The bombing of Novi Sad had implications for the environment. A United Nations study (the BTF ‘Industrial Sites’ and ‘Danube’ missions) found that there were serious environmental issues, "requiring immediate action", some of which resulted from the bombing.[5] The bombing of Novi Sad's refinery caused fires which burned 50,000 tons of crude oil, sending toxins and carcinogens into the air and contaminating groundwater. The BTF study was complicated by the heavy pollution that existed before the bombing, with the group noting that "the enforced shutdown of the refinery may even have led to local improvements in the aquatic environment, due to a possible reduction in chronic pollution".