Associate Certified Entomologist (ACE) Practice Exam

Which organochlorine is commonly associated with persistence in the environment?

1. Dieldrin

2. DDT

3. Heptachlor

4. All of the above

The correct answer is: All of the above

The correct choice is indicative of the general characteristics of these organochlorine compounds. Organochlorines are known for their stability and resistance to breakdown, which leads to their long-term persistence in the environment. Dieldrin, DDT, and Heptachlor all share these properties. DDT, in particular, gained notoriety for its prolonged presence in ecosystems, resulting in bioaccumulation and detrimental effects on wildlife, especially birds. Dieldrin, a derivative of aldrin, is similarly resistant to degradation and has been found to accumulate in soil and fatty tissues of organisms. Meanwhile, Heptachlor, often used as an insecticide, displays similar characteristics, leading to significant environmental persistence. Due to this shared property of being persistent in the environment, all three compounds are representative of organochlorine pesticides that pose long-term risks to ecological systems and human health. Thus, the inclusion of all three in the answer reflects their collective association with environmental persistence, confirming that each one is a valid example.