Expected Environmental Persistence of CS Tear Gas Following Repeated Urban Deployment: A Field-Based Case Report from Khartoum, Sudan

This research examines the long-term environmental persistence of CS tear gas in Khartoum, Sudan, from 2018 to 2025. Based on field observations and documented exposure patterns during periods of civil unrest, the work explores a simple but overlooked question: when tear gas is used repeatedly and at scale in densely populated cities, does it leave behind traces? Rather than offering definitive answers, this study documents patterns and observations that point to a need for serious, systematic research on how chemical irritants behave in real-world urban conflict environments, especially when populations face repeated exposure over years. The goal is to help fill the gap in research on tear gas persistence and its environmental and public health implications in conflict-affected cities.