Radioactive Sr-90 can enter and accumulate in human body through

Options

A. Breathing in contaiminate air
B. Drinking water
C. Soil
D. Food chain

Answer

**Step-by-Step Solution:**

1. **Understanding Radioactive Sr-90**: Strontium-90 (Sr-90) is a radioactive isotope that is a byproduct of nuclear fission. It is known for its long half-life of approximately 28 years, which means it remains radioactive and can pose health risks for a long time.

2. **Entry Points into the Human Body**: Sr-90 can enter the human body through various pathways:
- **Contaminated Air**: Breathing in air that contains radioactive particles.
- **Drinking Water**: Consuming water that has been contaminated with radioactive materials.
- **Soil**: Sr-90 can be present in the soil due to nuclear fallout or improper disposal of radioactive waste.
- **Food Chain**: The most significant pathway is through the food chain.

3. **Absorption by Plants**: Sr-90 can be absorbed by plants from contaminated soil. When plants take up water and nutrients, they can also absorb radioactive isotopes.

4. **Bioaccumulation and Biomagnification**: Once Sr-90 enters the food chain, it can accumulate in the bodies of organisms. As smaller organisms are eaten by larger ones, the concentration of Sr-90 increases at each trophic level, a process known as biomagnification.

5. **Health Risks**: The accumulation of Sr-90 in the human body can lead to serious health issues, particularly affecting the bones and bone marrow. It is associated with conditions such as leukemia and bone cancer, especially in children.

6. **Conclusion**: The primary way Sr-90 enters and accumulates in the human body is through the food chain, as it is absorbed by plants and then transferred to animals and humans who consume those plants or animals.

**Final Answer**: Radioactive Sr-90 can enter and accumulate in the human body primarily through the food chain.

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