A major part of the zinc present in surface waters is ultimately deposited in the sediments of rivers, estuaries and coastal areas where it binds to inorganic and organic matter, which reduces its bioavailability. There is a difference between the total zinc concentration and the dissolved zinc concentration in water. There is no relationship between total zinc concentration and the uptake of zinc by organisms.

It is the bioavailable zinc content which has ecological significance. This bioavailable fraction is usually estimated by filtering the water sample. However, many other factors such as temperature, water hardness, pH, and dissolved organic carbon content, in fact determine the bioavailability of zinc in water. In general, zinc bound to suspended organic matter will settle and for this reason, top sediment layers usually mirror the zinc levels in the overlying water. Sediment layers formed in rivers in recent years show decreasing zinc levels.

Airborne zinc particles are deposited on the land and surface waters. In the soil, zinc is bound to the soil complex, depending on different physicochemical soil factors such as pH and organic matter content. These factors determine the solubility of the zinc contained in soil, and consequently, its bioavailability for uptake by organisms. Changes in soil pH, for example, dramatically alter the bioavailability of zinc in soil. Soils and sediments are more static compartments of the environment than air and surface waters.

Separately, since the time of the Ancient Greeks, man has mined ore bodies to extract metals from the earth, refining them and converting them into various chemical forms for use in a wide variety of products. Zinc has been known as a separate metal since the Middle Ages, but the industrial extraction and refining of zinc began in Europe in the late 18th century. This industrial activity has resulted in anthropogenic (man-made) input of zinc to the environment and an increase in zinc levels in certain environments.

From the 1970s on, however, growing attention to the environment has led to a progressive reduction in zinc emissions to air and water and the zinc industry has achieved a major reduction in emissions during recent decades. Zinc emissions resulting from industrial activity have decreased significantly in recent decades and present-day zinc levels do not pose a risk to the environment. Nonetheless, in the vicinity of some old industrial sites, levels of zinc in the soil, usually in combination with other metals, can be elevated due to high emissions in the past (historical contamination). Such sites need specific attention and appropriate risk management to limit exposure of the local ecosystem and prevent contamination from spreading to surrounding areas. Promising results have recently been obtained with metal immobilizing compounds that, when mixed with contaminated soils, fix zinc and other metals to the soil complex, rendering them less available for uptake by organisms.

According to report published in 2002 by the World Health Organization International Program on Chemical Safety (WHO/IPCS), because the possibility exists both for a deficiency and for an excess of this metal, it is important that regulatory criteria for zinc, while protecting against toxicity, are not set so low as to drive zinc levels into the deficiency area.