Insight Into Bioaccumulation of Persistent Organic Pollutants (Pops) Acquired by Trophic Transfer

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Insight into bioaccumulation of persistent organic pollutants (POPs) acquired by trophic transfer

Viet D. Dang Postdoctoral Research Associate WI Symposium 11th Feb, 2014 Persistent Organic Pollutants (POPs)

• Ubiquitous in the environment.

• Most uses banned for decades Triclosan • Ecologically persistent and bioaccumulative

• ENDOCRINE DISRUPTORS POPs in an aquatic system

volatilization

water Input

sediment

Abiotic and biotic Sorption/desorption degradation pore water Contaminants of interest

Compound Log Kow FHM toxicity (96-hr LC50) (µg/L) p,p’-DDE 6.5 12

Dieldrin 5.4 4

Triclosan (TCS) 4.8 260

Triclocarban (TCC) 4.9 90

Fipronil 4.0 208-379

log Kow: octanol-water partitioning coefficient Lake Apopka north shore area

North shore area  The third largest lake in Florida.  Agriculture was a major activity for 4 decades.  Area was contaminated with organochlorine pesticides (OCPs)

DDT Methoxychlor Dieldrin Toxaphene Chlordanes Toxaphene soil concentration (SJRWMD, 2004) Lake Apopka mesocosm

• Largemouth bass were stocked into natural mesocosms for 3-4 months. • OCPs were detected in mesocosm fish

600 500 bass pre 400 bass post

300 How did fish 200 accumulate 40 30 so fast? 20

Contaminant conc (ug/g lipid) (ug/g conc Contaminant 10

0 DDE DDT Chlordanes MXC Toxaphene Dieldrin Contaminant Hypothesis

Water skin gills

food

Consumption of contaminated food was the major contribution of POPs in fish Trophic transfer model

Research aim 1: Research aim 2: worm uptake fish body burdens

exposure feeding chemicals

blackworm fathead minnow

Objective: to track the transfer of chemicals

• L. variegatus (blackworm): freshwater oligochaete • P. promelas (FHM): temperate freshwater fish Research Aim 1

Sediment exposure Water exposure

Ciw ~ Cipw Ciw < LC10

Determine bioaccumulation pattern of contaminants in blackworms in spiked sediment and water Sample extraction

120 Soil extraction efficiency Samples 100 80 60 Labeled standards added 40

20 Efficiency (%) Efficiency

Solvent extraction 0

13C-

analog

Fipronil

Dieldrin

13C-TCS

13C-TCC 13C-DDE Sonication & centrifugation Tissue extraction efficiency

120 Supernatants collected 100 80 Concentration, clean-up, 60 and solvent exchange 40

Efficiency (%) Efficiency 20 0

GC/MS or LC/MS/MS analysis

analog

Fipronil

13C-TCS 13C-TCC

Adapted from Glesleichter et al. 2005 13C-DDE 13C-Dieldrin Sediment sorption

• Contaminants spiked into the sediments at a nominal concentration of 2 µg/g dry sediment.

• Homogeneous distribution observed at 7 days

Chemical concentrations in spiked sediments (µg/g dry sediment, mean ± SD) Compounds 7-d interval 15-d interval 28-d interval

p,p’-DDE 2.5 ± 0.2 2.6 ± 0.1 2.3 ± 0.4

Dieldrin 2.0 ± 0.4 1.9 ± 0.1 1.6 ± 0.03

TCS 4.2 ± 0.5 2.0 ± 0.02 2.3 ± 0.1

TCC 2.9 ± 0.7 2.3 ± 0.5 2.2 ± 1.6

Fipronil 2.4 ± 0.6 2.6 ± 0.2 2.3 ± 0.3 Worm body burdens

Worms in spiked sediment Worms in spiked water

p,p'-DDE p,p'-DDE Dieldrin Dieldrin 280 Fipronil 80.0 Fipronil TCC TCC 210 TCS 60.0 TCS g/g lipid) 140 40.0



70 20.0

12 1.8

8 1.2

4 0.6

Worm body burdens ( burdens body Worm 0 0.0 0 2 7 14 21 28 0 2 7 14 21 28 Time (day) Time (day) Research Aim 2

Feeding

Determine the magnitude of bioaccumulation of contaminants in fish feeding on spiked worms Bioaccumulation in fish

Ciworm Cifish BAFss log Kow (ng/g) (ng/g) (Cifish/Ciworm) 200 p,p’-DDE 6.5 102.2 60.8 0.6 p,p'-DDE Dieldrin Dieldrin 5.4 827.0 89.6 0.1

150

100

Fish body burdens (ng/g wt) (ng/g burdens body Fish

0 0 2 7 14 21 Time (day) Conclusions

• Worms incur contaminant body burdens through 2 pathways, exposure to contaminated soils and contaminated water.

• For the more hydrophobic contaminants, uptake directly from sediments appears to be more significant than from water for worm body burdens.

• This study provides evidence that LMB may obtain their contaminant body burdens Future directions

• Link bioaccumulation to bioactivity of contaminants in fish by using gene expression techniques.

• Assess bioavailability of persistent contaminants in worms in sediments amended with granular activated carbon (GAC). Acknowledgements

• NIEHS SRP (Grant# R01-ES01020889) • Dr. Nancy Denslow, mentor • Kevin Kroll • Rolf Halden, ASU • Samuel Supowit, ASU • Labmates

References

• St. John River Water Management District (SJRWMD). 2004. Lake Apopka north shore restoration area feasibility study orange and lake counties, Florida.

• Gelsleichter, J.; Manire, C. A.; Szabo, Cortes, E.; Carlson, J.; Lombardi-Carlson, L. 2005. Organochlorine concentrations in bonnehead sharks (Sphyrna tiburo) from four Florida estuaries. Arch. Environ. Contam. Toxicol. 48: 474-483.