What are the units for measuring radon? Lesson 4 What are the units for measuring radon?

Radioactivity units Picocuries (pCi) Measures Activity (radioactive decays/second) 1 picocurie (pCi) = 0.037 decays/second = 1 decay/27 seconds = 2.22 decays/minute

Radon units Picocuries/Liter (pCi/L) Measures Activity (decays/minute) per volume (one liter of air) 1 pCi/L = 2.22 decays per minute per liter of air

EPA action level Picocuries/liter 4 pCi/L = 4 x 2.22 decays/minute/liter = 8.88 decays/minute/liter

International System (SI) Radioactivity units 1 becquerel (Bq) = 1 decay/second = 27 pCi 1 pCi = 0.037 decays/second = 0.037 Bq Henri Becquerel, discovered radioactivity in 1896

International System (SI) Radon units 1 pCi/L = 37 Bq/m3

EPA action level International System (SI) 4 pCi/L = 4 x 37 Bq/m3 = 148 Bq/m3

Measuring radon decay products (RDPs) Measure alpha radiation emitted by short-lived RDPs Polonium-218 Lead-214 Bismuth-214 Polonium-214

Measuring RDPs Working level (WL) = Concentration of RDPs produced from one liter of air that contains 100 pCi/L of radon = Amount of short-lived RDPs that exists at a single moment if a container is kept at a constant 100 pCi/L

Working level EPA action level 4 pCi/L = 0.02 WL

EPA action level Summary 4 pCi/L 148 Bq/m3 0.02 WL

Questions?

Characteristics of radon decay products (RDPs) Solid particles Electrically charged React chemically

Factors that affect radon and RDP concentrations Air circulation Air moving within a room Ventilation Fresh air entering a room Air filters Particles suspended in the air Dust Smoke Aerosols Some RDPs plated out

Secular (eventual) equilibrium Takes 3-4 hours At secular equilibrium, 1 WL = 100 pCi/L Radon decay products  Radon Radon

A home inspector’s lament and pledge Picocuries and becquerels; secular equilibrium. Radon decaying has made my brain cells go numb. But I do understand: breathing radon’s not healthy, So I’ll master these concepts, though they won’t make me wealthy. Convert all these measurements? Curse that uranium! I’m working at levels that hurt my poor cranium. This slide is intended as a little light relief and as a reminder of why this information is important. Read it aloud. Practice beforehand to get the rhythm, which is a bit tricky. And the rhymes are not perfect. I’ll learn proper techniques, use the right protocol, To help prevent cancer: that’s the goal of my role.

Summary EPA action level 4 pCi/L = 148 Bq/m3 = 0.02 WL 4 4 pCi/L = 148 Bq/m3 = 0.02 WL

Summary Factors affecting measurement Air circulation Ventilation Air filters Particles in the air Importance Factors affect conditions for testing a home