Our worlds and lives are awash with industrially-produced chemicals. This dizzying array of chemicals includes compounds, interactions, and health effects that are poorly, if at all, understood. While the vast majority of both natural and social science research continues to focus on the toxicities of single compound or classes of compounds, we propose a theoretical and methodological framework to attend to cumulative toxicities—known, unknown, interacting and in flux—in everyday life. Our approach builds on the empirical, methodological, and theoretical work of urban political ecology (UPE), anthropology of embodiment, and science and technology studies (STS), and uses radical cartography and ethnographic methods to gain insight into urban pollution’s complex and uneven entanglements, which are inseparably chemical, social, and ecological. We are developing this approach in three phases: ethnographically attending to the sensorial experiences and embodied knowledges of those most affected; creatively and cartographically producing representations and evidence; and identifying and supporting existing modes of action and harm reduction practices. Currently transitioning between the first and second phase, here we also share fresh insights from our recently wrapped grand tours of collective explorations.