In Washington state, researchers hope to glean a little information about pot use by studying wastewater in two separate cities. The pilot study, which is receiving some federal funding, could illustrate how use has changed since voters passed a bill legalizing the drug in 2012.“We’re trying to get a sense of the type of user,” says Dan Burgard, an associate chemistry professor who will be conducting the study. “If there’s more use on the weekends, maybe that’s more recreational. But if Sunday to Thursday use goes up as much, that might be a public health concern, with habitual users using
