It rained on the Monterey Peninsula in central California on Monday, November 2. This is on the West Coast, bordering the Pacific Ocean.
Measurements were taken in the morning in Monterey with an Inspector Alert radiation monitor.
The background air radiation level was approximately 31 CPM.(alpha, beta and gamma radiation)
The radiation monitor was then enclosed in a bag and placed in the rain. Measurements of beta and gamma radiation generally ranged from 70s to 113 CPM (alpha radiation was blocked by the bag). Readings in the 90s were common. Measurements might have been higher if alpha was included.
On Tuesday morning, the day after, a 10-minute timed measurement of air radiation levels. The reading average over 10 minutes was 44 CPM (alpha, beta, gamma) — a 42% increase in air radiation levels from Monday.
This was “hot” rain.
Rainfall and snowfall should be regularly tested for radiation levels. If you get higher than normal readings, alert your family, friends and schools. Children should not be playing in the rain unless low radiation levels are verified. They should also not be playing outdoors when airborne radiation spikes occur. School districts should have good quality radiation monitors, and post the numbers for students and staff to refer to.
When it rains or snows, use umbrellas, and use precautions in storing rain- and snow-contaminated items, such as shoes, inside your home. Dump bird baths and outside pet water after rain, wash out, and fill with fresh water. Frequently dump and refill due to fallout, and if getting high rad readings, do this daily. It won’t eliminate the exposure, but it will reduce their internal intake.