Response to comment on "Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999-2000: A national reconnaissance"

Environmental Science & Technology
By: , and 

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Abstract

Till (1) raised concerns that several aspects of how we handled the data in our study (2) may have caused unintended bias. First, Till (1) considers the “median detectable concentrations” listed in Table 1 (2) to be misleading because “higher median concentrations than is actually the case” were suggested. We interpret this concern raised by Till (1) to be that some readers may misinterpret our median detectable concentration to be an overall median concentration. Our intention was to provide the reader with information that could not easily be determined independently. For example, by examining the frequency of detection (2), it could easily be determined that the overall median concentration was less than the reporting level for all but six compounds (those having a detection frequency of>50%). Our goal for providing a median detectable concentration was to give a better sense of the concentrations when a particular compound was detected. Thus, we felt the combination of frequency of detection (how often a compound was found), median detectable concentration (median concentration when a compound was detected), and maximum concentration (highest concentration measured) would provide the greatest benefit to the readers. In future reports, we will modify the table headings to ensure that overall median concentration and median detectable concentration are clearly differentiated.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Response to comment on "Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999-2000: A national reconnaissance"
Series title Environmental Science & Technology
DOI 10.1021/es0202356
Volume 37
Issue 5
Year Published 2003
Language English
Publisher ACS Publications
Contributing office(s) Toxic Substances Hydrology Program, Iowa Water Science Center
Description 1 p.
First page 1054
Last page 1054
Online Only (Y/N) N
Additional Online Files (Y/N) N