Which of the following statements about polychlorinated biphenyls (PCBs) is/are FALSE?

Which of the following statements about polychlorinated biphenyls (PCBs) is/are FALSE?

• A. They are banned in many countries.
• B. They are biodegradable.
• C. PCBs can accumulate in the tissues of living organisms.
• D. PCBs are used in electrical equipment.

Answer: (B)

Polychlorinated biphenyls (PCBs) are synthetic organic chemicals that have been widely used in various industrial applications. The statement that they are biodegradable is false. PCBs are highly stable compounds that resist degradation in the environment, which means they do not break down easily and can persist for many years. This persistence in the environment leads to significant challenges in managing their effects on ecosystems and human health. In contrast, PCBs are banned in many countries due to their toxic effects and potential to bioaccumulate in food webs. They can accumulate in the fatty tissues of living organisms, leading to higher concentrations in higher trophic levels—a phenomenon known as biomagnification. Additionally, PCBs were commonly used in electrical equipment due to their insulating properties before being phased out, contributing to their legacy of environmental contamination.

Polychlorinated biphenyls (PCBs) are synthetic organic chemicals that have been widely used in various industrial applications. The statement that they are biodegradable is false. PCBs are highly stable compounds that resist degradation in the environment, which means they do not break down easily and can persist for many years. This persistence in the environment leads to significant challenges in managing their effects on ecosystems and human health.

In contrast, PCBs are banned in many countries due to their toxic effects and potential to bioaccumulate in food webs. They can accumulate in the fatty tissues of living organisms, leading to higher concentrations in higher trophic levels—a phenomenon known as biomagnification. Additionally, PCBs were commonly used in electrical equipment due to their insulating properties before being phased out, contributing to their legacy of environmental contamination.