The ingestion of certain trace metals has been a major concern of the world and there have been links to cancer, renal failure, anemia, cardiovascular and reproductive complications. Pacifiers are amongst the childcare objects that may expose children to potentially toxic metals through mouthing behaviors. Despite high levels of hazardous chemicals reported in some childcare products including pacifiers, there has been limited information on the chemical species formed in saliva and as a result their bioavailability levels. Using the Joint Expert Speciation System, this study determined chemical speciation and predicted bioavailability at a range of 18-92% for cadmium and 1-23% for lead of the total metal concentrations through the creation of simulated saliva models at low and high pH. The degree of predicted uptake using a net-neutral species approach was dependent on the total concentrations of lead and cadmium within a standard range of low molecular mass ligands and the pH of the saliva. These saliva models predicted cadmium to be more bioavailable than lead, indicating there may be an elevated risk from the mouthing action of pacifiers or similar items containing cadmium compared to lead. This study, therefore, offers regulatory bodies opportunities to strengthen safety compliance monitoring for materials used in pacifiers.
Growth and As uptake of mung bean (Vigna radiata) in roots, shoots, and grains of different genotypes grown in soil with high As level (30 mg kg(-1)) amended with arbuscular mycorrhizal fungi, selenium, and biochar was investigated. Arsenic content in grains was reduced on average by 45% with any of the soil amendments. More specifically, the As concentrations in grains were reduced by 57% with arbuscular mycorrhizal fungi and by 60% with Se amendments. Also, great differences in As-uptake between varieties have been observed.
Abstract Rotenone is a broadly used organic pesticide with neurotoxicity as a serious side effect for non-target organisms. The inhibition of mitochondrial complex I is the principal mechanism of rotenone toxicity that leads to oxidative stress, apoptosis, and decreased autophagy. Several chemical compounds have been demonstrated to exhibit antioxidant, antiapoptotic, and autophagy enhancement in both in vitro and in vivo studies. Some chemical agents can ameliorate rotenone-induced neurotoxicity through their antioxidant, anti-inflammatory, and anti-apoptotic properties. They also inhibit the accumulation of α-synuclein, control dopamine release, affect ion channels, and induce autophagy. Clinical trials are essential to reinforce the effectiveness of any chemical in managing patients with rotenone neurotoxicity.
The potential of biomimetic chromatography to predict ecotoxicological endpoints of pharmaceutical compounds was investigated. For this purpose, a data set of previously and newly measured chromatographic retention data for 36 structurally diverse drugs was used. Standardized retention times were measured on the immobilized artificial membrane, human serum albumin, and alpha-1-acid glycoprotein stationary phases. As ecotoxicological endpoints, half-maximal lethal concentration values of fish and half-maximal effective concentration (immobilization) values of a water flea (Daphnia magna spp.) determined with a two-day static method were considered. Ecotoxicity values correlated with octanol-water partitioning and the positive charge of compounds contributed even more to the toxicity. Models based on membrane partition exhibited the best statistics and predictive performance, attributed to lipophilicity and membrane electrostatic interactions. Alpha-1-acid glycoprotein binding led to satisfactory models, owing to its function as a binder of neutral and basic lipophilic compounds. Albumin binding, however, did not result in sound models, as it is governed by lipophilicity and the negative charge of compounds, contrary to the mechanism of toxicity. Both membrane and alpha-1-acid glycoprotein models were superior statistically from those derived from the octanol-water system. Overall, membrane and alpha-1-acid glycoprotein retention can be suggested as promising indices to assess the ecotoxicological risk of drugs.
Water pollution due to toxic metals may pose a significant effect on the environment and the biota indicating the necessity of careful management of their concentration in the system. On the other hand, a simplified and useable sample preparation technique is required for their trace analysis. In this report, a simple solid-phase extraction procedure was developed for fast extraction and preconcentration of Cu(II) and Cr(III) from waters using acetic acid modified zinc oxide nanoparticles prior to flame atomic absorption spectrometry. The extraction procedure was optimized with respect to sample volume, pH, adsorbent dose, eluent, and extraction time. Ionic strength and co-existing ions did not exhibit any significant effect on the extraction. Under optimum conditions, with an enrichment factor of 40 and recoveries of over 95%, the limits of detection for both analytes were in the low mu g L-1 range. Intra-day and inter-day precision were at about 3% to 4%. The method was applied for trace determination of the analytes in real water samples.
