Paraquat (1,10-dimethyl-4,40-bipyridium dichloride, PQ), the most widely used herbicides in the world, has been deemed as the most highly toxic pesticide for human.
Its mortality rate is highly correlated with plasma PQ concentrations. Acute ingesting 7–8 mL PQ can cause serious symptoms such as liver, lung, kidney, and heart failure that directly leads to death if without getting prompt treatment.
Although few of PQ poisoning appeared in developed countries, there are thousands of people died of PQ poisoning every year in developing countries