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Arsenic

Arsenic. The Poison of Kings. Claire M. Waggoner Aquatic Toxicology. Structures, Physical and Chemical Properties  Symbol As  Atomic Number 33  Atomic Mass 74.9216  Electron Configuration [ Ar ] 3d 10 4s 2 4p 3 Density @ 293 K 5.72 g/cm 3 Melting Point 1090 K

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Arsenic

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  1. Arsenic The Poison of Kings Claire M. Waggoner Aquatic Toxicology

  2. Structures, Physical and Chemical Properties •  Symbol As •  Atomic Number 33 •  Atomic Mass 74.9216 •  Electron Configuration [Ar] 3d104s24p3 • Density @ 293 K 5.72 g/cm3 • Melting Point 1090 K •  Boiling Point 886 K (sublimes) • Metalloid • Yellow, white, red, gray or metallic solid • garlic odor • similar to phosphorous

  3. Anthropogenic Production History • Emerald Green paint • Wallpaper (2.5kg/100m) • Quack medicines • -treat syphilis pre penicillin • -Mixed w/ vinegar and chalk, eaten to whiten skin, • prevent wrinkles, and improve complexion by Victorian women • Favorite murder weapon of the Middle Ages & Renaissance  • (cholera symptoms) • Industrial, Mining and byproducts • Chromated copper arsenate • Arsenopesticides: Weed killer, Rat poison, orchard/crop pesticide • Storage batteries, Light-emitting diodes (LEDs) , solar cells, bullets • 52,380 tons of As2O3 used globally in 1989 • 28,530 tons imported by the United States • 80% used for Pesticides and wood preservatives

  4. Chemical reactivity with water, chemical speciation, physical half-life etc • Does not react with water in the absence of air • As pH decreases, solubility increases, becomes more mobile • Arsenic is NOT Biodegradable Arsenic: As (metal) Arsenic acid, sodium salt: AsH3O4.xNa *** Arsenic trioxide (white): As2O3 Arsenic trioxide: As4O6 Arsine: AsH3 Arsenic sulphide (red): AsS, As2S2 Arsenic trisulphide (yellow): As2S3 Chromated copper arsenate (CCA) ***Inorganic arsenite: AsIII ***Inorganic arsenate: AsV Monomethylarsonous acid (MMA) Dimethylarsinous acid (DMA) Organic Arsenic: Arsenobetaine -most seafood, crustaceans Arsenosugars –seaweed & bivalves

  5. “Natural” As Abundance: • 20th most abundant element in Earth’s crust • Abundance of Arsenic: • Earth's Crust: 3.4 ppm • Seawater: • Pacific Surface: 1.45 µg/L • Pacific Deep: 1.75 µg/L • Colorado Lagoon: 4.9-11.3 µg/L • Sediment: • Natural: 1-40mg/kg Ave:5mg/kg • Colorado Lagoon: 4.7-9.2 µg/dry kg • Atmosphere: • Remote:1-3ng/m3 • Urban: 20-100 ng/m3

  6. “Natural” As Abundance (cont): • Freshwater: 1-5000μg/L • **World Health Organization recommends 10µg/L • Average person drinks 2L of water per day • =2-10,000μg • Levels In Humans: • Daily Dietary Intake: 40-140 μg • We need ~5-50 μg As a day • Total Daily intake= 42-10,140μg • .

  7. Mode of Entry in Aquatic Environment • Aerial deposition, rock weathering & volcanoes • Coal & wood combustion, waste incineration • CCA treated wood • Seepage, leeching • Stormwater run-off • (As-pesticides, mines, Industrial waste) • Marsh plants can make • metals bioavailable

  8. Mode of entry into organisms • Terrestrial: • Inhalation • Ingestion • Skin and/or eye contact • Aquatic: • Gills • Membranes • Ingestion • Mantle

  9. Toxic effects noted in Humans • Target Organs: Skin, respiratory system, kidneys, central nervous system, liver, gastrointestinal tract, reproductive system • Direct contact with the skin: redness & swelling. • Acute: • nausea, vomiting, and diarrhea • abnormal heartbeat, circulatory collapse • Respiratory failure • Gastrointestinal, kidney & liver damage • Chronic: • build up in skin & hair • small corns or warts on hands & feet  • reproductive complications • Skin, prostate, lymph, bladder, kidneys, liver, and lung cancer • CNS damage • LD50 pure arsenic: • 763 mg/kg (by ingestion) • 13 mg/kg (by intraperitoneal injection) • For a 70 kg (~155 lb) human, about 53 grams

  10. Toxicity to aquatic life • Copepod96-h LC50: 27.5 μg/L for arsenic • FW Clam 96-h LC50: 20.74 mg/L (20,740 μg/L) • As(III) bioaccumulate 300-1,000 μg/L • As(III) regulated below 100 μg/L • Juvenile milkfish 96-h LC50: 7.29 mg/L (7,290 μg/L)

  11. Toxic effects • Premature Anaphase • Alteration of Chromosome Number, • Doubling of chromosome number (left) • Endoreduplication (right) • multi-system organ failure • teratogenesis • cancer • death

  12. Molecular mode of toxic interaction of As(III) and As(V) • Disrupts ATP Production @ Citric Acid Cycle • Inhibits pyruvate and alpha-ketoglutaratedehydrogenase • Competes with phosphate-> uncouples oxidative phosphorylation • Toxic effects: • Prevents reduction of NAD+ • reduces mitochondrial respiration • Inhibits ATP synthesis • ↑ H2O2 production • ↑ oxidative stress • ↑ Substrates before dehydrogenase steps (pyruvate and lactate)

  13. Molecular mode of toxic interaction of As(III) • Binds thiol containing amino acids, peptides and proteins • Binds to key sulfhydryl groups, inhibiting enzyme action • Glutathione(GSH) is key xenobiotic detoxifying thiol enzyme • Low protein diet  low GSH  higher arsenite induced cellular toxicity • Binds to glucocorticoid receptor • Glucose metabolism • Growth • Reporoduction • Immune function • Anti-inflammatory response • Fetal development • Clam up or swim away • Active transport • Sequestering via metallothionene • *Proper Diet is necessary Blocks receptor from activating genes

  14. Biochemical metabolism and breakdown via METHYLATION • As(III) or As(V) Arsenobetaine Arsenosugars Methyltransferase CH3 S-adenosylmethionine Excreted in Urine Monomethylarsonous acid (MMA) Dimethylarsinous acid (DMA) • Plankton and aquatic organisms have similar mechanism

  15. The problem with Arsenic and METHYLATION • DNA is also typically methylated in order to regulate the expression genes, including oncogenes • DNA methylation requires same methyl donor that is consumed in arsenic methylation • DNA is undermethylated, or hypomethylated, unable to properly regulate gene expression

  16. Defense strategies for detoxification by humans • Bioassesment assays (ex. using a LacZ reporter gene to produce a pH response to the input of arsenate/arsenite molecules) • Dried roots from water hyacinth plant can rapidly remove arsenic from water (93-95% removal) • Specific Anion Nanoengineered Sorbents (SANS)

  17. Bibliography • Chu HA, Crawford-Brown DJ (2006). "Inorganic arsenic in drinking water and bladder cancer: a meta-analysis for dose-response assessment". Int J Environ Res Public Health 3 (4): 316–22. PMID 17159272 • Chung-Min Liao, Sheng-FengJau, Wei-Yu Chen, Chieh-Ming Lin, Li-John Jou, Chen-Wuing Liu, Vivian Hsiu-Chuan Liao, Fi-John Chang. 2008. Acute toxicity and bioaccumulation of arsenic in freshwater clam Corbiculafluminea. Environmental Toxicology. PMID: 18344212 • Elder, J.F. 1988. Metal Biogeochemistry in Surface-Water Systems - A Review of Principles and Concepts. U.S. Geological Survey Circular 1013. • Fisher B. Testing their metal. Environ Health Perspect. 1999 May;107(5):A244-5 • J. Forget, J. F. Pavillon, M. R. Menasria, G. Bocquene, Mortality and LC50Values for Several Stages of the Marine CopepodTigriopusbrevicornis(Muller) Exposed to the Metals Arsenic and Cadmium and the Pesticides Atrazine, Carbofuran, Dichlorvos, and Malathion, Ecotoxicology and Environmental SafetyVolume 40, Issue 3, , July 1998, Pages 239-244. (http://www.sciencedirect.com/science/article/B6WDM-45JB84T-2T/1/8de1563c332d793057b8a0f8fef511e1) Keywords: copepods; metals; pesticides; 96-h LC50 Knobeloch LM, Zierold KM, Anderson HA (2006). "Association of arsenic-contaminated drinking-water with prevalence of skin cancer in Wisconsin's Fox River Valley". J Health PopulNutr 24 (2): 206–13. PMID 17195561 • Johnson, B.L. and DeRosa, C.T. (1997) The toxicological hazard of superfund hazardous waste sites. Rev. Environ. Health.,12(4): 235-251 • Kohnhorst,A., L. Allan, and P. Pokethitiyoke. Groundwater arsenic in central Thailand . SUSTAINABLE ENVIRONMENTAL SANITATION AND WATER SERVICES. 28th WEDC Conference. Kolkata (Calcutta), India, 2002. http://wedc.lboro.ac.uk/conferences/pdfs/28/Kohnhorst.pdf • Meinrut 0. Andreae. Arsenic speciation in seawater and interstitial waters: The influence of biological-chemical interactions on the chemistry of a trace element’ . Limnol. Oceanogr., 24(3), 1979,440-452 . • Shaban W. Al Rmalli, Chris F. Harrington, Mohammed Ayub and Parvez I. Haris. A biomaterial based approach for arsenic removal from water. J. Environ. Monit., 2005, 7, 279 - 282, DOI: 10.1039/b500932d • Saha KC (2003). "Diagnosis of arsenicosis". Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering38 (1): 255-72. PMID 12635831 • Santos, H M; Diniz, M S; Costa, P M; Peres, I; Costa, M H; Alves, S; Capelo, J L. Environmental Toxicology [Environ. Toxicol.]. Vol. 22, no. 5, pp. 502-509. Oct 2007. MT induction • Thompson, DS. 1993. A chemical hypothesis for arsenic methylation in mammals. ChemBiol Interact. 88:89-114 • Weis, J.S. and Weis, P. 2002. Contamination of saltmarsh sediments and biota by CCA treated wood walkways. Marine Pollution Bulletin 44, 504-510 • .

  18. Websites www.usm.maine.edu/toxicology/research/arsenic.php-chromosome pictures http://www.bnl.gov/csc/projects/Adv_Sci_Computing/Vis_Collaboratory/default.asp EM gill http://www.newsobserver.com/content/news/health_science/water/story_graphics/20060326_water1ArsenicEffects.jpg ***www.environmentalchemistry.com- General Info ****http://books.google.com/books?id=KAu4rPfoplcC&pg=PA203&lpg=PA203&dq=arsenic+micronutrient&source=web&ots=Kq0245lV_Y&sig=8knIdycB1xkNQ6BZ0NAA7H2Dywo&hl=en#PPA211,M1 –Overview and Mechanisms Questions. . .

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