Why is mercury dangerous when it turns into vapor form?

Mercury in its vapor form is particularly hazardous because it can pass through the blood-brain barrier, where it can cause significant neurological damage. This bioavailability to the nervous system means that exposure to mercury vapor can lead to severe cognitive and motor function impairments, as well as behavioral changes. The accumulation of mercury in the brain can result in neurotoxic effects due to its ability to disrupt critical cellular processes and contribute to oxidative stress. Therefore, the association of mercury vapor with brain poisoning underscores its potential for causing serious and lasting harm to neurological health.