Residents of Unity approved a new ordinance prohibiting the intentional release of 10 or more balloons within a 24-hour period.

The town is looking to be proactive. Not that they are having mass balloon releasing issues. As home MOFGA and the common ground fair, Unity takes pride in being on the environmental protection edge.
A member of the board of selectmen indicated that often people mass release balloons for noble purposes, as a memorial for someone that has passed, or perhaps to celebrate an event like a wedding. However, there isn't much regard for where those balloons wind up once you release them into the air.
According to CalTec University, as the air gets thinner balloons can only rise up until the atmosphere surrounding it has the same weight as the helium in the balloon which is about 20 miles above Earth before they pop and the debris comes back down as litter.

The town of Unity does want people to know there are exceptions, and these include balloons released for scientific or meteorological purposes, hot air balloons that are recovered after launching,or balloons that are biodegradable.