Not just drowning victims. Many freshly dead persons will have Dihydrogen Monoxide in their system, including but not limited to their lungs. They try to keep it a secret. Doctors will usually not write it down outside of the mentioned drowning.
If the body decays, that’s a strong sign the person had the substance inside it at the time of death.
EV is do produce fine particles from brakes and mainly tires, but no combustion involved emissions. But it’s still a great win, especially for the air quality in cities and with that, the total health impact for the population they cause.