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Background. According to the European Food Safety Authority (EFSA), fish, seafood and seaweeds are foodstuffs that significantly contribute to dietary arsenic intake. With the exception of some algal species, the dominant compounds of arsenic in such food products are the less toxic organic forms. Both the Joint FAO/ WHO Expert Committee on Food Additives (JECFA) and EFSA recommend that speciation studies be performed to determine the different chemical forms in which arsenic is present in food due to the differences in their toxicity. Knowing such compositions can thus enable a complete exposure assessment to be made. Objectives. Determination of total and inorganic arsenic contents in fish, their products, seafood and seaweeds present on the Polish market. This was then followed by an exposure assessment of consumers to inorganic arsenic in these foodstuffs. Materials and Methods. Total and inorganic arsenic was determined in 55 samples of fish, their products, seafood as well as seaweeds available on the market. The analytical method was hydride generation atomic absorption spectrometry (HGAAS), after dry ashing of samples and reduction of arsenic to arsenic hydride using sodium borohydride. In order to isolate only the inorganic forms of arsenic prior to mineralisation, samples were subjected to concentrated HCl hydrolysis, followed by reduction with hydrobromic acid and hydrazine sulphate after which triple chloroform extractions and triple 1M HCl re-extractions were performed. Exposure of adults was estimated in relation to the Benchmark Dose Lower Confidence Limit (BMDL05) as set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) that resulted in a 0.5% increase in lung cancer (3.0 μg/kg body weight (b.w.) per day). Results. Mean total arsenic content from all investigated fish samples was 0.46 mg/kg (90th percentile 0.94 mg/kg), whilst the inorganic arsenic content never exceeded the detection limit of the analytical method used (0.025 mg/kg). In fish products, mean total arsenic concentration was 1.48 mg/kg (90th percentile: 2.42 mg/kg), whilst in seafood they were 0.87 mg/ kg (90th percentile: 2.23 mg/kg), for inorganic arsenic contamination at the 90th percentile was 0.043 mg/kg with most results however being less than 0.025 mg/kg. The highest inorganic arsenic levels were determined in the Hijiki algal species samples (102.7 mg/kg), whereas the other algal samples gave a mean inorganic concentration of 0.41 mg/kg (90th percentile 0.86 mg/kg). The estimated average adults exposure to inorganic arsenic in fish, seafood and seaweeds was less than 0.5% of the lowest BMDL0.5 dose. Only for the Hijiki seaweed it was at 4.9% BMDL0.5. Conclusions. Results demonstrate that dietary arsenic intake from fish, seafood and seaweed along with all their products do not constitute a significant health threat to consumers apart from the seaweed species Hizikia fusiformis in which over 40% of all the inorganic arsenic compounds were found.
This paper reports on a hydroponics experiment that was conducted to investigate the effect of inorganic arsenics on the seedlings of the rice cultivar Shanyou63. The seedlings were subjected to two treatments, i.e., As(III) and As(V). The results showed that the morphological traits of the seedlings were significantly altered after the arsenic treatments. Analysis of nitrogen, phosphorus, potassium, and arsenic contents of the roots and leaves of the seedlings indicated that the absorption of phosphorus and potassium was mainly affected by As(III), while that of nitrogen was mainly affected by As(V). The expression of 12 genes involved in the absorption and utilization of nitrogen, phosphorus, and potassium were all observed to be down-regulated after the arsenic treatments. As(V) significantly affected the absorption and utilization of nitrogen, while As(III) significantly affected those of phosphorus and potassium. The result obtained by realtime FQ-PCR regarding the difference in the gene expressions agreed with that of our hydroponics experiment.
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