Correct option is C
Polychlorinated Biphenyls (PCBs) are known for their persistence in the environment due to the following properties:
1. Chemical Stability (a): PCBs resist chemical degradation, which allows them to persist for long periods in the environment.
2. Thermal Stability (b): PCBs are stable at high temperatures, contributing to their usage in industrial applications and persistence.
3. Biological Stability (c): They are resistant to microbial degradation, leading to bioaccumulation in ecosystems.
4. Dielectric Constants (e): High dielectric constants make PCBs ideal for use in electrical applications.
Vapour Pressure (d): PCBs have low vapour pressure, which reduces their volatility. This property does not significantly contribute to their accumulation in the environment.
Thus, the correct factors contributing to the accumulation of PCBs are (a), (b), (c), and (e).
Information Booster: 1. Persistence: PCBs are part of the Persistent Organic Pollutants (POPs), characterized by high resistance to natural degradation.
2. Bioaccumulation: PCBs tend to accumulate in fatty tissues, leading to magnification in higher trophic levels.
3. Toxic Effects: PCB exposure has been linked to cancer, immune system damage, and hormonal imbalances in humans and wildlife.
4. Usage: Despite bans, PCBs were widely used in industrial applications like coolants, capacitors, and transformers.
5. Environmental Impact: Improper disposal and accidental releases have led to widespread contamination.
