HAZMAT Technician Practice Exam

How does increased persistence of a chemical affect its environmental impact?

1. It reduces its harmfulness over time

2. It increases its potential to cause harm long-term

3. It makes it easier to decompose

4. It improves its reactivity with other substances

The correct answer is: It increases its potential to cause harm long-term

Increased persistence of a chemical in the environment refers to its tendency to remain in that environment for an extended period without breaking down or degrading. When a chemical is persistent, it can accumulate in soil, water, and living organisms, leading to prolonged exposure. This extended presence can elevate its potential to cause harm long-term because: 1. **Bioaccumulation**: Persistent chemicals are more likely to be taken up by organisms and can accumulate in tissues over time. As these substances concentrate through food chains, they may pose greater risks to wildlife and humans. 2. **Toxicity**: Persistency often correlates with toxicity. Chemicals that do not break down tend to retain their harmful properties, meaning that their effects can last longer and potentially worsen over time. 3. **Environmental Persistence**: These chemicals can affect ecosystems for years, disrupting the balance and health of environmental systems. They can harm non-target species and degrade habitats. This understanding of persistence underscores why it substantially increases the long-term risks and potential environmental impact of certain chemicals, making this choice the most accurate reflection of the relationship between chemical persistence and environmental hazards.