What are the potential effects of Class 7 radioactive substances?

Class 7 radioactive substances, as defined in the context of hazardous materials, present various risks associated with their characteristics. The correct choice highlights that these materials can contaminate the environment and have the potential to induce biological effects.

Radioactive substances emit radiation that can interact with biological tissues, leading to possible health risks such as cell damage or cancer over prolonged exposure. Contamination can occur through various routes, including ingestion, inhalation, or direct contact, leading to environmental concerns as well.

In contrast, the other choices do not accurately reflect the nature of Class 7 radioactive substances. For example, suggesting that they cause skin burns but are harmless to the environment would misrepresent the dangers of not only human exposure but also environmental fallout. Additionally, labeling them as primarily safe for handling with minimal protection disregards the necessary precautions that must be taken when dealing with radioactive materials.

The option that discusses their utility solely as fuel without acknowledging any side effects oversimplifies the complex nature and inherent risks associated with handling radioactive substances. Thus, the understanding that they pose risks not only to people but also to the environment is crucial in acknowledging their potential effects accurately.