The greatest concentration of houses are immediately downwind from  the concrete plant toxic plume. The windrose showing prevailing winds for this area may be found here . A letter from a climatologist confirming the applicability of this information for the Weaverville area may be found here.

The area around the proposed concrete plant is essentially a bowl with little air movements to disburse toxins. The concentration of nearby residents are both downwind from the stack and uphill - placing them even closer to the source of emissions. The closest house is 70 feet away and their bedroom window is nearly level with the toip of the stack.