Abstract

The effect of the antioxidant gallic acid (GA) on Pb toxicity in blood, liver and kidney was investigated in the present study. Rats Wistar received Pb nitrate (50 mg/Kg/day, i.p., 5 days) followed by GA (13.5 mg/Kg, p.o., 3 days) or a chelating agent (EDTA, 55 mg/Kg, i.p.). As result, Pb decreased body weight, hematocrit and blood δ-aminolevulinic acid dehydratase (ALA-D) activity. In addition, high Pb levels were observed in blood and tissues, together with increased (1) lipid peroxidation in erythrocytes, plasma and tissues, (2) protein oxidation in tissues and (3) plasma aspartate transaminase (AST) levels. These changes were accompanied by decreasing in antioxidant defenses, like superoxide dismutase (SOD) activity in tissues and catalase (CAT) activity and reduced glutathione (GSH) in liver. GA was able to reverse Pb-induced decrease in body weight and ALA-D activity, as well as Pb-induced oxidative damages and most antioxidant alterations, however it did not decrease Pb bioaccumulation herein as EDTA did. Furthermore, EDTA did not show antioxidant protection in Pb-treated animals as GA did. In conclusion, GA decreased Pb-induced oxidative damages not by decreasing Pb bioaccumulation, but by improving antioxidant defenses, thus GA may be promising in the treatment of Pb intoxications.

Abstract

This study is aimed to assess the heavy metals contamination and health risk in Shrimp (Macrobrachium rosenbergii and Penaeus monodon ) collected from Khulna-Satkhira region in Bangladesh. The results showed that the Pb concentrations (0.52–1.16 mg/kg) in all shrimp samples of farms were higher than the recommended limit. The Cd levels (0.05–0.13 mg/kg) in all samples and Cr levels in all farms except tissue content at Satkhira farm were higher than the permissible limits. The individual concentration of Pb, Cd, and Cr between shrimp tissue and shell in all rivers and farms were not statistically significant (P > 0.05). Target hazard quotient (THQ) and hazard index (HI) were estimated to assess the non-carcinogenic health risks. Shrimp samples from all locations under the current study were found to be safe for consumption, the possibility of health risk associated with non-carcinogenic effect is very low for continuous consumption for 30 years.

Abstract

Electric vehicle battery performance near end-of-life is limited by mismatched cell degradation, leading to an estimated 5-10% cell capacity variation across the pack. Active cell balancing hardware architectures incorporating a Low-Voltage (LV) bus supply have been introduced to unlock lost capacity due to cell imbalance at reduced cost, through elimination of the vehicle's 400-to-12V dc-dc converter. In this work, a hierarchical model-predictive control scheme is applied to a time-shared isolated converter active balancing architecture that incorporates LV bus supply. The proposed controller efficiently divides computation among the battery management system hardware components. The energy-buffering capability of the lead-acid battery, which is connected to the LV bus, is used to trade-off balancing and bus regulation objectives, reducing peak power and improving the system cost-effectiveness. Simultaneous state-of-charge balancing and LV bus regulation is verified in simulation and experiment using real-world drive and LV load data collected from a GM Bolt electric vehicle. Similar controller performance compared to a central scheme is achieved in simulation. The experimental setup includes a custom 12S2P, 3.9kWh, liquid-cooled Lithium Nickel Manganese Cobalt battery module with embedded battery management system. The controller performance is evaluated with an initial maximum state-of-charge imbalance of 6.8%.

Abstract

The levels of six chemical elements (mercury, arsenic, lead, cadmium, zinc and copper) were examined in two species of Pacific salmon, genus Oncorhynchus, pink salmon (O. gorbuscha ), and chum salmon (O. keta ) that were caught in the Kuril waters in July 2013. Concentrations of toxic elements (Hg, As, Pb, Cd) in both species were shown to be below the maximum concentration limits of these trace elements for seafood. The concentrations of these elements were compared between wild salmon and hatchery salmon of the Pacific and Atlantic oceans.

Abstract

Interactions of metals with the biomass of plant organisms, including algae, are of interest for biology, biogeochemistry and biotechnology. This work studies the interactions of the unique thermophilic red algae Galdieria sulphuraria (Class: Rhodophyta, Family: Cyanidiaceae) with copper and lead in the aquatic environment. This extremophilic, acidophilic organism is found in such ecosystems as hot springs and geothermal habitats. This paper presents the results of experiments with the biomass and mortmass of this organism. The results indicate that the biomass of this organism immobilises copper after incubation in aquatic medium with heavy metals. Lead was also added to the incubation environment, but no immobilisation of lead from the aquatic environment was observed. The mortmass of G. sulphuraria immobilised neither copper nor lead.

Abstract

Lead is one of the most toxic heavy metals and its occupational exposure can generate plumbemia. For this reason, the objective of this investigation was to generate a baseline of lead concentrations in the blood of a group of battery factory workers in Guayaquil-Ecuador and of a control group not exposed to the metal at work, to establish the existence of occupational risk between sexes, ages, and jobs positions. For this, blood samples were taken from the workers and the control group. The samples were analyzed by atomic absorption spectrophotometry with a graphite furnace. 100 % of the workers presented Pb in an average concentration of 16.22 ± 6.82 µg / dL higher than the World Health Organization value, but lower than the limit established by Occupational Health and Safety Assessment of 40 µg / dL, also, the value was higher than of the control group (0.68 ± 0.15 µg / dL). Men presented higher levels of Pb than women and these values ​​varied depending on the job in the factory. In conclusion, 4.55 % of the workers did not present a risk of lead poisoning, 13.64 % low risk, 78.79 % medium risk, and only 3.00 % high risk.