Why were unions specifically to blame for your family leaving?
Union versus non-union is a quality versus quantity problem. Unions restrict the labour pool to increase wages. When that protects specialisation, it increases productivity. When it artificially constrains the labour pool, it decreases it.
A unionised job market showing unemployment (or underemployment) is usually an indication of the latter.
I have never seen someone leave due to pollution, other than just wanting to leave the city.
The poor economic outlook and lack of jobs is directly due to the unions. If there weren't unions, Detroit and Flint would still be the capital of the auto industry, and Erie PA would still be a major locamotive hub. Instead everyone was forced out because of the unions.
Not only is US freight traffic up, but freight traffic around the world went up as nations industrialized and raw material demands went up in places like Australia. Erie should have had its second coming, but instead everyone has seen what the UE did to the industry and workers don't want to work in union shops, and so the cities population has almost halved since its peak.
I'm not as familiar with Cleveland so I can't really speak on it.