If you are exposed to methyl parathion you may have headache, nausea, dizziness, anxiety, chest tightness, blurred vision, and restlessness. If exposed to significant amounts over time you may have a persistent lack of appetite, weakness, and malaise.
It can leave a yellow stain on areas where it has been sprayed and smells like rotten eggs, Swallowing, inhaling, and having skin contact with methyl parathion are all ways in which people can be exposed.