METALS & PAHs BIOLOGY 5868

Transcription

1 METALS & PAHs BIOLOGY 5868

2 METALS

3 BIOGEOCHEMICAL CYCLING

4 FORMER STEEL MILL ON THE St. LOUIS RIVER NEAR MORGAN PARK

5 DR. JEKYLL & MR. HYDE

6 REGULATORY PURVIEW CLEAN AIR ACT SETS MAXIMUM ALLOWABLE LEVELS & DICTATES EMISSION LEVELS CLEAN WATER ACT LIMITIS DISCHARGRS INTO NAVIGABLE WATERS RESOURCE CONSERVATION RECOVERY ACT (RCRA) ADDRESSES HAZARDOUS WATSES CRADLE TO GRAVE COMPREHENSIVE ENVIRONMENTAL RESPONSE, COMPENSATION & LIABILITY ACT (CERCLA) ADDRESSES HAZARDOUS RELEASES & REMEDIATION OF CONTAMINATED SITES; e.g. SUPERFUND

7 ECOTOX LISTS OF METALS (handout) RCRA 8 METALS PRIORITY POLLUTANT METALS TARGET ANALYTE LIST METALS Ag (SILVER) Ag (SILVER) Ag (SILVER) As (ARSENIC) As (ARSENIC) As (ARSENIC) Ba (BARIUM) Ba (BARIUM) Cd (CADMIUM) Cd (CADMIUM) Cd (CADMIUM) Cr (CHROMIUM) Cr (CHROMIUM) Cr (CHROMIUM) Hg (MERCURY) Hg (MERCURY) Hg (MERCURY) Pb (LEAD) Pb (LEAD) Pb (LEAD) Se (SELENIUM) Se (SELENIUM) Se (SELENIUM) Be (BERYLLIUM) Be (BERYLLIUM) Cu (COPPER) Cu (COPPER) Ni (NICKEL) Ni (NICKEL) Sb (ANTIMONY) Sb (ANTIMONY) Tl (THALLIUM) Tl (THALLIUM) Zn (ZINC) Zn (ZINC) Al (ALUMINIUM) Ca (CALCIUM) Co (COBALT) Fe (IRON) K (POTASIUM) Mg (MAGNESIUM) Mn (MANGANESE) Na (SODIUM) V (VANADIUM)

8 Ag (SILVER) Major users of silver are the photographic and imaging manufacturers. The Silver Council has substantially funded research on the ecotoxicological properties of silver. The ionic form of silver (Ag + ) is the most toxic and aquatic biota are primarily at risk. Toxicity is significantly reduced by reactions with suspended particles and colloids; e.g. dissolved organic carbon and reduced sulfur compounds. Municipal Wastewater Treatment Plants can reduce the levels of silver, significantly, in effluents entering aquatic environments.

9 As (ARSENIC) Contributions from mining (Au & Pb), the production of metal alloys, and the use of arsenic based wood preservatives and herbicides. A metalloid. Trivalent (As +3 ) forms are more toxic than pentavalent forms (As +5 ); e.g. AsO 3 > AsO 5 in toxicity. Fungi can methylate As to produce very toxic arsines (methyl, dimethyl and trimethyl). Arsenic is a carcinogen and a teratogen. However, some data now show trace amounts to be nutritionally essential. Terrestrial and aquatic biota are equally at risk.

10 Cd (CADMIUM) Used in the manufacture of batteries, pigments, metal coatings and plastics. A heavy metal (more dense than iron). A by product of zinc ore processing. Toxic, carcinogenic, teratogenic and a possible mutagen. No evidence of nutritional benefit. Can be found in sewage sludge; therefore, use of bio solids as fertilizers is impacted. Aquatic biota appear to be more susceptible than terrestrial biota.

11 Cr (CHROMIUM) A component of metal alloys and plating, pigments and wood preservatives. Concentrations appear elevated near Municipal Sewage Treatment Plants. Essential trace element in humans; however, a known carcinogen, teratogen and mutagen at elevated levels. Present in trivalent (Cr III) and hexavalent (Cr VI) forms. The hexavalent form is more toxic and is carcinogenic. Primarily mammalian and avian species, both terrestrial and semi aquatic, are at risk.

12 Efforts to establish a Hg Total Maximum Daily Load (TMDL) for the St. Louis River are ongoing. Hg (MERCURY) Associated with electronic equipment, dental amalgams, chlorine/alkali production, pigments/paints and mining. A heavy metal with no known benefits to living organisms. Predominant form in the environment is ionic or inorganic (Hg 2+ ), which affects the kidneys of avian and mammalian species. Less predominant but more toxic methyl Hg species (CH 3 Hg + and [CH 3 ] 2 Hg) are found in aquatic environments, including wetlands. Methyl Hg is more water soluble than inorganic Hg, which is more likely to be bioaccumulative (fish consumption advisories).

13 Aquatic and terrestrial organisms are at risk; N.B. recent ban of lead shot for waterfowl hunting. Pb (LEAD) Used in the production of batteries, ammunition, ceramics, medical/scientific equipment, plumbing pipes, and as a gasoline additive. A heavy metal. Atmospherically transported as particulates. Exists in the +2 oxidation state in surface waters. Not essential or beneficial to living organisms. Affects blood chemistry, inhibits the production of heme, and causes neurological dysfunction.

14 Se (SELENIUM) Used in the manufacture of electronics, glass, pigments and alloys. A metalloid by product of gold, copper and nickel mining. Also, a component of coal fly ash. An essential nutrient in sedimentary soils, existing predominantly as insoluble metallic selenides and soluble oxygen complexes. Microbial transformation yields alkylselenides, which are less toxic than the inorganic form (opposite of Hg). High levels disrupt amino acid metabolism by replacing sulfur in biosynthetic reactions. Aquatic biota are known to be sensitive to both depressed and elevated levels.

15 HOW MUCH IS TOO MUCH? Need to make comparisons to BACKGROUND levels. Need to have toxicity benchmarks and water quality criteria for comparison to analytically measured levels.

16 Background Source STORET (short for STOrage and RETrieval) is a repository for water quality, biological, and physical data and is used by state environmental agencies, EPA and other federal agencies, universities, private citizens, and many others.

17 BENCHMARKS Eastern Eastern Plant Soil Invertebrate EPA Region 4 U.S. U.S. ORNL EPA ORNL ORNL EPA Ecological Compound Background Background Phytotoxicity Terr. Plant Earthworm Soil Microbe Soil Invert Screening (mg/kg) Range 1 Mean 2 Benchmark 3 ECO SSL 2 Benchmark 1 Benchmark 1 ECO SSL 2 Value 4 Arsenic, Total N/A N/A 10 Cadmium, Total N/A Chromium, Total N/A N/A 0.4 Lead, Total Mercury, Total N/A N/A 0.1 Selenium, Total N/A N/A 0.81 Silver, Total N/A N/A 2 N/A N/A 50 N/A 2 1 Source Efroymson, Will, and Suter, 1997, Oak Ridge National Laboratory. 2 Source USEPA Ecological Soil Screening Levels Interim Final, November Source Efroymson, Will, Suter, and Wooten, 1997, Oak Ridge National Laboratory. 4 Source USEPA Region 4 Ecological Screening Values for Soil, November 30, 2001 N/A Not available.

18 AQUATIC BENCHMARKS Ontario MoE Ontario MoE Sediment Quality Guidelines US EPA EPA Region 5 Sediment Sediment Sediment TEC PEC Ambient Water Screening Levels 4 Compound Background Lowest Effect Severe Effect Sediment Sediment Quality Criteria Sediment Water (mg/kg) Values 1 Level Level Benchmark 2 Benchmark 2 ug/l 3 mg/kg ug/l Arsenic, Total Cadmium, Total Chromium, III Lead, Total Mercury, Total Selenium, Total N/A N/A N/A N/A N/A 5 N/A 5 Silver, Total N/A N/A N/A N/A N/A N/A Source Persaud et al, Ontario Ministry of the Environment. 2 Source MacDonald, Ingersoll and Berger, TEC Threshold Effect Concentration; PEC Probable Effect Concentration. 3 Source USEPA National Ambient Water Quality Criteria, April Source USEPA Region 5 Ecological Screening Levels. July N/A Not available.

19 PAHs Various Acronym Definitions Poly Aromatic Hydrocarbons Polynuclear Aromatic Hydrocarbons Polycyclic Aromatic Hydrocarbons

20 PAHs A group of compounds consisting of carbon and hydrogen and having 2 or more condensed benzenering structures. Present naturally in petroleum compounds as a product of aromatization of saturated compounds at low temperatures and high pressures (diagenesis); e.g. Naphthalene and Phenanthrene. Produced by the incomplete combustion of fossil fuels or other organic matter (pyrogenic); e.g. Flouranthene, Pyrene, Chrysene, Benzo a pyrene, etc. Associated with creosote and coal tar production/use.

21 PAHs, WHY THE CONCERN? They are ubiquitous in the environment. If one is detected many more will be found (suites of 15 to 17 are typical). They tend to be hydrophobic (water insoluble). Hydrophobic compounds can readily cross the cell membrane of organisms. They are potentially carcinogenic. They can be phototoxic. They can accumulate in the sediments of aquatic ecosystems. They are persistent.

22 Low vs. High Molecular Weight Low Molecular Weight Few rings Partitions to air (volatile) Water soluble (toxic to fish & plankton) Less Carcinogenic Less Bioaccumulative Naphthalene: 2 rings, MW 128, H 2 O sol. 30 mg/l High Molecular Weight Many rings Partitions to particulates Water insoluble (impacts benthic invertebrates) More Carcinogenic More Bioaccumulative Benzo[a]pyrene: 5 rings, MW 252, H 2 O sol. 6.0 mg/l

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24 Naphthalene Anthracene Benzo(a)pyrene CH 3 Phenanthrene CH 3 1,3 Dimethyl naphthalene (alkylated naphthalene)

25 Analyte Sediment Benchmarks (handout) *Screening Benchmark (mg/kg) 1 Freshwater TEC (mg/kg) 2 Ecotox Thresholds (mg/kg) 3 Ontario LEL (mg/kg) 4 EPA RegV ESL (mg/kg) PAHs Acenaphthene (2) 0.62 NV 0.62 NV Acenaphthylene (4) NV NV NV Anthracene NV Benzo(a)anthracene NV Benzo(b)fluoranthene (4) 10.4 NV NV NV 10.4 Benzo(k)fluoranthene (3,4) 0.24 NV NV Benzo(g,h,i)perylene (3,4) 0.17 NV NV Benzo(a)pyrene Chrysene NV Dibenz(a,h)anthracene NV Fluoranthrene Fluorene Indeno(1,2,3 cd)pyrene (3,4) 0.2 NV NV Methylnaphthalene (4) NV NV NV Naphthalene NV Phenanthrene Pyrene *Screening Benchmarks sources: 1. Freshwater Threshold Effect Concentration (TEC) from MacDonald, Ingersoll, and Berger (2000). 2. EPA Ecotox thresholds (USEPA, 1996) 3. Ontario Ministry of the Environment lowest effect level (LEL) from Persaud, et al., (1993). 4. EPA Region V ecological screening levels (ESL) (1999). All Screening Benchmarks are TECs (1) unless noted otherwise. Significant digits presented are as presented in the source document, up to four significant digits. NV No value.

26 Surface Water Criteria (handout) Analyte Ecological Screening Benchmark* (ug/l) National Ambient Water Quality Criteria 2 FCV or Tier II EPA RegV ESL (ug/l) 3 Oak Ridge National Laboratory 4 PAHs Acenaphthene FCV Acenaphthylene 4840 NV 4840 NV Anthracene NV Benzo(a)anthracene** NV Benzo(b)fluoranthene** (1) 0.03 NV 9.07 NV Benzo(k)fluoranthene** NV NV Benzo(g,h,i)perylene 7.64 NV 7.64 NV Benzo(a)pyrene** (2) Tier II Chrysene** (1) 0.03 NV NV Dibenz(a,h)anthracene** (1) 0.03 NV 5^ NV Fluoranthrene FCV Fluorene Tier II Indeno(1,2,3 cd)pyrene** (1) 0.03 NV 4.31 NV 2 Methylnaphthalene NV Naphthalene (2) Tier II Phenanthrene (2) FCV Pyrene NV NV Total PAHs** (1) 0.03 NV NV NV *Screening Benchm arks would be applied according to the following hierarchy: 1. Iowa W ater Quality Standards (567 Chapter 61) chronic value for significant resource warm waters [classification B(W W )]. 2. Tier II values and final chronic values (FCV) are from EPA Ecotox thresholds (USEPA, 1996) 3. EPA Region V ecological screening levels (ESL) (1999). N.B. the ESL values are currently under review and may be revised. ^The value for dibenz(a,h)anthracene is from TX Surface W ater Quality Standards (per D. Mazur, EPA Region V). 4. O ak Ridge National Laboratory Prelim inary Rem ediation Goals for Ecological Endpoints (Efroym son, et al. 1997) Significant digits presented are as presented in the source document. **Total PAHs value intended to include the sum of known and suspected carcinogenic PAHs, as m arked with **. If an ESL value [reference (3)] for a carcinogenic PAH was below 0.03 ug/l, the ESL value is shown. If the value given for a carcinogenic PAH in this table is 0.03 ug/l, this reflects the Iowa warm water criterion for the sum of concentrations of these com pounds, because there were no lower individual benchm arks available. NV No value.