Regulations, Standards, and Ethics
What you must understand
Key reference levels: EPA action level 4 pCi/L for homes; EPA recommends considering mitigation between 2 and 4 pCi/L. The World Health Organization recommends a reference level of 100 Bq/m³ (~2.7 pCi/L). EPA's 2012 radon standards (formerly covered by the National Radon Proficiency Program) define measurement and mitigation protocols, and ANSI/AARST standards govern device performance and practice. State programs may impose licensing, certification, and reporting requirements that supersede federal guidance. Ethics: report results honestly, never alter data, disclose conflicts of interest, respect client confidentiality, avoid scare tactics or guarantees, and refer mitigation to qualified professionals. Measurement providers should not condition results on selling mitigation. Keep records and follow disclosure rules.
Traps
Questions assume federal rules preempt state rules (state rules often are stricter), or that 4 pCi/L is a legal limit rather than an action level. Don't confuse WHO's 100 Bq/m³ with the U.S. 4 pCi/L. Watch for conflicts-of-interest scenarios.
Worked example
A result of 3.8 pCi/L is below the 4 pCi/L action level but within the 2–4 pCi/L consideration range - report accurately and discuss options without pressure. Rule of thumb: 4 pCi/L = act; 2–4 pCi/L = consider; WHO ≈ 2.7 pCi/L.