Use of Passive Samplers for Detecting Spatial Distribution

Use of Passive Samplers for Detecting Spatial Distribution of Organic Contaminants in Lake Mead, Nevada, U. S. A M. R. Rosen, S. L. Goodbred, D. A. Alvarez, and Thomas J. Leiker US Geological Survey

Background • This work is part of an ongoing study initiated in 1995 to assess potential for endocrine disruption in Lake Mead. • Objectives • Determine presence and potential sources of endocrine disrupting compounds (EDCs) in Lake Mead National Recreation Area (LAME) using passive samplers and sediment cores. • Importance of study • Determine what EDCs aquatic organisms might be exposed to at various locations in LAME and their potential sources.

Water Quality Issues in Las Vegas Bay, Lake Mead • • Historic use chemicals present in sediment & biota (i. e. chlorinated pesticides, PCB’s etc. ) Chemicals from manufacturing plants and defense related industries since 1940’s. (e. g. perchlorate etc). Tertiary treated effluent (currently >180 million gallons daily, expected to increase to 400 million gallons daily by 2050). Storm-water runoff and other non-point sources

Population Growth in Las Vegas Valley 1950 Pop 47, 000 2000 Pop 1, 300, 000

Lake Mead National Recreation Area Sampling Sites March, 2006 Las Vegas Wash Above STPs Las Vegas Wash Below STPs Las Vegas Bay Overton Arm Colorado R. Inflow Sentinel Island Colorado R. Outflow (Willow Beach)

Study Design Three 36” SPMDs, 3 POCIS discs both pharmaceutical and pesticide were deployed at 7 sites in LAME for one month in February 2006 all at 8 m water depth n SPMDs deployed in vertical gradient at Las Vegas Bay site n Analytical chemistry done on extracts by GC/MS n Performance Reference Compounds n

What are SPMDs and POCIS Samplers? Hydrophobic compounds Kow >3. 0 SPMD consists of Low density polyethylene lay-flat tubing containing lipid (fat-like organic compound made of triolein) similar to fish fat Hydrophilic compounds Kow<3. 0 POCIS consists of a microporous membrane containing various solid phase sequestering media

Vertical gradient Sampling Setup POCIS 8 M

Deployment and Retrieval of Samplers

Different Blank Used at Each Site n If compound detected in blank: Concentration in blank subtracted from reported value Above WWTPs Below WWTPs

Performance Reference Compounds used for SPMDs to calculate concentrations Anthracene – d 10 n Chrysene – d 12 n Las Vegas Bay inflow Boulder Basin site

Blanks are Important What did we find in blanks? Compound n Acetophenone creams) n Benzophenone n Oyxbenzone n Di limonene solvent n Methyl naphthalene cigarettes n Methyl salicylate Uses fragrance (soaps, sunscreens citrus based found in air, deep heat

Total Compounds Detected SPMD Total Compounds (30) Number of EDCs (17) POCIS Total Compounds (28) Number of EDCs (7)

EDCs Detected in Las Vegas Wash and Lake Mead National Recreation Area n n n n PCPs Galoxolide Tonalide 4 -tert-octylphenol Triclosan PAHs Pyrene Anthracene Phenanthrene Benzo (a) pyrene n n n Pesticides Chlorphrifos o, p’ DDE Trifluralin HCB Trans & Cis Chlordane Industrial BDE (47, 99, 100, 138, 146, 180)

Hydrophobic Compounds Total concentration (µg/L) and number of detects Overton Arm 0. 0003 (3) Las Vegas Wash Above STPs 0. 005 (12) Las Vegas Wash Below STPs 0. 45 (17) Las Vegas Bay 0. 06 (16) Sentinel Island 0. 001 (5) Colorado R Inflow Colorado R Outflow 0. 0006 (6) 0. 02 (6)

Where are EDCs Coming From? Example of Galaxolide (µg/L) at 8 m depth in Lake Mead Overton Arm <0. 0005 Las Vegas Wash Above STPs <0. 0005 Las Vegas Wash Below STPs 0. 4 Las Vegas Bay 0. 06 Sentinel Island 0. 001 Colorado R Inflow Colorado R Outflow <0. 0005

Where are EDCs Coming From? Example of Naphthalene (petrogenic) (µg/L) at 8 m depth in Lake Mead Overton Arm <0. 0009 Las Vegas Wash Above STPs <0. 0009 Las Vegas Wash Below STPs <0. 0009 Las Vegas Bay 0. 001 Sentinel Island <0. 0009 Colorado R Inflow Colorado R Outflow Estimated 0. 0002 0. 01

Where are EDCs Coming From? Example of Pyrene (pyrogenic) (µg/L) at 8 m depth in Lake Mead Overton Arm <0. 00005 Las Vegas Wash Above STPs <0. 00005 Las Vegas Wash Below STPs <0. 00005 Las Vegas Bay 0. 0003 Sentinel Island <0. 00005 Colorado R Inflow Colorado R Outflow <0. 00005

Vertical Gradient of Hydrophobic Contaminants in Las Vegas Bay

Hydrophilic Compounds ng/POCIS (pesticide EI and NCI) and # of detects Overton Arm 390 (8) Las Vegas Wash Above STPs 22, 551 (11) Las Vegas Wash Below STPs 24, 716 (11) Las Vegas Bay 136 (1) Sentinel Island 74 (3) Colorado R Inflow Colorado R Outflow 1, 033 (5) 0 (0)

Effects in Male Carp Intersex fish found in Las Vegas Wash EDCs found in carp include Methyl Triclosan, PBDEs, DDT (and metabolites) Las Vegas Wash downstream of WWTPs From high to low, reproductive condition by site can be classified as:

Effects in Male Largemouth Bass Only two sites have bass present No chemical data available yet The differences between sites were most evident just prior spawning period (March 2008) Relatively low KT levels and high E 2/KT ratios in Las Vegas Bay males are consistent with reduced health and reproductive condition

Conclusions n Las Vegas Wash below WWTPs major source of hydrophobic contaminants and EDCs in LAME n Sole source of Galaxolide and Tonalide, weakly estrogenic musk fragrances, is Las Vegas Wash below WWTPs. n Hydrophilic compounds come from both sites in the Wash. n Main source of PAHs is petrogenic compounds from within lake (boats) n Very few EDCs coming from inflows at Overton Arm, Colorado R. or present below Hoover Dam. n Overall, aquatic biota show impaired reproductive function in LVW and LVB and are most exposed to EDCs in LVW, Bay, and Boulder Basin, but

Research Team USGS personnel Partners Project coordinator: Michael R. Rosen mrosen@usgs. gov 775 -887 -7683 Toxicologist: Erik Orsak Toxicologist: Steven Goodbred goodbred@usgs. gov USFWS Erik_Orsak@f 916 -278 -9492 702 -515 -5243 Fish Biologist: Reynaldo Patiño Foodweb biologist: Sudeep Chand r. patino@usgs. gov UNR sudeep@cabnr. unr. ed 806 -742 -2851 775 -354 -4849 Chemist: David Alvarez. Microbiologist: Duane Moser dalvarez@usgs. gov DRI duane. moser@dri. edu 573 -441 -2970 702 -378 -7639 Risk analyst: Greg Linder linder 2@usgs. gov 503 -590 -3916 Fish microbiologist: Jill Jenkins jenkinsj@usgs. gov 337 -266 -8607