Human biologic monitoring based on blood donations to the National Blood Services.

BACKGROUND: The ambient exposure does not always reflect the internal levels of pollution absorbed in the body. While human biomonitoring (HBM) could provide a valid estimate of exposure extent, it is usually an expensive and a heavily manpowered enterprise. Using samples collected during blood donations for HMB may provide a more efficient platform for a routine biomonitoring. METHODS: The current study is aimed to explore the feasibility of using the national blood banking system for the purposes of HBM, to compare between residents of a suspected polluted area in northern Israel (Haifa Bay) to the rest of the country. Specifically, we will assemble a geographically representative sample of blood donors residing in the study area and of the general population, to test for four industry and traffic-related metals: lead (Pb), cadmium (Cd), arsenic (As) and chromium (Cr). Samples of whole blood from donors will be tested in the Laboratory of Public Health Services managed by the Ministry of Health. The information on donors' biomarkers levels will be further linked with the air pollution and meteorological data assessed at the location of the blood collection sites (short-term exposure) and donors' permanent address (long-term exposure), as recorded by the monitoring stations spread throughout Israel and the satellite-based exposure models. The association between biomarkers and ambient environmental exposures will be assessed. The samples' collection is planned for 2 years of 2020-2021. DISCUSSION: The information collected in this study could lead to environmental regulations within Haifa Bay area aimed to prevent exposure to high levels of hazardous chemicals.

Benzo[a]pyrene at human blood equivalent level induces human lung epithelial cell invasion and migration via aryl hydrocarbon receptor signaling.

Benzo[a]pyrene (B[a]P), a typical carcinogenic polycyclic aromatic hydrocarbon, exists worldwide in vehicle exhaust, cigarette smoke and other polluted environments. Recent studies have demonstrated a strong association between B[a]P and lung cancer. However, whether B[a]P at human blood equivalent level can promote epithelial-mesenchymal transition (EMT), a crucial molecular event during cell malignant transformation, remains unclear. Besides, whether B[a]P facilitates this progress via aryl hydrocarbon receptor (AhR) signaling pathway also lacks scientific evidence. In our study, the transwell assay showed that 5 µg/L of B[a]P promoted BEAS-2B cell invasion and migration. In addition, the mRNA and protein expression levels of AhR and its target genes involved in B[a]P metabolism, such as AhR nuclear translocator, heat shock protein 90 and CYP1A1, were significantly increased by B[a]P exposure. Moreover, the mRNA expression levels of downstream regulatory factors related to both AhR signaling pathway and EMT, such as NRF2, K-RAS and hypoxia-inducible factor 1-alpha, were significantly increased. Furthermore, the expression level of the epithelial marker E-cadherin was significantly downregulated, while the mRNA expression of mesenchymal phenotype markers, N-cadherin, fibronectin and vimentin, were significantly upregulated. Notably, the above changes induced by B[a]P were significantly attenuated or even stopped by resveratrol (RSV), a natural phenol, also an AhR inhibitor, when the AhR signaling pathway was inhibited by RSV, demonstrating the regulatory role of AhR signaling pathway in B[a]P-induced EMT. In conclusion, B[a]P at the human blood equivalent level induces BEAS-2B cell invasion and migration through the AhR signaling pathway.

High-throughput screening of toxic substances by extractive electrospray ionization mass spectrometry and their identification via databank construction.

More than 200 toxic substances (including narcotic drugs, psychotropic drugs, organic phosphorus compounds, carbamates, pyrethroids and other pesticides, veterinary drugs, rodenticides, natural toxins, and other drugs) were identified and quantified using an ion-trap mass spectrometer. The advantages of this technique-its selectivity, accuracy, precision, utilization of only small amounts of the sample, and short analysis time for a single sample (less than 30s)-render it a rapid and accurate methodology for toxin screening. Subsequently, an extractive electrospray ionization (EESI) mass spectrometry database was established by combining the Xcalibur data processing system with NIST database software. This allowed unknown toxicants in urine and blood samples, stomach contents, and liver samples, as provided by the Jiangxi Provincial Public Security Department, to be analyzed and identified. This EESI methodology and databank has the potential for widespread application to the large-scale analysis of practical samples. Graphical abstract ᅟ.

Flavored Versus Nonflavored Waterpipe Tobacco: A Comparison of Toxicant Exposure, Puff Topography, Subjective Experiences, and Harm Perceptions.

INTRODUCTION: Flavored waterpipe (WP) tobacco is the main type of tobacco used by young WP smokers, and a major factor attracting youth to smoke. However, evidence regarding the effect of limiting flavor on WP smokers' experience continues to be lacking. This study aims at evaluating the effect of flavor restriction on WP smokers' toxicant exposure, smoking topography, subjective experiences and harm perception. METHODS: Thirty-two WP smokers completed two, 45-minute ad libitum smoking sessions (preferred flavor vs non-flavored tobacco) in a crossover design pilot study. Plasma nicotine concentration and exhaled carbon monoxide (eCO) were measured before and after each smoking session. Puff topography was recorded throughout the smoking session. Participants completed survey questionnaires assessing subjective smoking experiences and harm perception. RESULTS: Significant differences were observed in plasma nicotine concentration between the two WP tobacco conditions, with a higher increase in plasma nicotine concentration following the flavored tobacco session. There were no significant differences between the two WP tobacco conditions for eCO and smoking topography measures. Compared with the non-flavored WP tobacco, we documented enhanced subjective smoking measures of satisfaction, calmness, taste, puff liking and enjoyment following the preferred flavored WP tobacco session. Cigarette harm perception was significantly higher among participants after smoking their preferred flavor compared with non-flavored WP tobacco. CONCLUSIONS: Limiting tobacco flavor has a substantial effect on WP smokers' nicotine exposure, subjective experience and harm perception. Therefore, eliminating or restricting WP flavors could be an essential element of comprehensive tobacco control policies to reduce the appeal of WP tobacco products for youth. IMPLICATIONS: This study highlights the important role of flavor in shaping WP smokers' experiences and exposures and the potential impact that regulating flavored WP tobacco may have on curbing WP use among youth in the US. Such regulations may reduce the appeal and the interest in WP smoking initiation and continued use.

Biomarkers of Tobacco Exposure Decrease After Smokers Switch to an E-Cigarette or Nicotine Gum.

INTRODUCTION: The aerosol composition of electronic cigarettes (ECs) suggests that exposure to toxicants during use is greatly reduced compared to exposure from combustible cigarettes (CCs). METHODS: This randomized, parallel-group, clinical study enrolled smokers to switch to Vuse Solo (VS) Digital Vapor Cigarettes (Original or Menthol) or Nicorette 4 mg nicotine gum (NG) in a controlled setting. Subjects who smoked CCs ad libitum for 2 days during a baseline period were then randomized to ad libitum use of either VS or NG for 5 days. Biomarkers of 23 toxicants were measured in 24-hour urine samples and blood collected at baseline and following product switch. RESULTS: A total of 153 subjects completed the study. Total nicotine equivalents decreased in all groups, but higher levels were observed in the VS groups compared to the NG groups, with decreases of 38% and 60%-67%, respectively. All other biomarkers were significantly decreased in subjects switched to VS, and the magnitude of biomarker decreases was similar to subjects switched to NG. Decreases ranged from 30% to greater than 85% for constituents such as benzene and acrylonitrile. CONCLUSIONS: These results indicate that exposure to toxicants when using VS is significantly reduced compared to CC smoking, and these reductions are similar to those observed with use of NG. Although statistically significantly decreased, nicotine exposure is maintained closer to CC smoking with VS use compared to NG use. This research suggests that use of VS exposes consumers to fewer and lower levels of smoke toxicants than CCs while still providing nicotine to the consumer. IMPLICATIONS: This is the first study to report changes in nicotine delivery and biomarkers of tobacco exposure following a short-term product switch from CCs to either an EC or NG in a controlled environment. The study shows that nicotine exposure decreased in both groups but was maintained closer to CC smoking with the EC groups. Biomarkers of tobacco combustion decreased to similar levels in both EC and gum groups.

Toxicokinetics of N-ethyl-2-pyrrolidone and its metabolites in blood, urine and amniotic fluid of rats after oral administration.

The toxicokinetics of N-ethyl-2-pyrrolidone (NEP), an embryotoxic organic solvent, has been studied in Sprague-Dawley rats after oral exposure. NEP and its metabolites 5-hydroxy-N-ethyl-2-pyrrolidone (5-HNEP) and 2-hydroxy-N-ethylsuccinimide (2-HESI) were measured in plasma of pregnant and non-pregnant rats, and fetuses after NEP administration by gavage for 14 consecutive days at 50 mg/kg/day, and in plasma of non-pregnant rats after a single NEP administration. Additionally, amniotic fluid and 24-h urine samples of the pregnant rats were analyzed for NEP metabolites. Furthermore, 24-h urine samples from a repeated dose 28-day oral toxicity study in female (non-pregnant) and male rats administered developmentally non-toxic (0, 5, and 50 mg/kg/day) or toxic (250 mg/kg/day) doses of NEP were analyzed. Median peak plasma concentrations in non-pregnant rats after a single dose and repeated doses were 551 and 611 (NEP), 182 and 158 (5-HNEP), and 63.8 and 108 µmol/L (2-HESI), respectively; whereas in pregnant rats and fetuses 653 and 619 (NEP), 80.5 and 91.7 (5-HNEP) and 77.3 and 45.7 µmol/L (2-HESI) were detected. Times to reach maximum plasma concentrations for NEP, 5-HNEP, and 2-HESI were 1, 4, and 8 h, respectively, and were comparable to N-methyl-2-pyrrolidone (NMP) and its corresponding metabolites. In pregnant rats, plasma elimination of NEP and metabolite formation/elimination was much slower compared to non-pregnant rats and efficient placental transfer of NEP was observed. Our data, overall, suggest differences in the toxicokinetics of chemicals between pregnant and non-pregnant rats which need to be addressed in risk assessment, specifically when assessing developmental toxicants such as NEP.

Maternal Concentrations of Perfluoroalkyl Substances and Fetal Markers of Metabolic Function and Birth Weight.

Perfluoroalkyl substances (PFAS) are ubiquitous, persistent chemicals that have been widely used in the production of common household and consumer goods for their nonflammable, lipophobic, and hydrophobic properties. Inverse associations between maternal or umbilical cord blood concentrations of perfluorooctanoic acid and perfluorooctanesulfonate and birth weight have been identified. This literature has primarily examined each PFAS individually without consideration of the potential influence of correlated exposures. Further, the association between PFAS exposures and indicators of metabolic function (i.e., leptin and adiponectin) has received limited attention. We examined associations between first-trimester maternal plasma PFAS concentrations and birth weight and cord blood concentrations of leptin and adiponectin using data on 1,705 mother-infant pairs from the Maternal Infant Research on Environmental Chemicals (MIREC) Study, a trans-Canada birth cohort study that recruited women between 2008 and 2011. Bayesian hierarchical models were used to quantify associations and calculate credible intervals. Maternal perfluorooctanoic acid concentrations were inversely associated with birth weight z score, though the null value was included in all credible intervals (log10 ß = −0.10, 95% credible interval: −0.34, 0.13). All associations between maternal PFAS concentrations and cord blood adipocytokine concentrations were of small magnitude and centered around the null value. Follow-up in a cohort of children is required to determine how the observed associations manifest in childhood.

Toxicants in folk remedies: implications of elevated blood lead in an American-born infant due to imported diaper powder.

Though most childhood lead exposure in the USA results from ingestion of lead-based paint dust, non-paint sources are increasingly implicated. We present interdisciplinary findings from and policy implications of a case of elevated blood lead (13-18 mcg/dL, reference level <5 mcg/dL) in a 9-month-old infant, linked to a non-commercial Malaysian folk diaper powder. Analyses showed the powder contains 62 % lead by weight (primarily lead oxide) and elevated antimony [1000 parts per million (ppm)], arsenic (55 ppm), bismuth (110 ppm), and thallium (31 ppm). These metals are highly bioaccessible in simulated gastric fluids, but only slightly bioaccessible in simulated lung fluids and simulated urine, suggesting that the primary lead exposure routes were ingestion via hand-mouth transmission and ingestion of inhaled dusts cleared from the respiratory tract. Four weeks after discontinuing use of the powder, the infant's venous blood lead level was 8 mcg/dL. Unregulated, imported folk remedies can be a source of toxicant exposure. Additional research on import policy, product regulation, public health surveillance, and culturally sensitive risk communication is needed to develop efficacious risk reduction strategies in the USA. The more widespread use of contaminated folk remedies in the countries from which they originate is a substantial concern.

Rapid detection of hazardous chemicals in textiles by direct analysis in real-time mass spectrometry (DART-MS).

Residues of chemicals on clothing products were examined by direct analysis in real-time (DART) mass spectrometry. Our experiments have revealed the presence of more than 40 chemicals in 15 different clothing items. The identification was confirmed by DART tandem mass spectrometry (MS/MS) experiments for 14 compounds. The most commonly detected hazardous substances were nonylphenol ethoxylates (NPEs), phthalic acid esters (phthalates), amines released by azo dyes, and quinoline derivates. DART-MS was able to detect NPEs on the skin of the person wearing the clothing item contaminated by NPE residuals. Automated data acquisition and processing method was developed and tested for the recognition of NPE residues thereby reducing the analysis time.

Maternal exposure to metals and persistent pollutants and cord blood immune system biomarkers.

BACKGROUND: The fetal time period is a critical window of immune system development and resulting heightened susceptibility to the adverse effects of environmental exposures. Epidemiologists and toxicologists have hypothesized that persistent organic pollutants, pesticides and metals have immunotoxic properties. Immunotoxic effects may manifest as an altered immune system profile at birth. Immunoglobulin E, thymic stromal lymphopoietin (TSLP), and interleukin-33 (IL-33) may be implicated in the etiology of childhood allergy and are detectable at birth. The objective of this study was to examine the potential relationship between maternal concentrations of metals, persistent organic pollutants, and pesticides and elevated umbilical cord blood concentrations of IgE, TSLP, and IL-33 in a Canadian birth cohort. METHODS: This study utilized data collected in the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a trans-Canada cohort study of 2,001 pregnant women. Of these women, 1258 had a singleton, term birth and cord blood sample. Logistic regression was used to determine associations between log-transformed continuous variables and immune system biomarkers. RESULTS: Inverse relationships were observed between lead, DDE, PCB-118, and a summary index of organophosphorous metabolites and jointly elevated concentrations of IL-33 and TSLP. None of the environmental contaminants were associated with increased odds of a high cord blood immune system biomarker concentration. CONCLUSIONS: In this primarily urban Canadian population of pregnant women and their newborns, maternal blood or urine concentrations of persistent organic pollutants, pesticides, and metals were not associated with immunotoxic effects that manifest as increased odds of elevated concentrations of IgE, TSLP or IL-33.

Preconcentration and determination of lead and cadmium levels in blood samples of adolescent workers consuming smokeless tobacco products in Pakistan.

The present study was aimed to evaluate the cadmium (Cd) and lead (Pb) levels in the blood samples of adolescent boys, chewing different smokeless tobacco (SLT) products in Pakistan. For comparative purpose, boys of the same age group (12-15 years), not consumed any SLT products were selected as referents. To determine trace levels of Cd and Pb in blood samples, a preconcentration method, vortex-assisted liquid-liquid microextraction (VLLME) has been developed, prior to analysis by flame atomic absorption spectrometry. The hydrophobic chelates of Cd and Pb with ammonium pyrrolidinedithiocarbamate were extracted into the fine droplets of ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate, while nonionic surfactant, Triton X-114 was used as a dispersing medium. The main factors affecting the recoveries of Cd and Pb, such as concentration of APDC, centrifugation time, volume of IL and TX-114, were investigated in detail. It was also observed that adolescent boys who consumed different SLT products have 2- to 3-fold higher levels of Cd and Pb in their blood samples as compared to referent boys (p < 0.001).

Comparative evaluation of essential and toxic elements in the blood of kidney failure patients and healthy referents.

The aim of the present study was to evaluate the comparative distribution, correlation, and apportionment of selected elements-aluminum (Al), calcium (Ca), cadmium (Cd), potassium (K), magnesium (Mg), sodium (Na), and lead (Pb)-in the blood samples of male kidney failure patients (KFP) and healthy subjects of age ranged 30-60 years. The blood samples were digested with nitric acid and perchloric acid mixture (2:1), followed by the quantification of elements by atomic absorption spectrometry. The concentration of essential elements in blood samples of KFP were found in the range of Ca (97-125), Mg (18-36), Na (2971-3685), and K (177-270) mg/L while, the levels of Al, Cd, and Pb were found in the range of (475-1275), (0.9-9.9), and (211-623) µg/L, respectively. In the healthy referents, concentration of electrolytes in blood samples was lower than KFP, but difference was not significant (p > 0.05). While the levels of toxic elements in blood samples of referents were three- to sixfold lower than KFP (p < 0.01). Principal component analysis (PCA) and cluster analysis (CA) of the element data manifested diverse apportionment of the selected elements in the blood sample of the KFP compared with the healthy counterparts.

High consumption of farmed salmon does not disrupt the steady state of persistent organic pollutants (POP) in human plasma and adipose tissue.

The aims of this study were to (1) determine any changes in the levels of persistent organic pollutants (POP) and mercury (Hg) in human plasma and adipose tissue and (2) examine associations between plasma levels of pollutants and dietary fat intake. Outpatients with different metabolic disorders (n = 42) consumed 380 g of farmed Atlantic salmon fillets or 60 g of salmon oil per week in two study periods of 15 wk each, and were compared with a control group (n = 14). Concentrations of POP and Hg were measured in salmon fillets, salmon oil capsules, plasma and abdominal fat biopsies from patients before and after intervention. Mean concentrations of hexachlorobenzene (HCB), p,p'-DDE, sum of indicator polychlorinated biphenyls (PCB) (id-PCB), and sum polybrominated diphenyl ethers (PBDE) in abdominal fat at intervention start were 21, 191, 267, and 4.2 ng/g lipid weight. After 15 or 30 wk of salmon consumption no significant changes in concentrations of POP and Hg in samples of human plasma and abdominal fat were observed, indicating that steady-state levels of these pollutants were not markedly affected. The lack of significant changes may partly be attributed to a limited number of samples, large interindividual variation in POP levels, and a large age span (20-70 yr). After adjusting for age, significant associations were found between different plasma long-chain fatty acid concentrations, including n-3 and n-6 fatty acids and oleic acid, and some of the POP. The results indicate that the latter have different food products as their main sources of human exposure.

High lead exposure is associated with telomere length shortening in Chinese battery manufacturing plant workers.

OBJECTIVES: Critically shortening of telomere length caused by various factors including environmental pollutants results in genome instability and age-associated diseases. Lead is one of the ubiquitous environmental and occupational pollutants, potentially affecting public health even at a low level. However, it is still unclear whether lead exposure affects telomere length. This study aims to investigate the association between lead exposure and peripheral white blood cell telomere length (PWBTL) in Chinese battery manufacturing plant workers. METHODS: Lead levels in blood (BLL) and urine (ULL) were evaluated using flame atomic absorption spectrometry and lead mobilisation test for body lead burden (BLB) assessment, respectively. Quantitative PCR was employed to determine relative PWBTL. Univariate and multivariate analyses were performed to examine the associations of telomere length and other variables. RESULTS: PWBTL averaged 1.76 (telomere/single-copy gene of albumin, T/S) in 144 battery plant workers. Significantly shorter PWBTL was observed in the workers with abnormal BLL and/or ULL than those with normal ones (1.66±0.63 vs 1.91±0.46, p=0.010). In all workers, PWBTL was in negative correlations with BLL, ULL, time working at the plant (working length) and body mass index. A strong inverse correlation was observed between PWBTL and BLB (r=-0.70, p<0.0001) in those with abnormal BLL and ULL. GLMSELECT model showed in the subgroup of inpatient workers, working length and BLB were significantly in inverse associations with PWBTL, while BLL was in weak positive association with PWBTL. CONCLUSIONS: These findings suggest that PWBTL shortening is associated with long-term lead exposure and that PWBTL may be one of the targets damaged by lead toxicity.

Perfluorooctanoic acid exposure is associated with elevated homocysteine and hypertension in US adults.

OBJECTIVE: To investigate the association between serum perfluorooctanoic acid (PFOA) concentration and cardiovascular disease, as measured by homocysteine level and blood pressure in a representative sample of US adults. METHODS: A cross-sectional study of 2934 adults (≥20 years) who participated in the 2003-2004 and 2005-2006 National Health and Nutrition Examination Survey and had detectable levels of PFOA in their serum. The health effects analysed as potentially associated with PFOA exposure included homocysteine level and blood pressure. RESULTS: The geometric mean value (95% CI) of the study participants' serum PFOA concentration was 4.00 µg/l (95% CI 3.86 to 4.13). The homocysteine and systolic blood pressure were shown to increase significantly with an increase in the log-transformed serum PFOA concentration, after adjusting for potential confounding variables. Adjusted ORs comparing participants at the 80th versus the 20th percentiles were 2.62 for hypertension (95% CI 2.09 to 3.14), and a positive association was also evident in models based on quartiles or based on restricted cubic splines. CONCLUSION: These findings suggest that background exposure to PFOA may continue a risk factor for the development of cardiovascular diseases.

Persistent increase of blood lead level and suppression of δ-ALAD activity in northern bobwhite quail orally dosed with even a single 2-mm spent lead shot.

Birds that display grit ingestion behavior are potentially at risk of lead (Pb) poisoning from mistaken ingestion of spent Pb shot pellets. The majority of available studies designed to assess such risk have used unspent shot pellets rather than field-obtained spent shot, which is oxidized and otherwise changed by weathering. Available studies also often administered more or heavier shot pellets to a bird than it might be expected to ingest. The current study dosed northern bobwhite quail (Colinus virginianus) weighing 194.6 ± 23.1 g (female birds) and 199.3 ± 12.2 g (male birds) with one to three spent no. 9 Pb shot collected from a skeet range, with particular interest in the toxicity that may occur from ingestion of a single 2-mm, 50 mg shot. An 8 week post-dosing clinical observation period was employed, over which feed consumption, body weight, blood Pb levels, and a battery of blood physiological parameters were made. Weight loss occurred in the birds, including male birds dosed with one Pb pellet. Erythrocyte delta aminolevulinic acid dehydratase (δ-ALAD) levels were decreased for the duration of the study across exposures and to levels associated with injury in wild bird populations. Decreased ALAD was particularly severe in female birds dosed with one Pb pellet and was still 92 % decreased at 8 weeks after dosing. Together, these results suggest that inadvertent ingestion of a single no. 9 Pb shot pellet can adversely affect the health of northern bobwhite quail.

Nonlinearity in the relationship between bone lead concentrations and CBLI for lead smelter employees.

494 smelter employees from New Brunswick participated in a bone lead survey conducted by McMaster University in 2008, using the four element "clover-leaf" geometry germanium detector system. The employees were measured at two different bone sites, tibia and calcaneus, each measurement lasting 30 minutes. Scattered photons, including Pb X-rays, were collected by the germanium detectors located behind the ¹°9Cd source. A strong positive correlation was observed between tibia and calcaneus lead concentrations. Having been provided with blood lead levels, a cumulative blood lead index (CBLI) was generated. The employees were classified into four groups based on their date of hire, and their CBLI levels were compared to their tibia and calcaneus lead concentrations in the different groups. The slopes of bone Pb versus CBLI varied amongst groups, with those hired earliest showing the steepest slopes. This could be taken to imply a non-linearity in the uptake of Pb by bone from blood. In this paper, the association of the bone lead concentrations versus CBLI has been expressed by a polynomial function for the whole group of employees.

Pyruvate kinase activity and δ-aminolevulinic acid dehydratase activity as biomarkers of toxicity in workers exposed to lead.

Lead (Pb(2+)) is a heavy metal that has long been used by humans for a wide range of technological purposes, which is the main reason for its current widespread distribution. Pb(2+) is thought to enter erythrocytes through anion exchange and to remain in the cell by binding to thiol groups. Pyruvate kinase (PK) is a thiol-containing enzyme that plays a key role in erythrocyte cellular energy homeostasis. δ-aminolevulinic acid dehydratase (δ-ALAD) is the second enzyme in the heme biosynthetic pathway and plays a role in the pathogenesis of Pb poisoning. Our primary objective was to investigate the effect of Pb(2+) on the activity of the thiolenzymes δ-ALAD and PK and on the concentration of glutathione (GSH), a nonenzymatic antioxidant defense, in erythrocytes from Pb-exposed workers. The study sample comprised 22 male Pb workers and 21 normal volunteers (15 men and 6 women). The Pb-exposed workers were employed in manufacturing and recycling of automotive batteries. Basic red-cell parameters were assayed and total white blood cell counts performed. PK and δ-ALAD activity and blood Pb (BPb) concentrations were determined in all subjects. Pb-exposed individuals had significantly greater BPb levels than controls. Both PK and δ-ALAD activity levels were significantly lower in Pb-exposed individuals than in controls. Pb significantly inhibited PK and δ-ALAD activity in a dose-dependent manner. We found that erythrocyte GSH levels were lower in Pb-exposed individuals than normal volunteers. Pb-exposed individuals had lower values than controls for several red cell parameters (hemoglobin, hematocrit, red blood cell count, mean corpuscular volume). These results suggest that Pb inhibits δ-ALAD and PK activity by interacting with their thiol groups. It is therefore possible that Pb disrupts energy homeostasis and may be linked with decreased glucose metabolism because it affects the heme synthesis pathway in erythrocytes, contributing to the cell dysfunction observed in these in Pb-exposed individuals. These results indicate an apparent dose-effect relationship between PK activity and BPb. PK activity in human erythrocytes can be used for biological monitoring of Pb exposure. Study of the mechanisms by which Pb acts may contribute to greater understanding of the symptoms caused by Pb.

Human bio-monitoring study--toxic elements in blood of women.

The article describes bio-monitoring study concerning recent and long-term exposure of Czech women to toxic metals. Blood cadmium, mercury and lead levels were measured in groups of women with various life styles, etc., to have comparable results in the course of a long study period; a strong emphasis was laid on the quality control of the whole process during the study. Higher cadmium level was found in smokers compared to non-smokers, lower mercury level was found in the group of women who never eat fish. A slight increase of blood lead level with age was observed. No significant differences were found between localities in a given period. Our results do not differ from those gained in other European countries.

Lead levels in breast milk, blood plasma and intelligence quotient: a health hazard for women and infants.

Lead levels in human breast milk and blood plasma or serum were analyzed and qualitatively their intelligence quotient (I.Q.) studied. Samples at different stages of lactation, from 5 days to 51 weeks post partum, were collected from 25 healthy breast-feeding mothers in Ranipet Industrial area of Vellore district of Tamil Nadu and from 25 lactating mothers in the non-industrial areas of the same district. The samples from mothers in non-industrial area showed lower lead levels ranging from 5 to 25 µg/L whereas samples from mothers in industrial area showed higher lead levels ranging between 15 and 44.5 µg/L. It was generally noticed that the lactating mothers from industrial area have lower I.Q. levels compared to mothers from non-industrial area.