Effects of storage temperature and duration on release of antimony and bisphenol A from polyethylene terephthalate drinking water bottles of China.

We investigated effects of storage temperature and duration on release of antimony (Sb) and bisphenol A (BPA) from 16 brands of polyethylene terephthalate (PET) drinking water bottles in China. After 1-week storage, Sb release increased from 1.88-8.

Arsenic and selenium toxicity and their interactive effects in humans.

Arsenic (As) and selenium (Se) are unusual metalloids as they both induce and cure cancer. They both cause carcinogenesis, pathology, cytotoxicity, and genotoxicity in humans, with reactive oxygen species playing an important role. While As induces adverse effects by decreasing DNA methylation and affecting protein 53 expression, Se induces adverse effects by modifying thioredoxin reductase.

Effect of aging on arsenic and lead fractionation and availability in soils: coupling sequential extractions with diffusive gradients in thin-films technique.

We coupled the diffusive gradients in thin-films (DGT) technique with two sequential extraction methods to investigate the influence of aging on As and Pb fractionation and availability in three soils spiked with As (40 or 400mgkg(-1)), Pb (150 or 1500mgkg(-1)) or As+Pb (40mgkg(-1) As and 150mgkg(-1) Pb). During aging, As moved from the more available (non-specifically and specifically sorbed) to less available (amorphous and crystallized Fe/Al) fractions while Pb moved from the first three fractions (exchangeable, carbonate and Fe/Mn hydroxide) to organic fraction. However, even after 33-week aging, much more As and Pb were in the least available residual fraction in spiked soils than native soils (11-59% vs.

Assessment of children's exposure to arsenic from CCA-wood staircases at apartment complexes in Florida.

Arsenic exposure from wood treated with chromated copper arsenate (CCA) remains a concern due to its presence around homes. This study evaluated children's exposure to As from CCA-treated staircases through determination of bioaccessible soil As and measurements of dislodgeable As on hand railings, steps and surfaces of household objects impacted by CCA-wood leachate. Total As concentrations in 84 soil samples from 4 apartment complexes were elevated at 1.

Antimony uptake, translocation and speciation in rice plants exposed to antimonite and antimonate.

Antimony (Sb) accumulation in rice is a potential threat to human health, but its uptake mechanisms are unclear. A hydroponic experiment was conducted to investigate uptake, translocation, speciation and subcellular distribution of Sb in rice plants exposed to antimonite (SbIII) and antimonate (SbV) at 0.2, 1.

Enhanced Cr(VI) reduction and As(III) oxidation in ice phase: important role of dissolved organic matter from biochar.

This study evaluated the impact of DOM from two biochars (sugar beet tailing and Brazilian pepper) on Cr(VI) reduction and As(III) oxidation in both ice and aqueous phases with a soil DOM as control. Increasing DOM concentration from 3 to 300mgCL(-1) enhanced Cr(VI) reduction from 20% to 100% and As(III) oxidation from 6.2% to 25%; however, Cr(VI) reduction decreased from 80-86% to negligible while As(III) oxidation increased from negligible to 18-19% with increasing pH from 2 to 10.

Pyrolytic temperatures impact lead sorption mechanisms by bagasse biochars.

The characteristics and mechanisms of Pb sorption by biochars produced from sugarcane bagasse at 250, 400, 500, and 600 °C were examined. The Pb sorption isotherms, kinetics and desorption were investigated. All biochars were effective in Pb sorption and were well described by Langmuir isotherm model and pseudo-second-order kinetic model.

Antimony uptake, efflux and speciation in arsenic hyperaccumulator Pteris vittata.

Even though antimony (Sb) and arsenic (As) are chemical analogs, differences exist on how they are taken up and translocated in plants. We investigated 1) Sb uptake, efflux and speciation in arsenic hyperaccumulator Pteris vittata after 1 d exposure to 1.6 or 8 mg/L antimonite (SbIII) or antimonate (SbV), 2) Sb uptake by PV accessions from Florida, China, and Brazil after 7 d exposure to 8 mg/L SbIII, and 3) Sb uptake and oxidation by excised PV fronds after 1 d exposure to 8 mg/L SbIII or SbV.

Ionic strength reduction and flow interruption enhanced colloid-facilitated Hg transport in contaminated soils.

The effects of ionic strength (IS) reduction (5-0.05mM) and flow interruption (FI, flow stopped for 7d) on colloid and Hg release in the leachate were examined in column experiment. Two Hg contaminated soils (13.

Source, distribution, and health risk assessment of polycyclic aromatic hydrocarbons in urban street dust from Tianjin, China.

To better assess and understand potential health risk of urban residents exposed to urban street dust, the total concentration, sources, and distribution of 16 polycyclic aromatic hydrocarbons (PAHs) in 87 urban street dust samples from Tianjin as a Chinese megacity that has undergone rapid urbanization were investigated. In the meantime, potential sources of PAHs were identified using the principal component analysis (PCA), and the risk of residents' exposure to PAHs via urban street dust was calculated using the Incremental Lifetime Cancer Risk (ILCR) model. The results showed that the total PAHs (∑PAHs) in urban street dust from Tianjin ranged from 538 μg kg(-1) to 34.

Influence of Cu and Ca cations on ciprofloxacin transport in saturated porous media.

Emerging contaminant ciprofloxacin (CIP) has been frequently detected in soils and groundwater; however, impacts of cations on its transport in the environment remain largely unknown. We examined CIP transport in saturated sand media under the influence of Cu/Ca by either mixing CIP with Cu/Ca in solution or preloading CIP onto sand then using Cu/Ca solution to mobilize CIP. Though the amount of Fe/Al oxides on native sand surface was limited, it significantly impeded CIP transport, delaying CIP breakthrough curve from 30 to >100 PV.

Wading bird guano contributes to Hg accumulation in tree island soils in the Florida Everglades.

Tree islands are habitat for wading birds and a characteristic landscape feature in the Everglades. A total of 93 surface soil and 3 soil core samples were collected from 7 degraded/ghost and 34 live tree islands. The mean Hg concentration in surface soils of ghost tree islands was low and similar to marsh soil.

Effects of arsenate, chromate, and sulfate on arsenic and chromium uptake and translocation by arsenic hyperaccumulator Pteris vittata L.

We investigated effects of arsenate (AsV), chromate (CrVI) and sulfate on As and Cr uptake and translocation by arsenic hyperaccumulator Pteris vittata (PV), which was exposed to AsV, CrVI and sulfate at 0, 0.05, 0.25 or 1.

Mechanistic investigation of mercury sorption by Brazilian pepper biochars of different pyrolytic temperatures based on X-ray photoelectron spectroscopy and flow calorimetry.

We investigated the mechanisms of Hg sorption onto biochars produced from Brazilian pepper (BP; Schinus terebinthifolius) at 300, 450, and 600 °C using different analytical techniques. The Hg sorption capacity of BP300, BP450, and BP600 was 24.2, 18.

Sparingly-soluble phosphate rock induced significant plant growth and arsenic uptake by Pteris vittata from three contaminated soils.

We evaluated the ability of As-hyperaccumulator Pteris vittata (PV) to remove As from As-contaminated soils over five harvests in 2.5 years in raised beds (162 kg soil/bed). We tested the hypothesis that a P-limiting environment would enhance PV growth and As uptake owing its unique ability to uptake P under As-rich environment.

Effects of Cu and Ca cations and Fe/Al coating on ciprofloxacin sorption onto sand media.

Emerging contaminant ciprofloxacin (CIP) has been frequently detected in soils. Its interactions with metals in soils remain largely unknown. We examined the effects of metal cations Cu and Ca and surface Fe/Al coating on CIP sorption by preloading Cu and Ca onto sand surface or mixing them with CIP in solution.

Bioavailability and oxidative stress of cadmium to Corbicula fluminea.

This work set out to study the effects of cadmium (Cd) in sediments on the antioxidant enzyme activities in the digestive gland of Asian clam Corbicula fluminea and to explore the potential for applying these responses to evaluate the Cd-contaminated sediment. Additionally, diffusive gradients in thin-films (DGT) technique was used to predict the response of its antioxidant defense system. The sediments, collected from Taihu Lake, were spiked with Cd at different concentrations (0.

Novel phytase from Pteris vittata resistant to arsenate, high temperature, and soil deactivation.

Arsenate interferes with enzymatic processes and inhibits inorganic phosphorus (Pi) uptake in many plants. This study examined the role of phytase and phosphatase in arsenate tolerance and phosphorus (P) acquisition in the arsenic hyperaccumulator Pteris vittata . Enzyme-mediated hydrolysis of phytate in P.

Impacts of two best management practices on Pb weathering and leachability in shooting range soils.

This study investigated the impacts of two best management practices (BMPs) recommended by US Environmental Protection Agency on Pb weathering and leachability in shooting range soils. The two BMPs included replacing soil berm with sand berm and periodically removing bullets or shot from a berm. A column experiment corresponding to the first BMP was conducted by mixing the bullets with sand/soil, or placing bullets on the surface of sand/soil.

Bacteria-mediated arsenic oxidation and reduction in the growth media of arsenic hyperaccumulator Pteris vittata.

Microbes play an important role in arsenic transformation and cycling in the environment. Microbial arsenic oxidation and reduction were demonstrated in the growth media of arsenic hyperaccumulator Pteris vittata L. All arsenite (AsIII) at 0.

Localised mobilisation of metals, as measured by diffusive gradients in thin-films, in soil historically treated with sewage sludge.

The two dimensional, small-scale, distribution of labile trace metals was investigated in a sandy loam soil historically treated with sewage sludge. After deployment of two DGT (diffusive gradients in thin-films) probes, their 1.8×15 cm windows were sliced into 5×5 mm and 5×8 mm rectangles to provide three vertical profiles with 5mm resolution.

Predicting arsenic bioavailability to hyperaccumulator Pteris vittata in arsenic-contaminated soils.

Using chemical extraction to evaluate plant arsenic availability in contaminated soils is important to estimate the time frame for site cleanup during phytoremediation. It is also of great value to assess As mobility in soil and its risk in environmental contamination. In this study, four conventional chemical extraction methods (water, ammonium sulfate, ammonium phosphate, and Mehlich III) and a new root-exudate based method were used to evaluate As extractability and to correlate it with As accumulation in P.

Transport and interactions of kaolinite and mercury in saturated sand media.

To evaluate the potential of Hg release and co-transport by colloids, it is important to understand how Hg, colloids and Hg-loaded colloids migrate in soils. Hg sorption by kaolinite and sand were nonlinear and fit the Langmuir model, with the maximum Hg sorption capacity being 1.2mg/g kaolinite and 0.

Calcium water treatment residue reduces copper phytotoxicity in contaminated sandy soils.

Calcium water treatment residue (Ca-WTR), an industrial by-product, was found to be effective in decreasing Cu availability in contaminated soils and transport to the environment. In this study, a greenhouse study was conducted to test the ability of Ca-WTR to reduce the toxicity and uptake of Cu by ryegrass (Lolium perenne L.) and lettuce (Lactuca sativa L.