Zinc metal is as essential to sustaining life as water. It plays an important role in the biological processes of all organisms and thankfully it is abundant in the Earth’s crust. Zinc is safely used for many consumer products and is a critical additive in agricultural fertilizers, especially in areas of the developing world where there is too little zinc in the soil to produce healthy crops. Zinc is naturally cycled through the environment by Mother Nature, with approximately six million tons constantly moving in flowing water, wind, precipitation, and erosion throughout our ecosystem each year. Worldwide, man-made point sources of zinc such as hot-dip galvanized poles, sign structures, bridges, and guardrail add another 62,000 tons per year. That one percent anthropogenic contribution is statistically very small, but any imbalance to nature must be critically assessed. Studies reveal zinc corrosion products emanating from hotdip galvanized steel products remain in very close proximity to the products themselves, meaning a very small area of the environment has elevated levels of zinc. With the exception of one measurement at 3 meters distance from the base of one tower in the study (Table 2, page 4), levels of zinc were far below the USEPA Ecological Soil Screening Level even in the most corrosive atmosphere to zinc. More importantly, very little of the zinc is actually available for absorption by organisms and thus remains harmlessly in the ground, to be redistributed by Mother Nature over the next centuries.
