Ingested inorganic arsenic (As) is known to be a human carcinogen. An intriguing question is whether there is a threshold for the carcinogenic effects of As, i.e., is there a level below which it does not induce the development of cancer(s)? This Roundtable will discuss the United States Environmental Protection Agency's As risk assessment using the Taiwan data from different viewpoints. It will also consider the hypothesis that there is a threshold for As and data for or against this hypothesis. For example, some scientists believe that epidemiological data cannot answer this question, while others feel that different study designs and larger sampling will provide adequate data. Reasons for each position are given. This Roundtable discussion demonstrates the controversy surrounding the use of the Taiwan data for risk assessment.
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http://dx.doi.org/10.1006/faat.1996.0018 | DOI Listing |
Environ Pollut
December 2024
Institute of Quality Standard and Testing Technology for Agro-products, Chinese Academy of Agricultural Sciences, And Key Laboratory of Agro-food Safety and Quality, Ministry of Agriculture and Rural Affairs, Beijing, 100081, China. Electronic address:
The potential health risks of microplastics (MPs) and their combined exposure with heavy metals such as mercury (Hg) in aquatic environment are increasingly concerned recently. In this work, zebrafish embryos were exposed to different levels of polystyrene microplastics (PS-MPs, ∼0.1 μm) coupled with Hg(II) or/and MeHg at 20 μg/L, to investigate the tissue biodistribution and accumulation of PS-MPs and Hg species, and their interaction, as well as embryo toxicity, oxidative stress and metabolic profiles.
View Article and Find Full Text PDFJ Hazard Mater
November 2024
Department of Environmental Toxicology, University of California Davis, Davis, CA 95616, USA.
Apex marine predators, such as toothed whales and large petrels and albatrosses, ingest mercury (Hg) primarily in the form of methylmercury (MeHg) via prey consumption, which they detoxify as tiemannite (HgSe). However, it remains unclear how lower trophic level marine predators, termed mesopredators, with elevated Hg concentrations detoxify MeHg and what chemical species are formed. To address this need, we used high energy-resolution X-ray absorption near edge structure spectroscopy paired with nitrogen (N) and Hg stable isotopes to identify the chemical forms of Hg, Hg sources, and species-specific δHg isotopic values in emperor penguin, a mesopredator feeding primarily on Antarctic silverfish.
View Article and Find Full Text PDFHeliyon
November 2024
Institute of Plant Protection, Liaoning Academy of Agricultural Sciences, Shenyang, Liaoning, 110161, China.
This study investigated the impact of three different fertilization modes (traditional [FP1], one-time application of organic and inorganic fertilizer [FP2], and one-time application of inorganic fertilizer [OPT]) on the quality of japonica rice ( ) during storage under a rice-crab co-culture system. A field study was conducted, with rice samples collected every two months over a one-year storage period for quality analysis. The results showed that protein accumulated with increasing the amount of nitrogen fertilization, whereas amylose content and eating quality showed the opposite trend, further causing changes in rice quality during storage.
View Article and Find Full Text PDFMar Pollut Bull
January 2025
Laboratory of Aquatic Systems: Marine and Continental Environments (AQUAMAR), Department of Biology, Faculty of Sciences, Ibn Zohr University, Agadir 80000, Morocco.
The pervasive presence of microplastics (MPs) in the environment is well established, yet many critical questions remain about their distribution and potential impacts on both ecological and human health. To assess the risks that MPs pose, especially through marine ecosystems and human consumption, monitoring their ingestion by fish in natural environments is essential. This study investigated the contamination of 12 fish species, the most commonly consumed in Morocco, collected from the Atlantic Ocean off the Moroccan coast.
View Article and Find Full Text PDFJ Hazard Mater
November 2024
Géosciences Rennes, UMR 6118, University of Rennes 1, Campus de Beaulieu, 35042 CEDEX Rennes, France.
This work shows that the plastic debris accumulated along with stranded Sargassum biomass in Guadeloupe's beaches contains different forms of arsenic. Results from synchrotron nano X-ray Fluorescence (nanoXRF) and nano X-ray Absorption Near Edge Structure (nanoXANES) show that arsenate (As(V) in a tetrahedral coordination) present in seawater is complexed in the algae cell walls in an octahedral As(V) form, which is subsequently reduced to As(III) within the algae. Inorganic As(III) is either excreted or may undergo methylation and/or binding to glutathione, which is then stored in the algal cells or excreted.
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