Scientists are dipping into city sewers in search of drugs. Why? The same reason people on parole take urine tests instead of surveys. You can always lie on a questionnaire; outwitting your toilet, on the other hand, can be a bit more challenging.
Drugs play a huge role in our lives, but it's hard to find in-depth research on how people take them and what effect it has on their lives. Here's your chance to help change that.