The environmental impact of zinc and of all essential elements cannot be assessed in the same way as man-made chemical compounds. Because zinc occurs naturally, eliminating it from the environment would not be possible.  Moreover, because zinc is essential, achieving such a goal would ultimately lead to detrimental effects throughout an ecosystem.  In other words, less is not necessarily better.

Zinc is a natural component of the earths crust and an inherent part of our environment. Zinc is present not only in rock and soil, but also in air, water and the biosphere. Plants, animals and humans contain zinc.
Minerals and metals are mostly obtained from the earths crust. The average natural level of zinc in the earths crust is 70 mg/kg (dry weight), ranging between 10 and 300 mg/kg (Malle 1992).

In some areas, zinc has been concentrated to much higher levels by natural geological and geochemical processes (5-15% or 50,000-150,000 mg/kg). Such concentrations, found at the earths surface and underground, are being exploited as ore bodies.