Arsenic in drinking water wells on the Bolivian high plain: field monitoring and effect of salinity on removal efficiency of iron-oxides-containing filters

In the rural areas around Oruro (Bolivia), untreated groundwater is used directly as drinking water. This research aimed to evaluate the general drinking water quality, with focus on arsenic (As) concentrations, based on analysis of 67 samples from about 16 communities of the Oruro district. Subsequently a filter using Iron Oxide Coated Sand (IOCS) and a filter using a Composite Iron Matrix (CIM) were tested for their arsenic removal capacity using synthetic water mimicking real groundwater. Heavy metal concentrations in the sampled drinking water barely exceeded WHO guidelines. Arsenic concentrations reached values up to 964 mu g L-1 and exceeded the current WHO provisional guideline value of 10 mu g L-1 in more than 50% of the sampled wells. The WHO guideline of 250 mg L-1 for chloride and sulphate was also exceeded in more than a third of the samples, indicating high salinity in the drinking waters. Synthetic drinking water could be treated effectively by the IOCS- and CIM-based filters reducing As to concentrations lower than 10 mu g L-1. High levels of chloride and sulphate did not influence As removal efficiency. However, phosphate concentrations in the range from 4 to 24 mg L-1 drastically decreased removal efficiency of the IOCS-based filter but had no effects on removal efficiency of the CIM-based filter. Results of this study can be used as a base for further testing and practical implementation of drinking water purification in the Oruro region

Impact of contamination on the development of controlled inundation areas along the Scheldt estuary (poster)

One of the objectives of the SIGMA-plan of the River Scheldt is the construction of a controlled inundation area in Kruibeke-Bazel-Rupelmonde. However this area is contaminated with heavy metals due to aerial deposition. On the other hand, as an inundation area, it will be flooded with contaminated water from the Scheldt. Therefore it is necessary to estimate the impact of contamination on the potential nature development in these areas.A case study was carried out last two years in a VLINA-project at a tidal marsh along the River Scheldt. The distribution of the contaminants over the different compartments was investigated during two years. The compartments were the soil and pore water, but also the vegetation and the dominant group of macrobenthos. Beside this an estimation was made of the input of contaminants due to the sedimentation of particles during flooding. Other processes that were studied are the sorption and desorption processes, which affect the bioavailability, and the effect on the uptake of contaminants and the bioaccumulation in reed (Phragmites australis) and Oligochaeta are studied in detail. The above- and belowground biomass of reed (Phragmites australis) was measured

Starches, Sugars and Obesity

The rising prevalence of obesity, not only in adults but also in children and adolescents, is one of the most important public health problems in developed and developing countries. As one possible way to tackle obesity, a great interest has been stimulated in understanding the relationship between different types of dietary carbohydrate and appetite regulation, body weight and body composition. The present article reviews the conclusions from recent reviews and meta-analyses on the effects of different starches and sugars on body weight management and metabolic disturbances, and provides an update of the most recent studies on this topic. From the literature reviewed in this paper, potential beneficial effects of intake of starchy foods, especially those containing slowly-digestible and resistant starches, and potential detrimental effects of high intakes of fructose become apparent. This supports the intake of whole grains, legumes and vegetables, which contain more appropriate sources of carbohydrates associated with reduced risk of cardiovascular and other chronic diseases, rather than foods rich in sugars, especially in the form of sugar-sweetened beverages