New Method for Simultaneous Arsenic and Selenium Speciation Analysis in Seafood and Onion Samples

A critical review on the organo-metal(loid)s pollution in the environment: Distribution, remediation and risk assessment

Toxic metal(loid)s, e.g., mercury, arsenic, lead, and cadmium are known for several environmental disturbances creating toxicity to humans if accumulated in high quantities. Although not discussed critically, the organo-forms of these inorganic metal(loid)s are considered a greater risk to humans than their elemental forms possibly due to physico-chemical modulation triggering redox alterations or by the involvement of biological metabolism. This extensive review describes the chemical and physical causes of organometals and organometal(loid)s distribution in the environment with ecotoxicity assessment and potential remediation strategies. Organo forms of various metal(loid)s, such as mercury (Hg), arsenic (As), lead (Pb), tin (Sn), antimony (Sb), selenium (Se), and cadmium (Cd) have been discussed in the context of their ecotoxicity. In addition, we elaborated on the transformation, speciation and transformation pathways of these toxic metal(loid)s in soil-water-plant-microbial systems. The present review has pointed out the status of toxic organometal(loid)s, which is required to make the scientific community aware of this pressing condition of organometal(loid)s distribution in the environment. The gradual disposal and piling of organometal(loid)s in the environment demand a thorough revision of the past-present status with possible remediation strategies prescribed as reflected in this review.

Aptamer and Electrochemical Aptasensor towards Selenate Ions (SeO42-)

Selenium is an essential inorganic compound in human and animal nutrition, involved in the proper functioning of the body. As a micronutrient, it actively contributes to the regulation of various metabolic activities, i.e., thyroid hormone, and protection against oxidative stress. However, Se exhibits a narrow concentration window between having a positive effect and exerting a toxic effect. In higher doses, it negatively affects living organisms and causes DNA damage through the formation of free radicals. Increased reactivity of Se anions can also disrupt the integrity and function of DNA-repairing proteins. As the permissible concentration of Se in drinking water is 10 µg/L, it is vital to develop sensitive and robust methods of Se detection in aqueous samples. In this study, for the first time, we proposed a selective aptamer for selenate ion detection, chosen following the SELEX process, and its application in the construction of an electrochemical aptasensor towards SeO42- ions. Measurement conditions such as the used redox marker and pH value of the measurement solution were chosen. The proposed aptasensor is characterized by good selectivity and an LOD of 1 nM. Conditions for biosensor regeneration and storage were also investigated in this research.

Speciation analysis of arsenic in honey using HPLC-ICP-MS and health risk assessment of water-soluble arsenic

It is well known that arsenic is one of the most toxic elements. However, measuring total arsenic content is not enough, as it occurs in various forms that vary in toxicity. Since honey can be used as a bioindicator of environmental pollution, in the present study the concentration of arsenic and its species (As(III), As(V), DMA, MMA and AsB) was determined in honey samples from mostly Poland and Ukraine using HPLC-ICP-MS hyphenated technique. The accuracy of proposed methods of sample preparation and analysis was validated by analyzing certified reference materials. Arsenic concentration in honey samples ranged from 0.12 to 13 μg kg-1, with mean value of 2.3 μg kg-1. Inorganic arsenic forms, which are more toxic, dominated in honey samples, with Polish honey having the biggest mean percentage of inorganic arsenic species, and Ukrainian honey having the lowest. Furthermore, health risks resulting from the consumption of arsenic via honey were assessed. All Target Hazard Quotient (THQ) values, for total water-soluble arsenic and for each form, were below 1, and all Carcinogenic Risk (CR) values were below 10-4, which indicates no potential health risks associated with consumption of arsenic via honey at average or recommended levels.

Health risk-benefit assessment of the commercial red mangrove crab: Implications for a cultural delicacy

Mangrove forests, provide vital food resources and are an endangered ecosystem worldwide due to pollution and habitat destruction. A risk-benefit assessment (RBA) was performed on the red mangrove crab (Ucides occidentalis) from the threatened Guayas mangroves in Ecuador. It was aimed to assess the combined potential adverse and beneficial health impact associated with crab consumption and define a recommended safe intake (SI) to improve the diet of the Ecuadoran population while ensuring safe food intake. Target hazard quotients (THQs), benefit quotients (Qs), and benefit-risk quotients (BRQs) were calculated based on the concentrations of the analyzed contaminants (121 pesticide residues, 11 metal(loid)s, antimicrobial drugs from 3 classes) and nutrients (fatty acids, amino acids, and essential nutrients). Except for inorganic arsenic (iAs), the THQ was below 100 for all investigated contaminants, suggesting that the average crab consumer is exposed to levels that do not impose negative non-carcinogenic or carcinogenic health effects in the long and/or short term. Concentrations of iAs (average AsIII: 25.64 and AsV: 6.28 μg/kg fw) were of the highest concern because of the potential to cause negative health effects on long-term consumption. Despite the thriving aquaculture in the Guayas estuary, concentrations of residues of the antimicrobial drugs oxytetracycline (OTC), florfenicol, and nitrofurans still were low. Based on the fact that different risk reference values exist, related to different safety levels, four SI values (0.002, 0.04, 4, and 18 crabs/day) were obtained. The strictest intake values indicate a concern for current consumption habits. In conclusion, the red mangrove crab contains various important nutrients and can be part of a balanced diet for the Ecuadorian population when consumed in limited portions. The present study emphasizes the importance of safeguarding the quality of the environment as a prerequisite for procuring nutritious and safe food.