Radiation readings around San Diego County haven't increased over the typical background levels in the past few days, according to a local nuclear expert who began the testing in light of the situation in Japan.
San Diego State University's Murray Jennex said he took baseline readings beginning last Wednesday of the radiation levels that naturally occur in the region, after hearing that contamination from Japan could arrive by last Friday.
Daily readings since then indicated little change from the baseline recordings, Jennex said.
"I took them to prove we didn't get anything," Jennex said.
Nuclear experts have struggled to contain the damage at a six-unit nuclear power plant north of Tokyo since the massive March 11 earthquake and resulting tsunami. They've had to release radiation occasional to keep the reactors from overheating.
Concerns have been raised that prevailing westerly winds across the Pacific Ocean could spread the radioactivity to Canada and the U.S. Pacific Coast.
Figuring the North County would be the first place to detect any radiation increase, Jennex tested several sites in Oceanside and one each in Vista and Encinitas. In San Diego, he took readings at SDSU, Horton Plaza and Pacific Beach.
The highest levels recorded with a handheld radiation detector were 17 micro rads per hour, with an average of about 15 micro rads per hour -- 30 times less than that allowed for workers at nuclear power plants, according to a chart he maintains on the Internet.
"The natural background radiation here is incredibly low -- it's less than what is in my office," Jennex said, noting that his office includes a rock that contains uranium.
Readings taken Sunday in Oceanside and Vista were between 9 and 14 micro rads, with little change today, he said.
Weather conditions probably accounted for the lower levels, the professor said.
Jennex said he would continue taking readings all week.
