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Environmental Chemicals II
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Examine the cause and effects of the release of an industrial cyanide/heavy metals impoundment into a major European river system. • Examine the heavy metals release from a tailings dam failure in Southwestern Spain. • Describe the science and toxicological impacts of ionizing radiation resulting from radionuclides.
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Nội dung Text: Environmental Chemicals II
- Principles of Environmental Toxicology Learning Objectives • Examine the cause and effects of the release of an industrial cyanide/heavy metals impoundment into a major European river system. • Examine the heavy metals release from a tailings Environmental Chemicals II dam failure in Southwestern Spain. • Describe the science Principles of Environmental Toxicology and toxicological impacts Instructor: Gregory Möller, Ph.D. of ionizing radiation University of Idaho resulting from radionuclides. 2 Principles of Environmental Toxicology Principles of Environmental Toxicology Learning Objectives Baia Mare, Romania • Understand the science and issues surrounding • Cyanide leak from a gold smelter pollutes a major mixed waste management European river system, January 2000. in the US. • A cyanide-containing slurry overflowed over a 25 m • Examine the technological difficulties associated length of a tailings dam. with subsurface radionuclide plumes of the Hanford – 100,000 cubic meters of waste into the Tisza and Reservation migrating Danube river system, Europe's largest waterway. towards the Columbia • The accident wiped out River. fish stocks and threatened water supplies in several countries downstream from the spill. 3 4 Principles of Environmental Toxicology Principles of Environmental Toxicology Baia Mare, Romania Cyanide Waste Water • Heavy snows caused an overflow of a tailings dam Baia Mare wall. • Waste water containing cyanide flowed into the adjacent Lapus River, then entered the Somes River, AP and crossed the border into Hungary, before reaching the Tisza River. Encarta 5 6 AP 1
- Principles of Environmental Toxicology Principles of Environmental Toxicology Acute, Chronic, Sub-lethal Toxicity Waste Material Fish Ingles • 100 thousand cubic meters liquid waste entered the LETHAL EFFECTS SUBLETHAL water with 7800 mg/L cyanide concentration EFFECTS – Hungarian authorities - conservative estimate. CN- ACUTE CHRONIC Activity or Organ Nature of Effect at – 100 tons cyanide. (Dynamic (Juniors/ Affected mg/L LC50 - 96 h) Adults) mg/L CN mg/L CN 0.05 - 0.2 0.0019 - Spawning -completely 0.005 0.07 Egg Production inhibited 0.01 Egg Viability -reduced by 42% 0.065 Spermatogenesis -eggs infertile 0.02 Abnormal -permanent 0.07 embryonic reduction development -severe deformities 0.01-0.1 Hatching -up to 40% failure 0.015 Swimming -reduced 90% at 7 8 6°C Principles of Environmental Toxicology Principles of Environmental Toxicology Scope of Contamination Plume: Spatial-Temporal Location Date Concentration HME CN 800 times higher than Spring Lonya (Romania) allowed concentration CN 32.6 mg/l, Zn 540 ug/l, Szamos at Csenger (Hungary) 2/1/00 Cu 12000 ug/l CN 13.5 mg/l, Zn 190 ug/l, Tisza at Lónya (Hungary) 2/3/00 Cu 7400 ug/l Under Bodrog: Tiszalök (Hungary) 2/5/00 CN 3.7 mg/l Before Kisköre (Lake Tisza, 2/8/00 CN 3.8 mg/l, Cu 2.4 ug/l Hungary) Szolnok(water works closed-120 2/9/00 CN 3.2 mg/l, Cu 0.2 ug/l thousand people) before Maros, at Szeged (Tape, 2/11/00 CN 2.2 mg/l Hungary) Below Szeged (Tiszasziget, 2/11/00 CN 1.49 mg/l Hungary) Danube at Beograd (Yugoslavia) 2/13/00 CN 0.6 mg/l 9 10 HME Principles of Environmental Toxicology Principles of Environmental Toxicology Mobility and Impact Environmental Impact • The polluted waters moved • Spill eradicated life for AP downstream to the Danube, approximately 250 miles of the which forms Romania's border river. with Bulgaria over more than • The accident killed thousands 500 miles. of fish in neighboring Hungary • Countries banned water intake and Yugoslavia. and Danube fishing as the spill moved downriver towards the Black Sea, – Black Sea Delta rich in wildlife. AP 11 12 2
- Principles of Environmental Toxicology Principles of Environmental Toxicology Fish Mortality Terrestrial Mortality AP AP AP AP 13 14 AP Principles of Environmental Toxicology Principles of Environmental Toxicology Public Health – Env. Quality Aznalcóllar, Spain • On April 25, 1998, a tailings dam failure of the Los AP Frailes lead-zinc mine at Aznalcóllar near Seville, Spain, released 4-5 million cubic meters of toxic tailings slurries and liquid into nearby Río Agrio, a tributary to Río Guadiamar. • The slurry wave covered 5,000 hectares of farmlands, AP including parts of the Doñana protected area. – One of the largest protected areas in the EU and it is a World Heritage Site. Fernandez 15 16 AP -Delgado Principles of Environmental Toxicology Principles of Environmental Toxicology Aznalcóllar, Spain Aznalcóllar, Spain Aznalcóllar An aerial view of the dike of a mine reservoir outside the southern Spanish southern city of Seville Monday, April 27, 1998 after it burst dumping an estimated 5 million cubic meters of toxic waste into the Guadiamar River. Hastily constructed dikes diverted the toxic liquid away from Donana Park, one of Encarta Europe’s most prized nature reserves, and toward the Guadalquivar River, Europe’ 17 18 which flows into the Atlantic Ocean 37 miles downstream.(AP) 3
- Principles of Environmental Toxicology Principles of Environmental Toxicology Aznalcóllar, Spain Dam Failure A black stain of toxic mud, coming from a broken dike at a mine reservoir, top center, covers the countryside, near Aznalcollar, Aznalcollar, southern Spain, after it spilled 5 million cubic meters of toxic waste on April 25, 1998. (AP) 19 20 Principles of Environmental Toxicology Principles of Environmental Toxicology Impacted Farmland Impacted Aquatic Habitat About 60 km of the Guadiamar principal river bed was absolutely destroyed. --Fernandez-Delgado 21 22 Universidad de Córdoba Principles of Environmental Toxicology Principles of Environmental Toxicology Ionizing Radiation Ionizing Radiation • Oxidative stress • Ionizing radiation (X-rays, alpha particles), cause chemicals reactions and alterations of chemicals in – Recall endpoints: lipid peroxidation, DNA strand breaks, enzyme inactivation, covalent binding to nucleic acids, tissues. covalent binding to proteins. – Can be toxic or fatal. • Direct ionization of organic molecules can yield carbonium • Much of the reactivity in organisms is with water. ions CH3+. • Produces: – Can alkalyate DNA. – Superoxide radical (O2• -), • Example: Radon, a noble gas Hydroxyl radical (HO•), that emits alpha particles. Hydroperoxyl radical (HOO•), – Results from the decay of U and and hydrogen peroxide. Ra in naturally occurring minerals. – Presents the most risk of any element to humans. Manahan 23 24 4
- Principles of Environmental Toxicology Principles of Environmental Toxicology Radiation Sickness Alpha Particle • Illness caused by the effects of radiation on body tissues. • A positively charged particle ejected spontaneously – May be acute, delayed, or chronic. from the nuclei of some radioactive elements. – May occur as a result of cumulative exposure to small – Low penetrating power and a short range. doses of radiation; high exposure to solar radiation; or • The most energetic alpha particle will generally fail to exposure to a nuclear event. penetrate the dead layers of cells covering the skin. – Symptoms may be mild and transitory, or severe, • Alphas are hazardous when an depending on the type of radiation, the dose, and the rate alpha-emitting isotope is at which exposure is experienced. inside the body. • Symptoms: weakness, loss of appetite, vomiting, diarrhea, a tendency to bleed, increased susceptibility to infection, and-in severe cases-brain damage and death, possible long-term genetic effects and increased cancer rates. NC-DRP NC-DRP 25 26 Principles of Environmental Toxicology Principles of Environmental Toxicology Beta Particle Gamma Ray • A charged particle emitted from a nucleus during • High-energy, short wavelength, electromagnetic NC-DRP radioactive decay. radiation (a packet of energy) emitted from the nucleus. – Mass equal to 1/1837 that of a proton. – Gamma radiation frequently accompanies alpha and beta – A negatively charged beta particle is identical to an electron; emissions and always accompanies fission. a positively charged beta particle is called a positron. • Gamma rays are very penetrating • Large amounts of beta radiation may cause skin and are best stopped or shielded burns, and beta emitters are by dense materials, such as harmful if they enter the body. lead or uranium. • Beta particles may be stopped • Gamma rays are by thin sheets of metal or plastic. similar to X-rays. 27 28 NC-DRP Principles of Environmental Toxicology Principles of Environmental Toxicology Half-life Curie • The special unit of • The time in which one half of the atoms of a radioactivity. particular radioactive substance disintegrates into • One curie is equal to another nuclear form. 3.7 x 1010 disintegrations/s. – Measured half-lives vary from millionths of a second to • Replaced by the becquerel billions of years. (Bq), which equates to one decay/s (1 Ci = 37 Gbq) 29 30 NC-DRP 5
- Principles of Environmental Toxicology Principles of Environmental Toxicology Environmental Radiation Standards Radioactive Decay • The decrease in the amount of any radioactive • Standards issued by the U.S. Environmental material with the passage of time, due to the Protection Agency (EPA) under the authority of the spontaneous emission from the atomic nuclei of Atomic Energy Act of 1954 (42 U.S.C. 2D11 et seq;), either alpha or beta particles, often accompanied by as amended. gamma radiation. – Impose limits on radiation exposures or levels, or concentrations or quantities of radioactive material, in the general environment outside the boundaries of locations under the control of persons possessing or using sources of radiation. NC-DRP 31 32 NC-DRP Principles of Environmental Toxicology Principles of Environmental Toxicology Three Mile Island Three Mile Island • The accident began about 4:00 a.m. on March 28, Stub ends of the broken fuel • Erroneous coolant water assemblies that are adhering 1979, when the plant experienced a failure in the level readings in the reactor to the bottom of the TMI secondary, non-nuclear section of the plant: main damaged Unit 2 reactor (AP) – Reading high actually low due coolant pump fails to gas bubble voids. • Back-up coolant pump valve non-reopened after a – H2 gas buildup in the containment structure. test 2-day earlier due to human error. • Top of the fuel rods melted. – Radioactive water to basement. 33 34 Principles of Environmental Toxicology Principles of Environmental Toxicology Three Mile Island Three Mile Island The cooling stacks for the Unit 2 reactor, foreground, at the Three Mile This was the scene in Goldsboro, Pa., on March 31, 1979, three Island Nuclear Facility are dormant on Wednesday, March 3, 1999, in days after the nuclear accident at the Three Mile Island nuclear Middletown, Pa. The reactor at Unit 2 ceased operations following a partial facility in Middletown, Pa. Most people in the area following the meltdown on March 28, 1979. Only the reactor and cooling stacks at Unit 1, nuclear accident either evacuated or stayed indoors. In the rear, have continued to produce power. March 28, 1999 was the 20th background at center is one of the cooling towers of the nuclear anniversary of the nation's worst nuclear accident. (AP) facility. March 28, 1999 was the 20th anniversary of the nation's worst nuclear accident. (AP) 35 36 6
- Principles of Environmental Toxicology Principles of Environmental Toxicology Public Health/Env. Impacts 20 Year Cancer Epidemiology • Thousands of environmental samples of air, water, milk, • The overall number of deaths from cancer among vegetation, soil, and foodstuffs were collected. the "exposed" population was not significantly – Very low levels of radionuclides could be attributed to different from the general population. releases from the accident. – Exposed = 5 mile radius. • Comprehensive investigations and assessments by several • There was a small rise in the number of lymphatic well-respected organizations have concluded that in spite of and blood cancer deaths among women in the serious damage to the reactor, most of the radiation was contained and exposed group. BBC; PDH that the actual release had negligible effects on the physical health of individuals or the environment. – Average dose < an X-ray and
- Principles of Environmental Toxicology Principles of Environmental Toxicology US Mixed Waste Challenge 3-Hydrogen (Tritium) • Mixed waste: combined radioactive (LLW, HLW, • Half life = 12.33 y. TRU) and hazardous waste. • Beta; 0.0186 MeV (weak). • Scale of soil contamination problem. • Highly mobile; commingle with H spontaneously • 99% appears as tritiated water (HTO). – 4,000 DOE sites. • Product of cosmic radiation, weapons production & reactors. – 7,313 DoD sites. • Natural sources = 30MCi. • Hazardous waste. • 4,500 MCi from 1960's weapons tests. – TCE, Cr, Pb, PHC. • Not a major toxicological hazard. • Radioactive waste. – 3-Hydrogen (Tritium), 14-Carbon, 99-Technetium, 129, 131-Iodine, 133-Xenon, 137-Cesium, 238-Uranium, 239-Plutonium, 241-Americium. 43 44 Principles of Environmental Toxicology Principles of Environmental Toxicology 14-Carbon 99m/99-Technetium • Half life - internal isomeric transition: two step decay • Half life = 5730 y • 6.01h for 99m; 2.13 x 105 y for 99 • Beta; 0.156 MeV • Gamma, 0.142 MeV for 99m and Beta, 0.293 MeV for 99 • Carbon chemistry (weak Gamma also) 14C is virtually inseparable from 12C • • 235U fission 99Mo decay 99Tc At sufficiently low concentrations, 14C is exempted from • • Tc+7, pertechnate ion TcO4- treatment as nuclear waste. • Tc+5, +4, +3 • No known chemical or physical process • TcO4 (oxidized- soluble, slightly can re-concentrate the radioisotope. sorbed to minerals; TcO2 • From cosmic radiation and nuclear (reduced- insoluble) are the most fission. common forms in groundwater. • About 300 MCi from natural sources • Trace concentration, 10-9 M • In the environment – carbonate system CO32+, CO2 45 46 Principles of Environmental Toxicology Principles of Environmental Toxicology 129,131 Iodine 133 Xenon 107 • Half life = 1.6 x y for 129 and 8.04d for 131 • Half life = 5.25 d. • Beta 0.150 MeV; Gamma 0.0396 MeV and e- for 129 and Energy - Beta 0.606 MeV and Gamma 0.081 MeV and e-. • Beta 0.606 MeV; Gamma 0.364 MeV for 131 • Nobel gas and therefore inert to chemical reaction. • 235U fission to 131I (most medical use) • Highly soluble in plastics/polymers. • I2 + 2e- = 2I- Eo = 0.535 eV • Not concentrated in living systems. • I- can be oxidized by O2 in solution. • Predominantly found as iodate ion in the environment, IO3- 47 48 8
- Principles of Environmental Toxicology Principles of Environmental Toxicology 137 Cesium 238 Uranium Half life = 4.468 x 109 y. • Half life 30.17 y • • Energy - Beta 0.512 MeV; Gamma • Energy - Alpha 4.20 MeV. 0.662 MeV and e- • Valence states from 0 to IV. • Group I Alkali metal - highly soluble. • Occurs in nature as UO2, U3O8, • 137Cs+ stable aqueous environmental U4+ and UO22+ in groundwater. form. • U(IV) and U(VI) oxides. • Strongly sorbed on common • Uranyl complexes such as rock from dilute solutions. carbonates soluble. – Especially micas and • GW/subsurface retardation clay minerals. varies widely. 49 50 Principles of Environmental Toxicology Principles of Environmental Toxicology 239 Plutonium 241 Americium • Half life = 2.411 x 104 y. • Half life = 432 y • Energy - Alpha 5.16 MeV and others. • Energy - Alpha 5.4857 MeV; Gamma 0.0595 MeV and • n activation of 238U followed by beta decay others. to 239U to 239Np and then to 239Pu. • Common alpha radiation source. • Oxidation states II through VII exist. • Am (IV) forms stable, relatively soluble AmO2. – All but Pu(II) can exist in water. • Am(III) stable in solution, often as Am(OH)3 • Environmental chemistry similar to uranium, • Strongly sorbed by all PuO22+, Pu3+. common rocks at ambient pH. – Can exist as a colloidal, stable • Complexation will reduce hydroxide. retention. • Sorption on natural rocks is fairly high, however complexing by organic ligands reduces retention. 51 52 Principles of Environmental Toxicology Principles of Environmental Toxicology The Mixed Waste Challenge Strategy • Reduce the toxicity, mobility and/or • Relative risk considerations. volume of the waste. – Material (half life, energy, mobility), receptor sites, costs. • Mixtures of organic and inorganic. • Separations. – Requires multiple remediation approaches. – Radioactive from non radioactive. – Organic from inorganic. • Mixtures of heavy metals and radioactive metals. • Can use some typical HW approaches. • Approaches limited by chemistry of the metals. • Volume reductions. – Multiple species. • Actinides: M(4+); MO2(2+); – Vitrification. M(3+); MO2(2+) • HLW and TRU to long term storage. – Complexations, sorptions. • Big "How To" questions remain! • Box it, bag it, barrel it, store it! – Many technologies are experimental. 53 54 DOE 9
- Principles of Environmental Toxicology Principles of Environmental Toxicology DOE Focus Areas DOE Focus Areas • Contaminant, plume containment and remediation. • HLW tank remediation. – Distribution and concentration? – 100's of deteriorating tanks. • Containment, in-situ treatment. • Landfill stabilization. • Mixed waste characterization, treatment, and • Migration; in situ containment/treatment. disposal. • Decontamination and decommissioning of – LLW regulations and standards? contaminated facilities. – Lack of accepted treatment • Treatment considerations. and disposal capacity. – Special chemistry of radionuclides will require targeted approaches. 55 56 DOE DOE Principles of Environmental Toxicology Principles of Environmental Toxicology Hanford, WA Hanford, WA This is a World War II file photo of the historic The Columbia River as it flows past the "B Reactor" at Hanford, Wash., which was the closed F Reactor on the Hanford world's first plutonium production reactor. The nuclear reservation near Richland, Hanford nuclear reservation sits along the Washington (AP). Columbia River. (AP) 57 58 Principles of Environmental Toxicology DOE Hanford • Case presentation: “Protecting the Columbia River” Video 59 10
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