Yeah, microplastics, too. And "pollution" being still broader than the list either of us have given so far. A car goes by smelling like gas? They are running their motor too rich and you're literally inhaling unburnt gasoline. A car whose exhaust stinks but not like gas? Running too lean and now you're inhaling various nitrogen compounds that aren't great for inhaling. Ratio is correct? Still inhaling more CO and CO2 than normal, but everyone is doing it so there might not even be a control population to compare the effects against.

Oh also all the food additives that get tested for acute safety but not so much chronic (as in "will it kill you or make you obviously sick if you eat it once or a few times?" gets studied but "will eating it twice a week for 30 years have any long term effects?" is ignored).