Forced integration is a government mandated program. Libertarians believe in freedom of association. That means you could move to a neighborhood that only allows the type of people you want to live with. Pollution is a more nuanced answer, but I'd point out that pollution is often a problem of the commons - people pollute the common area because no one owns it. People take better care of their own property. States typically aren't good at protecting the environment. It's easy for a big corporation to bribe the state so they can pollute. In a free society we'd kill the pedos.