Transcript µg/L
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] 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 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 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 “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 “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 . 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 Mode of entry into organisms Terrestrial: • Inhalation • Ingestion • Skin and/or eye contact Aquatic: • Gills • Membranes • Ingestion • Mantle 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 Toxicity to aquatic life Copepod 96-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) Toxic effects • • • • Premature Anaphase Alteration of Chromosome Number, Doubling of chromosome number (left) Endoreduplication (right) • • • • multi-system organ failure teratogenesis cancer death Molecular mode of toxic interaction of As(III) and As(V) Disrupts ATP Production @ Citric Acid Cycle • • Inhibits pyruvate and alpha-ketoglutarate dehydrogenase 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) 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 Biochemical metabolism and breakdown via METHYLATION As(III) or As(V) Arsenobetaine Arsenosugars Methyltransferase CH3 S-adenosylmethionine Monomethylarsonous acid (MMA) Dimethylarsinous acid (DMA) • Plankton and aquatic organisms have similar mechanism Excreted in Urine 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 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) 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-Feng Jau, 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 Corbicula fluminea. 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 CopepodTigriopus brevicornis(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 Popul Nutr 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 engineering 38 (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. Chem Biol 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 . Websites www.usm.maine.edu/toxicology/research/arsenic.phpchromosome pictures http://www.bnl.gov/csc/projects/Adv_Sci_Computing/Vis_Coll aboratory/default.asp EM gill http://www.newsobserver.com/content/news/health_science/w ater/story_graphics/20060326_water1ArsenicEffects.jpg ***www.environmentalchemistry.comGeneral Info ****http://books.google.com/books?id=KAu4rP foplcC&pg=PA203&lpg=PA203&dq=arsenic+mi cronutrient&source=web&ots=Kq0245lV_Y&si g=8knIdycB1xkNQ6BZ0NAA7H2Dywo&hl=en# PPA211,M1 –Overview and Mechanisms Questions. . .