Utah has one of the highest autism rates in a 14-state study — 1 in every 133 children. And the rate is higher still for boys, at 1 in 79, according to University of Utah researchers.

Additional information:  » "Autism Spectrum Disorders" report from the CDC (pdf)  » CDC's work on autism

"With numbers like this, I think it qualifies as an urgent public health concern," said Judith Zimmerman, Ph.D., assistant professor in the department of psychiatry at the U.

The study, sponsored by the Centers for Disease Control and Prevention, concluded that Utah's autism rate is 20 times higher than it was two decades ago. The results were released Thursday.

Overall, Utah ranks third in terms of prevalence based on population, with a rate of 7.5 children per 1,000, placing it about 12 percent higher than the national average, said Zimmerman. New Jersey had the highest rate, at 1 in 94, while Alabama had the lowest rate. Among boys, Utah is No. 2.

Autism is characterized by impaired social, communicative and behavioral development. It varies in severity.

The cause has long been debated, with genetics, environment, even childhood vaccines being blamed by some. The CDC says it's likely there are multiple causes, "due to complex interaction of genetic and environmental factors." For most cases, it adds, the cause is not known although it tends to occur more frequently than expected with certain other medical conditions, including Fragile X syndrome, tuberous sclerosis, congenital rubella and untreated phenylketonuria (PKU).

Utah had the most striking difference in the rates of autism among males vs. females, at 7 to 1. The researchers aid they found no difference in the three counties examined — Davis, Salt Lake and Utah — in terms of prevalence.

Zimmerman said Utah's numbers may be slightly higher simply because Utahns are good bookkeepers. "We had great access to records," she said.