Sample records for kepone

  1. STRUCTURES OF SOME KEPONE PHOTOPRODUCTS AND RELATED CHLORINATED PENTACYCLODECANES BY CARBON-13 AND PROTON NUCLEAR MAGNETIC RESONANCE

    EPA Science Inventory

    The pesticide Kepone, 1,1a,3,3a,4,5,5a,5b,6-decachlorooctahydro-1,3,4-metheno-2H-cyclobuta(cd)pentalen-2-one, the related compounds mirex, kelevan, a monohydro photoproduct of kelevan, kepone alcohol, kepone hydrate, and the mono- and dihydro photoproducts of Kepone hydrate and t...

  2. MASS SPECTROMETRIC ANALYSIS AND CHARACTERIZATION OF KEPONE IN ENVIRONMENTAL AND HUMAN SAMPLES

    EPA Science Inventory

    A specific portion of our environment has been contaminated with Kepone, or chlordecone. Additionally, some specific human exposures to high concentrations of Kepone have been confirmed. Gas chromatography mass spectrometry involving chemical ionization and high resolution mass s...

  3. Modelling Kepone in the striped bass food chain of the James River estuary

    NASA Astrophysics Data System (ADS)

    Connolly, John P.; Tonelli, Rosella

    1985-03-01

    A mathematical model that computes the accumulation of Kepone in the striped bass food chain of the James River estuary was developed. The purpose of the model was to help understand the relationship of Kepone levels in important fish species to sediment and water column Kepone concentrations and then to address the question of why these levels still exceed Food and Drug Administration limits eight years after discharge ceased. The model considers exposure through diet and respiration at rates based on species bioenergetics. It was successfully calibrated to the Kepone concentrations observed in the period 1976 through 1982 in striped bass, white perch, and Atlantic croaker. The model indicates that for the upper levels of the food chain, diet is the major route of contamination, accounting for 87-88% of the observed concentration in croaker and white perch and 91% of the observed concentration in striped bass. The two Kepone sources; sediment and water column, contribute approximately equally to the croaker and white perch. The water column is more significant for striped bass, being the original source for approximately 60% of the observed body burdens. It was estimated that a criterion requiring Kepone concentrations in fish to be at or below 0·3 μg g -1 would require dissolved water column and sediment Kepone concentrations to be reduced to somewhere between 3 and 9 ng l -1 and 13-39 ng g -1, respectively, depending on the species. Striped bass require the greatest reductions in dissolved water column and sediment Kepone concentrations to somewhere between 3 and 5 ng l -1 and 13 and 24 ng g -1, respectively.

  4. IRIS TOXICOLOGICAL REVIEW AND SUMMARY DOCUMENTS FOR CHLORDECONE (KEPONE) (2009 FINAL)

    EPA Science Inventory

    EPA is announcing the release of the final report, Toxicological Review of Chlorodecone (kepone): in support of the Integrated Risk Information System (IRIS). The updated Summary for Chlordecone (kepone) and accompanying Quickview have also been added to the IRIS Database....

  5. Using kepone to exemplify the importance of natural variability in estimating exposure to toxic chemicals from aquatic environments

    Treesearch

    Robert J. Huggett

    2000-01-01

    Kepone, decachlorooctahydro-l, 3, 4-metheno-2H-cyclobuta (cd) pentalen-2-one, is a known mammalian carcinogen. From at least 1967 to 1975 when production stopped, it contaminated the Chesapeake Bay. Action levels for kepone in seafood were established by the U.S. Environmental Protection Agency, and various species of finfish, oysters, Crassostrea virginica...

  6. Gas-liquid chromatographic determination of kepone in field-collected avian tissues and eggs

    USGS Publications Warehouse

    Stafford, C.J.; Reichel, W.L.; Swineford, D.M.; Prouty, R.M.; Gay, M.L.

    1978-01-01

    A procedure is described for determining Kepone (decachlorooctahydro-1,3,4-metheno-2H-cyclobuta [cd] pentalene-2-one) residues in avian egg, liver, and tissue. Samples were extracted with benzene-isopropanol, and the extract was cleaned up with fuming H2SO4-concentrated H2SO4. Kepone was separated from organochlorine pesticides and polychlorinated biphenyls on a Florisil column and analyzed by electron capture gas-liquid chromatography (GLC). The average recovery from spiked tissues was 86%. The analyses performed on 14 bald eagle carcasses and livers, 3 bald eagle eggs, and 14 osprey eggs show measurable levels which indicate that Kepone accumulates in the tissues of fish-eating birds. Residues were confirmed by GLC-mass spectrometry.

  7. Chlordecone (Kepone)

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 07 / 004F www.epa.gov / iris TOXICOLOGICAL REVIEW OF CHLORDECONE ( KEPONE ) ( CAS No . 143 - 50 - 0 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) September 2009 U.S . Environmental Protection Agency Washington , DC DISCLAIMER This document has

  8. ANALYTICAL METHODOLOGY FOR THE DETERMINATION OF KEPONE (TRADEMARK) RESIDUES IN FISH, SHELLFISH, AND HI-VOL AIR FILTERS

    EPA Science Inventory

    The recent discovery of the pollution of the environment with Kepone has resulted in a tremendous interest in the development of residue methodology for the compound. Current multiresidue methods for the determination of the common organochlorinated pesticides do not yield good q...

  9. The complexities of discussing soil vapor extraction techniques with non-scientists

    USDA-ARS?s Scientific Manuscript database

    The Centre County Kepone Site is approximately 32.2 acres on which a chemical manufacturing plant and a portion of the Spring Creek watershed are located. Kepone and mirex, were custom manufactured between 1959 and 1974. Earthen lagoons were used to manage onsite waste disposal. Concrete lagoons w...

  10. Report on the Biosphere 1976

    ERIC Educational Resources Information Center

    Woodwell, George M.

    1977-01-01

    Discusses contemporary challenges for biologists, environmentalists, technologists, teachers, and political supporters of science and education in solving global problems. Discussed are nation- and worldwide accumulation of toxic materials (DDT, PCB's, kepone, radioactivity, dieldrin, mirex), transformation of natural ecosystems, and instability…

  11. COMPARATIVE TISSUE DISTRIBUTION OF MIREX AND CHLORDECONE IN FETAL AND NEONATAL RATS

    EPA Science Inventory

    The transport of mirex and chlordecone (Kepone) across the placental during late gestation and through the milk during lactation was investigated in the rat. In the placental transport study, doses of 5 mg/kg were administrered on Day 15, 18 or 20 of gestation and animals were ki...

  12. Management of Bottom Sediments Containing Toxic Substances; Proceedings of the 6th U.S./Japan Experts Meeting Held at Tokyo, Japan on 16-18 February 1981.

    DTIC Science & Technology

    1982-03-01

    Most of the KEPONE was exported for use in the Caribbean and Central American banana fields, and in other countries for the control of potato beetles...quadrat: species diversity, stem density (by species), height (mean height of 10 randomly selected stems), flowering phenology (number of flowering stems

  13. Activated carbon, a useful medium to bind chlordecone in soil and limit its transfer to growing goat kids.

    PubMed

    Yehya, Sarah; Delannoy, Matthieu; Fournier, Agnès; Baroudi, Moomen; Rychen, Guido; Feidt, Cyril

    2017-01-01

    Chlordecone (Kepone) (CLD) is a highly persistent pesticide which was extensively used in the French West Indies; high levels of CLD can still currently be found in large agricultural areas. As CLD transfers from soil to animals mainly via involuntary ingestion, the consumption of foodstuffs derived from animals raised in contaminated areas may significantly contribute to exposure of humans to CLD. The present study was designed to test the efficacy of two different activated carbons (ACs) sources in limiting CLD transfer from soil to animal. Three soils (ASs) were prepared according to the OECD guideline 207. One standard soil (SS) lacking AC, and two modified preparations of SS supplemented with 2% coconut-based activated carbon (ORBO), SSO or with 2% lignite-based one (DARCO), SSD. All three soils were spiked with 10 μg of kepone per g of dry matter and aged for three weeks. This study involved 15 goat kids randomly assigned to the 3 experimental groups (n = 5/group), which were fed the experimental matrices at an exposure dose of 10 μg CLD per kg of body weight per day. After 21 d of oral exposure, CLD in adipose tissue and liver were analysed by LC-MS-MS. A significant decrease of 63.7% and 74.7% of CLD concentrations in adipose tissue and liver, respectively, were obtained from animals exposed using SS containing DARCO as compared to those receiving only SS. Decreases in CLD levels of 98.2% (adipose tissue) and 98.7% (liver) were obtained for animals exposed using SS containing ORBO. This study leads us to conclude that (i) the presence of AC in CLD-contaminated soil strongly reduces CLD bioavailability, and (ii) the efficacy depends on the nature and characteristics of the AC used.

  14. Activated carbon, a useful medium to bind chlordecone in soil and limit its transfer to growing goat kids

    PubMed Central

    Yehya, Sarah; Delannoy, Matthieu; Fournier, Agnès; Baroudi, Moomen; Rychen, Guido; Feidt, Cyril

    2017-01-01

    Chlordecone (Kepone) (CLD) is a highly persistent pesticide which was extensively used in the French West Indies; high levels of CLD can still currently be found in large agricultural areas. As CLD transfers from soil to animals mainly via involuntary ingestion, the consumption of foodstuffs derived from animals raised in contaminated areas may significantly contribute to exposure of humans to CLD. The present study was designed to test the efficacy of two different activated carbons (ACs) sources in limiting CLD transfer from soil to animal. Three soils (ASs) were prepared according to the OECD guideline 207. One standard soil (SS) lacking AC, and two modified preparations of SS supplemented with 2% coconut-based activated carbon (ORBO), SSO or with 2% lignite-based one (DARCO), SSD. All three soils were spiked with 10 μg of kepone per g of dry matter and aged for three weeks. This study involved 15 goat kids randomly assigned to the 3 experimental groups (n = 5/group), which were fed the experimental matrices at an exposure dose of 10 μg CLD per kg of body weight per day. After 21 d of oral exposure, CLD in adipose tissue and liver were analysed by LC-MS-MS. A significant decrease of 63.7% and 74.7% of CLD concentrations in adipose tissue and liver, respectively, were obtained from animals exposed using SS containing DARCO as compared to those receiving only SS. Decreases in CLD levels of 98.2% (adipose tissue) and 98.7% (liver) were obtained for animals exposed using SS containing ORBO. This study leads us to conclude that (i) the presence of AC in CLD-contaminated soil strongly reduces CLD bioavailability, and (ii) the efficacy depends on the nature and characteristics of the AC used. PMID:28723966

  15. Confirmation of uterotrophic activity of 3-(4-methylbenzylidine)camphor in the immature rat.

    PubMed Central

    Tinwell, Helen; Lefevre, Paul A; Moffat, Graeme J; Burns, A; Odum, Jenny; Spurway, T D; Orphanides, George; Ashby, John

    2002-01-01

    In this study we found that the ultraviolet sunscreen component 3-(4-methylbenzylidine)camphor (4MBC) is uterotrophic in immature rats when administered by either subcutaneous injection or oral gavage. These data confirm earlier reports of uterotrophic activity for this agent when administered to immature rats in the diet or by whole-body immersion; however, they are in contrast to negative unpublished immature rat uterotrophic assay results. Data also indicate that 4MBC binds to isolated rat uterine estrogen receptors and shows activity in a human estrogen receptor yeast transactivation assay; however, we considered both of these effects equivocal. In this study, we confirmed the original observation that 4MBC was active as a mitogen to MCF-7 breast cancer cells. We evaluated and discounted the possibility that the estrogenic activity of 4MBC is related to its bulky camphor group, which is of similar molecular dimensions to that of the weak estrogen kepone. Uncertainty remains regarding the mechanism of the uterotrophic activity of 4MBC. PMID:12003759

  16. Microbial Degradation of a Recalcitrant Pesticide: Chlordecone.

    PubMed

    Chaussonnerie, Sébastien; Saaidi, Pierre-Loïc; Ugarte, Edgardo; Barbance, Agnès; Fossey, Aurélie; Barbe, Valérie; Gyapay, Gabor; Brüls, Thomas; Chevallier, Marion; Couturat, Loïc; Fouteau, Stéphanie; Muselet, Delphine; Pateau, Emilie; Cohen, Georges N; Fonknechten, Nuria; Weissenbach, Jean; Le Paslier, Denis

    2016-01-01

    Chlordecone (Kepone®) is a synthetic organochlorine insecticide (C 10 Cl 10 O) used worldwide mostly during the 1970 and 1980s. Its intensive application in the French West Indies to control the banana black weevil Cosmopolites sordidus led to a massive environmental pollution. Persistence of chlordecone in soils and water for numerous decades even centuries causes global public health and socio-economic concerns. In order to investigate the biodegradability of chlordecone, microbial enrichment cultures from soils contaminated by chlordecone or other organochlorines and from sludge of a wastewater treatment plant have been conducted. Different experimental procedures including original microcosms were carried out anaerobically over long periods of time. GC-MS monitoring resulted in the detection of chlorinated derivatives in several cultures, consistent with chlordecone biotransformation. More interestingly, disappearance of chlordecone (50 μg/mL) in two bacterial consortia was concomitant with the accumulation of a major metabolite of formula C 9 Cl 5 H 3 (named B1) as well as two minor metabolites C 10 Cl 9 HO (named A1) and C 9 Cl 4 H 4 (named B3). Finally, we report the isolation and the complete genomic sequences of two new Citrobacter isolates, closely related to Citrobacter amalonaticus , and that were capable of reproducing chlordecone transformation. Further characterization of these Citrobacter strains should yield deeper insights into the mechanisms involved in this transformation process.

  17. Microbial Degradation of a Recalcitrant Pesticide: Chlordecone

    PubMed Central

    Chaussonnerie, Sébastien; Saaidi, Pierre-Loïc; Ugarte, Edgardo; Barbance, Agnès; Fossey, Aurélie; Barbe, Valérie; Gyapay, Gabor; Brüls, Thomas; Chevallier, Marion; Couturat, Loïc; Fouteau, Stéphanie; Muselet, Delphine; Pateau, Emilie; Cohen, Georges N.; Fonknechten, Nuria; Weissenbach, Jean; Le Paslier, Denis

    2016-01-01

    Chlordecone (Kepone®) is a synthetic organochlorine insecticide (C10Cl10O) used worldwide mostly during the 1970 and 1980s. Its intensive application in the French West Indies to control the banana black weevil Cosmopolites sordidus led to a massive environmental pollution. Persistence of chlordecone in soils and water for numerous decades even centuries causes global public health and socio-economic concerns. In order to investigate the biodegradability of chlordecone, microbial enrichment cultures from soils contaminated by chlordecone or other organochlorines and from sludge of a wastewater treatment plant have been conducted. Different experimental procedures including original microcosms were carried out anaerobically over long periods of time. GC-MS monitoring resulted in the detection of chlorinated derivatives in several cultures, consistent with chlordecone biotransformation. More interestingly, disappearance of chlordecone (50 μg/mL) in two bacterial consortia was concomitant with the accumulation of a major metabolite of formula C9Cl5H3 (named B1) as well as two minor metabolites C10Cl9HO (named A1) and C9Cl4H4 (named B3). Finally, we report the isolation and the complete genomic sequences of two new Citrobacter isolates, closely related to Citrobacter amalonaticus, and that were capable of reproducing chlordecone transformation. Further characterization of these Citrobacter strains should yield deeper insights into the mechanisms involved in this transformation process. PMID:28066351

  18. Theoretical study of chlordecone and surface groups interaction in an activated carbon model under acidic and neutral conditions.

    PubMed

    Gamboa-Carballo, Juan José; Melchor-Rodríguez, Kenia; Hernández-Valdés, Daniel; Enriquez-Victorero, Carlos; Montero-Alejo, Ana Lilian; Gaspard, Sarra; Jáuregui-Haza, Ulises Javier

    2016-04-01

    Activated carbons (ACs) are widely used in the purification of drinking water without almost any knowledge about the adsorption mechanisms of the persistent organic pollutants. Chlordecone (CLD, Kepone) is an organochlorinated synthetic compound that has been used mainly as agricultural insecticide. CLD has been identified and listed as a persistent organic pollutant by the Stockholm Convention. The selection of the best suited AC for this type of contaminants is mainly an empirical and costly process. A theoretical study of the influence of AC surface groups (SGs) on CLD adsorption is done in order to help understanding the process. This may provide a first selection criteria for the preparation of AC with suitable surface properties. A model of AC consisting of a seven membered ring graphene sheet (coronene) with a functional group on the edge was used to evaluate the influence of the SGs over the adsorption. Multiple Minima Hypersurface methodology (MMH) coupled with PM7 semiempirical Hamiltonian was employed in order to study the interactions of the chlordecone with SGs (hydroxyl and carboxyl) at acidic and neutral pH and different hydration conditions. Selected structures were re-optimized using CAM-B3LYP to achieve a well-defined electron density to characterize the interactions by the Quantum Theory of Atoms in Molecules approach. The deprotonated form of surface carboxyl and hydroxyl groups of AC models show the strongest interactions, suggesting a chemical adsorption. An increase in carboxylic SGs content is proposed to enhance CLD adsorption onto AC at neutral pH conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Soil thresholds and a decision tool to manage food safety of crops grown in chlordecone polluted soil in the French West Indies.

    PubMed

    Clostre, Florence; Letourmy, Philippe; Lesueur-Jannoyer, Magalie

    2017-04-01

    Due to the persistent pollution of soils by an organochlorine, chlordecone (CLD also known as Kepone © ) in the French West Indies, some crops may be contaminated beyond the European regulatory threshold, the maximum residue limit (MRL). Farmers need to be able to foresee the risk of not complying with the regulatory threshold in each field and for each crop, if not, farmers whose fields are contaminated would have to stop cultivating certain crops in the fields concerned. To help farmers make the right choices, we studied the relationship between contamination of the soil and contamination of crops. We showed that contamination of a crop by CLD depended on the crop concerned, the soil CLD content and the type of soil. We grouped crop products in three categories: (i) non-uptakers and low-uptakers, (ii) medium-uptakers, and (iii) high-uptakers, according to their level of contamination and the resulting risk of exceeding MRL. Using a simulation model, we computed the soil threshold required to ensure the risk of not complying with MRL was sufficiently low for each crop product and soil type. Threshold values ranged from 0.02 μgkg -1 for dasheen grown in nitisol to 1.7 μgkg -1 for yam grown in andosol in the high-uptake category, and from 1 μgkg -1 for lettuce grown in nitisol to 45 μgkg -1 for the leaves of spring onions grown in andosol in the medium-uptake category. Contamination of non-uptakers and low-uptakers did not depend on soil contamination. With these results, we built an easy-to-use decision support tool based on two soil thresholds (0.1 and 1 μgkg -1 ) to enable growers to adapt their cropping system and hence to be able to continue farming. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Mercury, selenium, cadmium and organochlorines in eggs of three Hawaiian seabird species

    USGS Publications Warehouse

    Ohlendorf, H.M.; Harrison, C.S.

    1986-01-01

    Eggs of three representative species of seabirds (wedge-tailed shearwater Puffinus pacificus; red-footed booby Sula sula; and sooty tern Sterna fuscata) were collected in 1980 to determined differences in heavy metal, Se, and organochlorine residues among species nesting in the Hawaiian Archipelago and among the four nesting sites sampled (Oahu, French Frigate Shoals, Laysan, and Midway). Hg and Se were present in all eggs analysed, but Cd was not detected. Hg was usually highest in booby eggs, and there was a southeast-to-northeast trend toward higher concetrations in this species; booby eggs from Midway contained the highest mean concentration of Hg (0?36 :g g-1, wet weight). Se consistently occurred at lowest concentrations in booby eggs. When Se and Hg concentrations were expressed as nanomoles per gram, Se constituted 94?96% of the combined total at each location for shearwater and tern eggs. In booby eggs, the proportion as Se declined significantly (' = 0?05) from Oahu (93?4%) westward to Midway (85?9%). Although DDT occurred in most of the shearwater eggs from each site, it was not found in booby or tern eggs. DDE occured in all eggs, but mean concentrations did not exceed 0?6 :g g-1. DDE concentrations were higher in eggs from the two south-eastern nesting sites and were consistently highest in shearwater eggs. PCBs were found in most of the shearwater and booby eggs, but were not detected in tern eggs. Other organochlorines usually occurred more frequently in eggs of shearwaters than in other species. The only exception were '-HCH and HCB, which occurred more frequently in booby eggs. Kepone, heptachlor epoxide, chlordane compounds, and toxaphene were not detected. Differences in residue concentrations seem to reflect differences in diets and seasonal movements of the birds, and perhaps other factors such as atmospheric and oceanic transport of chemicals and physiological differences among the species.

  1. Environmental Chemistry Update

    NASA Astrophysics Data System (ADS)

    1995-08-01

    Human Health Effects of the Chernobyl DisasterIncreased Incidence of Thyroid CancerThe release of radioactivity from the famous explosion at the fission nuclear power reactor at Chernobyl eight years ago has resulted in a substantial increase in the incidence of thyroid cancer in children in the immediate area but no great increase in the incidence of childhood leukemia, tumors, or genetic defects. In the region of the Belarus republic closest to Chernobyl, the childhood thyroid cancer rate has reached over 100 cases per million children, compared to less than 3 per million in most countries. More than 500 children in Belarus and Ukraine have been diagnosed with this disease. The likely cause of the cancers is radioactivity from the isotope 131-I and perhaps 133-I released during the explosion (1). Lead PollutionAnalysis of snow in the Greenland ice sheet indicates rather high levels of lead pollution in air from 500 BC to AD 300 and AD 1000-1500. The earliest lead pollution was associated with mining in Greece and then mining by the Romans, especially in Spain. The later pollution was due mainly to lead and silver smelting in Germany (2). Detrimental Effect of Lead upon IQ in AustraliaStudies of children in Port Pirie, Australia have produced further evidence of the detrimental effect of lead upon IQ. The cumulative exposure to lead of the children from birth to age seven years was determined by analyzing for the element in their baby teeth (3). Ozone Hole PhenomenaThe AntarcticThe Antarctic ozone hole appeared earlier than usual in 1994; it was as large and as severe as the holes in 1992 and 1993. The region of severe depletion covered about 24 million square kilometers, which is approximately the size of North America (4). The Role of Nitric AcidOur knowledge of the role of nitric acid in the formation of ozone holes over polar areas has recently been improved by a joint publication from researchers in Scotland and the United States. Using data obtained by satellite, Santee and coworkers discovered that the nitric acid trihydrate (NAT) crystals, HNO33H2O, which first form when the lower stratosphere cools in the dark polar winter over Antarctica, can grow large enough and last long enough to sediment. Thus, they partially denitrify this region of the atmosphere for several months. (Because the so-called type II crystals that form at even lower temperatures are even larger, they experience fallout from the lower stratosphere even faster.) In contrast, the reduction in gas-phase HNO3 concentrations in the Arctic lower stratosphere during the 1992-1993 winter was "less intense, more localized, and more transient", indicating no significant denitrification. For that reason, no Arctic ozone hole was formed. Once significant sunlight appeared (required before chlorine can participate in catalytic cycles that destroy ozone), the nitric acid photolyzed to NO2, which combined with chlorine monoxide to deactivate the chlorine. The increased cooling of the Arctic lower stratosphere in future winters could be sufficient to intensify the loss of nitric acid and thereby lead to greater depletions of Arctic ozone (5). Stratospheric Ozone Depletion in Nonpolar RegionsThe Role of the HalogensS. Solomon and coworkers have recently speculated that iodine, as well as its fellow halogens, chlorine and bromine, may play a role in stratospheric ozone depletion. Biogenic processes in the ocean release methyl iodide to the atmosphere, where most of it is destroyed in a few days. However, tropical thunderclouds could transport some of it to the lower stratosphere before it is destroyed. In combination with chlorine and bromine oxides, IO and I could participate in cycles that destroy ozone. Chlorine and bromine alone cannot account for all the ozone destruction observed over nonpolar regions in the low stratosphere (6). Cycles that Remove OzoneExperimental measurements of free radical concentrations in May, 1993 between 15 oN and 60 oN indicate that the OH/HOO reaction chain is responsible for 30-50% of the ozone loss in the low stratosphere. Chains involving nitrogen radicals are less important in this region than previously thought. Almost one-third of the loss is due to cycles involving halogens, including that initiated by collision of ClO with Br. Equally important is the following cycle, reminiscent of the "dimer" mechanism that operates in ozone holes, for the 2O3 --> 3O2 process. Cl + O3 --> ClO + O2 OH + O3 --> HOO + O2 ClO + HOO --> HOCl + O2 HOCl + sunlight --> OH + Cl The same mechanism with bromine replacing chlorine is also important. The greatest removal rate for ozone at these latitudes should occur in spring and fall, when ozone production is minimal. Although the sunlight then is not sufficient to dissociate much O2, it is adequate to drive the free radical processes (7). The feasibility of A. Y. Wong's scheme to reduce stratospheric ozone destruction due to reactions involving chlorine has been questioned. The scheme involves the introduction of electrons into the stratosphere, which would allow the conversion of chlorine to chloride ion and its hydrates and potentially the subsequent removal of the chloride ions. A. A. Viggiano and colleagues have noted that chloride ions react quickly after their formation (to reform chlorine radicals) and never amount to more than a tiny fraction of the anions present. The dominant ions are NO3- and CO3-. Viggiano et al. also note the very large energy requirements for the electron production and for removal of the 2.4 X 10^9 kg of chlorine from the stratosphere (8). Pesticides and DioxinGreat LakesThe herbicide atrazine and its metabolite, in which the nitrogen-based ethyl group is removed, were found in all 490 samples of water from the Great Lakes in a 1990-1992 study. Highest concentrations of atrazine were found in Lakes Ontario and Erie (70-110 parts per trillion (ppt)), with lower levels (20-35 ppt) in Lakes Huron and Michigan. It was estimated that the Great Lakes may contain more than 600,000 kg of the herbicide and that its residence time there is in years. Atrazine concentrations in rivers that flow into these lakes can exceed 20,000 ppt (i.e., 20 ppb) (9). There are about 600 basic ingredients in the 34,000 pesticides registered with the U.S. EPA. Approximately 75% of all U.S. cropland and 70% of livestock are treated with pesticides. In 1991, 495 million pounds of herbicides, 175 million pounds of insecticides, 75 million pounds of fungicides, and 72 million pounds of other pesticides were used; this accounted for three-quarters of all pesticide use in the United States (10). Environmental EstrogensDDT and its metabolite DDE, as well as methoxychlor, dieldrin, kepone, and some PCB's are thought to be environmental estrogens. These synthetic compounds are found in the environment and mimic the action of the sex hormone estrogen because they can bind to the estrogen receptor in cells. Some scientists are worried that they can disrupt the hormone balance in human eggs and fetuses, thus causing reproductive abnormalities. Examples of reproductive problems caused by such chemicals have already been observed in wildlife, such as alligators in Florida. They may also play a role in inducing cancer in humans (11). The U.S. EPA has issued a 2000-page draft of its reassessment of the health risks of dioxins. The report reaffirms their 1985 conclusion that it is a probable cause of cancer in humans. Even trace amounts of dioxins may also disrupt regulatory hormones, produce reproductive and immune-system disorders, and lead to abnormal fetal development. Although waste combustion produces 95% of all known dioxin emissions in the United States, about half its source is unknown. Dioxin levels in the environment were small until about 1930, peaked about 1970, and have declined since then. Human body burdens of dioxins may also have declined. The Toxic Equivalent intake of dioxins and furans of Americans is currently about 111 pg, leading to a body fat concentration of about 40 ppt (12). Lithium Battery AdvancesRechargeable Power SourceRecent advances in lithium ion battery technology may allow these devices to become the rechargeable power source of choice in electric cars of the future. Due to their high voltage, they can store a large amount of energy per given mass or volume of battery. In the past, however, such batteries have been somewhat impractical because they had to be hermetically sealed and required nonaqueous electrolytes due to lithium's violent reaction with water. In the newly developed battery, the electrolyte is water that already contains a high concentration of Li+ ions; elemental lithium (present as LiMn2O4 in one electrode) is unreactive in this medium unless an external connection to the other electrode is made (13). Air-Pollution Control for Power PlantsA process called SNOX, which removes both NOx and SO2 from the flue gases produced by coal-fired power plants, has been developed and demonstrated. The nitrogen oxides are first reduced to N2. The resulting gas is then heated and catalytically oxidized to sulfur trioxide, which is then hydrated to sulfuric acid. More than 90% of the NOx and SO2 were removed from the flue gases in the demonstration held at an Ohio Edison plant (14). Literature Cited Williams, D. Nature 1994, 371, 556. Emsley, J. New Scientist 1994, (Oct 1), 14. McMichael, A. J. American Journal of Epidemiology 1994, 140, 489-499. Chemical and Engineering News 1994, (Oct 10), 5. Santee, M. L. Science 1995, 267, 849-852. Chemical and Engineering News 1994, (Nov 14). Solomon, S. Journal of Geophysical Research 1994, 99, 20491-20499. Wennberg, P. O. Science 1994, 266, 398-404. Viggiano, A. A. Science 1995, 267, 82-84. Summary in Chemistry and Engineering News 1995, (Jan 9), 23. Schottler, S. P.; Eisenreich, S. J. Environmental Science and Technology 1994, 28, 2228-2232. Lang, L. Environmental Health Perspectives 1993, 101, 578-583. Chemical and Engineering News 1994, (Jan 31), 19. Chemical and Engineering News 1994, (Sept 19). Glanz, J. Science 1994, 264, 1084; Li, W. Science 1994, 264, 1115-1118. Durrani, S. M. Environmental Science and Technology 1994, 28, 88A-90A.

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