Colder-to-warmer changes in children's blood lead concentrations are related to previous blood lead status: Results from a systematic review of prospective studies

ObjectiveTo estimate the extent of changes in mean BLLs from colder to warmer months, in children aged 1–5 years with different status of lead in colder months.MethodologyWe performed a systematic review using an in-house algorithm developed in MEDLINE, EMBASE, Web of Science, and CINHAL. Search was performed between November 2012 and July 2013, and data evaluation and extraction were subsequently conducted. The mean BLLs observed in the warmer months was divided by the one observed in the colder months to obtain the warmer-to-colder ratio (WCR). Study-specific WCRs were pooled using the fixed-effects method of Mantel–Haenszel to estimate the combined WCR.ResultsFrom 4040 papers initially identified, eight cohort studies were considered relevant for inclusion. The combined WCR was inversely related to the BLLs observed during colder months. The values were 1.25 (95% CI: 0.90–1.60), 1.06 (95% CI: 0.92–1.19), and 0.95 (95% CI: 0.51–1.39) for children showing baseline BLLs of <10 μg dL⁻¹, 10–20 μg dL⁻¹and ≥20 μg dL⁻¹, respectively. The combined WCR was influenced neither by children's age nor place/date of study.ConclusionThe extent of the summer increase in BLLs depends on the BLLs in the colder months.     

Comparison of biometric data of children with high and low levels of lead in the blood

This paper deals with a biometric study of 312 boys and girls, aged 2.5-16 years, living in an area with a long history of pollution by lead. The aim was to search for eventual relationships between ten biometric variables and measures of lead absorption in the bodies, i.e. the amount of lead in the blood (PbB), of these children. Standardized values of the biometric variables were compared in the high-PbB and low-PbB categories, by multivariate analysis of variance. Comparison of the vectors of the ten biometric variables reveals a significant difference between the two categories of PbB levels. We found some evidence that the younger children (below 8 years of age) are more likely to absorb lead in the body and are more vulnerable to the effects of subclinical lead intoxication than their older counterparts. The differences between the averages of biometric variables in the two PbB categories are consistently (although not significantly) greater among younger children. This trend disappeared in the older age group. These results confirm data from the literature that young children are especially at risk. It can be concluded that there is a subtle, but significant, influence of lead absorption on the biometric profiles of children and that this effect is probably more important in children below 8 years of age.     

Bioaccumulation of lead nitrate in tissues and its effects on hematological and biochemical parameters of Clarias gariepinus

Clarias gariepinus, weighing 119.18 ± 5.21 g, were exposed to 0%, 20%, 40%, and 60% of the LC₅₀ lead nitrate, Pb(NO₃)₂, which represents the following treatments 0 (control), 16, 32, and 48 mg/l, respectively, for a period of 10 and 20 days. The results showed that the bioaccumulation of Pb(NO₃)₂ in gills were significantly increased (p < 0.05) after 10 days having 0.17 ± 0.07, 5.05 ± 1.04, 6.01 ± 0.82, and 9.61 ± 1.76 mg/100 g wet weight, respectively, for the treatments. However, after 20 days these values increased ((0.17 ± 0.07, 4.34 ± 1.27, 10.83 ± 0.97, and 19.18 ± 2.40 mg/100 g) for 0%, 20%, 40%, and 60% of LC₅₀ Pb(NO₃)₂ respectively. There was an increase with each increasing concentration level of Pb(NO₃)₂ as compared with that of the control group. The accumulation of Pb(NO₃)₂ in the liver, showed a significant increase (p < 0.05) with the increasing period of exposed and Pb concentration with LC₅₀ values ranging between 3.32 ± 0.91 and 4.42 ± 0.78 after 10 days as compared with that of the control group 0.08 ± 0.02 mg/100 g wet weight. Although white muscles and skin displayed lower values of bioaccumulation than gills and liver after 10 days, after 20 days the results were slightly more increased in the white muscles than in the skin. However, the observed pattern of increase was the same compared to that of the control group. Therefore, hematological parameters, such as red blood cells (RBCs), hemoglobin (Hb), and hematocrit (Hct) showed significant (p < 0.05) concentration-dependent decreases in fish exposed to Pb(NO₃)₂ during both periods. However, the values of white blood cells (WBCs) showed a significant reduction when levels of Pb concentration increased. Hepatic enzyme activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) displayed a significant increase with increasing concentrations and exposure time.     

Plasma and erythrocyte lipid peroxide levels in workers with occupational exposure to lead

The plasma and erythrocyte lipid peroxide levels were measured in a group of male subjects occupationally exposed to lead for an average period of 17 yr, and compared to those from an age-matched control group living in the same city in a similar socioeconomical environment. The blood lead and plasma zinc levels were measured by atomic absorption spectroscopy. The plasma and erythrocyte lipid peroxide levels were established by the malondialdehyde determination method. Significant differences were found in the blood lead levels in lead-exposed workers, 15.00±10.15 μg/dL as compared to controls, 2.37±0.89 μg/dL. The plasma (2.67±0.69 μM) and erythrocyte (27.53±6.28 nmol/g Hb) lipid peroxide levels in workers with occupational exposure to lead were significantly higher than controls, 1.23±0.61 μM and 14.35±2.08 nmol/g Hb, respectively. There were no significant differences of the zinc levels in both groups. The blood lead levels had a statistically significant positive correlation with age and with duration of exposure in both groups, but showed no relationship to the corresponding blood zinc levels. The results presented in this study indicate that the increase of plasma and erythrocyte lipid peroxide levels in workers exposed to lead may be related to the lead concentration, age and duration of exposure.     

Association of blood lead levels with neurobehavior and BDNF expression in school going children

BackgroundChildhood Lead (Pb) toxicity has been an ongoing concern for decades; however, its underlying pathogenesis remains unclear. Although its prevalence has come down in developed countries (USA, Europe); it is relatively high in low to middle-income countries of South-East Asia. The current study aimed to evaluate the association of blood lead levels (BLLs) with neurobehavioral alterations and changes in Brain-Derived Neurotropic Factor (BDNF) expression in Indian school children.MethodologySchool going children in age group of 9–15 years (N = 72) were included in the study. Neurobehavioral changes were assessed using Childhood Psychopathological Measurement Schedule (CPMS) and BLL were measured by Graphite Furnace Atomic Absorption Spectrophotometry (GFAAS). BDNF mRNA expression and serum BDNF levels were assessed by Real-Time PCR and ELISA, respectively.ResultsMedian BLL was 4.95 μg/dL (IQR = 4.47), very close to the recommended toxic cut off levels (<5 μg/dL). BLLs had a direct correlation with both CPMS scores and BDNF expression. Depression was found to be significantly higher in boys than in girls with high BLLs. BDNF mRNA expression and serum BDNF levels were higher among children with high BLL, although not to significant levels.ConclusionWe report a significant association of neurobehavioral changes with the prevalence of high Pb levels in Indian children. Additionally significant correlation of BDNF with BLL in these children suggests a causal role of BDNF in Pb induced neurological damage.     

Comparative assessment of the effects of salinomycin and monensin on the biodistribution of lead and some essential metal ions in mice,subjected to subacute lead intoxication

In this study, we present a comparative assessment of the effects of two polyether ionophorous antibiotics (monensin and salinomycin) on the concentrations of lead (Pb), cooper (Cu), zinc (Zn) and iron (Fe) in the kidneys, spleen, liver and brain of Pb-intoxicated animals. Our data demonstrated that the intoxication of ICR male mice with Pb salt resulted in a significant accumulation of Pb in all studied organs of the mice compared to the untreated control animals. The biodistribution of the toxic metal was in the order kidneys > spleen > liver > brain. The treatment of the Pb-intoxicated animals with tetraethylammonium salts of monensic and salinomycinic acids significantly decreased the concentration of the toxic metal ion compared to the toxic control. The effect varied in the interval 38% (for kidneys) to 52% (for brain) compared to the toxic control group (Pb). The tetraethylammonium salt of salinomycinic acid was more effective in reducing the Pb concentration in the brain of the Pb-treated mice compared to monensin. Pb-intoxication did not affect significantly the Zn endogenous concentration compared to the normal values. The treatment of ICR male mice with Pb-salt decreased the Cu concentration in the spleen and increased the Cu concentration in the liver compared to the untreated control animals. The detoxification of the Pb-intoxicated mice with tetraethylammonium salts of salinomycinic and monensic acids restored the Cu concentration in the spleen, but did not affect the Cu levels in the liver. The Pb-intoxication of the ICR mice resulted in a significant decrease of the Fe-concentration in the spleen and liver compared to the untreated control animals. The administration of the tetraethylammonium salts of salinomycinic and monensic acids to the Pb-treated animals restored the levels of Fe in both organs.     

Blood lead levels in children from Sardinian villages at high risk of environmental crisis

This study reports blood lead levels measured in 1998 in children from three Sardinian villages: Portoscuso, Sant'Antioco, and Sestu. Portoscuso is located about 2 km from one of the most important industrial complexes in Sardinia. Sant'Antioco, together with the villages of Carbonia, Gonnesa, Portoscuso and San Giovanni Suergiu, is in the Sulcis-Iglesiente zone, defined as an “area of high risk of environmental crisis” on the basis of the Decree of the Italian Council of Ministers dated November 30, 1990. Sestu, a semi-urban centre about 10 km from Cagliari (the island's capital), can be considered not exposed to lead pollution. Blood lead concentration was determined in heparinized venous blood samples by graphite furnace atomic absorption spectrophotometry. Comparing the mean blood lead levels for the boys of Portoscuso measured in 1993 (9.27 μg/dl) and 1998 (11.30 μg/dl), we found an increase of 21.90%, whereas the mean values for the girls are practically identical in 1993 (7.35 μg/dl) and 1998 (7.39 μg/dl). In contrast, in the boys and girls of Sestu, the mean blood lead levels decrease from 1993 to 1998 by 55.62% and 29.09% respectively (from 6.71 μg/dl to 4.09 μg/dl in the boys; from 4.71 μg/dl to 3.34 μg/dl in the girls). In the Sant'Antioco children, we found a 52.65% decrease from 1987 (8.30 μg/dl reported for a sample not subdivided by sex)) to 1998 (3.93 μg/dl for males and females combined). Our results confirm the findings of previous investigations of blood lead levels in children from Sardinian villages with different environmental risks of lead pollution: the children of Portoscuso present higher blood lead levels than other groups of Sardinian children.     

Evidence that cognitive deficit in children is associated not only with iron deficiency,but also with blood lead concentration: A preliminary study

ObjectiveTo investigate whether blood lead concentrations are elevated in iron-deficient children, and to examine the association between iron deficiency and/or elevated blood lead concentration and cognitive deficits in children.MethodThe present study is a component of the Mothers’ and Children's Environmental Health (MOCEH) study, a multi-center birth cohort project in Korea that began in 2006. The study cohort consisted of 194 children who underwent testing of blood lead and serum C-reactive proteins (CRPs) and ferritin concentrations, and the Korean version of the Wechsler Preschool and Primary Scale of Intelligence, revised edition (WPPSI-R), at 60 months of age. In addition, the mothers’ blood lead concentrations during pregnancy were included in the analyses. Multivariate linear regression analysis was performed to analyze the correlation between high blood lead and low serum ferritin concentrations, after adjustment for covariates, in children, as well as to analyze the association of verbal IQ with serum ferritin and blood lead concentrations.ResultsLead and ferritin concentrations were inversely and significantly associated in children after adjustment for covariates. Moreover, both concentrations were associated with verbal IQ, after adjustment for covariates, and each was associated with cognitive deficits after adjustment for the other. Sobel test statistics showed that blood lead concentration was a significant partial mediator for the relationship between iron deficiency and verbal IQ.ConclusionDue to the results discussed in the present study, cognitive deficit in children seems to be associated not only with iron deficiency, but also with blood lead concentration.     

An assessment of time-dependent effects of lead exposure in algerian mice (Mus spretus) using different methodological approaches

Time-dependent effects of lead (Pb) toxicity were studied in Algerian mice (Mus spretus) treated with Pb acetate via drinking water (1 g Pb acetate/L) for different periods of exposure (15, 45, and 90 d). End points included the determination of hepatic Pb concentration and the assessment of some morphophysiological, biochemical and cytogenetical parameters. A control group receiving distilled water was also monitored for comparative purposes. Hepatic Pb accumulation increased with the time of exposure and was significantly higher in treated mice when compared to controls. In association with significant body mass loss in Pb-exposed mice, for 15 and 45 d, a significant increase in the relative spleen mass was observed after 45 d of intoxication. Pb-exposed mice also showed significant decreases in red blood cells, hematocrit, and mean corpuscular hemoglobin. On the contrary, changes in plasma transferases (aspartate aminotransferase and alanine aminotransferase) and hepatic superoxide dismutase activities did not reach statistical significance. A significant increase in the frequency of micronucleated polychromatic bone marrow erythrocytes was also found in the 90-d-exposed mice, compared to nontreated mice and the other exposed groups. Exposure to Pb acetate resulted also in a slight time-dependent decrease of the polychromatic-normochromatic ratio. These results support the concept that a long-term chronic exposure to Pb induced alterations upon some morphophysiological and genetic paramaters in Algerian mice.     

Blood lead level and its relationship to essential elements in preschool children from Nanning,China

ObjectiveOur study aimed to assess the distribution of blood lead level and its relationship to essential elements in preschool children in an urban area of China.Design and methodsA total of 6741 children aged 0- to 6-year-old were recruited. Levels of lead, zinc, copper, iron, calcium, and magnesium in whole blood samples were determined using atomic absorption spectrometry.ResultsThe mean blood lead level (BLL) and the prevalence of BLL ≥ 10 μg/dl (5.26 ± 4.08 μg/dl and 6.84%, respectively) increased with age gradually, and there was a gender-difference for blood lead, copper, zinc and iron levels. Compared with the group of children who had BLLs < 5 μg/dl, the groups of 5 ≤ BLLs < 10 μg/dl and 10 ≤ BLLs < 15 μg/dl showed higher blood zinc, iron and magnesium levels, and a lower blood calcium level. A positive correlation of lead with zinc, iron and magnesium, and a negative correlation of lead with calcium were found in the group of children with BLL < 5 μg/dl.ConclusionAge- and gender-differences were found when assessing the BLL and intoxication prevalence in preschool children. Metabolic disorder of essential elements was found even with a low level of lead exposure.     

Biokinetics of lead in various organs of rats using radiotracer technique

Uptake, distribution, and elimination of lead in various organs of rats have been studied using a radiotracer technique. The elimination data for various organs, except whole blood, is fitted to a double-exponential function using a computer program. The biological half-lives along with the percent elimination of lead by two different decay modes in testis, epididymis, prostate, and seminal vesicles are being reported together with that in liver, kidney, blood, and whole body. It is evident from this study that the elimination of lead is limited for all the organs and permits lead accumulation in the bone, where it is stored and becomes almost unavailable for elimination. Lead levels in blood, testis, and femur of lead acetate-fed rats measured using atomic absorption spectroscopy have been correlated to the uptake of²¹⁰Pb in various organs.     

Relationship of lead and essential elements in whole blood from school-age children in Nanning,China

ObjectivesThe aim of this study was to investigate blood lead level and its relationship to essential elements (zinc, copper, iron, calcium and magnesium) in school-age children from Nanning, China.MethodsA total of 2457 children aged from 6 to 14 years were enrolled in Nanning, China. The levels of lead (Pb), zinc (Zn), copper (Cu), iron (Fe), calcium (Ca) and magnesium (Mg) were determined by an atomic absorption spectrometer.ResultsThe mean blood lead level (BLL) was 57.21 ± 35.00 μg/L. 188 (7.65%) asymptomatic children had toxic lead level higher than 100 μg/L. The school-age boys had similar lead level among different age groups, while the elder girls had less BLL. The blood Zn and Fe were found to be increased in the boys with elevated BLL, but similar trends were not observed in the girls. Positive correlations between Pb and Fe or Mg (r = 0.112, 0.062, respectively, p < 0.01) and a negative correlation between Pb and Ca (r = −0.047, p < 0.05) were further established in the studied children.ConclusionsLead exposure in school-age children was still prevalent in Nanning. The boys and girls differed in blood levels of lead and other metallic elements. Lead exposure may induce metabolic disorder of other metallic elements in body.     

Decreased thiamine and magnesium levels in the potentiation of the neurotoxicity of lead in occupational lead exposure

The relationship between blood lead (Pb) and serum levels of calcium and of neural nutrients such as thiamine and magnesium (Mg) has been determined in a Nigerian population that is occupationally exposed to Pb. Forty-seven male Pb workers were recruited as test subjects and 25 males unexposed to Pb served as controls. The test subjects were classified into three groups, based on severity of exposure to Pb. Blood lead (BPb) and the serum levels of Mg, thiamine, and calcium were determined in both test subjects and controls. The mean blood Pb level was not significantly higher in Pb workers. In contrast, Mg and thiamine levels were significantly decreased (p<0.05; p<0.01, respectively). However, the calcium level was not significantly lower in test subjects than in controls. Also, there was a significant negative correlation between serum thiamine and blood Pb levels (r=-0.50; p<0.01). Furthermore, there was a significant negative correlation between serum calcium and BPb levels (r=-0.41; p<0.01). This study has shown that relatively low BPb levels can enhance Pb absorption and also potentiate Pb neurotoxicity in the presence of decreased serum thiamine and Mg levels.     

Influence of L-lysine and zinc administration during exposure to lead or lead and ethanol in rats

Influence of lysine and zinc administration on the lead-sensitive biochemical parameters and the accumulation of lead during exposure to lead or lead and ethanol was investigated in rats. The lead exposure inhibited blood δ-aminolevulinic acid dehydratase (ALAD) activity, increased blood zinc protoporphyrin (ZPP), urinary δ-aminolevulinic acid (ALA), serum glutamic oxalacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), blood and tissue lead levels, and decreased blood and hepatic glutahione (GSH) contents. Some of these effects were enhanced on coexposure to ethanol. The simultaneous administration of lysine and zinc reduced tissue accumulation of lead and most of the lead-induced biochemical alterations irrespective of exposure to lead alone or lead and ethanol. The depletion of endogenous calcium and magnesium owing to lead or ethanol exposure was also prevented by co-administration of lysine and zinc.     

成人脂肪肝与体重指数和血脂水平的关系研究

目的:研究成人脂肪肝与体重指数(BMI)和血脂水平的关系。方法:选取2012年1月到2014年11月我社区成年人800例,检测所有入选者的体重和身高,并计算BMI,检测入选者的血脂水平和脂肪肝情况,应用Logistic回归分析来分析脂肪肝与BMI和血脂之间的关系。结果:共检测出脂肪肝376例,占47.0%,肥胖者532例,占66.5%;肥胖者伴随脂肪肝的发生率64.7%,显著高于非肥胖者脂肪肝的发生率11.9%,两者比较差异具有统计学意义(P0.05);脂肪肝者总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白(LDL-C)显著高于非脂肪肝者,而高密度脂蛋白(HDL-C)显著低于非脂肪肝者,两者比较差异具有统计学意义(P0.05);Logistic回归分析显示:脂肪肝与BMI和血脂之间存在相关关系(P0.05)。结论:BMI和血脂水平与成人脂肪肝存在较大关系,应该注意控制体重,进而降低脂肪肝的发生率,改善脂肪肝的情况。     

Low level lead (Pb) exposure during gestation and lactation: assessment of effects on pubertal development in Fisher 344 and Sprague-Dawley female rats

Studies using both Fisher 344 and Sprague-Dawley (SD) rat lines have shown that gestational and/or lactational maternal lead (Pb) exposure causes delayed reproductive maturation in their respective female offspring. Because these studies utilized different experimental regimens for dosing and for monitoring Pb levels, it has not been possible to determine which rat line provides the best model for low level Pb toxicity studies. This study was designed to address this issue. Adult Fisher and SD female rats were dosed with either a solution of PbAc containing 12 mg of Pb/ml or sodium acetate (NaAc) for controls. Dosing began 30 days prior to breeding and continued until their pups were weaned at 21 days of age. At the time of breeding and through weaning the blood lead (BPb) levels in the Fisher dams averaged 37.3 microg/dl and the SD dams averaged 29.9 microg/dl. Pb delayed the timing of puberty (p < 0.01) in Fisher offspring, and suppressed serum levels of luteinizing hormone (LH, p < 0.001) and estradiol (E2, p < 0.01). These effects did not occur in the SD offspring. Doubling the dose given to the SD rats increased their BPb levels to 62.6 microg/dl, yet there were still no effects noted. These results indicate that Fisher offspring are more sensitive to maternal Pb exposure with regard to puberty related insults than are SD rats, suggesting that the Fisher line may be a more reliable rodent model to study the effects of low level Pb toxicity.     

The prevalence of wheezing and its association with serum zinc concentration in children and adolescents in Brazil

ObjectiveTo assess the influence of zinc serum status on the prevalence of wheezing in a sample of children and adolescents in Northeastern Brazil.Research methods and proceduresThis is a cross-sectional study which included 592 students of 6–12 years old, from the public elementary schools of São Francisco do Conde, Bahia, Northeastern Brazil. Report of wheezing in the past 12 months was collected using a questionnaire of the International Study of Asthma and Allergies in Childhood Program (ISAAC) phase III, adapted to Portuguese. The determination of serum Zn levels was performed using a flame atomic absorption spectrometer. Data on anthropometric status, level of physical activity, pubertal development and socioeconomic information, for each participant were obtained. Multivariate logistic regression analyses were used to assess the associations of interest.ResultsOf the students, 8.6% (95% CI 6.30–10.9) reported having wheezing. The mean (SD) serum zinc level was 114 (22.9 μg/dL). The results of the multiple logistic regression analysis showed, after adjustments, positive and significant association between low serum zinc levels and wheezing. Students categorized as being below the median for serum Zn concentration presented an almost 1.9-fold increase in the wheezing prevalence ratio (OR = 1.9; 95% CI 1.03–3.53).ConclusionThe main findings of this study suggest that the level of zinc may influence the risk of wheezing in late childhood on the study population.     

红腹锦鸡、石鸡和雉鸡的部分血液生理生化指标

为了解红腹锦鸡、石鸡和雉鸡的血象、血液生理生化参数正常值及其特点,为人工饲养繁殖与健康检测提供参考资料,采用改良纽巴氏法、沙利氏比色法、离心法、瑞氏染色等方法和全自动血液生物化学分析仪对红腹锦鸡、石鸡和雉鸡的血象和16项生化指标进行了测定,通过SDS-PAGE分析了血浆蛋白质。结果表明:红腹锦鸡的平均红细胞体积、淋巴细胞、嗜酸性粒细胞、嗜中性粒细胞、血浆总蛋白、血浆白蛋白、血浆钠和血浆氯在性别之间有显著差异,所测其它生理生化指标在性别之间无显著差异;红腹锦鸡的红细胞、平均红细胞体积、凝血细胞、尿素氮和肌肝与石鸡和雉鸡存在显著差异,红腹锦鸡与石鸡的白细胞存在显著差异,所测其它生理生化指标在三者之间无显著差异。种属不同可能是导致3种雉科鸟类血液生理常值差别的主要原因,而采样时的机体状况、营养状况及测试操作方法也有一定的影响。     

Lead exposure in children: Levels in blood, prevalence of intoxication and related factors

Lead is a highly toxic metal, the main source of which iscontamination from combustion of unleaded petrol.The aims of this work were todetect the degree of lead exposure in a large sample of children; determinetherelationship between blood lead levels (BPb) and age, sex, habitat and season of the year;andcorrelate BPb with zinc protoporphyrin (ZPP) values. A cross-sectional study wascarried out. Blood fromroutine extractions drawn at our centre was used. BPb and ZPP weremeasured by atomic absorptionspectrophotometry and haematofluorimetry,respectively. We analysed 1158 blood samples from children.BPb (mean ± SEM): 0.22 ±0.04 mol l . Correlation BPb-age: BPb = 0.19 + 0.086 x age (months),r =0.129, P < 0.0001. BPb was greater in boys (0.23 ± 0.007 versus 0.20 ±0.006 mol l , P < 0.0002).No differences were observed between habitats(urban versus rural). BPb were higher in the warm months(0.24 ± 0.013versus 0.21 ± 0.007 mol l , P < 0.0001). Prevalence of lead intoxication (BPb > 0.48 mol l )was 4.2%. No differences in prevalence were found among the different groups. The correlationbetweenBPb and ZPP showed r = 0.0969, P = 0.0024. Utility for screening:sensitivity of 53.7% and specificity of 59.3% (cut-off point of 60 mol ZPPmol haem). We can conclude that lead exposure in children inoursample was in the range reported in similar studies in other areas andcountries, and below the toxic limit.None of the factors analysed significantlyinfluenced lead intoxication prevalence. There was no goodcorrelationbetween ZPP and BPb in our sample and the ZPP cut-off point used did not presentgoodspecificity and sensitivity values.     

An ultrasound study of the effect of chronic lead exposure on endometrial cycle changes in the female cynomolgus monkey.

The effect of up to 10 years of lead (Pb) exposure (1500 micrograms/kg BW/day) on endometrial cycle changes in adult cynomolgus monkeys (n = 30) were examined by real-time ultrasound. Pb exposure had no effect on peak serum estradiol (E2) or progesterone (P4) concentrations, menstrual cycle length, and endometrial response to gonadal steroids as determined by ultrasound.