Question

Explain why the householder should not be concerned about his yearly radiation dose from the ganite worktop

Answer 1

The granite worktop can contain certain amount of radioactive elements such as uranium or thorium. These radioactive elements will decay into radon - a radioactive gas which can cause lung cancer. But little amounts of radon that released from the granite worktop successfully removed from the household by ventilation. Therefore, the granite worktop can't increase housholder's yearly radiation dose and he should not be concerned about this.