{ "id": "radon-terminology", "title": "Radon Terminology Dataset", "description": "A controlled vocabulary for residential radon: term, definition, the category it belongs to, and the common misunderstanding each term attracts.", "version": "1.0.0", "status": "published", "provenance": "editorial-taxonomy", "license": "CC BY 4.0 — reuse with attribution to Radon Connect and a link to the dataset page.", "published": "2026-07-29", "canonical": "https://radonconnect.com/datasets/radon-terminology/", "schema": [ { "key": "term", "label": "Term", "type": "string", "description": "The term as a homeowner encounters it." }, { "key": "category", "label": "Category", "type": "enum", "values": [ "measurement", "mitigation", "regulatory", "transaction", "building-science" ], "description": "Domain the term belongs to." }, { "key": "definition", "label": "Definition", "type": "string", "description": "Plain-language definition." }, { "key": "commonMisreading", "label": "Common misreading", "type": "string", "description": "The mistaken understanding this term reliably produces, and why it matters." } ], "methodology": { "question": "What does each term of art in residential radon actually mean, and what does a homeowner reliably get wrong about it?", "construction": [ "Terms were selected because they appear in homeowner-facing decisions on this platform and carry a recurring misreading — not because they are technically interesting.", "Definitions follow the framing used in EPA publications where those publications define the term.", "The misreading column is original editorial work drawn from the decision content across this site." ], "inclusion": [ "A term qualifies when a homeowner encounters it in a test report, a quote, a disclosure form, or an inspection report.", "Terms used only between professionals are excluded." ], "limitations": [ "This is a vocabulary, not a standard. Where a term has a precise regulatory definition in a specific state, that state’s definition governs.", "The misreading column is an editorial observation, not a measured frequency. We have not surveyed homeowners and do not claim to have." ] }, "rowCount": 22, "rows": [ { "term": "pCi/L", "category": "measurement", "definition": "Picocuries per litre — the US unit for indoor radon concentration.", "commonMisreading": "Treated as a linear danger scale. It is a concentration; risk rises with it, but no value is a safety boundary." }, { "term": "Action level", "category": "regulatory", "definition": "The concentration at which EPA recommends taking action to reduce radon: 4 pCi/L.", "commonMisreading": "Read as the point where radon becomes dangerous. It is a feasibility threshold for a national programme, and guidance also recommends considering action between 2 and 4." }, { "term": "Closed-building conditions", "category": "measurement", "definition": "Windows and exterior doors kept closed except for normal entry, for 12 hours before a short-term test and throughout it, with whole-house fans and window units off.", "commonMisreading": "Assumed to mean the house must be empty. Occupancy is fine; deliberate ventilation is not." }, { "term": "Lowest lived-in level", "category": "measurement", "definition": "The lowest floor occupied or reasonably occupiable, where a measurement device belongs.", "commonMisreading": "Read as \"where we spend time\". It is a conservative, comparable benchmark, which is why an unused basement still sets the number." }, { "term": "Sub-slab depressurization", "category": "mitigation", "definition": "The standard active method: a fan lowers pressure beneath the slab so soil gas is drawn out and vented above the roofline instead of entering the house.", "commonMisreading": "Described as \"venting the basement\". It works on the soil beneath the slab, not on room air." }, { "term": "Suction point", "category": "mitigation", "definition": "A penetration through the slab where the system draws from the sub-slab layer.", "commonMisreading": "Assumed one is always enough. How many are needed is determined by measuring how far the pressure field actually extends." }, { "term": "Pressure field extension", "category": "mitigation", "definition": "The diagnostic that measures how far suction reaches across a slab, using test holes and a micromanometer.", "commonMisreading": "Skipped as optional. It is the measurement that decides fan size and suction-point count; a quote without it is a guess." }, { "term": "Manometer", "category": "mitigation", "definition": "The gauge on a mitigation pipe showing the pressure difference the fan is developing.", "commonMisreading": "Read as a radon meter. Offset columns mean the fan is pulling; the gauge says nothing about the concentration in the room." }, { "term": "Passive system", "category": "mitigation", "definition": "Radon-resistant construction piping that relies on stack effect rather than a fan.", "commonMisreading": "Treated as a result. It reduces levels in many houses and is insufficient in others, which is why a new house still needs a test." }, { "term": "Activation", "category": "mitigation", "definition": "Converting a passive rough-in to an active system: diagnostics, sealing, a fan sized to measured conditions, and verification.", "commonMisreading": "Described as \"adding a fan\". The buried half was installed by someone else and has to be evaluated first." }, { "term": "Sub-membrane depressurization", "category": "mitigation", "definition": "The crawl-space equivalent: a sealed membrane over exposed soil with suction drawn from beneath it.", "commonMisreading": "Confused with encapsulation. Encapsulation is moisture control; without suction and a roofline discharge it is not a radon system." }, { "term": "Post-mitigation verification test", "category": "mitigation", "definition": "The measurement after at least 24 hours of continuous operation that proves the indoor number fell.", "commonMisreading": "Treated as a formality and dropped from cheap bids. It is the deliverable; without it you own equipment, not a result." }, { "term": "Short-term test", "category": "measurement", "definition": "A measurement over a few days reporting an average under controlled conditions.", "commonMisreading": "Read as a fixed property of the house. It is one sample from a distribution that moves with season and weather." }, { "term": "Long-term test", "category": "measurement", "definition": "An alpha-track or similar detector exposed for 90 days or more, reporting an annual-scale average.", "commonMisreading": "Expected to match a short-term result. They answer different questions and disagreeing is normal." }, { "term": "Continuous radon monitor", "category": "measurement", "definition": "An instrument logging hourly concentrations, often with tamper and condition data.", "commonMisreading": "The hourly graph is read as a second result. The average is the result; the log shows whether conditions held." }, { "term": "Stack effect", "category": "building-science", "definition": "Warm air rising and escaping high in a building, drawing replacement air in low — including soil gas through the foundation.", "commonMisreading": "Ignored when comparing seasons. It is why the same house reads higher in the heating season." }, { "term": "Radon-resistant new construction", "category": "building-science", "definition": "Building provisions — aggregate layer, membrane, sealing, vent pipe — intended to limit soil-gas entry in new homes.", "commonMisreading": "Read as exemption from testing. It improves odds; it does not produce a number." }, { "term": "EPA Map of Radon Zones", "category": "regulatory", "definition": "A county-level classification of predicted indoor average, produced for public-health planning.", "commonMisreading": "Used as an address-level prediction. Zone 1 houses test low and Zone 3 houses test high routinely." }, { "term": "Seller disclosure", "category": "transaction", "definition": "The statutory or form-based obligation to report known conditions, including radon results a seller holds.", "commonMisreading": "Confused with a duty to test. Disclosure attaches to what you know; no state we serve requires testing an existing home." }, { "term": "Inspection contingency", "category": "transaction", "definition": "The contract period in which a buyer may investigate and respond to findings.", "commonMisreading": "Assumed to be long enough. A radon test needs 12 hours of setup plus the measurement plus time for a quote." }, { "term": "Buyer credit", "category": "transaction", "definition": "A negotiated sum at closing in lieu of the seller performing the work.", "commonMisreading": "Sized from a national average. It should come from a written quote on the actual house." }, { "term": "NRPP / NRSB", "category": "regulatory", "definition": "The two national radon proficiency programmes that certify measurement and mitigation professionals.", "commonMisreading": "Treated as optional extras. In states that do not license radon work, national certification is the credential." } ] }