The current paper determines heavy metals in sediments of six freshwater wetlands of greater Dhaka district from November 1999 to September 2000. The sampling took place in summer, rainy season, and winter, wherein for each season five soil samples were collected from the wetland at a depth of 0 – 15 cm. To assess the status of heavy metal pollution in the sediments, geo-accumulation factor (Ig...

It is important to examine mechanisms of Pb and Cd sorption in soils to understand their bioavailability. The ability of three tropical soils to retain Pb, Cd, and Ca was evaluated. The objectives of this study were to (1) determine the extent to which soil sorption sites are metal specific, (2) investigate the nature of reactions between metals and soil surfaces, and (3) identify how metals co...

The toxicity of Pb and Cd+Pb was assessed on the Collembola F. candida in two cultivated soils (SV and AU) with low organic matter (OM) content and circumneutral to basic pH, and an acid forested soil (EPC) with high OM content. Collembola reproduction and growth as well as metal content in Collembola body, in soil, exchangeable fraction and soil solutions, pH and DOC were investigated. Pb and ...

BACKGROUND Metal pollution of waterways directly affects human health and can impact the food chain. Seafood living in polluted water can accumulate trace metals. The purpose of this study was to analyze the toxic metals Pb and Cd and the dietary essential metals Zn and Mn in 120 cans of tuna species from four different brands processed in Iran and purchased in 2012. RESULTS The mean level of...

Pb and Cd in water samples were determined by cloud point extraction (CPE) with sodiumdiethyldithiocarbamate (DDTC) as the chelating agent and octylphenoxypolyethanl (Triton X-114) asthe surfactant prior to flame atomic absorption spectrometry (FAAS) determination. The main factorsof affecting the extraction and detection processes were optimized. The preconcentration of 10 mL ofstandard soluti...

Two hypotheses were tested: (1) heavy metals such as Zn, Pb and Cd can suppress the respiration rate of forest litter at low-moderate pollution levels, and (2) mineral nutrients such as K, Ca and Mg can counteract the toxicity of heavy metals when applied onto the polluted litter. In a completely randomised design, three doses of heavy metals were used: Cd-10, 50, 250; Pb-100, 500, 2500; Zn-200...

The pollution characteristics of Pb, Cd, Zn, Cu and Ni in soil of lead−zinc mining area were studied. The results indicate that the contamination degree followed the sequence of Cd>Pb>Zn>Ni>Cu and concentrations of Pb, Cd and Zn exceeded corresponding limits of the Chinese National Soil Environmental Quality Standard III. The soil was extremely polluted by Cd (Iego=5.26), moderately to heavily ...

In this work, a novel electrochemiluminescence (ECL) sensor based on Au nanoparticles-hybridized Pb (II)-β-cyclodextrin (Pb-β-CD) metal-organic framework for detecting hexavalent chromium (Cr(VI)) was developed. Pb-β-CD shows excellent ECL behavior and unexpected reducing ability towards Au ions. Au nanoparticles could massively form on the surface of Pb-β-CD (Au@Pb-β-CD) without use of any add...

This work investigated the distribution and speciation of Cd, Cu, Pb, Fe and Mn in the shallow sediments of Jinzhou Bay, Northeast China, which has been heavily contaminated by nonferrous smelting activities. The concentrations of Cd, Cu and Pb in sediments were found to be 100, 13 and 7 times, respectively, being higher than the national guideline (GB 18668-2002). Sequential extraction test sh...

This study presents the effect of metal-enriched rice on concentrations of Pb, Cd, Zn, and Cu in the tissues of chicken. The experimental group of chicken (fed with contaminated rice) accumulated high concentrations of Pb (1.00, 0.73, 0.52, 0.99, and 13.8 mg/kg dw in kidney, liver, muscle, blood and feather, respectively), being 2, 1.2, 3.5, 3, and 3.5 times the corresponding tissue Pb in the c...