A class at CSUN has been testing rainwater for radioactive elements that may have escaped a nuclear reactor damaged in the magnitude 9.0 earthquake and tsunami that struck Japan March 11. The class has not detected an increase in levels of radiation, but facilities with more advanced equipment have.
Professor of nuclear physics Duane Doty leads an advanced nuclear lab class in monitoring a sodium iodine detector that has been running around the clock since it was turned on. The detector tests rainwater the class has collected around campus and Doty’s home in Chatsworth.
Doty estimates CSUN has had this detector for about seven years and it cost about six thousand dollars. It has not registered higher levels of radiation since the last time it was used, about seven years ago.
“This is good news for us and I was happy, but now we’re not going to be famous,” Doty said.
A March 23 study at University of California Berkeley’s Department of Nuclear Engineering found advancing levels of radioactive iodine-131. Doty said this discovery was made because Berkeley has an air filter that takes in a larger volume of air, essentially allowing one test to monitor the equivalent of a room full of air at once.
The U.S. Environmental Protection Agency (EPA) has been testing radiation levels in the air, precipitation, rainwater and milk. They have found low levels of radiation in all categories in several states, including California, Alaska, Nevada, South Carolina and Washington. Low levels of radiation have been detected in other countries as well, including Israel, Great Britain and Russia.
Melissa Dankel, spokeswoman for the Agency for Toxic Substances & Disease Registry (ATSDR), a government organization that monitors the EPA’s tests said this is not surprising.
“We expected this and knew the levels would be very low, but the public needs to remember that these levels are not harmful,” Dankel said.
Doty said a half-life is a value that indicates how long it takes for a substance to lose half its level of radioactivity. The length of time it takes for a substance to lose all its radioactivity cannot be calculated by doubling its half-life. Iodine’s half-life is eight days, it will loose half of its half-life after an additional eight days and continue to decrease in value until there it no radiation left.
“After iodine travels from Japan for four days it will have about 70 percent its original radiation value, after two weeks about a quarter,” Doty said. “Cesium (another radioactive element that escaped the reactor) is the real problem because its half-life is 30 years, so people my age don’t have to worry but people around your age could still have radiation in their bodies during their child bearing years, which is not good.”
Effects from radiation vary depending on level of exposure and age. According to the American Cancer Society, ionizing radiation, which is caused by radioactive materials, can damage DNA and cause cancer.
According to the EPA children are affected by smaller amounts of radiation than adults because they are growing and more cells are dividing. The EPA states its standards take this into consideration.
While government organizations do not appear concerned about radioactive elements such as iodine-131, tellurium-132, cesium-134, and cesium-137 being detected in rainwater, others are. Elanor Starmer is the western regional director for the Food and Water Watch, a nonprofit organization. She is asking more people to get involved in demanding more information from the government as well as goals towards making the environment safer.
“We’re (Food and Water Watch) a consumer advocacy group. We push our government to keep our drinking water safe and sustainable, so we can all trust in the things we are eating,” Starmer said.
“When they (EPA) says it’s (current radiation levels) not harmful, I point out that the National Academy of Sciences a few years ago came out saying even low levels of radiation can be harmful because the impact of radiation is cumulative,” Starmer said. “Second, they are comparing apples and oranges, ingesting food is different than being near a microwave. Assessment of radiation levels are mostly for the average adult male, and don’t capture the impact on children, especially with food, because kids consume much more food than adults.”
