There is limited evidence on the non-health impacts of air pollution, including productivity in the workplace and behavior. We examine the effect of air pollution on participation, collaboration, and feedback provision in a workplace setting. Our experiment randomly assigns air purifiers to rooms at three large academic conferences to investigate the causal impact of air pollution on participants' engagement behavior. We construct a participant engagement index based on 12 presentation-level behavioral outcomes directly measured by conference observers through an online form and weigh each behavioral outcome using weights elicited from an expert survey. Conference rooms treated with air purifiers exhibit 48% less PM2.5 concentration compared to control rooms. However, we do not find a statistically significant change in engagement. Communication in the workplace might not be a large driver of the empirical relationship between air quality and productivity, albeit more research is needed across workplaces and measures of communication.