Screening of “Exotic” Chemicals in Swift Current Creek, Saskatchewan, Canada
Yuan, H.a, Codling, G.a, Giesy J. P.ac, Wheater H.bd, Hecker M. ab, and Jones, P. D.ab
aToxicology
bSchool
Centre, University of Saskatchewan, Saskatoon, SK, Canada
of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK, Canada
cDepartment
of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, Canada
dGlobal
Institute for Water Security, University of Saskatchewan, Saskatoon, SK, Canada
Analysis Approach, Material and Methods
Abstract
A wastewater treatment plant (WWTP) is situated on Swift Current Creek, SK. Although the plant carries out complete
secondary treatment followed by UV disinfection, a suite of chemicals is still released into the receiving water. In
addition, the City of Swift Current used lagoon treatment for 27 years prior to the construction of WWTP. The Swift
Current Creek flows into the South Saskatchewan River Basin, which is a main drinking water source for many
Saskatchewan residents. Thus, we wish to construct a chemical profile throughout the year to monitor the fate and
potential effects of pollutants. Chemical contaminants of interest include hormones, insecticides/pesticides, fertilizers,
industrial chemicals and pharmaceuticals and personal care products. Due to the complex nature of the contaminant
mixture we utilized a series of in vitro bioassay procedures to screen water sample extracts prior to chemical
characterization. A total of 11 sites upstream, downstream and on-site of the WWTP were sampled once or twice a
month in 2011 and 2012. Water samples were filtered and extracted using solid-phase extraction with HLB cartridges. A
suite of cell bioassays were conducted to screen for (anti)-androgenic/estrogenic effects, dioxin-like chemicals/PAH’s,
hormones and mutagenic effects. Preliminary results show that effluent samples exhibit higher estrogenic effects than
upstream sites but the effect level decreases rapidly further down the creek. No PAH or dioxin-like chemical activities
were detected.
Sampling
•Collect monthly water samples from 11 sites, upstream and downstream of the Swift Current WWTP over 2 year period
•Samples were stored in 4L amber glass bottles at 4 oC
Cell Bioassay
•Extracted samples are screened using different cell bioassays to target different group of chemicals
•Cell bioassay is a quick and relatively low cost method that expresses total and mixed chemical effects of each sample
•However, cell bioassay only measures toxic equivalencies but cannot identify and quantify specific chemicals.
•The cell bioassay mechanism works as illustrated in the figure below
Background
• Surface water has long been used as an effluent repository for domestic and agricultural sewage.
• The South Saskatchewan River is the main drinking water source for many Saskatchewan residents.
• The Swift Current Wastewater Treatment Plant was constructed in 2006. Prior to this, the City of Swift Current had
been using Lagoon treatment for 27 years.
Extraction
•Water samples are pre-filtered using wastewater recommended GFC filter paper through vacuum suction filtration
•Total of 2L of each water sample is extracted using Oasis® HLB 6cc cartridges.
•Cartridges were eluded using ~5 mL of methanol followed by ~5 mL of 1:1 hexane:dichloromethane
•Solution is then nitrogen blown down completely and reconstituted in 250 μL of isooctane to achieve 8000X
concentration.
• H4IIE cell lines are used to detect polycyclic halogenated aromatic hydrocarbons (PAHs) and dioxin like chemicals
• MDA and T47D cell lines are used to measure (anti)-androgenic and (anti)-estrogenic effects respectively
• Chemical activities and measured luminescence level exhibit dose-response relationship, which allows us to
calculated TEQ in each sample.
• After determining bioassay activities in each sample, we used high resolution LC/MS to identify and quantify
targeted chemicals.
• The plant carries out complete secondary treatment and UV disinfection (shown in diagram above), before
discharging effluent to Swift Current Creek, which eventually flows into South Saskatchewan River.
• Possible types of chemical contaminants released by the WWTP include hormones, insecticides/pesticides,
fertilizers, industrial chemicals and pharmaceuticals and personal care products.
• We have two questions to address:
1. Are ‘exotic contaminants’ currently an issue of concern in the South Saskatchewan River – if so, which
chemicals are of greatest concern or potential concern?
2. What are the potential future issues associated with ‘exotic contaminants’ in the context of predicted
changes in the hydrology, land use and chemical loadings to the river?
Results
Conclusions
Adrogenicity in Swift Current Creek
TCDD Potency in Swift Current Creek
2
Estrogenicity in Swift Current Creek
6
3
5
2.5
4
2
1.8
1.6
1.4
Aug 1, 2011
1
Aug 29, 2011
August 29, 2011
January 9, 2012
3
March 5, 2012
Apr 16, 2012
July 18, 2011
1.5
August 29, 2011
January 9, 2012
Aug 27, 2012
July 30, 2012
Jan 9, 2011
0.8
Fold Change
Fold Change
July 18, 2011
Fold Change
July 18, 2011
1.2
2
Aug 27, 2012
Sep 24, 2012
1
Sep 24, 2012
0.6
1
0.5
0.4
0.2
0
Duncairne
Dam
0
Site 1
Site 2 Eff
Site 2 Inf
Lagoon
Site 5
Site 12
Figure 1: H4IIE cell bioassay data illustrating dioxin-like or PAH activities in Swift
Current samples. Each sample were dosed at final concentration of 20X
concentrated. All samples analyzed were expressing baseline response.
• WWTP effluents has elevated level of estrogen agonist and androgen agonist effects compared to upstream
samples. Effect level decreases further down the creek.
• Significant large decrease of estrogen and androgen agonist level found in the effluents compare to the influents.
• Lagoon expresses same level of estrogenic and androgenic effects found in effluents
• H4IIE cell bioassay did not detect any PAH or dioxin-like activities in any samples. However, results were expected
since PAH contamination usually results from urban runoffs
• Levels of contaminants are constant among different months in a year
• We are also interested to determine any anti-androgenic/estrogenic activities in our samples. Preliminary results
indicated that could a possibility.
• Screening samples with outstanding androgenicity and estrogenicity will also be analyzed using high resolution LCMS. A chemical profile can be constructed using the said method and we can also identify and quantify active
agents.
• By analyzing respective downstream site samples, we can also using the chemical profile to track the fate of active
agents that are causing concerns.
Site 1
Site 2 Inf Site 2 Eff
Lagoon
Site 5
Site 8
Site 10
Site 11
Site 12
Sask
Landing
Site
Figure 2: MDA cell bioassay data illustrating androgen activities in Swift Current
samples. Each sample were dosed at final concentration of 20X concentrated.
Influent samples illustrate very high androgenicity, but the activity sharply
decreased in effluent and lagoon samples and furhter downstream.
0
Duncairne
Dam
Site 1
Site 2 Inf Site 2 Eff
Lagoon
Site 5
Site 8
Site 10
Site 11
Site 12
Sask
Landing
Acknowledgements
Site
Figure 3: MT47D cell bioassay data illustrating estrogen activities in Swift Current
samples. Each sample were dosed at final concentration of 20X concentrated.
Influent samples shows elevated estrogenicity. Some effluent and lagoon samples
also express estrogen activities though lower than influent.
The author would like to thank his committee members: Dr. Paul Jones, Dr. Markus Hecker and Dr. Lorne Doig for their
guidance throughout this project. Funding of this project is provided by the School of Environment and Sustainability
and the Global Institution for Water Security. The author would also like to thank Environment Canada and The City of
Swift Current for their co-operation on this project. Lastly, the author would like to thank Postdoctoral Fellow Dr. Garry
Codling and Dr. Henry He for there help and advice and lab assistance from Bryan Sarauer, Allison Hill and Timothy
Tse.