## 2 Results and Discussion
### Characteristics of the T/O Compounds in Freshwaters of the World
#### 2.4.1 Spatiotemporal Distribution of T/O Compounds in Freshwater Sources Worldwide

Table 3. Cont. \begin{table}
\begin{tabular}{l l l l l l l l} \hline \hline
**County and Region** & **Sampling Site** & **Sampling Time** & **Geosmin (ng-L\({}^{-1}\))** & **2-Methyl Isobemed** & \(\beta\)**-Cydeitral** & \(\beta\)**-Ionne** & **Reference** \\ \hline Korea & Paldang Lake & June 2012-September 2012 & 0-4384 (July 2012) & 0-22 (July 2012) & & & \\  & Paldang Lake & April 2017-November 2018 & 2-31 (July 2020) & & & [15, 82, 83, 84] & \\  & North Han River and & December 2011 & 2-1640 & & & [85] \\  & Han River & 2011-2015 & 0-810 & & & [18] \\  & Bukhan River & 2011-2015 & 0-75 & & & [18] \\  & Namhan River & 2011-2015 & 0-75 & & & [18] \\  & & & & (September 2015) & & [18] \\ Switzerland & Lake Zurich & 1995-1996 & 31-23 & & & [86] \\  & & & & (December 1995) & & \\ Thailand & Phyao Lake & June 2012-February & 0-12.0 (October 2012) & 0.1-1.1 & & [87] \\  & Eastern Ontario Lake & 2013 & & & & [88] \\ North America & and the Upper Saint & 1996-1997 & 5-20 & & 2-25 & \\  & Lawrence River & & September 1996 & (September 1996) & & [88] \\  & & July 1998, & 0-20 & 0-60 & & [89] \\  & & September 1998 & (September 1998) & (September 1998) & & [89] \\  & Ontario Lake & 2007 published & 0-200 & & & [90] \\  & Saint Lawrence River & 2000-2001 & 8-60 & & 0-26 & [19] \\  & & 2007 published & 10-60 & & 10-60 & & [90] \\ Wales, U.K. & Nine reservoirs & July 2019–August 2020 & 0.3-420 & 0.57–58 & & [91] \\ United States of & California Aqudetect & August 1990–October & 3–48 (August 1990) & & & [24] \\ America & & July 1991– & & & & [24] \\  & & November 1991– & & & & [24] \\  & & August 1999–October & 0-37 (July 2000) & 0-2 & & [14] \\  & & 2000 & May 2001–June 2015 & 1-113 (July) & & & [20] \\  & Diamond Valley Lake & May 2000 & 0-750 & & & [25] \\ \hline \hline \end{tabular}
\end{table} 
Table 3: _Cont._ \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Country and Region** & **Sampling Site** & **Sampling Time** & **Geosmin (ngL\({}^{-1}\))** & **2-Methyl Isobomeal** & \(\beta\)**-Cyclotrical** & \(\beta\)**-Ionone** & **Reference** \\  & & & & **(ngL\({}^{-1}\))** & **(ngL\({}^{-1}\))** & **(ngL\({}^{-1}\))** & **Reference** \\ \hline  & October 2004 & 2-63 & & & & [25] \\  & & October 2004 & (October 2004) & 0-2237 & & & [49] \\ Eagle Creek Reservoir & 2008-2010 & 0-1094 & (October 2009) & (May 2010) & & [49] \\  & January 2013– & 0-77.3 & 0-111.8 & & & [28, 29] \\  & December 2013 & (May 2013) & (May 2013) & & & [28, 29] \\ McDaniel Lake & 1983-2002 & 0-33 & 0-90 & & [92] \\ San Vicente Reservoir & 1996 & 23 & & & [93] \\ Wimebago Lake & August 20, 1996 & 18 (August 1996) & & 133 (August 1996) & [40] \\ Three water supply & 1999-2002 & 0-2 (September 2000) & 0-46 (September 2000) & & [41] \\ reservoirs & May & & & & [41] \\ Four Reservoirs & 2001-December 2012 & 0-133 & 0-224 & & [94] \\  & November 2013– & & & & [94] \\ Drinking water & December 2013, & 10-289 & & [27, 95] \\ Reservoir & 06/2014-August 2014 & (August 2014) & & [27, 95] \\ \hline \hline \end{tabular} Note: DWITs: drinking water treatment plants; RW: raw water, MSSNWD = nine sampling sites along the main canal of the Middle Route of South-to-North Water Diversion Project; LNSW = local water supply plant, Shanghai, China.  
\end{table} 
Table 3: _Cont._GSM and MIB are two of the most prominent musty/earthy compounds detected in natural water systems, exhibiting significant concentrations that pose potential risks. GSM concentrations have reached alarmingly high levels, with a record of 7200 ng\(\cdot\)L\({}^{-1}\) reported in the YH Reservoir in Hebei Province, China, in July 2007 [26]. Similarly, MIB concentrations peaked at 5302.7 ng\(\cdot\)L\({}^{-1}\) in fishponds in Tianjin, China, in July 2006 [70]. The documented concentrations of GSM and MIB in 91% and 81% of the 67 and 64 studies, respectively, surpassed their respective OTCs of 4 and 15 ng\(\cdot\)L\({}^{-1}\). This indicates the widespread occurrence of these compounds and their potential impact on water quality.