Transcript Document
Zinc
JESSICA YOUNG
Structure & Properties
Zn
Atomic number: 30
5 Stable isotopes
Zn64, Zn66, Zn67, Zn68, Zn70
Many radio isotopes
Zn65, Zn72
Exists in oxidation states
Zn, Zn1+, Zn2+
Also found in many compounds
ZnO, ZnCl2, ZnS, and ZnSO4
Relatively long half life (4.3 X 1018 years)
Uses & Applications
Oxidated form (Zn2+) 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
ZnCl2
ZnSO4
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
33.18 mg/ kg in site 5 sediment sample
35.19 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
http://www.epa.gov/iris/toxreviews/0426tr.pdf
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. 9776-9780 http://pubs.acs.org/doi/pdf/10.1021/ac8019587
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. 227-248
http://www.jstor.org/stable/2820034
US Dept of Health and Human Services, Agency for Toxic Substances and Disease
Registry; 2005; Toxicological Profile for Zinc
http://www.atsdr.cdc.gov/ToxProfiles/tp60.pdf
National Institutes of Health, Office of Dietary Supplements
http://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/
Sigel, Astrid; Sigel, Helmut; Sigel, Roland K. O.; Metallothionines and Related
Chelators; Metal Ions in Life Sciences; v. 5;
http://www.springer.com/chemistry/inorganic+chemistry/book/978-1-84755899-2?detailsPage=reviews
Zinc Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review
http://www.pwrc.usgs.gov/infobase/eisler/chr_26_zinc.pdf