## 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
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Country and Region** & **Sampling Site** & **Sampling Time** & **Geosmin (ng.1-1)** & **2-Methyl Isobomeal** & \(\beta\)**-Cyclotistral** & \(\beta\)**-Ionone** & **Reference** \\  & & & & **(ng.1-1)** & **(ng.1-1)** & **(ng.1-1)** & **(ng.1-1)** \\ \hline \multirow{9}{*}{Taihu Lake} & East Tailhu Lake & September 2017 & 4.7–16.8 & 13:1–32.7 & \multirow{9}{*}{15.0-37.2} & 4.1–13.8 & \multirow{9}{*}{[44]} \\  & & August 2020- & & 0.5–14.6 & & & [50] \\  & & November 2021 & & (August 2021) & & & [50] \\  & & January 2009- & 0–4 & 0-325 & 5–2080 & 32-573 & \multirow{9}{*}{[23]} \\  & & December 2009 & (September 2009) & (September 2009) & (September 2009) & (August 2009) & \\  & & June 2009–May 2010 & 0.2–4 & 2-152 & 1–360 & 2-80 & \\  & & June 2009–May 2010 & (July 2009) & (July 2009) & (September 2009) & [64] \\  & & & 0.3–12 & 0–2.1 & & 22–1976.4 & \multirow{9}{*}{[22]} \\  & & September 2017 & (September 2017) & (September 2017) & & & [50] \\  & & 2020 published & 1–20 & 15–100 & 22-530 & 8-600 & [35] \\  & & & 11–17-1446 & & & [65] \\  & & August 2021 & & 0–271.5 & 0–378.4 & \multirow{9}{*}{[66]} \\ Xionghe Reservoir & May 2007–April 2008 & (July 2007) & (April 2008) & & & [66] \\  & & November 2007– & 0–4826.7 & 0–481.8 & & & [67] \\  & & October 2008 & (November 2007) & (April 2008) & & & [67] \\ FH Reservoir & July 2018-June 2019 & & & 30 \(\pm\) 2.3–524 \(\pm\) 8.4 & & & [68] \\  & & & & 0.4–940.6 & & & [47] \\ Lake Yangheng & 2018-2019 & & & (August 2018) & & & [47] \\ Seven landscape takes & May & & 1–3509 & 0–6000 & & & [45,69] \\ in Beijing & 2016–September 2016 & & (July 2016) & (May 2016) & & & [45,69] \\ Seven important & & & & & & [43] \\ reservoirs in eastern & August 2019 & 13.11 & 18.39 & 0 & 0 & [21] \\ China & & & & & & [45] \\ RW from eight cities & 2005-2007 & 0–7200 & 0–255 & & & [46] \\ RW from rivers of & November 2019-March & 0–6.1 & 0–25.8 & & & [10] \\ DWITs & 2010 & & & & & [10] \\ RW from & November 2019-March & & & & & [10] \\ lake/reservoir of & 2010 & & & & & [10] \\ DWITs & 2011– & & & & & [43] \\ \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 (ng L\({}^{-1}\))** & **2-Methyl Isobomeed** & \(\beta\)**-Cyclotrical** & \(\beta\)**-Ionone** & **Reference** \\ \hline \multirow{9}{*}{MRSNNWDP} & \multirow{2}{*}{Fishpends} & April & 0.3–12.1 & 0.5–5302.7 & & & [70] \\  & & September 2018- & September 2018- & & (July 2006) & & \\  & August 2019 & & 7.431 \(\pm\) 9.631 & 12.371 \(\pm\) 12.800 & 11.973 \(\pm\) 20.643 & [71] \\  & & March & & & & [72] \\  & & 2016-December 2017 & 5.15-17.66 (Winter) & & & & [72] \\  & & Liangati River & September 2018 & 3-10 & 30-119 & 18-229 & 50-350 & [51] \\  & & Namping Reservoir & 2017-2020 & & 0-113 (August 2020) & & & [73] \\  & & March-April 2021 & & 51.7 \(\pm\) 12.8 (April 2021) & & & [73] \\  & & & 0-193 & & & & [74] \\  & & & August 2018 & & & 0-49.05 & \\  & & China & 2018-September 2019 & & & & [48] \\ Egypt & & March 1997, June 1997, & – & – & & & [75] \\  & & July 1997, August 1997 & – & – & & & [76] \\ Germany & & Schleinese Lake & 1984,1985 & & 0-180 (July 1984) & & & [76] \\  & & May-October & & & & [16] \\  & & 2006-2009 & 0-600 (August) & 0 & & & [16] \\ Italy & & Amo River & May 1995 & 15-70 (May 1995) & 0 & 0–57 (May 1995) & 0–7 (May 1995) & [34] \\  & & September 1989- & 0-50 & & & & [9] \\ Japan & & Lake Kasumigura & October 1990 & (September 1989) & 0-150 (October 1990) & & & [9] \\  & & 1994-1997 & (-560) & 0-185 & & & [77] \\  & & & March 1995 & (April 1995) & & & [77] \\  & & October 2009 & (October 2009) & & & & [77] \\  & & October & 2010-September 2012 & 0-520 & 0-1400 & & & [78] \\  & & & December 10 th, 2019 & 0-9.53 & & & & [79] \\  & & Lake Y in Nagasaki & March-July 2022 & \textless[2\] & 0-13 & & & [80] \\ Spain & & Libbergait River & 1997-1999 & 5-200 & 10-20 & 0 & & [81] \\ \hline \hline \end{tabular}
\end{table}