Question: Is radiation poisoning contagious? … I ask because if that nuke alert had not been a false alarm, a lot of people would have been affected.

Answer: Yes, in the sense that a person contaminated by radioactive material, either externally or internally, could contaminate others, the U.S. Centers for Disease Control and Prevention explains on its website. Rapid decontamination is critical.

External contamination occurs when radioactive material (liquid, dust or powder, including from a nuclear blast) comes in contact with a person’s skin, hair or clothing — in other words, the outside of the body.

Internal contamination occurs when a person swallows or breathes in radioactive material, or when it enters the body through an open wound or is absorbed through the skin, the CDC says.

A person with external contamination can spread it to people, surfaces or objects. If a person has radioactive dust on their clothing and hugs another person, sits down in a chair or walks through a house, all could be contaminated, the CDC notes as examples.

As for internal contamination, radioactive materials can accumulate in a person’s blood and internal organs or be excreted in their sweat, urine and feces — posing a risk to anyone who comes into contact with those bodily fluids.

The CDC offers tips for people to “self-decontaminate” during a radiation emergency:

>> Get out of the affected area immediately. Go inside the nearest safe building.

>> Carefully remove outer layer of clothing; doing so can remove up to 90 percent of radioactive material. Avoid shaking radioactive dust loose while disrobing.

>> Seal clothing in a plastic bag or other container and keep it away from people and pets. Keep cuts and abrasions covered when handling contaminated clothing.

>> Wash all body parts that were uncovered during the radiation emergency. Use lots of soap and lukewarm water. Pay special attention to your hands and face. Avoid spreading contamination to skin that may not have been initially exposed.

>> Put on clean clothes. Seek medical attention when it is safe to do so. If internal contamination has occurred, medication might reduce radioactive material in your body.

Q: My mother is a widow. She’s pretty isolated, with no social life to speak of except for visits from me (I have no siblings). She doesn’t belong to a church and has never been a “joiner.” I think she is depressed, although there are some activities she enjoys, like walking. I think she would benefit from some sort of group therapy, where she is with other people. But every time I bring it up, she says, “Medicare won’t cover that.” Is that true?

A: Not necessarily. Original Medicare (which consists of Part A and Part B) doesn’t pay for support groups that bring people together to socialize, but it does cover group psychotherapy, according to “Medicare & Your Mental Health Benefits,” a booklet published by the Centers for Medicare and Medicaid Services, which oversees the U.S. health insurance for people over 65.

The latter may be an option for your mother if she is diagnosed with depression or some other illness for which group psychotherapy is beneficial. You can read the full booklet at 808ne.ws/medther.

You mentioned that your mom is not inclined to join clubs but that she does enjoy walking. Exercise can be therapeutic — physically and mentally! Perhaps you could walk with her or encourage her to invite a neighbor or a friend to walk, too. Such outings could lead her to eventually consider joining an organized activity for senior citizens, of which there are many.

Write to Kokua Line at Honolulu Star-Advertiser, 7 Waterfront Plaza, Suite 210, 500 Ala Moana Blvd., Honolulu 96813; call 529-4773; fax 529-4750; or email kokualine@staradvertiser.com.