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Benzo[a]pyrene and Polychlorinated Biphenyls

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  1. Benzo[a]pyrene and Polychlorinated Biphenyls http://smokingbloomberg.typepad.com/smoking_bloomberg/images/benzoapyrene.jpg http://acc6.its.brooklyn.cuny.edu/~scintech/hudson/What%20are%20PCB%27s_files/image001.jpg

  2. Structures and Chemical Properties • Consists of aromatic rings • Highly nonpolar • BaP • May degrade in atmosphere by: UVradiation, NO2, 03 and other oxidants in the atmosphere (Ambe and Mukai 1997) • PCBs • 209 congeners, 1-10 chlorines attached to biphenyl ring • “more chlorines = more hydrophobic, less mobile” • Highly stable • Occurs as liquids or solids • Inflammable (high boiling point) • Insulation properties • Safe 1992

  3. Uses and Application PCBs • Used in industry as a coolants, lubricators, dielectric insulators (Safe 1992) • Marketed as Aroclor, Clophen etc by chlorine content (ex. Aroclor 1262) • Produced in the US from 1929-1979 BaP • Found in coal tar, automobile exhaust, burning of organic material (includes smoke and burned food), fuels (esp. diesal)

  4. Mode of Entry in Aquatic Environment • PCBs: • Industry use • Improper disposal • Found more in the northern hem than in the southern (this includes water, air, plankton, fish and marine mammals) • In 1988, 370 x 103 tons of PCBs were estimated to be present in the environment • ~ 360 x 103 tons retained in coastal sediments and open ocean water (Tanabe 1988)

  5. Mode of Entry in Aquatic Environment • BaP • Binds to strongly sediment and particulate matter • Oil (petroleum) spills/leaks (Varanasi and Gmur 1981) • Combustion (Dusk particles in air…potential for transportation) • Disposal of fossil fuels and fossil fuel-derived products (Kanaly et al 2000)

  6. Chemical Reactivity • BOTH compounds are highly stable, not very biodegradable, and environmentally persistent!(Cerniglia 1992; Tanabe 1988) • Lipophilic • Therefore, have high potential to bioaccumulate through food webs*(Wasserman et al., 1979; Tanabe et al. 1981; Peakall, 1987) *unless metabolized

  7. Toxicity to Aquatic Life • PCBs: • Differences depending on the structure, order/placement of chlorines, and number of chlorines • Ex. Planar/nonplanar • “dioxin like” PCBs • 77*, 81*, 105, 114, 118, 123, 126*, 156, 157, 167, 169*, 189 • * = most potent in activating AhR and Cyp1A Toxicity Equivalent Factors: n TEQ = ∑(C i ×TEFi ) i =1 http://www.menlh.go.id/apec_vc/osaka/eastjava/hap_en/filter/4.html US EPA 2009

  8. Nebert and Dalton 2000

  9. Toxicity to Aquatic Life • BaP: • Metabolites more toxic than parent compound (Huberman et al 1976; Gelboin 1980) • Formation of DNA adducts http://herkules.oulu.fi/isbn9514270398/html/x203.html

  10. Toxic Effects Noted • PCBs • Wide ranging and varying with species! • Endocrine disruption (Brouwer et al. 1989; Subramanian et al. 1987; Boon et al. 1992) • Immune suppression (Lahvis et al. 1995; Jepson et al. 1999) • Reproductive failure (Reijnders 1986)

  11. Toxic Effects Noted • BaP • Skin and scrotal cancer (Slaga et al. 1976) • Lung and colon cancer • Ex. Levels of BaP adducts to DNA in St. Lawrence beluga brain and liver near those associated with carcinogenis in small laboratory animals (Béland et al. 1993) http://www.solarnavigator.net/animal_kingdom/animal_images/whale_beluga_submerged.jpg

  12. Mode of Entry into Organisms • Water (passive absorption) (LeBlanc 1995) • Food • Bioaccumulation • Ex. Western North Pacific estimated bioconcentration factor of 107 in striped dolphins (Tanabe et al. 1984)

  13. Molecular mode of toxic interaction • Both are metabolized via Cytochrome P450 systems • Oxidative stress • BaP • “bioactivation” • DNA adducts and binding to cellular macromolecules • benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE) • Quinones (undergo redox cycling to produce reactive O2 species) (Wood et al 1976) • Hormone mimics (PCBs) • Hydroxylated PCBs mimic estrogens (Kuiper et al 1998) • Ex. Changes in human menstral cycles of fish-consumers (Mendola et al. 1997)

  14. Metabolism and Breakdown • PCBs • VERY SLOW natural breakdown • Metabolism differences depending on the structure of PCB • Bioaccumulation • BaP • Fast metabolism • Bacteria breakdown (Kanaley et al 2000)

  15. Defense strategies • PCBs • Anti-oxidants (Jin et al 2001) • Adaptation (reduced inducibility) • Hudson River tomcod (Yuan et al. 2006) • BaP • Epoxide hydrase (formation of diols) • NAD(P)H:quinone oxidoreductase (Joseph and Jaiswal 1994)

  16. References PIUSJOSEPHAND ANILK.JAISWAL. 1994. NAD(P)H:quinone oxidoreductase1 (DT diaphorase) specifically preventstheformationofbenzo[a]pyrenequinone-DNAadducts generated by cytochrome P4501A1 and P450 reductase. Proc. Nati.Acad. Sci. USA Vol. 91, pp. 8413-8417 Xiaolei Jin, Sean W. Kennedy, Tamara Di Muccio, and Thomas W. Moon. Role of Oxidative Stress and Antioxidant Defense in 3,3,4,5- Pentachlorobiphenyl-Induced Toxicity and Species-Differential Sensitivity in Chicken and Duck Embryos. Toxicology and Applied Pharmacology 172, 241-248 (2001) ROBERT A. KANALY, RICHARD BARTHA, KAZUYA WATANABE, AND SHIGEAKI HARAYAMA. 2000. Rapid Mineralization of Benzo[a]pyrene by a Microbial Consortium Growing on Diesel Fuel. APPLIED AND ENVIRONMENTAL MICROBIOLOGY, p. 4205-4211 Pauline Mendola,Germaine M. Buck, Lowell E. Sever, Maria Zielezny and John E. Vena. 1993. Consumption of PCB-contaminated Freshwater Fish and Shortened Menstrual Cycle Length. Am. J. Epidemiol. 146 (11): 955-960. George G. J. M. Kuiper, Josephine G. Lemmen, Bo Carlsson, J. Christopher Corton, Stephen H. Safe, Paul T. van der Saag, Bart van der Burg and Jan-Åke Gustafsson. 1998. Interaction of Estrogenic Chemicals and Phytoestrogens with Estrogen Receptor ß. Endocrinology Vol. 139, No. 10 4252-4263 Marshall,C.J.,Vousden,K.H.& Philips,D.J.(1984)Nature. (London)310,586-589. Monks,T.J.,Hanzlik,R.P.,Cohen,G.M.,Ross,D.&Graham,D. G. (1992) Toxicol. Appl. Pharmacol. 112, 2-16. Wood, Levin, Lu, Yagi, Hernandez, Jerina, Conney. 1976. Metabolismof Benzo [czlpyrene and Benzo [a]pyrene Derivatives to Mutagenic Products by Highly Purified Hepatic Microsomal Enzymes. THE JOURNU OF BIOI.O(:ICAI. CHEMISTRY Vol. 51. No. 16. pp. 4882-4890, 19i6 LeBlanc. 1995. Trophic-level Differences in the Bioconcentrrrtion of Chemicals: Implications in Assessing Environmental Biomagification. Environ. Sci. Techno/.1995, 29, 154-160 Tanabe, S., Tanaka, H. & Tatsukawa, R. (I 984). Polychlorobiphenyls, EDDT, and hexachlorocyclohexane isomers in the western North Pacific ecosystem. Arch. Environ. Contarn. Toxicol., 13, 731-8. Tanabe, S. 1988. PCB Problems in the Future: Foresight from Current Knowledge. Environmental Pollution 50:5-28

  17. References Thomas J. Slagaa, Aurora Viajea, David L. Berrya, William Brackena, Steven G. Butyb and John D. Scribnerb. 1976. Skin tumor initiating ability of benzo(a)pyrene 4,5- 7,8- and 7,8-diol-9,10-epoxides and 7,8-diol. Cancer Letters Volume 2, Issue 2, Pages 115-121 Pierre Béland, Sylvain DeGuise, Christiane Girard, André Lagacé, Daniel Martineau, Robert Michaud, Derek C.G. Muir, Ross J. Norstrom, Émilien Pelletier, Sankar Ray and Lee R. Shugart. 1993.Toxic Compounds and Health and Reproductive Effects in St. Lawrence Beluga Whales. Journal of Great Lakes Research Volume 19, Issue 4, Pages 766-775

  18. References • Gelboin,H.V.(1980)Physiol.Rev.60,1107-1166.) Identification of mutagenic metabolites of benzo(a)pyrene in mammalian cells. 1976. E, Huberman, L Sachs,S K Yang, and V Gelboin. PNAS vol. 73 no. 2 607-611. Nebert and Dalton. 2006. The role of cytochrome P450 enzymes in endogenous signaling pathways and environmental carcinogenesis. NATURE REVIEWS CANCER. VOLUME 6 947 • (Cerniglia, C. E. 1992. Biodegradation of polycyclic aromatic hydrocarbons. Biodegradation 3:351-368. Peakall, D. B. (1987). Accumulation and effects on birds. In: PCBs and the environment, Vol. 2, ed. by J. S. Waid, 31-48. Boca Raton, Florida, CRC Press. Wasserman, M., Wasserman, D., Cucos, S. & Miller, H. J. (1979). World PCB map: Storage and effects in man and his biologic environment in the 1970s. Ann. N. Y. Acad. Sci., 320, 69-1124. USHA VARANASJ and DENNIS J. GMUR. 1981. HYDROCARBONS AND METABOLITES IN ENGLISH SOLE (PAROPHRYS VETULUSj EXPOSED SIMULTANEOUSLY TO [3H]BENZO[a]PYRENE AND [14C] CINAPHTHALENEIN OIL-CONTAMINATEDSEDIMENT. AquaticToxicology, 1. pp49-67 Safe, S. 1992. Toxicology, Structure-Function Relationship, and Human and Environmental Health Impacts of Polychlorinated Biphenyls:Progress and Problems. Environmental Health Perspectives Vol. 100,pp. 259-268. Yoshinari Ambe and Hitoshi Mukai. 1997. LONG TERM STABILITY OF BENZO[a]PYRENE IN STORED ATMOSPHERIC PARTICULATEMATTER SAMPLES. Chemosphere.Vol. 34, Nos 900, pp. 2023-2028.