Problema con esalazioni del vicino?

Hello,
I hope someone can help me with the following situation:
I live in a three-storey building, one of which is inhabited by a neighbor and the remaining two by my family. For about 4 years, both apartments have smelled of smoke and a constant noise from a motor all year round after the neighbor has installed some kind of stove in the center of the house.
He was notified through a lawyer but claims he did nothing.
In recent months this smell of smoke has become more intense and there are times of the day when both my elderly parents and I have burning throats and eyes, a red face and a sensation of smoke in the throat. My father suffers from allergic asthma.
Last year in February the doctor in charge of the ASL came and found nothing except a problem with the neighbor's flue that we have all been aware of for years but never solved. A year later, no one came from the municipality to verify the situation.
We are looking for someone to help us but it is a challenge! Not even the mayor responds and a municipality employee told my father that the traffic police are not competent in the matter.
How can we resolve this issue?

Thanks.