Water
Zinc is naturally present. The geology can determine the natural background concentrations of zinc in the overlying water.
Crust
Zinc is the 24th most abundant element in the Earth’s crust – for every kg of crust there’s 70 mg of zinc!
Soil
Zinc is naturally present. The geology can determine the natural background concentrations of zinc in the overlying soil.
Plants
All life on earth is developed in the presence of zinc and it is essential in 100% of living organisms.
Humans
With ~8 billion humans on earth, an average of 2.5 g of zinc per person = 20 thousand tonnes of zinc in living human beings on Earth today.