Champaign-Urbana is like most of the cities in the US in that it is surrounded by agriculture. Over the last few years, the favorite herbicide has been Monsanto's Roundup. However, the "weeds" have evolved Roundup resistance. No new herbicide has been developed. The Ag industry is going back to the highly volatile Dicamba and 2,4-D. These herbicides can drift through the air in both a droplet (during application) or gaseous (evaporate from the crop) form. The latter was used mainly more than 20 years ago. We know that these herbicides are toxic to a variety of plants. No graph arbors exist any more in Champaign-Urbana, IL for example. We thus know that these herbicides have drifted into the urban areas but we have only anecdotal information on human health effects, either the applicators, the farmers, farm families and those in the nearby urban areas. We need a device to detect and record the concentrations of these herbicides in various parts of these urban areas. I need your help.