Paraquat, also known as paraquet lung (1,1'-dimethyl-4,4'-dipyridiumdichloride), is a strong weed killer herbicide with strong toxic effects on humans and livestock. Most cases are caused by accidental ingestion or suicide, but it can also be absorbed through the skin and cause poisoning and death. The clinical manifestations of paraquat poisoning are: ingestion of herbicides can cause burning sensations in the tongue, mouth and pharynx, esophagitis and gastritis, vomiting and abdominal pain. Drug excretion from the kidneys can damage the renal tubules, produce proteinuria, hematuria, increased blood urea nitrogen and creatinine, and other manifestations of renal damage. The respiratory system is mainly manifested by progressive dyspnea and cyanosis, which eventually lead to respiratory failure and death. Chest X-ray manifestations: initially scattered fine speckled shadows, more in the lower lung fields. Rapid progression, lesions merge to form a severe pulmonary edema-like morphology. The main manifestations of lung function are carbon monoxide diffusion disorder, moderate airway obstruction and (or) restrictive ventilation abnormalities. Heart, liver and adrenal poisoning can cause corresponding symptoms and signs. Paraquat is a bipyridine compound. This type of herbicide will damage most internal organs after swallowing, especially the lungs, heart, liver, and kidneys, and can be fatal within a few hours after taking a large amount. Most paraquat poisonings are caused by deliberate suicide. Although the absorption rate of the metabolite bipyridine in the intestine is relatively slow, after taking paraquat orally in excess of the toxic dose, bipyridine will be distributed in large quantities in the body within 6 to 18 hours, and the amount in various important organs and tissues can reach a lethal level. At this time, even if measures are taken immediately to remove bipyridine from the blood, it is not easy to reduce the load on various organs in the body. </p