Association between blood lead exposure and mental health in pregnant women: Results from the Japan environment and children's study.

OBJECTIVE: Although environmental lead exposure has decreased, several studies have shown that low-level lead exposure can result in adverse psychological symptoms. However, few studies have examined lead neurotoxicity in pregnant women. We investigated the association between lead exposure and psychological symptoms in pregnant women, and between socio-economic status and blood lead levels. METHODS: Blood lead levels were measured in 17,267 pregnant women in the Japan Environment and Children's Study. Odds ratios (ORs) for high blood lead levels were calculated using multinomial logistic regression. Psychological symptoms were assessed using the Kessler Psychological Distress Scale (K6). ORs for depression (K6 ≥ 13 or ≥5) were calculated using logistic regression with adjustment for potential confounders. RESULTS: The geometric mean of whole blood lead levels was 0.58 µg/dl (range 0.14-6.75 µg/dl). Higher blood lead levels were associated with older age (OR 1.79, 9 5% confidence interval [CI] 1.46-2.19), unmarried status (OR 1.75, 95 % CI 1.31-2.33), lower household income (OR 1.76, 95 % CI 1.38-2.24), and lower educational attainment (OR 1.34, 95 % CI 1.20-1.48). The percentage of women with K6 scores ≥13 and ≥5 was 3 % and 28.2 %, respectively. There was no significant association between lead exposure and K6 score (K6 ≥ 13: OR 1.00, 95 % CI 0.76-1.32; K6 ≥ 5: OR 0.98, 95 % CI 0.88-1.09). CONCLUSION: Our results indicate a small but significant association between higher blood lead levels and lower socio-economic status in a population with low blood lead levels, but no association between low-level lead exposure and psychological symptoms.

Environmental and Occupational Lead Exposure Among Children in Cairo, Egypt: A Community-Based Cross-Sectional Study.

The aim of this study was to assess childhood lead exposure in a representative sample of Cairo, and to investigate the possible risk factors and sources of exposure. This cross-sectional study was conducted from November 2014 through April 2015. The target population was children aged 6 to 18 years, recruited into 4 groups, garbage city, moderate-living standard area, urban and suburban schools, and workshops in the city of Cairo. Blood lead levels (BLLs) and hemoglobin (Hb) concentrations were measured. Also, potential local environmental sources were assessed for hazardous lead contamination. Analysis on 400 participants has been carried out. A total of 113 children had BLLs in the range 10 to 20 µg/dL. Smoking fathers, housing conditions, playing outdoors, and exposure to lead in residential areas were significantly correlated with high BLLs. The mean values of hemoglobin were inversely correlated with BLLs. Children involved in pottery workshops had the highest BLLs and the lowest Hb values with a mean of (43.3 µg/dL and 8.6 g/dL, respectively). The mean value of environmental lead in workshop areas exceeded the recommended levels. Also, those values measured in dust and paint samples of garbage city were significantly high. Moreover, the mean lead levels in the soil samples were significantly higher in urban schools (P = 0.03) than the suburban ones. Childhood lead poisoning accounts for a substantial burden in Egypt, which could be preventable. Development of national prevention programs including universal screening program should be designed to reduce incidence of lead toxicity among children.

[The role of toxininduced autoimmune activity in formation of the endotoxemia during the lead exposure].

Here presented the features of formation of endotoxemia at microsaturnism. Here are the results of the retrospective study of toxininduced autoimmune activity and their role in toxemia depending on the degree of exposure of lead. Investigated the mechanisms of production of toxins and damaging potentials activity, molecular size toxins and parameters of their distribution and accumulation in the blood stream, due to the strength of toxinbearing fractions depending on the degree of microsaturnism.

Association of maternal and child blood lead and hemoglobin levels with maternal perceptions of parenting their young children.

Biological and psychosocial factors affect child development and behavior. Whereas biological underpinnings behind the neurotoxic effects of lead are studied extensively, the effects of psychosocial factors contributing to poor behavioral outcomes in lead-exposed children are not well understood. Parental attributes and practices may moderate or mediate the effects of lead on children's behavioral outcomes. We investigated the hypothesis that maternal and child lead and hemoglobin levels are associated with maternal perceptions of their parenting. Specifically, we hypothesized that children with higher blood lead (BLL) and lower hemoglobin concentrations would be associated with poorer maternal self-assessments of their parenting skills or the mother-child relationship. Children aged 13-55 months and their mothers (n=109) were recruited from among the participants of a previous lead and anemia screening study and from preschools in Montevideo, Uruguay. The mother-child pair attended two study visits: one to collect biological samples and answer demographic and child questionnaires, including statements regarding parenting; and a second to evaluate maternal IQ, depression and stress, and child development. Of the children, 51.6% had blood lead concentrations (BLLs) ≥ 5 µg/dL, 18.0% had anemia, and 8% had both conditions. Among mothers, 48.4% had BLLs ≥ 5 µg/dL, 16.0% had anemia, and 11% had both. BLLs ≥ 5 µg/dL in mother or child were associated with lower maternal perceptions of being skilled at discipline (p<0.05). Maternal anemia was associated with lower likelihood that mothers would let their children explore and play (p<0.05), whereas child anemia was associated with maternal perception of lower emotional support (p<0.01). In addition to shared environmental exposures, parenting and family interactions need to be considered as potentially contributing factors to poorer outcomes in lead-exposed children.

Blood lead, serum homocysteine, and neurobehavioral test performance in the third National Health and Nutrition Examination Survey.

Regression analysis was used to estimate and test for relationships between blood lead, serum folate, red blood cell folate, serum vitamin B12, serum homocysteine, and neurobehavioral test performance in adults, 20-59 years old, participating in the third National Health and Nutrition Examination Survey. The three neurobehavioral tests included in the survey were simple reaction time, symbol-digit substitution, and serial digit learning. Serum folate, red blood cell folate, and serum vitamin B12 decreased as the blood lead concentration increased. Serum homocysteine increased as the blood lead concentration increased. Serum homocysteine decreased as the serum folate and serum vitamin B12 concentrations increased. Neurobehavioral test performance was not related to the blood lead, serum folate, or serum vitamin B12 concentrations. In adults 20-39 years old, performance on the serial digit learning test improved as the serum homocysteine concentration increased. In adults 40-59 years old, neurobehavioral test performance was not related to the serum homocysteine concentration. Homocysteine may impair cognitive function by acting at N-methyl-D-aspartate receptors, and improve cognitive function by acting at N-methyl-D-aspartate or gamma-aminobutyric acid receptors.

Possibilities of newer ALAD polymorphism influencing human susceptibility to effects of inorganic lead on the neurobehavioral functions.

OBJECTIVE: A cross-sectional study was conducted to study the association between some new ALAD polymorphism and susceptibility to effects of inorganic lead on the neurobehavioral functions. METHOD: We recruited 120 healthy male workers with lead exposure in a factory which manufacture lead stabilizer. The ALAD SNPs studied were HpyCH4, HpyIV RFLP in intron 6, Rsa and Msp RFLP in exon 4, Sau3A in intron 12 and Rsa39488 in exon 5. The World Health Organization Neurobehavioral Core Test Battery (WHO-NCTB) and a few other tests were used. General linear model (GLM) was applied to compare outcome scores between subgroups of each ALAD SNP while controlling for possible confounders. RESULTS: The mean age of the workers was 39.7 years (S.D. 10.7), mean exposure duration of 10.2 years (S.D. 7.9) and mean blood lead of 22.1 microg/dl (S.D. 9.4). Among the 6 SNPs studied, Rsa and Rsa39488 appear to be the main candidate SNPs. Workers with Rsa and Rsa39488 ALAD 2-2 genotypes fare significantly better in the Aiming Pursue Test Correct (AC), Groove Peg Board non-preferred hand (GPNP), Groove Peg Board Mean (GPM), San Ana Preferred Hand (SAP), San Ana Both Hands (SAB) and AC, GPNH, GPM, Digit Symbol (DIS) tests; respectively compared to Rsa and Rsa39488 ALAD 1-1/1-2 genotypes adjusted for age, race, exposure duration and blood lead levels. CONCLUSION: The presence of the homozygote Rsa and Rsa39488 ALAD 2-2 seems to offer some protection against the effect of lead on motor dexterity function. While it may appear that newer ALAD polymorphism other than the commonly reported Msp SNP might influence human susceptibility to effects of inorganic lead on the neurobehavioral functions further study involving a larger cohort of workers with Rsa and Rsa39488 ALAD2 allele would be needed to confirm this inference.

Ayurvedic medicine: patients in peril from plumbism.

Heavy metals are commonly incorporated into Ayurvedic preparations as ashes or 'bhasmas'. A widely disseminated belief within Ayurvedic medicine is that these heavy metals can be valuable therapeutic components. Western toxicology refutes this contention. We report eight cases of lead poisoning occurring in or near the Auckland region of New Zealand. In all cases, poisoning was attributable to consumption of Ayurvedic 'herbal medicines'. Whole blood lead levels ranged from 1.5 to 6.9 micromol/L. Six patients had symptomatic lead poisoning, requiring treatment with chelation therapy. A high index of suspicion is required to detect lead poisoning, which should be suspected in people taking Ayurvedic remedies, especially if they have associated anaemia or abdominal symptoms.

The relationship between blood lead levels and neurobehavioral test performance in NHANES III and related occupational studies.

OBJECTIVES: The goals of this study were two-fold: (1) to assess the relationship between blood lead levels and neurobehavioral test performance in a nationally sample of adults from the third National Health and Nutrition Evaluation Survey and (2) to analyze the results from previously published studies of occupational lead exposure that used the same neurobehavioral tests as those included in the survey. METHODS: Regression models were used to test and estimate the relationships between measurements of blood lead and performance on a simple reaction time, a symbol-digit substitution, and a serial digit learning test in adults aged 20-59 years who participated the survey. Mixed models were used to analyze the data from the occupational studies. RESULTS: The blood lead levels of those participating in the survey ranged from 0.7 to 41.8 microg/dl. The estimated geometric mean was 2.51 microg/dl, and the estimated arithmetic mean was 3.30 microg/dl. In the survey, no statistically significant relationships were found between blood lead concentration and performance on the three neurobehavioral tests when adjusted for covariates. In the occupational studies, the groups exposed to lead consistently performed worse than control groups on the simple reaction time and digit-symbol substitution tests. CONCLUSIONS: The results from the survey and the occupational studies do not provide evidence for impairment of neurobehavioral test performance at levels below 25 microg/dl, the concentration that the Centers for Disease Control and Prevention define as elevated in adults. The average blood lead level of the exposed groups in the occupational studies was 41.07 microg/dl, less than 50 microg/dl, the minimum concentration that the Occupational Safety and Health Administration requires for medical removal from the workplace. Given the evidence of impaired neurobehavioral performance in these groups, the 50 microg/dl limit should be reevaluated.

Differential effects of lead exposure on components of verbal memory.

AIMS: To determine if verbal learning and memory requiring acquisition and retention of information is differentially affected by lead exposure. METHODS: The Rey Auditory Verbal Learning Test (RAVLT), a test of verbal learning and memory, was administered to 256 English speaking lead smelter workers who had a mean (SD) age of 41 (9.4) years and employment duration of 17 (8.1) years. Lead exposure variables, based on up to 25 years of prior blood lead data, included a mean (SD) current blood lead (PbB) of 28 (8.8) microg/dl, working lifetime time weighted average blood lead (TWA) of 39 (12.3) microg/dl, and working lifetime integrated blood lead index (IBL) of 728 (434.4) microg-y/dl. Associations of these chronic and recent lead exposure variables with measures from the RAVLT were modelled through multiple linear regressions after controlling for age and educational achievement. RESULTS: PbB was not associated with any of the RAVLT variables. However, TWA and IBL contributed significantly to the explanation of variance of measures of encoding/storage and retrieval but not to immediate memory span, attention, and learning. Grouping study participants by RAVLT performance according to three recognised clinical memory paradigms showed significantly higher TWA and IBL in the group with "generalised memory impairment" after adjusting for age and educational achievement. We examined recall mechanisms in each group by serial position in the word list and found stronger primacy (recall of words from the beginning of the list) in the "no impairment" and "retrieval difficulties" groups while the "generalised memory impairment" group had better performance on recency (recall of words from the end of the list). CONCLUSIONS: Lead exposure over years and not PbB interfered with the organisation and recall of previously learned verbal material. Chronic lead exposure affects encoding/storage and retrieval of verbal information.

[Diagnostic problems in case of environmental exposure to tetraethyl lead]. / Problemy diagnostyczne w przypadku srodowiskowego narazenia na czteroetylek olowiu.

UNLABELLED: The aim of this study was the presentation of the chronic tetraethyl lead poisoning of the 4 person family in the place of settlement. CASE REPORT: 15.5-years-old man was admitted to the regional Pediatric Ward because of changes of behavior, hallucinations, agitation. Nausea, vomiting, metallic taste and diarrhea were observed prior to the admission. In the case history, there were no data suggested of the toxic origin of the disorder . The CSF examination and CT of the brain were normal. Increased activity of CPK, ALT, AST, GTP, LDH in the blood were found. Paranoid syndrome was diagnosed by psychiatric evaluation. The patients' mother presented similar signs in almost the same time. The laboratory tests of the blood taken from the patients' father and older brother revealed the increase activity of the same enzymes (CPK, ALT, AST, LDH). All family was admitted to the Department of Clinical Toxicology in Kraków because of suspicion of the heavy metal poisoning. The toxicological laboratory test showed in all described patients the toxic serum lead concentration accordingly: 440 microg/l--older brother, 490 microg/l--father, 508 microg/l--mother and 635 microg/l--primary described patient. Because of the fact, that were no characteristic for lead poisoning changes in blood picture, the toxicological investigations were continued. As a result of these examinations presence of a diethyl lead in urine was confirmed. In the evaluation of the multiorgan damages connected with tetraethyl lead poisoning, we paid special attention on CSN dysfunctions. The USG and scintigraphy examinations revealed the liver damage. The different kinds of arrhythmias indicated on cardiovascular system damage. Based on clinical presentation and laboratory investigations the chronic tetraethyl lead poisoning was diagnosed.

Association of chronic and current measures of lead exposure with different components of brainstem auditory evoked potentials.

Current blood lead (PbB) affects brainstem auditory evoked potentials (BAEPs) in children but whether a similar association exists in lead-exposed adults remains unclear. During an investigation of the neurobehavioral effects of occupational lead exposure we performed BAEPs on 359 English- and French-speaking, currently exposed, male, lead smelter workers having a mean (S.D.) age of 41 (9.0) years, employment duration of 17 (7.9) years, PbB of 28 (8.4)microg/dl, working-lifetime weighted average blood lead (TWA) of 39 (11.9) microg/dl, and working-lifetime integrated blood lead (IBL) index of 719 (421.0) microg.year/dl, the latter a measure of cumulative lead dose. BAEPs were performed at a click stimulation of 10s(-1) for 1000 repetitions, at an intensity 75dB above the threshold of the ear tested. Right-sided latencies for peak waves I, III, and V and the corresponding interpeak intervals (IPI) I-V, I-III, and III-V were chosen for analyses. Age correlated significantly with BAEPs, PbB, TWA, and IBL. Partial correlation analyses adjusting for age found PbB and TWA significantly associated with wave I latency r=0.13, P<0.01 and r=0.11, P<0.05, respectively, and IBL significantly associated with wave III latency r=0.16, P<0.01. The contribution of age, PbB, TWA and IBL to the variances of different BAEPs was assessed using multiple regression analysis. In the regression model of the full group, after the contribution of age, PbB and TWA accounted for significant variance of wave I, Deltar(2)=1.8, P<0.01 and Deltar(2)=1.2%, P<0.04, respectively, and IBL accounted for significant variance of wave III latency, Deltar(2)=2.8%, P=0.00 and I-III interpeak interval, Deltar(2)=1.4%, P<0.03. Four groups similar in age were created with increasing abnormalities based upon clinical cut-off scores for wave I latency and I-V interpeak interval. PbB, TWA, and IBL were significantly higher in the group with abnormalities of both latency in wave I and IPL I-V. Lead exposure interferes with BAEPs in a dose-dependent manner. Current lead exposure in this population of lead smelter workers preferentially affected conduction in the distal auditory nerve while chronic lead exposure appeared to impair conduction in the auditory nerve and the auditory pathway in the lower brainstem.

Pattern of blood lead levels over working lifetime and neuropsychological performance.

The authors examined the impact on neuropsychological performance of past high lead exposure, followed by lower proximate lead exposure, in 2 groups of smelter workers selected on the basis of their patterns of blood lead levels (BLLs) over time. Prior to 1980 (past exposure), both groups had more than 90% of their BLLs > or = 40 microg/dl. During and subsequent to 1980 (proximate exposure), those subjects with more than 90% of their BLLs remaining at > or = 40 microg/dl were assigned to the high-high (H-H) pattern group (n = 40); whereas those with 90% of levels below 40 microg/dl were assigned to the high-low (H-L) pattern group (n = 40). Means (and standard deviations) for pre-1980 time-integrated blood lead (IBL) levels were similar for the H-H pattern [633.2 (202.2) microg/yr-dl] and the H-L pattern [556.5 (144.8) microg/yr x dl]; however, IBLs from 1980 on were significantly different [H-H pattern = 646.9 (58.70) microg/yr x dl and H-L pattern = 408.8 (46.37) microg/yr x dl; p < 0.0001]. Age, education, and years of employment were similar for both groups. Examination of 5 neuropsychological measures revealed that verbal memory was significantly better in the H-L pattern group than in the H-H group. Multivariate examination of the data showed that pattern of exposure contributed significantly to verbal memory performance, after adjustment for the covariates, current BLL, and IBL. A partial correlation analysis between verbal memory and IBL for past high exposure showed an association with H-H pattern, but none with H-L pattern. Pattern of BLLs over a working lifetime contributed unique variance to verbal memory. Absence of an association between past high lead exposure and verbal memory in the H-L pattern group suggests that reversibility of function may occur when proximate BLL is maintained below 40 microg/dl.

Subclinical cerebellar anterior lobe, vestibulocerebellar and spinocerebellar afferent effects in young female lead workers in China: computerized posturography with sway frequency analysis and brainstem auditory evoked potentials.

By computerized static posturography with sway frequency analysis, subclinical effects of lead on postural balance was examined in 29 female workers (lead workers) employed at a glass factory for 3-17 (mean 7.9) years in Beijing, China, in relation to brainstem function assessed by brainstem auditory evoked potential (BAEP). Their blood lead concentrations ranged from 26 to 79 (mean 55.7) microg/dl; ages were 21-30 (mean 28) years. Control subjects, aged 22-29 (mean 27.0) years, were 14 healthy female workers at a textile factory located in the same district. With eyes closed, power of the sway of high (2-4 Hz) and low (1 Hz or less) frequencies in lead workers was significantly larger than that in controls; with eyes open, their power of the sway of low frequency was significantly larger (p<0.05). The multiple regression analysis showed that the power of high frequency sway with eyes closed and of low and high frequencies with eyes open were significantly related to blood lead concentrations in lead workers (p<0.05). On the other hand, no significant differences in BAEP latencies between lead workers and controls were observed. The low frequency sway with eyes open was significantly correlated with the high frequency sway with eyes closed in the lead workers. The pattern of changes in postural balance suggested that the anterior cerebellar lobe, vestibulo-cerebellar and spinocerebellar afferent systems were affected asymptomatically in female lead workers; the sway of vestibulo-cerebellar and anterior cerebellar lobe types were simultaneously affected by lead. It appears that a computerized static posturography with sway frequency analysis is useful technique for assessment of subclinical lead neurotoxicity.

Neurobehavioural testing in workers occupationally exposed to lead: systematic review and meta-analysis of publications.

Although the toxic effects of lead on the central nervous system have been well described, the blood concentration at which lead begins to exert adverse effects remains the focus of debate. A meta-analysis of occupational studies was conducted evaluating the association between neurobehavioural testing results and moderate blood lead concentrations.

A meta-analysis for neurobehavioural results due to occupational lead exposure with blood lead concentrations <70 microg/100 ml.

The size of performance effects caused by exposure to inorganic lead was determined by a meta-analytical procedure. Twenty-two studies covering exposure conditions of <70 microg/100 ml blood lead concentration were considered as to whether the methods of recording performance deficits were comparable. As a consequence of different test procedures and insufficient documented test results only 13 tests out of 12 studies could be included in the analysis. For the tests Block Design, Logical Memory and Santa Ana performance deficits were found, which may be interpreted as 'small' effects in accordance with a convention for evaluating effect sizes. For the example of Block Design it could be shown that these effects are nevertheless serious. The extent of the exposure related decrease of performance was comparable with those changes of performance which can be expected during aging of up to 20 years. Subsequently, a blood lead concentration of 70 microg/100 ml cannot be considered as a safe limit against long-term decreases of psychological performance.