Which statement best describes organochlorines (OCs)?

• A. They are unstable, hydrophilic compounds with high vapor pressure.
• B. They are unstable and tend to degrade quickly in sunlight.
• C. They are stable, lipophilic compounds with high vapor pressure.
• D. They are stable, lipophilic compounds with low vapor pressure and a tendency to biomagnify.

Answer: (D)

Organochlorines are persistent organic pollutants that stay in the environment for a long time because they are chemically stable and resistant to degradation. Their chlorine atoms make them strongly lipophilic, so they prefer fats and accumulate in the fatty tissues of living organisms rather than staying dissolved in water. They also have low vapor pressure, meaning they don’t readily evaporate into the air. Because they persist and accumulate in organisms, their concentrations increase as you move up the food chain—a process called biomagnification. This combination of persistence, fat-loving nature, low volatility, and biomagnification best matches the statement describing stable, lipophilic compounds with low vapor pressure and a tendency to biomagnify.