WHAT IS RADON?
Radon is a relatively new issue in California. Although you can’t see, smell or taste it, there may still be a radon problem in your home. Radon comes from the natural breakdown of uranium in soil, rock and water. While this process is natural, the effects of radon are very dangerous, and very few people are aware that radon ranks as the second leading cause of lung cancer in the United States – second only to smoking cigarettes.
Levels of radon in an outdoor environment are usually quite low, and not much of a health risk to humans. Indoors, however, radon levels can be very high. Radon can enter homes and buildings through cracks in floors, walls or foundations, quickly leading to dangerous levels in confined spaces. Testing is the only way to know if your home has elevated radon levels. Testing is inexpensive and easy, whether you hire a professional or purchase a test kit (available at most hardware stores for around $13). If high levels are detected, radon reduction systems can bring the amount of radon down to a safe level at an inexpensive cost relative to the size and design of your home.
RADON IN CALIFORNIA
Back in 2003, local newspaper headlines in Palos Verdes read, “High School Science Project Leads to Federal Radon Study in California”. What began as 15-year-old Lauren Fukumoto’s high school science project soon expanded to a USGS study of the geologic causes of indoor radon in her south of Los Angeles school district. Awareness of California’s radon problems quickly spread throughout the country. From the CGS website, the story relates that geologist Ron Churchill was dispatched to Palos Verdes to discuss the radon issue with the school district and to observe and provide assistance to a special USGS study. He met geophysicist Joe Duval, USGS’ top radon expert, and the mapping began. Since that time, Mr. Churchill has produced a number of maps, including the Lake Tahoe Area, Eldorado County, Placer and San Luis Obispo County, Santa Cruz, Monterey County, Ventura County, Santa Barbara County and Los Angeles County.
A few years ago I called Mr. Churchill and spoke to him about the radon data, as we had started using the maps in our disclosure reports. He explained his concerns about the accuracy of the radon potential maps and suggested comparing them with the actual test results from “zip code data”. There were too few test results to really draw hard conclusions, so I included both sets of data at that time, in order to obtain the best picture possible. Since then, we have started using the zip code data alone, as there is now enough test result data to get a more reliable picture – but it is still by no means complete. With all the ongoing testing, the data will become more accurate over time.
In addition, we have reviewed the CGS data with the test results collected by Air Chek Inc. (radon.com), which offers a variety of test kits and has a wealth of information on radon in California and throughout the country.
The map shown to the left is the EPA’s predicted average indoor screening by county and zone. On the right is the Lawrence Livermore map of predicted MEDIAN annual average living area concentration of radon.
WHAT ARE THE MAPS TELLING US?
Are the maps showing that California’s radon problem is limited to just a few counties? I don’t think so! California’s radon problem is widespread and serious.
The Berkley map contains the following disclaimer: “Colors may be hard to distinguish, particularly among the greens.” But this map, isn’t intended to give really detailed predictions anyway. Remember, these are predictions. There is some uncertainty in each county’s actual median! Note; only three counties are green (2 or 2.5 pCI/L or above). Having taught statistics I know it can be confusing for the unfamiliar, if not misleading, so I am going to use simple odds. – see below.
The EPA Map (left) has a different disclaimer: “The purpose of this map is to assist national, state, and local organizations to target their resources and to implement radon-resistant building codes. This map is not intended to be used to determine if a home in a given zone should be tested for radon. Homes with elevated levels of radon have been found in all three zones. In my opinion, all homes should be tested regardless of geographic location.
Map by Zip Code and County: These maps will give a different perspective. Based on actual tests, the colors change and the odds are clearer. However, these maps are still not complete, and there is still not enough hard and specific data at the address level.
CONCLUSION
These maps show that California has a widespread and serious radon problem. With the data gathered, we have narrowed the location to where the odds are highest. Still, with insufficient data in most areas of the state, my response will continue to be, “Let’s test and find out!”
Although you can’t see it, smell it, or taste it, radon is a serious health risk to Californians. As the second leading cause of lung cancer in the United States, radon is not something to be taken lightly. Fortunately, testing for and eliminating radon is simple, easy, and relatively inexpensive. Of all the natural hazards affecting California homes, radon is the easiest and cheapest to eliminate. With the dangers great, and elimination easy, there are simply no excuses for allowing the dangers of radon in any home.
