A polluting war: Risk, experts, and the politics of monitoring wartime environmental harm in Eastern Ukraine

War always harms the environment. As the fog of war produces unreliable data, it also obstructs our capacity to monitor those harms. While some call for more data collection to advance a clear narrative of the origins of environmental harm, sociologists of risk and professional risk assessors find that the urgency of environmental hazards depends not on data alone but on who has the authority to define those risks. Without a clear understanding of how environmental experts engage in the socio-political struggles over the interpretations of risk during armed conflict, we may undervalue, first, how assessments and adequate action remain practically and politically difficult, and second, how data may be misused. Drawing on interviews with environmental experts and reports, I examine the politics of environmental expert knowledge on conflict pollution in the war in Donbas (2014–2022), a region hosting over 4500 hazardous industrial enterprises. By going beyond technological evidence collection, the article broadens our understanding of the obstacles of knowledge production and the attribution of environmental harm in highly politicized and violent contexts. Based on insights from environmental politics, the article finds that experts manage three issues undermining the reliability of environmental risks in an active warzone: pre-existing industrial pollution, environmental damage spread across government and non-government-controlled territories, and disinformation.