Do we truly know about all of the things in the environment that can do harm to people and other living things? No, but we can measure. And when that's not possible, we can send in bees.
It's not only true, it happens already: A Belgian company called BeeOdiversity uses bees to assist in collecting information from the landscape, by collecting pollen from the bees when they return to the hive. The pollen can yield a wealth of information about pollutants, biodiversity, and other factors in the environment.
A recent project focused on the Klamath Basin. We get details on the information it yielded from Lorena Corzatt, who heads the Klamath Basin Beekeepers Association, and David Strelneck, who heads the company Nourish(n). He is the US coordinator for the project.