An Experimental Evaluation of Strategies for Reducing Airborne Dust in Desert Cities

The effect of buildings on Ihe drv deposition ot dust was invesligaled in Be ʹer Sheva, a desert city in southern Israel. and al two reference points in Ihe surrounding countryside. The mineral and chemical composilion ()fdust sampled at all sites was similar. re/lecling the composition of the local loess soil, its likely origin. However. dust deposited in the traps set up in the ricinity of buildings in the city was significantly coarser than the dusl which accumulaled in similar traps at exposed sites in the countryside. The amount of dusl in Ihe urban dust traps was on average more than twice the amount deposited in the rural area. The differences in grain-si::e distribution and quantity of dust are accountedfor by the disturbances 10 the natural enlʹironmenl caused by the presence of buildings and br human aClitʹitv in the cillʹ. This study suggesis that str~tegies commonly employed in the design ot buildings and urban space to reduce exposure to dust, such as the construction of walled courtyards, are not effective. A significant reduction in the concentration of dust in the lʹicinity of buildings in desert cities may require a comprehensire approach which deals with the entire urban area and its immediate surroundings. particularly with a !ʹin,. to reducing Ihe awilability of erodible particles by means of plan ling or paving all exposed land surfaces