I make no judgement about its invasiveness or usefulness. A possible future is for this monitoring to go further upstream to become more personalized and cross

I make no judgement about its invasiveness or usefulness. A possible future is for this monitoring to go further upstream to become more personalized and cross boundaries into other monitoring domains, as other comments noted many pharmaceutical products or metabolites can be detected in human waste. Possibly something holding practical implementations back is all the other waste put into sewage, which may stop things up in the manner of “fatbergs.” [0] A related idea I have percolating is to change municipal composting programs from bins and trucks to grind and pipe by deploying more sink fixtures that grind food materials into small pieces so they go thru the drain. Then focus extracting/separating biological materials from other effluvium. https://en.wikipedia.org/wiki/Fatberg https://en.wikipedia.org/wiki/Fatberg