JESSICA YOUNG Zinc

Structure & Properties Zn Atomic number: 30 5 Stable isotopes  Zn 64, Zn 66, Zn 67, Zn 68, Zn 70 Many radio isotopes  Zn 65, Zn 72 Exists in oxidation states  Zn, Zn 1+, Zn 2+ Also found in many compounds  ZnO, ZnCl 2, ZnS, and ZnSO 4 Relatively long half life (4.3 X years)

Uses & Applications Oxidated form (Zn 2+ ) occurs naturally in minerals in the earth’s crust (70 mg/kg) Anthropogenic sources  Smelting  used to protect against corrosion  Batteries  Brass & Bronze manufacturing  Brakes and car exhaust found to be leading cause of zinc pollution in Sao Paulo, Brazil study

Uses & Applications Applications of zinc compounds  Herbicides, medical and dental products, household items (makeup, shampoo, sunscreen)

Zinc in Aquatic Environments How it gets there…  Industrial & urban runoff Cations, zinc-inorganic coumpoudns, zinc-organic compouds Zinc ions have a low mobility in sediment and are readily taken up by plants and animals Bioconcentration factors estimated to be 1000 and 2000 for freshwater and marine fish, respectively

Properties in water As a cation, it is non soluble in water and is partitioned into sediment by adsorption onto organic molecules Other common forms are much more soluble  ZnCl 2  ZnSO 4 Other solubility factors  Temperature  pH  Mineral composition of water

Necessity & Toxicity Zinc is an essential micronutrient found in most foods; absorbed through gastrointestinal tract  Necessary for enzyme function Miners exposed to acute high levels of zinc oxide in the air experienced respiratory problems Interference with absorption of copper and iron  Effects on cardiovascular, respiratory, and immune systems  Low leves of HDL  Stimulated production of amylase and lipase by pancreas  One incident of human fatality attributed to zinc overdose

Zinc at the Colorado Lagoon mg/ kg in site 5 sediment sample mg/kg in site 8 clam tissue  CO Lagoon clams contains 16 mg/ pound  Recommended Daily Allowance is 8-11 mg/ day  Tolerable Upper Limit is 40 mg/ day

Detoxification Metallothionine (MT)  Cysteine rich proteins found in Golgi  Found to play key role in uptake, regulation, and distribution of zinc in organisms Zinc is efficiently regulated in mammals and excess zinc can be excreted via nephridial system

References EPA; 2005; Toxicological Review of Zinc and Compounds Gioia, S., Weiss, D., Coles, B., Arnold, T., Babinski, M.; 2008; Accurate and Precise Zinc Isotope Ratio Measurements in Urban Aerosols; Analytical Chemistry; v. 80 (24); p Skidmore, J. F.; 1964; Toxicity of Zinc Compounds to Aquatic Animals, with Special Reference to Fish; The Quarterly Review of Biology; V. 39 (3); p US Dept of Health and Human Services, Agency for Toxic Substances and Disease Registry; 2005; Toxicological Profile for Zinc National Institutes of Health, Office of Dietary Supplements Sigel, Astrid; Sigel, Helmut; Sigel, Roland K. O.; Metallothionines and Related Chelators; Metal Ions in Life Sciences; v. 5; ?detailsPage=reviews Zinc Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review