Environmental Fate & Effects of Lampricides TFM and Niclosamide

Environmental Fate and Effects of the Lampricides TFM and Niclosamide Briefing for the Enviromental Protection Agency November 5, 2012 1

Lampricide Fate and Effects TFM Hubert, T. D. 2003. Environmental Fate and Effects of the Lampricide TFM: A Review. Journal of Great Lakes Research. 29(Supplement 1):456-474. Niclosamide Dawson, V. K. 2003. Environmental Fate and Effects of the Lampricide Bayluscide: A Review. 29(Supplement 1):475-492. 2

EPA Assessment Human Health Moderate to low toxicity Risk of exposure low No developmental toxicity No carcinogenicity No mutagenicity Conclusion No risk to general population 3

EPA Assessment Environmental Fate and Effects Chemically stable and persistent Some impacts to aquatic organisms Aquatic communities recover quickly Conclusions Risks reduced by Flushing action of stream Rapid repopulation from non-treated portions of stream Treatment on 3-5 year cycles 4

Additional studies TFM Photodegradation Niclosamide Photodegradation Aerobic aquatic metabolism Anaerobic aquatic metabolism 5

OH Cl Cl O C N NO2 CF3 H OH NO2 TFM Niclosamide 6

Environmental Fate - Hydrolysis TFM Resistant to hydrolysis Half-lives over 1400 days Niclosamide Resistant at basic pH Half-life at pH 5 120 hours 7

Photodegradation pH TFM t1/2 (h) 11.6 Niclosamide t1/2 (h) 7.2 5 7 9 4.15 3.36 11.7 30 8

Photodegradation Degradation products Low molecular weight organic acids Substituted 2, 3, and 4 carbon organic acids (maleic, oxalic, glyoxylic) Carbon dioxide 9

Binding to sediment Milakokia River 1997 Sandy sediment Chemical fell below detection in 24 to 96 hours Carp River and Fish Creek 2010 Slight organic content sediment Same result: below detection in 24 to 96 hours 10

Aerobic/anaerobic degradation TFM Half-lives 2 to 5 days RTFM, incorporation in high MW organic matter, polymers, humic or fulvic acids Niclosamide Half-lives ~ 5 days aerobically; 0.65 to 2.79 days anaerobically Small carbon compounds and incorporation into humin 11

Metabolism OGlu OH glucuronyl transferase CF3 CF3 NO2 NO2 12

Metabolism Aquatic Insects TFM: Sulfation, glucuronidation Niclosamide: hydrolysis, conjugation Fish TFM: glucuronidation Niclosamide: glucuronidation, sulfation Mammals TFM: glucuronidation, reduction and acetylation, sulfation Niclosamide: glucuronidation 13

Uptake and Elimination Species studied - green algae, aquatic plants, isopods (sowbug), amphipods, crayfish, mayfly, caddisfly, annelid worms (leeches), snails, fingernail clams, and fish Half-lives ranged from 7 hours to 18 days Exception: annelid worms, t1/2 = ~ 221 days Bioconcentration factors (BCF) for whole body and tissues ranged from less than 1 to ~ 62 Dioxin: BCF 5,840 in fathead minnow 14

Effects on Plants TFM Aquatic Plants Toxic at >15 mg/L Effects at 5 mg/L but plants recover Green Algae/Blue-green Algae Reduction in growth at < 10 mg/L Minor reductions in pH and dissolved oxygen Niclosamide No effects at treatment concentrations 15

Fish TFM Toxicity low to high depending on species Generally high margins of selectivity Niclosamide Highly toxic to most fish Margin of selectivity lower than TFM 16

American eel Tested elvers Highly resistant to TFM or TFM/niclosamide mixtures 4 to 7 times MLC for sea lamprey 17

Effects on Aquatic Invertebrates TFM Slightly to moderately toxic Niclosamide Slightly to highly toxic 18

Endangered Hungerfords crawling water beetle Surrogate Haliplus spp tested Adults and larvae Survival unaffected at up to 3.9X MLC Adults appeared to avoid chemical by crawling out of water 19

Mussels Giant floater, fragile papershell, pink heelsplitter, black sandshell, snuffbox, ellipse At concentrations of TFM required to kill lampreys mortality is minimal. Adults, juveniles, glochidia are resistant; recruitment not affected. TFM/1% niclosamide caused some mortality 20

Native lamprey study Lampetra, Ichthyomyzon, Petromyzon No significant difference in median lethal concentration Slight difference in MLC between Lampetra and Petromyzon Some lampetra will survive treatments Native lamprey will be impacted 21

Effects on Reptiles and Amphibians TFM Turtles No effects Frogs Effects that vary depending on species, stage of development, and route of exposure Mudpuppies Reports of sensitivity and population declines UMESC study adults not affected (2.4X MLC) Juveniles < 100 mm are less resistent to TFM (1.5X MLC) Juveniles more sensitive to TFM/niclosamide mixture Niclosamide Turtles No effects at treatment concentrations Frogs No effects at treatment concentrations 22

Effects on Birds TFM Oral toxicity ranged from 250 mg/kg to 546 mg/kg body weight Water concentrations of between 15 mg/L and 50 mg/L Uncoordination and lethargy depending on length of exposure Niclosamide Oral toxicity ranged from 500 mg/kg to over 2000 mg/kg Water concentration of 0.10 mg/L Produced slight uncoordination in one animal 23

Common tern St. Marys River Risk from eating dead larvae In lab exposed larvae to bayer granular and wettable powder Analyzed for niclosamide 3.49 ppb tissue concentration Low acute toxicity exposure risk 24

Piping plover Endangered Estimate exposure risk Residues in water and caged insects Likely exposure for adults 85X below NOEC Likely exposure for chicks 17X below NOEC 25

Effects on Mammals TFM Oral toxicity 141 to 387 mg/kg Dermal toxicity: > 2000 mg/kg Moderate dermal and eye irritation Niclosamide Oral toxicity >5000 mg/kg Dermal toxicity >2000 mg/kg Inhalation toxicity 1.95 mg/L Mild eye irritation, no dermal irritation 26

Effects on Mammals TFM No effects to decreased body weights, increased liver weights, and reduced weights in offspring No cancer, mutations, developmental toxicity or increased tumor incidence No reproductive effects Niclosamide No effects to decreased body weights, increased liver weights, and reduced weights in offspring No cancer, mutation, developmental toxicity, or increased tumor incidence Abnormal sperm morphology in mice 27

Summary Effects transient Do not persist Relatively non-toxic 28

Questions 29