Are my neighbours cooking up crack/meth/some other type of stuff?

I have not long moved into a house,. Every damn couple of weeks and sometimes weekly, there is a disgusting smell coming through the window upstairs. It smells like fire, dirty cigarettes, burnt plastic, fumes, wee, ammonia and all sorts. It smells like someone has smoked 20 packs of wet cigarettes and blown all the smoke on purpose into the windows. It lasts for hours, sometimes over a day. Then it just suddenly stops. I can hear and see cars pull up and give loose change to one of the houses. I was once asked if I was hanging any washing out because they were lighting up a fire.