joint effect of earphone use and lead exposure was not statistically significant.

Application of benchmark dose on renal injury in people chronically exposed to lead

Objective: To screen sensitive indicators of renal injury in lead workers using benchmark dose method. Methods: Of the 486 subjects,116 did not occupationally contact to lead as a control. The blood lead was considered as exposure biomarker, while Uβ2-MG and UNAG as effect biomarkers for renal injury. The BMD and BMDL of blood lead were estimated at the 10% benchmark response using BMDS Version 2.6. Results: There was statistical rise in blood lead between the lead group and control group (P<0.05) ; and the blood lead level was divided into four groups by quarterback spacing method, among which UNAG was statistically different (P<0.05) . There was an increased prevalence of abnormal rates of Uβ2-MG and UNAG with increasing blood lead concentration (P<0.05) , after trend chi-square test. BMD and BMDL of UNAG and Uβ2-MG were 602.784/431.838 μg/L and 130.398/100.981 μg/L caculated by Log-Probit model, respectively. Conclusions: Occupational lead exposure may cause kidney damage, and UNAG could be as a more sensitive marker for monitoring early renal injury than Uβ2-MG.

Lead Residues in Milk and Blood of Cows at Selected Localities of Chittoor District of Andhra Pradesh, India

The present study was planning to evaluate the concentrations of lead in blood and milk of crossbred cows reared in five different industrial areas in chittoor district of Andhra Pradesh. A total of 100 milk and 100 blood samples were collected from crossbred milk cows randomly in and around five factories, which were present in Chittoor District of Andhra Pradesh, India such as Batteries factory at Karakambadi, Nutrine factory and Sugar factory at chittoor and Lamco (Iron pipes) factory at Erpedu and Sugar factory at Puttur. The samples such as blood and milk were subjected for acid digestion method [1], then these samples were used for lead residual estimation by following method of Perkin-Elmer 3100 (USA) double beam atomic absorption spectrophotometer-meter with hallow cathode lamp of lead. The highest lead concentration was found in the blood of cows reared in and around Karakambadi area (1.5 mg/L) then followed by cows of Erpedu (1.2 mg/L), Chittoor (Nutrine factory) (1 mg/L), Puttur (1.0 mg/L) and Chittoor (Sugar factory) (0.9 mg/L). Significant correlation was noticed between high levels of increased blood lead and milk lead levels in cows that were at near in different factories. There was significant increase in blood lead concentration simultaneously increase in milk lead concentration. The increase blood lead in relation with increase milk lead might be due to the excretion of lead through milk increases with increase in blood lead level.

Environmental lead exposure and attention deficit/hyperactivity disorder symptom domains in a community sample of South Korean school-age children.

BackgroundLow-level environmental exposure to lead has been associated with both reduced intelligence and symptoms of attention deficit/hyperactivity disorder (ADHD). However, few studies have estimated the association of lead and intelligence independent of ADHD, and it is not clear from previous studies whether lead is associated with both inattention and impulsivity ADHD symptoms.ObjectivesWe estimated mutually adjusted associations of environmental lead exposure with both intelligence and ADHD symptoms, and associations between lead and specific ADHD-related domains.MethodsBlood lead concentrations were measured in a general population of 1,001 children 8–11 years of age. We used multivariable linear regression models to estimate associations of blood lead concentrations with IQ scores, teacher and parent ratings of ADHD symptoms, and measures of inattention and impulsivity. Models were adjusted for demographic variables and other environmental exposures (blood levels of mercury and manganese, urinary concentrations of cotinine, phthalate metabolites, and bisphenol A).ResultsAssociations of blood lead with lower IQ and higher impulsivity were robust to adjustment for a variety of covariates. When adjusted for demographic characteristics, other environmental exposures, and ADHD symptoms or IQ, a 10-fold increase in blood lead concentration was associated with lower Full-Scale IQ (–7.23; 95% CI: –13.39, –1.07) and higher parent- and teacher-rated hyperactivity/impulsivity scores (ADHD Rating Scale, 1.99; 95% CI: 0.17, 3.81 and 3.66; 95% CI: 1.18, 6.13, respectively) and commission errors (Continuous Performance Test, 12.27; 95% CI: –0.08, 24.62). Blood lead was not significantly associated with inattention in adjusted models.ConclusionsLow-level lead exposure was adversely associated with intelligence in school-age children independent of ADHD, and environmental lead exposure was selectively associated with impulsivity among the clinical features of ADHD.CitationHong SB, Im MH, Kim JW, Park EJ, Shin MS, Kim BN, Yoo HJ, Cho IH, Bhang SY, Hong YC, Cho SC. 2015. Environmental lead exposure and attention deficit/hyperactivity disorder symptom domains in a community sample of South Korean school-age children. Environ Health Perspect 123:271–276; http://dx.doi.org/10.1289/ehp.1307420

A comparison between lead-containing (rifle) and non-lead containing (archery) hunting methods

Lead contamination in deer meat (venison) has been documented extensively throughout the past decade as a result of the use of lead ammunition in deer hunting. Bullets have been consistently documented to disintegrate into a cloud of fragments and contaminate venison. Many studies have shown that the consumption of lead-contaminated meat is directly correlated to increased blood lead concentrations that pose several human health risks; most of them are associated with neurological and renal disorders. It was hypothesized that there would be a higher lead concentration in rifle-harvested meat than archery-harvested meat primarily because archery arrows do not contain lead. In this experiment, meat samples from rifle-harvested deer and archery-harvested deer were analyzed for lead quantities using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Random samples were collected from local meat lockers as donations for this experiment. The data show no significant difference in lead levels (t=0.734; p=0.467) between rifle and archery harvested meat samples. Results of this study also point to lead contamination in some archery samples, as deer may survive lead bullet wounds and be killed by another means.

Sex-specific Profiles of Blood Metal Levels Associated with Metal-Iron Interactions.

The mechanisms by which iron is absorbed are similar to those of divalent metals, particularly manganese, lead, and cadmium. These metals, however, show different toxicokinetics in relation to menarche or menopause, although their interaction with iron is the same. This review focuses on the kinetics of these three toxic metals (manganese, lead, and cadmium) in relation to menarche, pregnancy, and menopause. The iron–manganese interaction is the major factor determining sex-specific differences in blood manganese levels throughout the whole life cycle. The effects of estrogen overshadow the association between iron deficiency and increased blood lead concentrations, explaining why women, despite having lower ferritin concentrations, have lower blood lead concentrations than men. Iron deficiency is associated with elevated cadmium levels in premenopausal women, but not in postmenopausal women or men; these findings indicate that sex-specific differences in cadmium levels at older ages are not due to iron–cadmium interactions, and that further studies are required to identify the source of these differences. In summary, the potential causes of sex-specific differences in the blood levels of manganese, lead, and cadmium differ from each other, although all these three metals are associated with iron deficiency. Therefore, other factors such as estrogen effects, or absorption rate as well as iron deficiency, should be considered when addressing environmental exposure to toxic metals and sex-specific differences in the blood levels of these metals.

Consumption of lead-shot cervid meat and blood lead concentrations in a group of adult Norwegians

Several recent investigations have reported high concentrations of lead in samples of minced cervid meat. This paper describes findings from a Norwegian study performed in 2012 among 147 adults with a wide range of cervid game consumption. The main aim was to assess whether high consumption of lead-shot cervid meat is associated with increased concentration of lead in blood. A second aim was to investigate to what extent factors apart from game consumption explain observed variability in blood lead levels.Median (5 and 95 percentile) blood concentration of lead was 16.6µg/L (7.5 and 39µg/L). An optimal multivariate linear regression model for log-transformed blood lead indicated that cervid game meat consumption once a month or more was associated with approximately 31% increase in blood lead concentrations. The increase seemed to be mostly associated with consumption of minced cervid meat, particularly purchased minced meat. However, many participants with high and long-lasting game meat intake had low blood lead concentrations. Cervid meat together with number of bullet shots per year, years with game consumption, self-assembly of bullets, wine consumption and smoking jointly accounted for approximately 25% of the variation in blood lead concentrations, while age and sex accounted for 27% of the variance. Blood lead concentrations increased approximately 18% per decade of age, and men had on average 30% higher blood lead concentrations than women. Hunters who assembled their own ammunition had 52% higher blood lead concentrations than persons not making ammunition. In conjunction with minced cervid meat, wine intake was significantly associated with increased blood lead. Our results indicate that hunting practices such as use of lead-based ammunition, self-assembling of lead containing bullets and inclusion of lead-contaminated meat for mincing to a large extent determine the exposure to lead from cervid game consumption.