Arsenic, antimony and selenium in urban soils: potential risks for human health in urban gardening

The benefits of urban agriculture are many and well documented, ranging from health improvement to community betterment, more sustainable urban development and environment protection. On the negative side, urban soils are commonly enriched in toxic trace elements that have accumulated over time through the deposition of atmospheric particles (generated by automotive traffic, heating systems, historical industrial activities and resuspended street dust), and the uncontrolled disposal of domestic, commercial and industrial wastes. This in turn has given rise to concerns about the level of exposure of urban farmers to these elements and the potential health hazards associated with this exposure. Research efforts in this field have started relatively recently and have almost systematically omitted the influence of Sb and Se, and to a lesser extent of As, although all three have proven toxic effects.

Gas sensor based on room temperature optical properties of Surface QDs

Self-organized InGaAs QDs are intensively studied for optoelectronic applications. Several approaches are in study to reach the emission wavelengths needed for these applications. The use of antimony (Sb) in either the capping layer or into the dots is one example. However, these studies are normally focused on buried QD (BQD) where there are still different controversial theories concerning the role of Sb. Ones suggest that Sb incorporates into the dot [1], while others support the hypothesis that the Sb occupies positions surrounding the dot [2] thus helping to keep their shape during the capping growth.