Copper (Cu) is an important essential element for plants and humans. Even so, in too high concentrations it is toxic to living organisms. In modern agriculture, a variety of agricultural practices are being implemented, which bring too much copper into the soil. There is less and less water in the world. This problem is forcing farmers in arid areas to use industrial and urban sewage for irrigation. In intensive agricultural landscapes, they use copper-rich slurry. These are added to the feed. The traditional use of copper-based plant protection products is a major contaminant of agricultural soils. These preparations are mainly used for the control of fungal and bacterial diseases. The availability of copper for plants is conditioned by soil and environmental characteristics. Copper is absorbed into plants as it is essential for the normal course of biochemical processes. With the tendency of plants to over-absorb, excessive concentrations of copper begin to accumulate in the plant parts. It is important to control copper concentrations in soil and in edible parts of plants, since it can enter the human body through food chain. Excessive copper concentrations can be detrimental to human health. In order to reduce human health hazards, research and state institutions shall prescribe recommended and toxic daily intakes of copper for humans and limit values for soil copper. Excessive concentrations of copper in soil limit the production of agricultural crops.