Updated

Close to 1 percent or an average of 1 out of every 110 8-year-olds in the U.S. has an autism spectrum disorder, according to a study released by the U.S. Centers for Disease Control and Prevention Friday.

The results of the 2006 study, reported in the CDC’s Morbidity and Mortality Weekly Report, represent a 57 percent increase in the number of children identified with some form of autism since a similar study was conducted in 2002.

It’s estimated that 40,000 new cases of autism were diagnosed in this year alone. Catherine Rice, a behavioral health scientist with the National Center on Birth Defects and Developmental Disabilities, called the problem “an urgent health concern,” during a CDC media briefing Friday.

Rice said the rate of increase of autism disorders in children is 4 to 5 percent higher in boys than it is in girls.

She said the CDC is currently studying risk factors both during the mother’s pregnancy and the first few years of a child’s life. Rice added that there are multiple causes of autism spectrum disorders and that a single cause will not be identified. She also said that some of the increase is due to better diagnosing of the disorder.

“A simple explanation is not apparant," she said. "We know that there are multiple complex genetic and environmental factors that cause autism.”

The study was conducted on more than 2,750 8-year-olds in 10 communities across the U.S. It used only 8-year-olds in the study because previous research has indicated that most children with autism spectrum disorders, which include both autism and other forms of the disease such as Asperger’s syndrome, have been identified and are receiving services by this age.

Specifically, autism spectrum disorders are a group of developmental disabilities characterized by atypical development in socialization, communication, and behavior

The study, which included a review of health and education records, found sharp variations in a number of children with ASD in the communities surveyed. Researchers found that in Florida, for example, 4.2 out of every 1,000 children had an autism spectrum disorder, but in Arizona and Missouri as many as 12.1 out of 1,000 children were diagnosed with some form of autism.

Mark Blaxill, a director with SafeMinds, a nonprofit organization that funds research on a possible connection between autism and mercury exposure from vaccines and environmental factors such as power plants, called the release of the CDC data on the Friday before Christmas shameful.

“I’d offer that the CDC is doing a terrible job on autism,” Blaxill told FoxNews.com Friday. “They’re doing the best they can to bury this. I would say that releasing something the Friday before Christmas is about as deep as you can bury something.”

Blaxill said the CDC and National Institutes of Health need to develop a plan of action and work harder to find out why autism spectrum disorders are increasing at such a rapid rate.

"Autism was first identified in the 1940s," said Blaxill, who has a 14-year-old daughter with autism. "Back then, 1 in 10,000 children were believed to have it and now 1 percent of our children have autism. And it's not only improvements in the way we diagnose autism. ... We're outraged and we want more research."

Blaxill said stronger studies on environmental and genetic causes of autism are needed.

“We’re not anti-vaccination,” Blaxill said. “I support vaccines. ... But we see what’s happened with the concern over Methicillin resistant Staphylococcus aureus and the overuse of antibiotics. One thing that’s changed dramatically over the years is the number of vaccinations we’re pumping into our kids. What we’re saying is, let’s investigate our vaccine program. Let’s evaluate safety.”