I don't think there's anything as bad as lead, so all of these are distant runners-up:
* Particulate matter from internal combustion engines, brake pads (contributes to cardiovascular disorders)
* Plastics leeching chemicals into food
* Second-hand drugs in our drinking water
* Microplastics (maybe)
If I can stand on a soapbox for a minute, it would be nice if there were any societal move to reduce these risk factors, but we can see from the California "Prop 65" warnings how far people will go to deflect from doing something useful.
* Particulate matter from internal combustion engines, brake pads (contributes to cardiovascular disorders)
* Plastics leeching chemicals into food
* Second-hand drugs in our drinking water
* Microplastics (maybe)
If I can stand on a soapbox for a minute, it would be nice if there were any societal move to reduce these risk factors, but we can see from the California "Prop 65" warnings how far people will go to deflect from doing something useful.