during the stay-at-home order that began in the first week of our study period , and air pollutants related to traffic decreased during stay-at-home orders in other locations . With fewer cars on the road, less benzotriazole washes off cars onto the road, and thus less is dissolved the in the runoff water that enters the combined sewer system. Benzotriazole is also used on aircrafts as a de-icer and corrosion inhibitor .