Which substance is an insecticide that is also toxic to animals and humans?

Which substance is an insecticide that is also toxic to animals and humans?

• A. Neon
• B. Ammonium
• C. DDT
• D. Chlorofluorocarbons

Answer: (C)

DDT is a synthetic pesticide that affects nerve signaling. In insects, it disrupts normal nerve function by keeping sodium channels open, causing repeated nerve firing, paralysis, and death. That same mechanism can affect animals and humans because their nervous systems use the same basic ion-channel processes, so exposure can be toxic. In addition, DDT is highly lipophilic and persistent in the environment, so it builds up in fat tissues and becomes more concentrated higher up the food chain. This combination of broad toxicity and long-lasting environmental presence led to widespread wildlife harm and health concerns for people, prompting bans and strict controls. The other substances listed aren’t used as insecticides in the same way and don’t share this problematic combination of insecticidal action plus long-term toxicity: neon is a nonreactive gas, ammonium compounds are mainly used in fertilizers or cleaners, and chlorofluorocarbons are refrigerants/solvents with different hazards.

DDT is a synthetic pesticide that affects nerve signaling. In insects, it disrupts normal nerve function by keeping sodium channels open, causing repeated nerve firing, paralysis, and death. That same mechanism can affect animals and humans because their nervous systems use the same basic ion-channel processes, so exposure can be toxic. In addition, DDT is highly lipophilic and persistent in the environment, so it builds up in fat tissues and becomes more concentrated higher up the food chain. This combination of broad toxicity and long-lasting environmental presence led to widespread wildlife harm and health concerns for people, prompting bans and strict controls. The other substances listed aren’t used as insecticides in the same way and don’t share this problematic combination of insecticidal action plus long-term toxicity: neon is a nonreactive gas, ammonium compounds are mainly used in fertilizers or cleaners, and chlorofluorocarbons are refrigerants/solvents with different hazards.