Copper mining and smelting were important activities in various predesert wadis during the Iron Age, Nabatean, Roman, and Byzantine periods in southern Jordan and major spoil tips to gether with slag heaps remain as a legacy of such enterprises. Barley has grown in the area for a prolonged period and currently wild barley plants are affected by toxic cations, which reduce their yields. It is considered that such plants provide an adequate model to assess how similar plants would have performed, in terms of productivity, in the past. The population of miners/slaves, guards, etc., would have been subject to bioac cumulation of heavy metals, which conceivably would have led to detrimental effects on their health. Inhalation and ingestion of particulate pollutants cannot be discounted. It is argued that the population may have been further weakened as a consequence of food shortage, due to reduced plant productivity, as cereals are important foods for both humans and the animals upon which they are dependent. A sizeable mining community could only have been maintained by large-scale importation of food or a massive intensification of agricultural activity.