Tag: zoology

DDT is highly persistent in the environment. The soil half-life for DDT is from 2 to 15 years and in an aquatic environment, is about 150 years. Due to slow degradation DDT causes air, soil and water pollution.

Organochlorine pesticides are chlorinated hydrocarbons used in agriculture and mosquito control. Representative compounds in this group include DDT, ethoxychlor, dieldrin, chlordane, toxaphene, mirex, kepone, lindane and benzene hexachloride

Because of DDTs chemical properties, it has the tendency to accumulate in animals. As animals lower on the food chain are eaten by other animals higher up, DDT becomes concentrated in the fatty tissues of the predators. This continues until reaching the primary predator of the food chain, who receives the highest dose of DDT. In food chain seaweed-limpet - crab - seagull, Sea gulls are the predators and snatch the top position of food web.

Malathion is an organophosphate insecticide. It interferes with the nervous system by blocking an enzyme acetyl cholinesterase that normally acts as an off switch by ending the signal. Without the enzyme, the nerve keeps firing and eventually the nervous system fails. Malathion is used both in agricultural and residential settings.

Fumigants are volatile and poisonous substances used to kill insects, nematodes that damage stored foods or seeds, human dwellings, clothing, and nursery stock. Ethylene dichloride is used to treat open storage areas and as soil fumigants. It is a low-pressure compound which diffuses more slowly.

Paul Muller also known as Pauly Mueller was a Swiss chemist who received the 1948 Nobel prize in Physiology or Medicine for his 1939 discovery of insecticidal qualities and use of DDT in the control of vector diseases, such as malaria and yellow fever.

2,4-D is one of the more useful herbicides. This herbicide is selective for broad leaf weeds. This makes it useful to control such weeds as dandelions, plantains, knotweed, pigweed, and many others. It is a systemic herbicide, which means that it is absorbed into the plant tissue and transported throughout the plant, including into the root system.

Pyrethroids are a class of synthetic pesticides used widely in home insect - control products, including flea bombs, roach sprays, ant bait, flea - and - tick pet shampoos, and lice shampoos. Examples of pyrethroid pesticides include: cypermethrin, permethrin, deltamethrin, bifenthrin, and cyfluthrin.

Propoxur is a nonfood carbamate insecticide, marketed under the registered trademark name 'Baygon'.  It is used to control cockroaches, flies, mosquitoes and lawn and turf insects.