Sean Carbonaro Nathan Howell Dr. Hanadi Rifai NSF REU Civil - - PowerPoint PPT Presentation

Sean Carbonaro Nathan Howell

• Dr. Hanadi Rifai

NSF REU Civil Engineering @ UH July 29, 2009

Background

Polychlorinated biphenyls (PCBs) Group of 209 congeners 1929: Man-made chemical used as a dielectric fluid in

transformers and hydraulic fluid

1936: Toxicological effects discovered 1976: Banned in US Still persistent

Bioaccumulation

Bioaccumulation factor (BAF): Regulate fish concentration by regulating water quality

Objective: Determine BAF of PCBs for Atlantic Croaker and Hardhead Catfish in Houston Ship Channel

High volume sampler

Sampling

By boat By land

Sampling

Sediment Fish

Results

Exceed standards for

water and/or fish tissue at 24 of 25 stations

Year 2002- 2003 2008 Percent reduction (%) Water (Total) (ng/L) Standard: 0.885 ng/L All congeners 2.58 1.98 23.1 Water (Dissolved) (ng/L) All congeners 1.68 1.55 8.0

at 24 of 25 stations surveyed

General decline in

concentrations of PCBs from 2002-2003 to 2008

Water (Suspended) (ng/L) All congeners 0.89 0.43 51.6 Sediment (ng/g) All congeners 228 26 88.8 Catfish tissue (ng/g ww) Standard: 47 ng/g All congeners 154 112 27.6 Catfish tissue (ng/g lipid) All congeners 9033 9023 0.1

2008 2002-2003 Water Species R² p-value BAF (L/kg lipid) R² p-value BAF (L/kg lipid) Total (All cong) Catfish 0.022 0.563 1.28E+06 0.102 0.17 1.02E+06 Dissolved (All cong) Catfish 0.007 0.752 1.28E+06 0.042 0.329 1.03E+06 Dissolved (All cong) Catfish 0.007 0.752 1.28E+06 0.042 0.329 1.03E+06 Suspended (All cong) Catfish 0.064 0.325 6.09E+06 0.145 <0.05 2.48E+06 Total (All cong) Croaker 0.696 <0.05 2.65E+06 Dissolved (All cong) Croaker 0.656 <0.05 3.45E+06 Suspended (All cong) Croaker 0.394 <0.05 5.38E+06

Catfish

y = 1276.3 1276.3 1276.3 1276.3x + 9113.5 R² = 0.025 p=0.752

20000 30000 ncentration (ng/g lipid) 10000 1 2 3 4 Catfish tissue concen Dissolved water concentration (ng/L)

Croaker

y = 3453.8 3453.8 3453.8 3453.8x - 281.02 R² = 0.6556 p<0.05

8000 12000 ncentration (ng/g lipid)

y = 3453.8 3453.8 3453.8 3453.8x - 281.02 R² = 0.6556 p<0.05

4000 1 2 3 4 Croaker tissue conce Dissolved water concentration (ng/L)

5.E+06 5.E+07 (L/kg lipid) 5.E+05

2002 Catfish Total 2008 Catfish Total 2008 Croaker Total 2002 Catfish Dissolved 2008 Catfish Dissolved 2008 Croaker Dissolved

BAF (L/k

y = 0.0266x + 3E+06

5.E+06 er BAF (L/kg lipid)

y = 0.0266x + 3E+06 R² = 0.0835 p=0.338

1.E+06 3.E+06 1.0E+06 2.1E+07 4.1E+07 6.1E+07 Croaker B Catfish BAF (L/kg lipid)

Conclusions

Bioaccumulation factor (BAF) is species-specific, but

may remain constant over time may remain constant over time

Simple, linear statistical model cannot predict BAF for

all fish species in a region

Differences in diet and life cycle

Acknowledgement

The research study described herein was sponsored by

the National Science Foundation under the Award No. EEC-0649163. The opinions expressed in this study are those of the authors and do not necessarily reflect the those of the authors and do not necessarily reflect the views of the sponsor.

Questions?