By Margaret Henderson
The Minnesota Department of Health's Environmental Health Division works to protect Minnesotans from environmental health hazards in their homes, workplaces and communities. As a component of its program to address radon hazards, the Indoor Air Unit of the division uses technical and scientific approaches to make public health policy decisions, improve quality and use of data, address radon exposure in the workplace, and improve mitigations.
A basic and essential consideration is the quality assurance and quality control (QA/QC) of radon testing because the test results guide the decisions residents and employers make concerning mitigation when test results exceed the EPA recommended action levels of 4pCi/L. The components of QA/QC testing including testing “blanks” to assure the test kits have not been contaminated in storage, testing “duplicates” to determine if two kits will return the same result when exposed to the same concentrations and conditions, and testing “spikes” which have been exposed to known levels of radon and moisture.
Improvement in managing data from test results reported provide greater specificity about radon levels for mapping areas of concern, tracking progress on public health goals, and for making public health decisions about guidance and resources. The Minnesota Commissioner of Health has classified radon test levels in residences as private health data, such that the program can collect the data at address level and protect identity as well. Formerly, data reports were provided at zip code level and did not differentiate between pre- and post-mitigation results, multiple test results at the same location, or whether the building was residential, commercial or a school. With the distinction made about private health data, analysis of the data will be more informed and specific.
The Indoor Air Unit has conducted studies to evaluate water plant operations that may lead to excessive radon exposures, improvements made by Radon Resistant New Construction, and the suitability of some intrusion mitigation systems.
In 2012, the Indoor Air Unit tested radon levels in 14 drinking water treatment plants in a statewide study concerning radon release from aerated untreated water. Test results, when analyzed with employee exposures while operating the plants, allowed the program to give plant operators insights about reducing exposures when necessary through changing ventilation or worker activities.
In 2012 and 2013, the Indoor Air Unit designed and conducted a study of radon levels in passive and active Radon Resistant New Construction (RRNC) homes. Participating in the study were 815 homes with passive systems and 86 homes tested with active systems. (The study was designed to evaluate radon concentrations in homes with passive systems compared to homes when operating with active systems.) Findings showed that on average, passive RRNC systems result in radon levels 40% less than other homes in the same counties. Homes with active systems had very low radon levels.
Vapor intrusion mitigation systems were evaluated by the radon staff by inspection. Staff inspected eight systems, visually and for performance based on the Minnesota Pollution Control Agency standards. The inspections concluded the systems met standards of suitability.
Additionally, the radon program staff provides technical assistance on problematic mitigation scenarios. When contractors find that unique features and factors limit their success in performing successful mitigations, the department staff can troubleshoot and assist with technical consultations and provide information.
With scientific examination and technical approaches, the Indoor Air Unit furthers the goal of reducing environmental health hazards to Minnesotans.
For further information, contact:
Dan Tranter, M.P.H.
Supervisor
Indoor Air Unit
P.O. Box 64975
St. Paul, MN 55164
Office: (651) 201-4618
Mobile: (651) 331-6548
Fax: (651) 201-4606
Web: http://www.health.state.mn.us/divs/eh/air
Radon: http://www.health.state.mn.us/divs/eh/indoorair/radon/index.html
Source:
Minnesota Department of Health
Indoor Environments & Radiation Section
Indoor Air Unity State Indoor Radon Grant 22-24 Final Report, October 1, 2011- September 30, 2014
http://www.health.state.mn.us/divs/eh/indoorair/radon/sirgreport12014.pdf
United States