What were the environmental consequences?

Balloonfest '86 was a fundraising event in Cleveland, Ohio, United States, held on September 27, 1986, in which the local chapter of United Way set a world record by releasing almost 1.5 million balloons.[2] The event was intended to be a harmless publicity stunt. However, the released balloons drifted back over the city and Lake Erie and landed in the surrounding area, causing problems for traffic and a nearby airport. In consequence, the organizers faced lawsuits seeking millions of dollars in damages,[1] and cost overruns put the event at a net loss.[3]