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.     

Chemical speciation and bioavailability of lead and cadmium in an aquatic system polluted by sewage discharges

Abstract

A physico-chemical scheme encompassing anodic stripping voltammetry (ASV) as an analytical tool, and ultraviolet irradiation techniques, has been applied to determine the species of lead and cadmium in sewage polluted and unpolluted fresh-waters of a major perennial river located downstream of a metropolitan city in India. The physico-chemical and bioavailable species that have been identified and quantified include ASV-labile (bioavailable), particulate bound, total dissolved, non-labile or bound and organically bound metal. For precise and rapid assessment of the toxic bioavailable fraction, the ASV technique has been proposed as an analytical tool.

The river stretch, divided into reference, impact and recovery zones, has been monitored for any alteration in the distribution and partitioning of Pb and Cd amongst various physico-chemical forms. An attempt has been made to assess the impact of effluent discharge upon the receiving river by correlating concentrations of various metal-species with reference to the properties of the stream and drainage basin. Speciation analysis revealed complete association of Cd with particulates and a significant proportion of Pb in labile form, downstream of effluent outfall, thus an immediate toxic impact on the aquatic system may be posed.     

Cribra orbitalia and trace element content in human teeth from neolithic and early bronze age graves in southern Poland

Determination of element levels in bones and teeth can complement knowledge of the diagnostics and etiology of various diseases in prehistoric populations. Calcium (Ca), cadmium (Cd), copper (Cu), iron (Fe), and lead (Pb) content were analyzed in teeth from human skeletons dated to 3,000–1,400 BC from Malopolska Upland loess. Levels of iron and calcium were determined using atomic absorption spectroscopy (AAS), and lead, cadmium, and copper levels were measured using anodic stripping voltametry (ASV). Molar teeth from specimens with cribra orbitalia were selected for analyses, and teeth from specimens with no pathological changes were used as a control. No significant correlations between the content of particular elements and the tooth class, specimen age, or depth of burial pit were observed. The Fe content in specimens with cribra orbitalia is not the best measure for this disease's etiology. Thus, interelement correlations and proportions might give a better picture of the biological condition of the specimen and of the investigated groups. Am J Phys Anthropol 103:201–207, 1997. © 1997 Wiley-Liss, Inc.     

Uptake of lead,cadmium and zinc by the fairy shrimp,Branchinecta longiantenna (Crustacea: Anostraca)

Individuals of the fairy shrimp, Branchinecta longiantenna, were subjected to 5 concentrations (0.1 to 15 mg l^–1) of Pb in diluted habitat water at 13 °C. Lead concentrations (mg kg^–1 wet weight) in the animals were determined at 2-day intervals by digestion in nitric acid followed by atomic absorption analysis. The shrimp were also subjected to 0.1 mg l^–1 media of Cd and Zn, separately.Uptake rates by the fairy shrimp for the three metal ions at 0.1 mg l^–1 were: 0.111, 0.0885, and 0.0460 mg kg^–1 day^–1 for Zn, Pb, and Cd, respectively. After 2 days in 1.0 mg l^–1 Cd or Zn, the animals expired; but they surviced for 8 days in a 10 mg l^–1 Pb medium and for 2 days in 25 mg l^–1 Pb. Lead uptake demonstrated a linear dependence on the Pb concentration in the media.Shrimp survived at much higher tissue accumulations of Pb compared to Zn and Cd. Estimated lethal doses were 20, 1.2–2.4, and 0.4–1.4 mg kg^–1 wet weight for Pb, Zn, and Cd, respectively. Pb was found to be at much lower concentration than Cd or Zn in the natural pond water but between Cd and Zn levels in the sediment. Thus Cd and Zn probably present a greater threat to B. longiantenna than Pb, although Pb may be in higher concentration in the environment.Contribution 47, Laboratory of Ecology, The Claremont Colleges, Claremont, CA 91711, USA. Send reprint requests to Clyde Eriksen.     

The protective influence of ascorbic acid against the genotoxicity of waterborne lead exposure in Nile tilapia Oreochromis niloticus (L.)

The present study investigated the effects of lead (Pb) and ascorbic acid (AA) on Nile tilapia Oreochromis niloticus using the micronucleus (MN) and nuclear abnormality (NA) tests for periods of 7, 14 and 21 days. The MN frequencies in the erythrocytes, gill, liver and fin cells were analysed comparatively to evaluate the sensitivity and suitability of these different cell types. The NA shapes in erythrocytes were scored into blebbed nuclei (BL), lobed nuclei (LB), notched nuclei (NT) and binuclei (BN). It was observed that fish showed significant sensitivity to the different treatments. In general, the highest value of both MN and NA cells were significantly increased in the Pb-treated group followed by the combination of the Pb and AA-treated group. On the other hand, the MN and NA frequencies in erythrocytes were the most sensitive to the treatment and could provide more valuable information than those in gill, liver and fin cells. The frequencies of each NA shape in erythrocytes of all treatments were observed in the following ranked order NT > LB > BN > BL. The results demonstrated the efficacy of AA in reducing genotoxicity in fish induced by Pb. They showed the sensitivity and suitability of MN and NA frequencies in erythrocytes as pollution biomarkers.     

Zur Schwermetallbelastung der Borkenkäfer

Zusammenfassung Es wurde der Schwermetallgehalt (Cd, Mn, Pb, Zn) de für die Ernährung von Borkenkäfern relevanten Gewebe an Fichten (Picea abies Karst.) unterschiedlicher Standorte untersucht sowie dessen Auswirkung auf den Metallgehalt der dort minierenden Käfer (Ips typographus L.,Pityogenes chalcographus L. undPolygraphus poligraphus L., - Scolytidae) ermittelt. Für Cadmium und Zink konnte eine deutliche Anreicherung in den Käfern sowie eine entsprechende Abhängigkeit von der Konzentration im Futter nachgewiesen werden. Der Bast von Fichten weist teilweise sehr hohe Mangankonzentrationen und eine sehr breite Streuung auf. Die in diesem Bast entwickelten Käfer zeigen dagegen einheitlich niedrige Konzentrationen (unsicher beiI. typographus). Die Bleikonzentrationen waren in den Käferproben geringfügig höher als in den Bastproben, eine Abhängigkeit der Konzentrationen in Käfer und Bast wurde im untersuchten Konzentrationsbereich jedoch nicht gefunden. Die verschiedenen Entwicklungsstadien der Käfer wurden ebenfalls vergleichend auf ihren Schwermetallgehalt hin untersucht.

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Heavy metal contamination of bark beetles

Summary Heavy metal concentrations (cadmium, lead, manganese, zinc) in bark and wood of the sprucePicea abies Karst. from different locations were determined by AAS-method and compared with that of the bark-beetles feeding on it (Ips typographus L.,Pityogenes chalcographus L.,Polygraphus poligraphus L. — Scolytidae).In the case of cadmium and zinc a positive correlation of metal concentration in beetles and food as well as an accumulation in the beetles could be shown. We found considerable variation of manganese content (up to a factor of 100) in the inner bark (the main feeding substrate of the animals) but relatively uniform concentration in the insects (uncertain in the case ofI. typographus). Mean lead concentrations were slightly higher in beetles than in food, but no correlation between the insects and their feeding substrate could be detected in the range investigated. The heavy metal concentrations of different stages of development are compared and a short-circuit Cd-excretion mechanism in the larval stage is discussed.

     

Lead inactivation in soils by zeolites

Three-year pot experiments, carried out in a greenhouse, and laboratory investigations proved that the introduction of synthetic zeolites into lead-contaminated soils led to a reduction in the lead content of plants and thus contributed to a reduction in lead in the nutrient cycle. Lettuce leaves grown on a lead-contaminated soil amended with zeolites were 49–73% lower in Pb content than those on soils with no zeolites added.For grasses, these reductions were 47–77%, for the aboveground parts of oats 58–68%, for beet leaves 62%, and for beet roots 26–83%.     

Lead Tetraacetate-Thiocarbohydrazide-Silver Proteinate Method for Light Microscopy of Polysaccharides

Lead tetraacetate-thiocarbohydrazide-silver proteinate reaction sequence for light microscopy of polysaccharides was evaluated on Carnoy's fixed rat liver sections. The results of this evaluation suggest that, on the light microscopic level, the lead tetraacetate-thiocarbohydrazide-silver proteinate method may serve as a practical and histochemically specific alternative to the lead tetraacetate-Schiff reaction for the localization of tissue carbohydrates.     

Lead (II) Ion Inhibition of Respiration and Replication in a Toluene-Enriched Microbial Population

Bioremediation is inhibited in mine leachate water because of high concentrations of heavy metals and low pH. Inhibition of cellular respiration (A_N) and replication (U_N) by lead ions were measured at pH values near 5 for a mixed microbial culture from a wastewater treatment plant, grown aerobically using toluene as the primary carbon source. Gram-negative microorganisms dominated the toluene-selected microbial population. Microorganisms sequestered lead at binding sites having two different strengths. The stronger binding sites were saturated at about 0.5 mg/L Pb(II) concentration; no evidence of saturation of weaker binding sites was observed up to 15 mg/L of Pb(II). Most of the weak-binding capacity for lead was extracellular, which increased with lead ion concentration without saturating; the intracellular portion of the weak-binding capacity saturated at about 1.0 mg of lead per milligram of dry cells. Lead toxicity, measured by inhibition of respiration and replication, increased as lead accumulated at weak binding sites. However, toxicity to respiration and replication exhibited significantly different dose dependences with lead ion exposure. Replication decreased linearly with the amount of lead sequestered by the cells, consistent with nonspecific inhibition of reproductive catalysis. Respiration was correlated with lead ion activity in solution. Dependence of acute respiration toxicity on Pb(II) concentration and pH were consistent with a modified free ion activity model involving bis binding of lead at inhibition sites. Using a few easily determined parameters, inhibition of respiration and inhibition of reproduction for a natural microbial populations by Pb(II)-contaminated water at low pH are described by the modified free-ion activity model coupled with an appropriate dose-response function.     

Preparation and enantioseparation of a mixed selector chiral stationary phase derived from benzoylated tartaric acid and 1,2‐diphenylethylenediamine

L ‐Dibenzoyl tartaric acid was mono‐esterified with benzyl alcohol, and then chlorinated with SOCl₂ to give (2S,3S)‐1‐(benzyloxy)‐4‐chloro‐1,4‐dioxobutane‐2,3‐diyl dibenzoate (Selector 1 ). (1R,2R)‐1,2‐Diphenylethylenediamine was mono‐functionalized with phenyl isocyanate and phenylene diisocyanate in sequence to give (1R,2R)‐1,2‐diphenyl‐2‐(3‐phenylureido)ethyl 4‐ isocyanatophenylurea (Selector 2 ). Two brush‐type chiral stationary phases (CSPs) of single selector were prepared by separately immobilizing selectors 1 and 2 on aminated silica gel. Selectors 1 and 2 were simultaneously immobilized on aminated silica gel to give a mixed selector CSP. The enantioseparation ability of these CSPs was studied. The CSP of selector 1 has strongest separation ability, while the enantioseparation ability of the mixed selector CSP is relatively lower. Chirality 2010. © 2009 Wiley‐Liss, Inc.