We've had a century in which we've allowed some industries to basically pollute the air, pollute the water, pollute the ground, pollute the rivers, and we've been trying sporadically to clean air acts and ways of regulating them. But we now are sitting in a world that's filled with all sorts of materials that we don't really know the impact of. It's not like they're necessarily all poisonous but it's odd to put all these materials into our environment and watch.