Trace metals are part of the fundamental building blocks of the earth.
Soils, water, and bedrock naturally contain these elements in varying concentrations. They include metals like arsenic, cadmium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc. Trace metals are present throughout the environment including soils, food, drinking water, humans, animals, plants, and biosolids. Yes, biosolids contain trace concentrations of metals. The trace metals found in biosolids come from both industrial and residential sources.