Apex, N.C. — Environmental testing near a hazardous waste operation that caught fire last month found no off-site contamination as a result of the fire, state officials said Friday.

An Oct. 5 chemical fire at the Environmental Quality Industrial Services facility prompted the evacuation of about 17,000 Apex residents. It has led to calls for tighter regulation of hazardous waste sites across North Carolina.

Extensive testing during and immediately after the fire found no short-term contamination problems, but local officials pressured the state to test for heavy metals and other signs of contamination to determine if the fire released anything that might have long-term health effects for residents.

Inspectors took water and soil samples and swabbed interior surfaces of about 30 locations in Apex upwind and downwind of the fire.

"What we were looking for was any indication that homes or businesses might have been contaminated with heavy metals or other chemicals from the fire that could present a health risk to Apex citizens," Robin Smith, assistant secretary for the environment at the state Department of Environment and Natural Resources, said in a statement. "We didn't find that. We found the kind of thing you would find at low levels in any urban area."

If offsite contamination had occurred as a result of the fire, areas downwind from the fire would be likely to show contamination with chemicals that were found in ashes on the EQ site, state officials said.

The ashes on the fire site primarily contained barium, cadmium, chromium and lead, none of which were found in unusual concentrations offsite, officials said. There was no difference between tests conducted upwind and downwind of the fire, they said.

"While the fire may have caused some short-term respiratory problems -- particularly for first responders -- luckily, its contamination has been contained to the facility site," State Epidemiologist Dr. Jeff Engel said.

Neither soil tests nor swabs of building exteriors showed high levels of any of the chemicals found in ashes at the EQ site, officials said. Concentrations were well below levels at which adverse health effects would be observed in the general population, they said.

"It is so very gratifying to now be assured by the testing just completed that the hazardous materials were not spread across the Apex community, but instead are confined to the fire scene and are now being safely contained, removed and disposed of elsewhere," Apex Mayor Keith Weatherly said.

Local residents also breathed sighs of relief at hearing the results, but some said worries will linger for a while.

"I think it eases the mind, resident Carla Hassell said. "I think there's always going to be a question down the road. You never know what's under the ground and what's in the ground."

Soil sample analyses indicated a natural presence of a number of metals -- including arsenic, mercury, manganese and silver -- widely distributed across the entire area sampled, both upwind and downwind of the fire, officials said. Three arsenic hot spots were associated with identifiable arsenic sources, such as treated wood decks and an auto maintenance facility, they said.

Although an outside consultant reported finding elevated levels of mercury at Apex Gymnastics near the EQ site, state tests found only normal levels.

"As a result of hearing those concerns, we tested for mercury vapor at 26 sites -- inside and outside -- and the levels we found we very low," said Bill Pate, of the state Division of Public Health.

Also, interior sampling found one house with higher than normal lead levels, but officials said the older house likely has lead-based paint.

The state paid $150,000 for the tests, and officials said they might ask EQ to reimburse the cost.