Assuming 1.5 L/day for 36 year and Earth’s freshwater volume of 3.5 × 10¹⁹ L, that would be a concentration of ~0.00000000056 ppm, if perfectly mixed.
A 50 L shower has ~1.7×10²⁷ water molecules… assuming perfect mixing of her water in Earth’s freshwater… roughly 1 trillion Monroe-source water molecules per shower.
Assuming 1.5 L/day for 36 year and Earth’s freshwater volume of 3.5 × 10¹⁹ L, that would be a concentration of ~0.00000000056 ppm, if perfectly mixed.
A 50 L shower has ~1.7×10²⁷ water molecules… assuming perfect mixing of her water in Earth’s freshwater… roughly 1 trillion Monroe-source water molecules per shower.
And now I am regretting my life decisions.