Microwave ovens can potentially become dangerous after being struck by lightning. If a microwave is struck by lightning, the intense electrical surge can cause damage to its internal components. This damage may lead to malfunctioning or even render the microwave hazardous to use. Therefore, if a microwave oven is struck by lightning, it is essential to have it inspected by a qualified technician before attempting to use it again.
As for the second question, there is no conclusive evidence to suggest that using a microwave oven causes cancer. Microwave ovens work by emitting electromagnetic radiation in the microwave frequency range, which excites water molecules in food, causing them to heat up and cook the food. This process is entirely different from ionizing radiation, which is the type of radiation known to increase the risk of cancer.
Microwave ovens are designed and regulated to prevent harmful radiation from leaking out during operation. As long as a microwave is in good working condition, properly sealed, and used according to the manufacturer's instructions, there is no significant risk of microwave radiation exposure to users.
It's worth noting that concerns about microwave ovens and cancer arose due to misunderstandings about the technology and the incorrect association of microwave radiation with harmful ionizing radiation. However, numerous scientific studies and organizations, including the World Health Organization (WHO) and the US Food and Drug Administration (FDA), have deemed microwave ovens safe when used as intended. There is no credible evidence linking the proper use of microwave ovens to an increased risk of cancer or any other health issues.