Cigarettes are way more toxic than PM2.5. Cigarette smoke contains over 7,000 chemicals, including carcinogens (benzene, formaldehyde), heavy metals (arsenic, cadmium), carbon monoxide, radioactive materials (like polonium-210)
Meanwhile, PM2.5 is primarily a mixture of soot, dust, sulfates, nitrates, and other combustion byproducts.
Fun fact: most of the above is contained in vape vapor too - just at lower quantities. Higher temperature vapes contain more. Duration matters too: taking 100 puffs from a vape is worse than smoking 1 cigarette. That's what a lot of people don't understand, especially in Thailand, they think it's harmless candy and suck on it continuously throughout the night - that's the equivalent of having a cigarette every half an hour or so. If you have a few puffs here and there yes it's less harm, but if you continuosly puff it's pretty much the same or worse.