What protects you, and what does not
Protection from radiation comes down to three things: less time exposed, more distance from the source, and dense material in between. A building does all three. The middle of a brick or concrete building, or a basement, puts walls, floors and earth between you and whatever is outside.
Nothing you can wear stops gamma radiation. A respirator, including a full-face mask with canisters, only reduces the radioactive dust you might breathe in. It does nothing about radiation passing through walls or clothing. We sell respirators and a Shelter-in-Place Kit, and neither is radiation protection. Sealing a room keeps contaminated dust out for a short period. It is a temporary measure, to be used when authorities advise it and ended when they say so.
Potassium iodide (KI)
Potassium iodide tablets fill the thyroid gland with stable iodine so that it absorbs less radioactive iodine. That is all they do. The Canadian Nuclear Safety Commission is explicit that KI protects only the thyroid, only against radioactive iodine, and is not an antidote to radiation.
Take KI only when public health authorities tell you to. In Ontario that instruction comes from the Chief Medical Officer of Health. Taking it early or without direction has no benefit and carries some risk.
ICEKIT does not sell potassium iodide. In Ontario, tablets are delivered automatically to homes and businesses within 10 km of a nuclear station, and anyone living or working within 50 km can order them free at preparetobesafe.ca. Elsewhere, ask your provincial emergency management office or a pharmacist.
Before and during
Preparation is mostly ordinary household readiness, with a plan to stay indoors. Government of Canada guidance is to be ready to shelter in place for at least 24 hours.
- Find out whether you live or work in a nuclear planning zone, and read your municipality's public information.
- Keep water, food, medications and a battery or crank radio where you would shelter. A crank radio works when power and mobile networks do not.
- If an emergency is declared, go indoors, close windows and doors, and switch off fans, air conditioners and furnaces that draw in outside air.
- Follow official broadcasts and Alert Ready messages. They will say whether to shelter, take KI or evacuate, and by which route.
- If you were outside during a release, take off your outer clothing, bag it, and wash with soap and water.
Common mistakes
The errors here mostly come from marketing and films.
- Buying a mask for radiation. No mask, filter or suit blocks gamma radiation. Particle filters reduce inhaled dust only.
- Calling KI an anti-radiation pill. It protects one organ from one substance.
- Taking KI on your own initiative. Wait for the instruction.
- Evacuating without being told to. Sitting in traffic can mean more exposure than staying inside a solid building.
- Relying on a home Geiger counter for decisions. Consumer instruments give rough readings. Official monitoring guides the instructions you will receive.