JAMB - Biology (2021 - No. 17)
People who suck petrol with their mouths run the risk of increasing in their blood the concentration of
iron
lead
calcium
magnesium
Explication
It's discovered that tetraethyl lead (better known as lead) provided octane to gasoline, to fix knocking or pinging in engines that could damage them and waste gasoline.
Extremely high lead levels can lead to seizures, coma, and death.