Radon Exam Questions and Answers Already Graded A

Radon Exam Questions and Answers Already Graded A According to the US EPA Citizens Guide to Radon, radon levels in most homes, can be reduced to: 2 pCi/L or less Homeowners should be advised to have their mitigation contractors stipulate that they will follow: Radon Mitigation Standards such as the US EPA, AARST, ASTM, or as recognized by their state radon office Prolonged exposure to radon is considered dangerous because radon can cause: lung cancer The most common radon mitigation technique at this time is: Active soil depressurization The Radon Action Level in the United States is: 4.0 pico Curies per liter of air The submembrane mitigation strategy is applicable to which of the following foundation types? Crawl space houses What is radon? An invisible, odorless, tasteless, naturally occurring, radioactive gas. What is the minimum deployment/sampling period for a short-term test? Two days What is the purpose of the US EPA Map of Radon Zones? To suggest where radon resistant new construction techniques would be the most cost-effectively employed. Which of the following best represents the recommendation of the U.S. EPA for citizen exposure to radon? Long-term exposure to elevated radon can increase the potential for lung cancer Which of the following is an acceptable location for the discharge of an active soil depressurization system? Above the eave of the roof. Which of the following locations is appropriate for the fan of an active soil depressurization system? Attic Which of the following Radon measurement approaches best estimates occupant exposure? A yearlong test with an alpha track detector in the lowest occupied level of the home with no special precautions for closed building conditions. A correct statement regarding radon testing in Zone 3 areas of the EPA Radon Potential Map is that such testing: is recommended. A significant difference between one room and the next in a building with a large central air handling system is often caused by: An unbalanced air distribution system After 25 years of updates by testers and state agencies, the US EPA Map of Radon Zones is a good predictor of where indoor radon levels will not be elevated. False How can you tell if a house contains elevated levels of radon? Test for radon. If a short-term, closed building radon test is conducted in the basement of a home with a result of 10 pCi/L, what can be said about the radon levels on the first floor above the basement? The first floor radon level is likely to be equal to or less than the basement measurement of 10 If the water for a home comes from an underground well that has 60,000 pCi/L in the water, how much radon will be added to the air of the home due to normal usage of water? 6 to 10 pCi/L In a cold climate, stack effect is typically higher during the: Winter In a house with a forced air heating and cooling system, which of the following conditions would most likely increase short-term indoor radon concentrations the most? Return ducts under the slab with the air blower on. In most homes the main source of elevated radon levels is: the soil. Indoor Radon levels are always higher during the winter months (November through March) than any other time of year. False On a nationwide basis, which of the following radon entry mechanisms account for the greatest amount of radon entry? Convective movement of soil gas into the building. On an overall basis for similarly constructed homes in the same climatic area, under which of the following conditions might one expect the highest radon entry into a home? Highly permeable soil with high radium content beneath the house which is entirely built over a crawl space. Pipe chases up through interiors of apartment buildings can provide radon pathways to upper level units. True Temperature induced stack effect is greatest when: The outdoor temperatures are very low relative to interior temperatures The primary reason indoor radon levels are generally higher in basements is the fact that: the basement is closest to the radon source. The radon concentration of a private well for a home was determined to be 15,000 pCi/L of water. Which of the following is the most appropriate recommendation? Before proceeding to reducing the radon in the water, a radon-in-air test should be conducted. The water supply to a home has been determined to be 9,500 pCi per liter of water. A radon in air test was also conducted while it was occupied with a result of 22 pCi/L of radon in the air. What is the predominant source of radon? From the soil What is one of the main differences between testing for radon in schools versus testing in single family homes? More robust forced air systems can cause significant differences from one room to another in a school What is the neutral pressure plane within a home? It is the general location within the home, above which the house is at positive pressure relative to the outdoors and below which the house is at negative pressure relative to the outdoors. What is the typical effect that the addition of outdoor air has on indoor radon levels? It typically reduces indoor radon When is fresh air typically provided to large buildings such as schools? During occupied hours Which of the following mechanical ventilation systems or conditions would most likely reduce radon entry? Evaporative cooler Which of the following situations is caused by wind blowing on a home built on a hillside? Soil pressurization and increased radon entry. Which of the following variables is the best predictor of potential radon concentrations in buildings? Radium content in the soil. Short-term tests conducted in the same location with the house being under closed building conditions will not vary more than 10 percent when tests are conducted at different times of the year. False A curie is defined as: the radioactivity of one gram of radium. A house was tested for radon and radon decay progeny. The results were 10 pCi/L and 0.08 WL. What would most likely account for these measurements? The ventilation rate is very low and has high particulate count in air. ER = WL X 100 / Rn ER = 0.08 X 100 / 10 ER = 8/10 = 0.8 or 80% This is higher than the typically assumed 50%, which means there are more decay products in the air than is typical. This would be caused by stagnant air or lots of particulates in the air. A measurement of 2 WL is made in a home. Using typical equilibrium ratio assumptions, the radon concentration is: 400 pCi/L A measurement of 4 pCi/L is made in a home. Using typical equilibrium ratio assumptions, the working level is: 0.02 WL Use the equilibrium equation to solve for radon decay products in units of working levels (WL). Assume 50% ER since no additional information was provided.