Total and inorganic arsenic in dietary supplement supplies in northern Mexico.

The aim of this study was to evaluate the presence of total and inorganic arsenic in dietary supplements composed of herbal plants and seaweed, and to determine the potential toxicological risk. Total arsenic was determined by dry ashing and hydride generation atomic absorption spectrometry, and inorganic arsenic was determined by acid digestion, solvent extraction, and hydride generation atomic absorption spectrometry. Total and inorganic arsenic in the supplements ranged from 0.07 to 8.31 mg kg(-1) dry weight and from 0.14 to 0.28 mg kg(-1) dry weight, respectively. Daily intake of total arsenic ranged from 0.05 to 12.46 µg day(-1). Inorganic arsenic intake ranged from 0.21 to 0.83 µg day(-1), values that are below the Benchmark Dose Lower Confidence Limit recommended by the Word Health Organization. Therefore, there appears to be a low risk of adverse effects resulting from excess inorganic arsenic intake from these supplements. This is the first study conducted in Mexico that investigates total and inorganic arsenic in dietary supplements. Although the results do not suggest toxicological risk, it is nonetheless important considering the toxicity of inorganic arsenic and the increasing number consumer preferences for dietary supplements. Moreover, it is important to improve and ensure the safety of dietary supplements containing inorganic arsenic.

Content of selenium, total and inorganic arsenic and bioaccessibility of arsenic in children diets of Mexico.

BACKGROUND: The aim of this study was to evaluate the intake of selenium, total and inorganic arsenic and the bioaccessibility of arsenic in diets of Mexican schoolchildren using an in vitro method. RESULTS: Total and inorganic arsenic concentrations in the diets ranged from 0.05 to 1.15 mg kg(-1) dry weight (DW) and from 0.023 to 0.088 mg kg(-1) DW respectively, while selenium levels were between 0.08 and 0.20 mg kg(-1) DW. Daily intake of total and inorganic arsenic ranged from 0.15 to 10.49 µg day(-1) kg(-1) body weight (BW) and from 0.06 to 1.11 µg day(-1) kg(-1) BW respectively, while that of selenium varied from 0.29 to 2.63 µg day(-1) kg(-1) BW. Bioaccessibility of total and inorganic arsenic ranged from 4 to 97% (mean 44 ± 21.5%) and from 33 to 97% (mean 71 ± 22.5%) respectively. CONCLUSION: Inorganic arsenic levels in the diets were low. Therefore there appears to be a low risk of adverse effects resulting from excess inorganic arsenic intake from these diets.

Dissolved and particulate metals in water from Sonora Coast: a pristine zone of Gulf of California: metals in water from Sonora Coast.

The purpose of this study was to investigate the distribution of metals (Cd, Pb, Hg, Cu, Fe, Mn, and Zn) in dissolved and particulate fractions in seawater from Bacochibampo Bay, Northern part of Mexico. Water samples were collected from November 2004 to October 2005. Metal analysis was done by graphite furnace atomic absorption spectroscopy. Results indicated highest concentrations of dissolved Cd and Zn in the sites localized at the mouth and center of the bay. During summer and spring, the highest levels of Cd, Mn, and Fe were detected, Zn in fall, and Pb and Cu in winter and spring. Mercury was the only metal that was not found in this fraction. In particulate fraction, Fe, Hg, and Mn were the most abundant elements in all the sampling sites, followed by Zn, Cu, Pb, and Cd. The highest levels of the majority of the metals were observed in the coastline, suggesting a continental and/or urban source for these chemicals. The highest level of Cd was detected during the summer and the rest of the metals in the fall. Statistically significant correlations were observed between dissolved and particulate forms of Pb:Mn, Cu:Fe, and Cu:Mn. The mean partition coefficient values were as follows: Fe>Mn>Cu>Pb>Cd>Zn. All dissolved metal concentrations found, except Pb, were lower than EPA-recommended water quality values. The levels of dissolved metals in this study reveal low bioavailability and toxic potential. However, further toxicological and sediment chemistry studies in this area are needed for a full risk assessment.