LETTER pubs.acs.org/est
Concerning the Viewpoint; “An Anti-Doping Sampling Strategy Utilizing the Sewerage Systems of Sport Villages”
T
he authors present the concept of wastewater sampling to measure or detect the use of controlled substances in sports.1 Extrapolating concentrations of drug metabolites in sewage to population dose rates has been questioned.2 The authors claim that this is not the direct intention of their scheme, where detection alone indicates breach of regulations by someone using that part of the wastewater system. However, they imply implicitly that an autosampler is able to integrate one flush event containing the substance or its metabolites from one user. What sampling regime do they propose in order to achieve this? Continuous flow sampling would be required which would generate unmanageable volumes of sewage effluent when considering existing limits of detection. At no point during their presented sampling strategy are flow rates or frequency addressed other than “bigger sampling volumes in the morning or late evening, thus at times when people normally urinate”. However, where detection would be proof of presence, nondetection would not be proof of absence and is just as likely to be caused by an inadequate sampling regime.3 This sampling error will increase with a decreasing number of wastewater pulses containing the substance of interest, that is, “upstream” in the sewage system, as the sampled population becomes smaller and thus the need to adequately integrate single toilet flush events increases.3 Even assuming an adequate sampling mode can be achieved, the practicalities of the approach remain problematic. For example the London 2012 Olympic village will have >50 accommodation blocks to house athletes. Thus using the proposed scheme >100 autosamplers would be required, generating thousands of samples at unreasonable cost. Limitations of access, space, and power requirements mean it is also unlikely that all the necessary points could be sampled. Additionally, based on the limited number of competitors who tested positive at the Beijing games in 2008, what is the likelihood of detection? Lastly the authors offer little consideration to the analysis of steroids in wastewater
which is hampered by the number of controlled compounds, some naturally occurring and some prescribed legally, the complexities of metabolism and the use of the wastewater system by noncompetitors. Few other compounds currently on the World Anti-Doping Agency banned substance list appear applicable to sampling in wastewater.4 We believe that the only currently available technique which may achieve the objectives of such a study is the replacement of each autosampler with a simple passive sampling device. Work conducted in our laboratory shows that this is at least possible to measure drug metabolites in wastewater using passive sampling methods. Many of the practical issues would be eliminated and the costs reduced dramatically. However, while overcoming the perils of representative sampling, passive sampling for polar analytes brings new challenges, including adjusting the sampling rates for environmental conditions and the need for calibration. In conclusion we commend the authors for highlighting this application of sewage epidemiology. We find the idea valid, but unfortunately, not their approach.
sampling modes and optimization strategies. Environ. Sci. Technol. 2010, 44, 6289–6296. (4) World Anti-Doping Agency (WADA). The 2011 Prohibited List: International Standard; Montreal, Quebec, Canada, 2011. http://www.wada-ama.org/en/World-AntiDoping-Program/Sports-and-Anti-DopingOrganizations/International-Standards/Prohibited-List/ (accessed 12/02/2011).
Christopher Harman,* Malcolm Reid, and Kevin V. Thomas Norwegian Institute for Water Research (NIVA), Gaustadalleen 21, NO-0349, Oslo, Norway.
’ AUTHOR INFORMATION Corresponding Author
*
[email protected].
’ REFERENCES (1) Katsoyiannis, A; Jones, K. C. An antidoping sampling strategy utilizing the sewerage systems of sports villages. Environ. Sci. Technol. 2011, 45, 362–363. (2) Ort, C.; Lawrence, M. G.; Rieckermann, J.; Joss, A. Sampling for PPCPs and illicit drugs in wastewater systems: Are your conclusions valid? A critical review. Environ. Sci. Technol. 2010, 44, 6024–6035. (3) Ort, C.; Lawrence, M. G.; Reungoat, J.; Mueller, J. F. Sampling for PPCPs in wastewater systems: Comparison of different
r 2011 American Chemical Society
4191
Received: March 14, 2011 Accepted: March 18, 2011 Revised: March 15, 2011 Published: April 18, 2011
dx.doi.org/10.1021/es200839n | Environ. Sci. Technol. 2011, 45, 4191–4191
