Spatial and seasonal mercury distribution in the Ayapel Marsh, Mojana region, Colombia.

Geographical and temporal changes of total mercury (T-Hg) concentrations in sediments, macrophytes and fish were evaluated in the Ayapel Marsh, Mojana, Colombia. Sampling was conducted during 2006-2007, including both rainy and dry seasons, and T-Hg was measured using atomic absorption spectroscopy. Distribution of T-Hg in sediments and the macrophyte Eichhornia crassipes showed that higher concentrations were found along the flooding pathway of the Cauca River. Hg has also polluted the food chain. Highest T-Hg concentrations in fish were detected for the carnivorous Pseudoplatystoma fasciatun (0.432 ± 0.107 µg/g, fresh weight [fw]), and lowest in the non-carnivorous Prochilodus magdalenae (0.143 ± 0.053 µg/g, fw), with differences between trophic levels. T-Hg for fish samples (0.298 ± 0.148 µg/g, fw) did not exceed the limit consumption level (0.50 µg/g, fw). It is concluded that mercury-polluted sediments from the Cauca River, contribute to Hg deposition into the Ayapel Marsh. Accordingly, interventions must be conducted to decrease Hg accumulation in fish.

Potentially-toxic and essential elements profile of AH1N1 patients in Mexico City.

During spring of 2009, a new influenza virus AH1N1 spread in the world causing acute respiratory illness and death, resulting in the first influenza pandemic since 1968. Blood levels of potentially-toxic and essential elements of 40 pneumonia and confirmed AH1N1 were evaluated against two different groups of controls, both not infected with the pandemic strain. Significant concentrations of potentially-toxic elements (lead, mercury, cadmium, chromium, arsenic) along with deficiency of selenium or increased Zn/Cu ratios characterized AH1N1 cases under study when evaluated versus controlled cases. Deficiency of selenium is progressively observed from controls I (influenza like illness) through controls II (pneumonia) and finally pneumonia-AH1N1 infected patients. Cases with blood Se levels greater than the recommended for an optimal cut-off to activate glutathione peroxidase (12.5 µg/dL) recovered from illness and survived. Evaluation of this essential element in critical pneumonia patients at the National Institutes is under evaluation as a clinical trial.