Distribution of 26 major and trace elements in edible seaweeds from the US market.

In this study we present an elemental profile of 46 edible seaweed samples purchased in the United States. The seaweeds were grouped in 13 subgroups/species based on DNA barcoding analysis. The seaweeds were decomposed by microwave accelerated acid digestion followed by quantification of 26 elements by ICP-MS. Elements were grouped into macronutrient (Na, K, Ca, S, Mg and P), essential (Fe, Zn, Mn, V, Cu, Cr, Ni, Mo and Se), non-essential including toxic elements (Sr, Ba, Th, Sn and Sb As, Cd, Pb, U, W and Hg). The highest levels were found for Na and the lowest were for Hg. The elemental profiles depended on the taxonomy of the species and several elements (Fe, Ba, Cr, Pb, W and Th) also exhibited high intraspecies variations, likely due to geographic origin or food processing conditions. Higher Cd and Pb accumulation was observed in wakame, hijiki and nori, with Cd as high 4.05 mg/kg and Pb as high as 2.85 mg/kg in kombu. A study of correlation between the elements using Pearson's coefficients revealed multiple pairs of highly correlated elements in seaweed, as well as triple and quintuple correlations of certain elements.

Connecting inorganic mercury and lead measurements in blood to dietary sources of exposure that may impact child development.

Pre-natal and post-natal chemical exposures and co-exposures from a variety of sources including contaminated air, water, soil, and food are common and associated with poorer birth and child health outcomes. Poor diet is a contributing factor in the development of child behavioral disorders. Child behavior and learning can be adversely impacted when gene expression is altered by dietary transcription factors such as zinc insufficiency or deficiency or by exposure to toxic substances permitted in our food supply such as mercury, lead, or organophosphate pesticide residue. Children with autism spectrum disorder and attention deficit hyperactivity disorders exhibit decreased or impaired PON1 gene activity which is needed by the body to metabolize and excrete neurotoxic organophosphate pesticides. In this current review we present an updated macroepigenetic model that explains how dietary inorganic mercury and lead exposures from unhealthy diet may lead to elevated blood mercury and/or lead levels and the development of symptoms associated with the autism and attention deficit-hyperactivity disorders. PON1 gene activity may be suppressed by inadequate dietary calcium, selenium, and fatty acid intake or exposures to lead or mercury. The model may assist clinicians in diagnosing and treating the symptoms associated with these childhood neurodevelopmental disorders. Recommendations for future research are provided based on the updated model and review of recently published literature.

Speciation analysis of arsenic in prenatal and children's dietary supplements using microwave-enhanced extraction and ion chromatography-inductively coupled plasma mass spectrometry.

A study was conducted to develop a microwave-enhanced extraction method for the determination of arsenic species in prenatal and children's dietary supplements prepared from plant materials. The method was optimized by evaluating the efficiency of various solutions previously used to extract arsenic from the types of plant materials used in the dietary supplement formulations. A multivitamin standard reference material (NIST SRM 3280) and a prenatal supplement sample were analyzed in the method optimization. The identified optimum conditions were 0.25 g of sample, 5 mL of 0.3 mol L(-1) orthophosphoric acid (H3PO4) and microwave heating at 90 °C for 30 min. The extracted arsenic was speciated by cation exchange ion chromatography-inductively coupled plasma mass spectrometry (IC-ICP-MS). The method detection limit (MDL) for the arsenic species was in the range 2-8 ng g(-1). Ten widely consumed prenatal and children's dietary supplements were analyzed using the optimized protocol. The supplements were found to have total arsenic in the concentration range 59-531 ng g(-1). The extraction procedure recovered 61-92% of the arsenic from the supplements. All the supplementary products were found to contain arsenite (As(3+)) and dimethylarsinic acid (DMA). Arsenate (As(5+)) was found in two of the supplements, and an unknown specie of arsenic was detected in one product. The results of the analysis were validated using mass balance by comparing the sum of the extracted and non-extracted arsenic with the total concentration of the element in the corresponding samples.