What do you know about zinc smelting?

Question

We live in a rural town whose only industry from 1900-1980 was zinc smelting. There was extensive damage done to the ground and mountains here, and the town became a Superfund cleanup site in the 80's.

Now it's clean (so they say...). But the school district bought the old R&D lab from the now-closed zinc plant, and they cleaned it up and converted it to an elementary school.

My son will start Kindergarten there this fall. They claim it is fine for the kids, while we (parents) say it is most certainly NOT. What do you guys think? Are the kids safe, or should we be checking out the local Catholic school?

Answer 1

I am not qualified to say if it is safe or not. If you do not trust the people who ARE qualified to say, then you just have to use your own judgment.

Answer 2

Zinc is in every thing like it was way back then as now a day

[edit] Chemical and Biosensor applications

Zinc oxide (ZnO) has received considerable attention because of its unique optical, semiconducting, piezoelectric, and magnetic properties. ZnO nanostructures exhibit interesting properties including high catalytic efficiency and strong adsorption ability. Recently, the interest has been focused toward the application of ZnO in biosensing because of its high isoelectric point (9.5), biocompatibility, and fast electron transfer kinetics. Such features advocate the use of this material as a biomimic membrane to immobilize and modify biomolecules [2]

[edit] As a food additive

Zinc oxide is added to many breakfast cereals, as a source of zinc; a necessary nutrient. (Other cereals may contain zinc sulfate, for the same purpose.) Some prepackaged foods also include trace amounts.

[edit] As a pigment

Zinc white is used as a pigment in paints and is more opaque than lithopone, but less opaque than titanium dioxide. It is also used in coatings for paper. Chinese white is a special grade of zinc white used in artists' pigments. Because it absorbs both UVA and UVB rays of ultraviolet light, zinc oxide can be used in ointments, creams, and lotions to protect against sunburn and other damage to the skin caused by ultraviolet light (see sunscreen). It is the broadest spectrum UVA and UVB absorber that is approved for use as a sunscreen by FDA, and is completely photostable. It is also a main ingredient of mineral make-up mainly because of its vast array of colors.

[edit] Rubber manufacture

Zinc oxide and stearic acid are ingredients in the commercial manufacture of rubber goods. A mixture of these two compounds allows a quicker and more controllable rubber cure. Zinc oxide can also be used as a filler in some rubber mixtures.

[edit] Electronic materials

ZnO is a semiconductor with a direct bandgap energy of 3.37 eV at room temperature. The most common applications are in laser diodes and light emitting diodes since it has an exciton and biexciton energies of 60 meV and 15 meV, respectively. It is expected that this exciton properties of ZnO will be improved further by epitaxy.

Most ZnO has n-type character, even in the absence of intentional doping. Native defects such as oxygen vacancies or zinc interstitials are often assumed to be the origin of this, but the subject remains controversial[3]. An alternative explanation has been proposed, based on theoretical calculations, that unintentional substitutional hydrogen impurities are responsible[4].

n-type doped films are often used in thin film technology, where zinc oxide serves as a TCO (transparent conducting oxide). n-type doping is possible by introduction of aluminium, indium, or excess zinc[5]. p-type doping is difficult and is currently an active area of research, with arsenic as the leading candidate dopant[6]. Thin-film solar cells, LCD and flat panel displays are typical applications of this material. Appropriately doped ZnO may be transparent and conductive, and can therefore be used as a transparent electrode. Indium tin oxide (ITO) is another transparent conducting oxide often used in microelectronics.

ZnO has also been considered for spintronics applications because of theoretical predictions of room temperature ferromagnetism. Unsubstantiated reports of ferromagnetism have been made, but presence of dilute magnetic semiconductors remains a large unanswered question in physics.

The piezoelectricity in textile fibers coated in ZnO have been shown capable of "self-powering nanosystems" with everyday mechanical stress generated by wind or body movements.[7][8]

ZnO layers are mainly deposited by sputter deposition and chemical vapor deposition (CVD). The latter method allows the growth of a rough layer, which can diffuse the incoming light by scattering, increasing the efficiency of solar cells.

ZnO has been observed to act as a chemical reagent for Friedel-Craft Acylation Reaction.

[edit] Pyroelectric coefficients

Primary pyroelectric coefficient: -6.8 µC/m²·K

Secondary pyroelectric coefficient: -2.5 µC/m²·K

Total pyroelectric coefficient: -9.4 µC/m²·K