Urinary Lead Levels Research Articles

Simultaneous Determination of Chromium, Cadmium, and Lead and Evaluation of the Correlation between Chromium and Cotinine in Chinese Smokers

Heavy metals in tobacco caused wide public concern. To study the impact of heavy metals in smokers, 193 smokers and 58 nonsmokers were surveyed, and their urinary levels of chromium (UCr), lead (UPb), and cadmium (UCd) were assayed. In this study, UCr, UPb, and UCd in smokers (33.41 ± 14.99, 3.21 ± 1.34, 0.38 ± 0.64 μg/24 h, respectively) and nonsmokers (27.45 ± 10.49, 3.02 ± 0.88, 0.20 ± 0.16 μg/24 h, respectively) were determined by inductively coupled plasma mass spectrometry. The results showed that the content of UCr, UPb, and UCd in smokers were higher than in nonsmokers. Further analyses of correlations between the levels of urinary chromium and cotinine revealed positive relationship (correlation coefficient r = 0.51).

The Role of Urinary Cadmium and Lead Level on Pregnant Women Renal Function

Cadmium (Cd) and lead (Pb) are heavy metals which used in many industry and were confirmed as environmental toxin and mainly effects reproductive system and toxic to growing fetus. Determination of cadmium and lead level generally measure by spectrophotometric methods. But in this study, we used a method based on approach adjusting specific gravity. This study aimed to evaluate the potential effect of cadmium and lead exposure on pregnancy outcome by measuring their correlation on renal function. This study was performed between January to May 2013 and targeted 57 pregnant women as the control group (32 patients of normal pregnancy) and case group (25 patients of preeclampsia). For analyzing of the data, SPSS software version 17 was used and was examined by Mann- Whitney test and Spearman correlation test. We found that there are significant correlation between Cd an Pb exposure on urea level, urea-creatinine ratio, and GFR of the pregnancy patients (p < 0,05) but unlike to the creatinine serum. 

Assessment of Adult Bone Health by Lead Burden

Background: Lead exposure continues to be an important issue for human health. Previous studies indicated that lead may directly affect osteoblast and osteoclast function, and indirectly influence bone turnover due to kidney dysfunction. Some animal research also demonstrated that lead exposure was associated with decreasing bone mineral density. However, the evidence from the human study is lacking. Aims: Our objective is to investigate the association between lead exposure and adult bone health. Methods: Participants' data (n=439) were drawn from the Nutrition and Health Survey in Taiwan (NAHSIT) for 2005-2008. It was a national survey with high representativeness in Taiwan. Bone health was divided into normal (T-score &gt; -1), osteopenia (T-score between -1 and -2.5) or osteoporosis (T-score &lt; -2.5). We used inductively coupled plasma mass spectrometry (ICP-MS) to analyze urinary cadmium and urinary lead levels. Every participant completed the questionnaire including their education, household income, smoking status, alcohol consumption, diet supplement consumption, and outdoor activity. Results: In multivariable logistic regression, increasing age (OR = 1.07; 95% CI = 1.04-1.10; p &lt; 0.001), former smoker (OR = 2.99; 95% CI = 1.20-7.44; p = 0.01) and high urinary lead level (OR = 1.98; 95% CI = 1.00-3.90; p = 0.04) were found to be associated with osteopenia or osteoporosis. After further stratification by gender, increasing age still associated with osteopenia or osteoporosis in both men and women. High urinary lead level was observed to increase risk of osteopenia or osteoporosis in women (OR = 2.66; 95% CI = 1.01-7.06; p = 0.04), but not in men. Conclusions: The results suggest that women with high urinary lead level have higher risk of osteopenia or osteoporosis.

The Impact of Lead-acid Battery Manufacturers on the Environment and Human Lead Burden

Aim: In order to understand the impact of lead-acid battery manufacturers on the environmental and the human health, we viewed and summarized lead level in the workplace of lead-acid battery manufacturers and surrounding environment, as well as the burden of lead in workers and nearby children. Methods: Through the dataset of CNKI, Science Direct database, PUBMED and Google Scholar we searched published articles reported the survey on the lead-acid battery manufacturers from 1990 to 2011. Finally, 45 articles were selected, which covered 34 battery manufacturers from 34 cities in 15 provinces, China. Results: The range of reported average lead dust and lead fume in the workplace were 0.032?2.880 mg/m3 and 0.027?0.710 mg/m3, respectively?which exceeded national standard limitation with proportion of 0.0?100.0% and 25.0?95.6%. The reported average blood lead level (BLL) and urinary lead level of workers were 138.0?869.4?g/L and 0.28?1.24?mol/L. Of them, 0.0?100.0% and 4.8?74.4% were reported higher than the occupational exposure limits. The lead levels in the atmosphere, surface water and soil around the lead-acid battery manufacturers were 0.0004?1420.0mg/ m3, 0.003?29.925mg/L and 0.05?2980.00 mg/kg, respectively. The average BLLs of children nearby lead-acid battery manufacturers were 91.20?531.68?g/L, the percentage of elevated blood lead level was 8.9%?97.1%. Conclusion: There were series lead pollution in the workplace of lead-acid battery factories, China. The burden of lead for workers is higher, too. The surroundings nearby the battery factory have been contaminated by lead as well. The BLLs of children living around the battery factory was higher than those living in urban or rural districts without lead-emission industrious enterprise. Funded by the National Basic Research Program (973) of China (NO.2012CB525005) and the CRAES Basic Scientific R &amp; D Business Special for the Central Nonprofit Research Institutes (NO. 2009KYYW19)

Toxicological Status of Children with Autism vs. Neurotypical Children and the Association with Autism Severity

This study investigates both the level of toxic metals in children with autism and the possible association of those toxic metals with autism severity. This study involved 55 children with autism ages 5-16 years compared to 44 controls with similar age and gender. The study included measurements of toxic metals in whole blood, red blood cells (RBC), and urine. The autism group had higher levels of lead in RBC (+41 %, p = 0.002) and higher urinary levels of lead (+74 %, p = 0.02), thallium (+77 %, p = 0.0001), tin (+115 %, p = 0.01), and tungsten (+44 %, p = 0.00005). However, the autism group had slightly lower levels of cadmium in whole blood (-19 %, p = 0.003). A stepwise, multiple linear regression analysis found a strong association of levels of toxic metals with variation in the degree of severity of autism for all the severity scales (adjusted R(2) of 0.38-0.47, p < 0.0003). Cadmium (whole blood) and mercury (whole blood and RBC) were the most consistently significant variables. Overall, children with autism have higher average levels of several toxic metals, and levels of several toxic metals are strongly associated with variations in the severity of autism for all three of the autism severity scales investigated.

Biochemical Effects of Lead Exposure on Battery Manufacture Workers with Reference to Blood Pressure, Calcium Metabolism and Bone Mineral Density

Lead is one of the most widely scattered toxic metals in the environment and used by mankind for over 9,000years. Lead in the environment may be derived from natural or anthropogenic sources. In humans, lead can cause a wide range of biological effects depending upon the level and duration of exposure. The purpose of this study was to find out the effect of lead exposure on systolic and diastolic blood pressure, serum calcium, ionized calcium, phosphorus, parathyroid hormone and vitamin D and examine the overall effect of all these parameters on the bone mineral density of battery manufacture workers. For this study ninety battery manufacture workers were selected and divided in three groups depending upon duration of lead exposure. Group I-workers with duration of lead exposure 1-5years, Group II-workers with duration of lead exposure 6-10years and Group III-workers with duration of lead exposure more than 10years. Each group consisted of thirty workers. Thirty age matched healthy control subjects were taken for comparison. Demographic, occupational and clinical data were collected by using questionnaire and interview. The venous blood samples were collected from the study groups and normal healthy control group. At the time of blood collection random urine samples were collected in amber coloured bottles. The biochemical parameters were estimated by using standard assay procedures. Statistical analysis of the data was done using independent student't' test for parametric variables. Values were expressed as mean±standard deviation (SD). P values of 0.05 or less were considered to be statistically significant. The blood lead levels and urinary lead levels of all workers were significantly increased (P<0.001) in proportion to the duration of lead exposure as compared to controls. Systolic and diastolic blood pressure were significantly raised (P<0.001) in all three study groups of battery manufacture workers as compared to controls. Serum Calcium, Ionized calcium, phosphorus were significantly decreased (P<0.001) in all the three study groups. Serum vitamin D levels were lowered (P<0.01) and serum PTH was increased (P<0.01) in workers as compared to controls. The results of this study clearly indicate that the absorption of lead is more in these workers which adversely affects blood pressure, disturbs calcium and phosphorus metabolism which further impairs mineralization of bone resulting in decreased bone mineral density observed in these workers. Lead toxicity is still persistent in battery manufacture workers though they are using sophisticated techniques in these industries. There is a need to protect the workers from the health hazards of occupational lead exposure.

Low-level environmental exposure to lead and renal adverse effects: A cross-sectional study in the population of children bordering the Mbeubeuss landfill near Dakar, Senegal

This study deals with the health effects within a child population, neighbouring a landfill. After detecting metals in soil and air samples collected in the surroundings of the landfill and in a control site, we have studied: (i) levels of lead (Pb) and exposure biomarkers in blood and urine, (ii) oxidative stress biomarkers and (iii) renal injury by applying a set of early effect biomarkers. Levels of Pb were higher in the exposed site (i.e. 1129 mg/kg and 640 ng/m(3) in soil and air samples, respectively) versus those in the control site (i.e. 14.3 mg/kg and 9.3 ng/m(3) in soil and air samples, respectively). Pb impregnation and levels of delta-aminolevulinic acid in urine were influenced by the living site that shows the prevailingly alarming situation in the Mbeubeuss landfill. Malondialdehyde changes indicated Pb-induced excessive production of reactive oxygen species. Lactate dehydrogenase activities and proteinuria were found to be higher in the children living in the exposed site. These evidences may reveal the usefulness of these two effect biomarkers to monitor the kidney injury entailed by relatively low-environmental exposure to Pb. Overall, these results show that the Mbeubeuss landfill constitutes a real source of environmental and health risk, be it living or working on site, of the surrounding population, predominantly for children.

Effect of fluoride exposure on the intelligence of school children in Madhya Pradesh, India.

Objective:To assess the relationship between exposure to different drinking water fluoride levels and children's intelligence in Madhya Pradesh state, India.Materials and Methods:This cross-sectional study was conducted among 12-year-old school children of Madhya Pradesh state, India. The children were selected from low (< 1.5 parts per million) and high (≥1.5 parts per million) fluoride areas. A questionnaire was used to collect information on the children's personal characteristics, residential history, medical history, educational level of the head of the family, and socioeconomic status of the family. Levels of lead, arsenic, and iodine in the urine and the levels of fluoride in the water and urine were analyzed. The children's intelligence was measured using Raven's Standard Progressive Matrices. Data analysis was done using the chi-square, one way analysis of variance, simple linear regression, and multiple linear regression tests. P value <0.05 was considered statistically significant.Results:Differences in participant's sociodemographic characteristics, urinary iodine, urinary lead, and urinary arsenic levels were statistically not significant (P>0.05). However, a statistically significant difference was observed in the urinary fluoride levels (P 0.000). Reduction in intelligence was observed with an increased water fluoride level (P 0.000). The urinary fluoride level was a significant predictor for intelligence (P 0.000).Conclusion:Children in endemic areas of fluorosis are at risk for impaired development of intelligence.

Associations between microRNA (miR-21, 126, 155 and 221), albuminuria and heavy metals in Hong Kong Chinese adolescents

Background and aimPathogenetic mechanisms underlying albuminuria are not completely understood. Heavy metals might lead to atherosclerosis and kidney damage. miR-21, 126, 155 and 221 regulated endothelial function and might contribute to the development of albuminuria. To date, no clinical trial has explored the relationship between miRNAs, microalbuminuria and heavy metals in human. In this study, we aimed to examine the association between microalbuminuria, miRNAs and heavy metals in adolescents. Materials and methodsFrom a cross-sectional, population-recruited study, we identified 60 school children aged 12–19years with microalbuminuria (defined as spot urine albumin–creatinine ratio >3.5mg/mmol). We compared the urine heavy metals (arsenic, mercury, cadmium and lead) and miRNAs levels (miR-21,126, 155 and 221) with another 60 age-and sex-matched normoalbuminuric adolescents as control. ResultsMean age of the study cohort was 15.5±2.1years. 43% were boys. Among the four miRNAs tested, only miR-21 was associated with microalbuminuria (p=0.02). Urinary arsenic and lead levels had a negative association with both miR-21 and miR-221. No significant association was found between heavy metals examined and microalbuminuria. ConclusionThe results of our study suggest an association between microalbuminuria, miR-21 and heavy metals (arsenic and lead). This might imply that miR-21 is involved in the pathogenetic mechanisms linking heavy metals exposure and albuminuria.

Elevated risk of hypertension induced by arsenic exposure in Taiwanese rural residents: possible effects of manganese superoxide dismutase (MnSOD) and 8-oxoguanine DNA glycosylase (OGG1) genes

Heavy metals, including arsenic and lead, may lead to cellular oxidative damage that is linked to hypertension. Manganese superoxide dismutase (MnSOD) is a scavenger of reactive oxygen species, and 8-oxoguanine DNA glycosylase (OGG1) is the major glycosylase that repairs DNA lesions. Interestingly, whether there is an elevated risk of hypertension with arsenic or lead exposure in individuals with genetic variations in MnSOD or OGG1 has not yet been investigated. Questionnaires were administered to 240 Taiwanese rural residents. Blood pressure and biochemical indicators were assessed in each subject. Urinary levels of arsenic and lead were measured with atomic absorption spectrometry; and MnSOD and OGG1 genotypes were identified via polymerase chain reaction. There was a dose-response relationship between urinary arsenic levels and risk of hypertension (P = 0.021, test for trend). However, there was no association between urinary lead levels and hypertension risk. Individuals with high urinary arsenic levels and the MnSOD Val-Ala/Ala-Ala genotypes had a greater risk of hypertension than those with low urinary arsenic levels and the MnSOD Val-Val genotype (odds ratio [OR] = 4.2, 95% confidence interval [CI] = 1.7-10.3). Subjects with a high urinary arsenic level and the OGG1 Cys-Cys genotype also had a greater risk of hypertension than those with a low urinary arsenic level and the OGG1 Ser-Ser/Ser-Cys genotypes (OR = 3.4, 95% CI = 1.1-10.7). Thus, both MnSOD and OGG1 genotypes may be prone to an increased risk of hypertension associated with arsenic exposure.

Biochemical effects of lead exposure on systolic & diastolic blood pressure, heme biosynthesis and hematological parameters in automobile workers of north karnataka (India).

The purpose of this study was to find out the effect of lead exposure on systolic and diastolic blood pressure, heme biosynthesis related and hematological parameters of automobile workers. For this study 30 automobile workers were selected and compared with 30 age matched healthy control subjects. Significantly increased blood lead (364%, P<0.001) and urinary lead (176%, P<0.001) levels were observed in automobile workers (study group) as compared to controls. Systolic blood pressure (5.32%, P<0.05) and diastolic blood pressure (5.87%, P<0.05) were significantly increased in the automobile workers as compared to controls. The significantly decreased non-activated erythrocyte δ-aminolevulinic acid dehydratase (δ-ALAD) (-18.51%, P<0.01) and activated δ-ALAD (-13.29%, P<0.05) levels were observed in automobile workers as compared to normal healthy control subjects. But the ratio of activated/non-activated δ-ALAD was significantly increased (43.83%, P<0.001) in automobile workers as compared to controls. Excretions of δ-aminolevulinic acid (83.78%, P<0.001) and porphobilinogen (37%, P<0.001) in urine were significantly increased in the study group as compared to the controls. In automobile workers heamoglobin (-11.51%, P<0.001), hematocrit (-4.06%, P<0.05), mean corpuscle volume (-3.34%, P<0.05), mean corpuscle hemoglobin (-5.66%, P<0.01), mean corpuscle hemoglobin concentration (-7.67%, P<0.001), red blood cell count (-14.6%, P<0.001) were significantly decreased and total white blood cell count (11.44%, P<0.05) increased as compared to the controls. The results of this study clearly indicate that the absorption of lead is more in automobile workers and it affects on blood pressure, heme biosynthesis and hematological parameters observed in this study group.

Ultrasonic energy as a tool to overcome some drawbacks in the determination of lead in brain tissue and urine of rats

An ultrasonic assisted solid–liquid extraction method was developed to determine the level of lead in the brain and urine of rats. Lead was determined by electrothermal atomic absorption spectrometry with longitudinal-Zeeman background correction. Several analytical drawbacks were addressed and overcome, namely small brain sample mass and the formation of precipitate in the urine samples. Utrasonication provided by an ultrasonic probe succeeded in extracting lead from brain samples. Furthermore, it was demonstrated that the formation of a precipitate lowered the lead content in the liquid phase of the urine. Lead was back extracted from the precipitate to the liquid phase with the aid of ultrasonic energy and acidifying the urine with 10% v/v nitric acid. A microwave-assisted acid digestion protocol was used to check the completeness of the lead extraction. The within bath and between bath precision was 5% (n=9) and 7% (n=3) respectively. The limit of quantification was 1.05μgg−1 for brain samples and 2.1μgL−1 for urine samples. A total of 6 samples of urine and 12 samples of brain from control rats and another 6 samples of urine and 12 samples of brain from rats fed with tap water rich in lead acetate were used in this research. Lead levels in brain and urine from exposed rats ranged from1.9±0.2μgg−1 to 3.5±0.2μgg−1 and from 752±56μgL−1 to 60.9±1.2mgL−1 respectively. Statistically significant differences of levels of lead in brain and urine were found between exposed and non exposed rats.

URINARY LEVELS OF ARSENIC, LEAD AND MERCURY AMONG CHILDREN AND NEUROBEHAVIOURAL TOXICITY: AN EXPLORATORY STUDY

Background: Diet and living near to chemical/metal industries are a potential source of environmental exposure to metals such as lead, mercury and arsenic, which are recognized causes of neurological disorders in children. Our objective was to explore the relationship between urinary levels of arsenic, lead and mercury, and neurobehavioral performance (subclinical effect) in children aged 9-11. Methods: Spot urine samples were obtained from 79 children recruited from cities representative of five different environmental scenarios in Andalusia (Spain): 14 from urban/residential, 34 from urban/industrialized, 7 from mining, 14 from rural, and 10 from rural/industrialized. Neurobehavioral performance was satisfactorily assessed in 37 boys and 36 girls by the Behavioral Assessment and Research System (BARS) using Spanish instructions. Multielemental ICP-MS was used to quantify urinary levels of arsenic, lead and mercury. General linear models were used including age, gender, social class, global physical activity, and shore fish consumption as covariates, plus the exposure variable (log transformed urinary levels of each metal separately) to predict each of 14 neurobehavioral outcome variables. Results: Higher levels of mercury were associated with a worse performance of the Alternate Hand Finger Tapping (AHFT) test (measures “coordination”) (p=0.03), of the Digit Span Forward test (measuring “attention”) (p=0.08) and of the Errors on Simple Reaction test (measures “response speed”) (p=0.02); and with better performance of the Continuous Performance Hit Latency test (measures “attention”) (p=0.001). Children with higher arsenic levels scored better on the Continuous Performance False Alarm Latency test (p=0.08), and tended to score worse on the AHFT test (p=0.10). No statistically significant associations were observed for urinary lead, although children with higher levels tended to perform better with the AHFT test (p=0.09), and worse with the Continuous Performance Correct Rejections test (p=0.15). Conclusions: Our results suggest that urinary levels of mercury are related with poorer neurobehavioral performance among children.

Urine Lead in 1430 Pupils in Tangshan

PP-29-058 Background/Aims: To investigate the urine lead levels in adolescent in Tangshan, and to provide baseline data in the assessment of lead pollution in children. Methods: Multistage stratified sampling methods are used to choose 1430 pupils in Grade 3–Grade 4 from 67 primary school in 14 counties in Tangshan area. Morning urine (10–30 mL) was collected and sent to our laboratory in 2 hours. Atomic absorption spectrophotometry was adopted to measure the lead concentration in urine. The results were expressed as geometric mean. Results: The geometric mean of urine lead was 0.87 μg/L, and the P50, P75, P90, P95 were 1.9 μg/L, 4.3 μg/L, 7.9 μg/L, 11.9 μg/L, respectively. Urine lead level is lower in male (0.78 μg/L) than in female (0.996 μg/L) (t = 2.34, P = 0.0194). Luan Nan County (3.98 μg/L), Zun Hua County (3.58 μg/L), and Luan Xian County (3.15 μg/L) were among the first 3 counties with the highest urine lead. Conclusion: Higher urine lead levels were found in the urban and downtown area in Tangshan, which should be taken as a in environmental monitoring.

Urinary heavy metal levels and relevant factors among people exposed to e-waste dismantling

Primitive electronic waste (e-waste) recycling has become a growing environmental concern, and toxic heavy metals released from e-waste activities may continue to threaten the health of local people. To study the impact of heavy metals in people around e-waste sites, 349 people from e-waste recycling sites (exposure group) and 118 people from a green plantation (control group) were surveyed, and their urinary levels of lead (UPb), cadmium (UCd), manganese (UMn), copper (UCu), and Zinc (UZn) were assayed. Questionnaire surveys for risk factors were also performed and analyzed by using the Pearson correlation analysis. Results indicated that the levels of urinary Cd in both occupational dismantling people {GM(GSD) 0.72(0.71) ug/L} and non-occupational dismantling people {GM(GSD) 0.50(0.79) ug/L} were higher than the control group {GM(GSD) 0.27(0.85) ug/L}. Further analyses of correlations between urinary heavy metal levels and exposure factors in the exposed group revealed positive relationship between the duration of dismantling and the level of UPb (p < 0.05). Meanwhile, rice sources from local village have a positive correlation with the level of UPb and UCd (p < 0.01). Other factors, however, may also have influences on heavy metal burden, and not all urinary heavy metal levels can be contributed to e-waste dismantling exposure levels. Primitive e-waste recycling activities may contribute to the changes of urinary heavy metal levels and increase the health risk for those chronically working on e-waste dismantling.

Estimation of lead in urine of school children in south western Nigeria and effect of ascorbic intervention

This study was carried out to investigate the level of lead in the air and urine of pupils in selected schools in south western Nigeria and ascertain the effect of ascorbic acid, with a view to providing baseline data on lead levels in children. A total of 197 pupils in schools in urban and rural communities of Ife Central Local Government, Osun State in the south west of Nigeria (that is Sabo, Iremo and Ajebamidele (n = 119) and Kajola and Abagboro (n = 78), respectively), The pupils in both communities were randomised into experimental and control group, the experimental group were placed on 500 mg of ascorbic acid daily for five days. Urine samples were collected on the first, third and fifth day of the study from the pupils in experimental and control groups and analysed for lead using Atomic Absorption Spectrophotometer. Air samples were collected using the LaMotte air sampling pump and analysed for lead using the same method. The cross sectional survey indicated that the mean lead levels in the air in the school environment in the urban communities on the first, third and fifth day of the study were (8.69 ± 0.070, 9.27 ± 0.09 and 9.27 ± 0.09 µg/m³) respectively and significantly higher than lead levels in rural communities (3.73 ± 0.030 µg/m³). The lead concentration in the urine of the pupils in experimental group in urban (5.51 ± 1.07 µg/m³) and rural communities (5.27 ± 0.98 µg/m³) were similar on the first day of the study. The ingestion of ascorbic acid increased excretion of lead in the urine of pupils significantly (11.22 ± 1.48 µg/m³) on the third day and decreased marginally on the fifth day (9.87 ± 1.20 µg/m³) in the urban communities. Similarly in the rural communities there was a significant increase (11.52 ± 1.41 µg/m³) in the excretion of lead in the urine of pupils on the third day but a marginal increase on the fifth day (12.88 ± 2.27 µg/m³) of the ascorbic acid ingestion. The lead level in the air on the first day of the study had no linear relationship with urinary lead level in the urban and rural communities whilst on the third and fifth day of the study, a linear relationship was observed between lead levels in the air and urinary lead levels of the pupils in the urban and rural communities. Key words: Urinary lead levels, air lead levels, school children, ascorbic acid intervention

Chromium, Cadmium, and Lead Levels in Urine of Children with Autism and Typically Developing Controls

Although potentially harmful effects of heavy metals are well known, limited numbers of studies exist regarding their relationship with autism. The aim of this study was to investigate urine levels of some heavy metals such as of chromium (Cr), cadmium (Cd), and lead (Pb) in children with autism and healthy subjects. Urine levels of Cr, Cd, and Pb were measured by atomic absorption spectrometry in 30 children with autism and compared with 20 healthy controls. Urine Cd and Pb levels were found as significantly decreased in children with autism compared to healthy subjects (p < 0.05). On the other hand, urine Cr levels were significantly higher in children with autism than healthy subjects (p < 0.05). This study suggested that autism may be associated with significant decrease in excretion rate of Cd and Pb and a significant increase excretion rate in the levels of Cr in the urine. These results have indicated that further studies are warranted for investigation of possible roles of heavy metals in autism.

Genetic background of lead and mercury metabolism in a group of medical students in Austria

Information on the impact of genetic predisposition on metal toxicokinetics in the human body is limited. There is increasing evidence that certain genetic polymorphisms modify lead and mercury toxicokinetics. This called for analysis of further candidate genes. Medical students (N=324) were examined in order to detect potential associations between lead exposure and polymorphisms in HFE, VDR, ALAD, and MT genes, as well as between mercury exposure and GSTT1, GSTM1, GSTA1, GSTP1, GCLC, and MT polymorphisms. The levels of lead and mercury exposure of students were determined by blood, urine, and hair analyses (ICP-MS, CV-AAS). Genotyping of common polymorphisms was examined by MALDI-TOF MS and the TaqMan methodology. Associations between lead and mercury exposures and genetic background were examined by bivariate analysis, and by categorical regression analysis (CATREG) controlled by metal- and matrix-specific variables. Lead and mercury levels in urine, blood, and hair indicated low exposures. VDR polymorphism and joint presence of VDR/ALAD polymorphisms were significantly and independently associated with urine lead concentrations (CATREG P<0.05). Polymorphisms in GSTP1-114 and MT4 genes as well as dual gene combinations including GSTP1, GCLC, GSTT1, and GSTM1 polymorphisms were independent variables related to mercury body burdens (CATREG P<0.05). GSTP1-114/GSTT1 and GSTP1-105/GCLC combinations showed synergistic effects on hair mercury levels compared to single-gene variants. We found evidence that certain genetic backgrounds were associated with lead and mercury metabolism, suggesting gene-environment and gene-gene-environment interactions. The modes of interaction remain to be evaluated.

Effects of chelation therapy with succimer in young rabbits of moderate lead poisoning

To explore the effect of chelation therapy with succimer (DMSA) in male rabbits of moderate lead poisoning during juvenile stage. Twenty-four 45-day-old male New Zealand rabbits were randomly divided into three groups (therapy group, TG; positive control group, PG and negative control group, NG, n=8). The TG and PG were orally exposed to lead acetate (5 mg x kg(-1) x d(-1)) for 6 weeks. Rabbits in TG were orally supplied DMSA 1050 mg/m2 in the first week and 700 mg/m2 in the next two weeks, while the other two groups wren't blood and urinary samples of all rabbits were collected per week. The tissues and organs of all rabbits were collected after 12 weeks. The blood lead levels (BLLs) were determined by atomic absorption spectrometer. The urine lead levels and the lead contents of tissue and organ were determined by inductively coupled plasma-mass spectrometry. Histopathology of tissue and organ was observed by light microscope. Compared with PG, the lead level in the morning urine of TG with DMSA chelating was increased significantly. The level was peaked at (1246.96 +/- 157.91) microg/L on the first day after chelating. While the base line was (40.97 +/- 1.77) microg/L before chelating. Meanwhile, the BLLs were sharply declined from (429.63 +/- 10.82) microg/L to (238.50 +/- 11.82) microg/L. The urine lead levels of TG decreased through the 3-week chelating and 3-week discontinuation. The urine lead levels of these two groups were significantly different (F=2934.35, P<0.01). Compared to each two groups in these three groups, there were significant difference (P<0.01). The authors found the reversion of BLLs in first week after stop chelating. The BLLs of PG presented the slow course of declining in the same time, were (135.50 +/- 7.09) microg/L, very close to the level of TG for (149.88 +/- 11.39) microg/L. Compared with treatment discontinuation for 3 weeks, the urine lead levels and the body weight gain of the therapy group increased more than that of PG, and the BLLs and the lead concentrations in tissues and organs decreased more than that of PG, and histopathology in the liver tissues and testicle tissues were improved. DMSA chelating for the rodent models of moderate lead poisoning might reduce the BLLs and soft tissue lead contents quickly and effectively, decrease toxic effects of lead in a short period of time, thus alleviate the impairment of lead poisoning on tissues and organs by decreasing lead burden, and bring out improvement on the growth retardation caused by lead poisoning.

Lead-induced peripheral neuropathy following ayurvedic medication

Lead poisoning following intake of Ayurvedic medication is one of the recent areas of concern. We report a case of a 58-year-old type II diabetic man who was stable with diet control and 30 mg pioglitazone per day. He took Ayurvedic medication for generalized weakness and developed peripheral neuropathy following its intake. He was found to have high blood and urinary lead levels and was diagnosed to have subacute lead poisoning. He was treated with d-Penicillamine for 8 weeks, following which his lead levels became normal. The use of d-Penicillamine was proved highly effective in treating a case of lead poisoning.