The actual solution is "stop spewing so much shit into the air", but that's hard to do and very expensive.
The alternative is more expensive - shutting down factories / telling people they can't drive to work. Not really a long term solution or any kind of decent solution. All it does is negate some of the worst pollution on the worst days, it doesn't address the problem that many Chinese cities have - a constant huge pollution problem.
Addressing the problem properly will create jobs and lower health costs.