Radiation detector "breathing" fresh air in my window in Overland Park
With the troubled nuclear reactors in Japan there is considerable interest in radiation levels and whether radiation might be spreading from Japan to as far away as Kansas.
Recently Kansas Meadowlark reported the background radiation was about normal in Overland Park over the period March 19 to March 21.
At that time the average background level was about 10.2 µR/hr when “normal” ranges up to about 23 µR/hr.
See this earlier article for additional information about background radiation, measurements and units.
From March 21 till March 24 the average level was negligibly higher at 10.3 µR/hr but days later from March 24 till March 27 the average was negligibly lower at 9.8 µR/hr.
The background radiation chart from March 24 – March 27 is shown below:
Chart of background radiation measures by minute in Overland Park, March 24-March 27. Red trend line shows a flat level. Click on chart to see enlarged version.
The red trend line above is flat.
The background radiation levels from March 28 till April 3 shows a trend of a slight increase.
While the average over this period was still about 9.8 µR/hr, the trend line shows a steady increase from about 9.2 to 10.6 µR/hr.
Chart of background radiation measures by minute in Overland Park, March 27-April 3. Red trend line shows a flat level. Click on chart to see enlarged version.
The cause of the measurable but negligible increase is not known, but it could be related to dust in the air cause by high winds from the south of the last few days — or possibly other causes including the Japanese reactors.
This page suggests there can be increase in gamma radiation during times of rainfall.
With the passage of the cold front late Sunday, and the end of the rain storms, it will be interesting if the level goes back down.
The slight changes seen in background radiation are insignificant compared with background levels at higher elevations, like in Colorado.
From March 2003, here is a chart of the background radiation level near the base of Copper Mountain in Colorado where the average level was about 22 µR/hr.
In March 2003 the average background radiation level at the base of Copper Mountain in Colorado was about 22 microroentgen/hour. Click on chart to see enlarged version
The base elevation for Copper Mountain is about 9712 feet while the elevation in Overland Park is only about 1000 feet. The “thicker” air at lower elevations serves as a better protection from cosmic radiation than the “thinner” air at altitude.
A chart on this page shows real-time radiation at Chadds Ford, Pennsylvania. For the last week the average was about 15.2 µR/hr.
So while there was a slight increase in detected background radiation in Overland Park, it is still well below other parts of the country, including Colorado and Pennsylvania.
Kansas Meadowlark will continue to periodically publish background radiation levels in Overland Park until the problem in Japan gets better.
Related:
- Kansas officials: Radiation from Japan ‘minuscule’, Wichita Eagle, Apr. 7, 2011.
- Path of radiation leak at Japan plant unclear, Breitbart, April 4, 2011.
- Background radiation is normal in Overland Park, Kansas Meadowlark, March 21, 2011.
Contact: Earl F Glynn, editor@KansasMeadowlark.com
Tags: Aware Electronics, Background radiation, Kansas, Overland Park, RM-70, Roentgen, Sievert
