Paraquat: A poisonous dipyridilium compound used as contact herbicide. Contact with concentrated solutions causes irritation of the skin, cracking and shedding of the nails, and delayed healing of cuts and wounds.Herbicides: Pesticides used to destroy unwanted vegetation, especially various types of weeds, grasses (POACEAE), and woody plants. Some plants develop HERBICIDE RESISTANCE.Maneb: Manganese derivative of ethylenebisdithiocarbamate. It is used in agriculture as a fungicide and has been shown to cause irritation to the eyes, nose, skin, and throat.Poisoning: A condition or physical state produced by the ingestion, injection, inhalation of or exposure to a deleterious agent.Superoxide Dismutase: An oxidoreductase that catalyzes the reaction between superoxide anions and hydrogen to yield molecular oxygen and hydrogen peroxide. The enzyme protects the cell against dangerous levels of superoxide. EC 188.8.131.52.Oxidative Stress: A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).Carbaryl: A carbamate insecticide and parasiticide. It is a potent anticholinesterase agent belonging to the carbamate group of reversible cholinesterase inhibitors. It has a particularly low toxicity from dermal absorption and is used for control of head lice in some countries.Selenium Oxides: Inorganic compounds formed through the oxidation of selenium.