Chapel Hill police officials sent the material to the state public health laboratory after a Chapel Hill resident received an envelope containing a white powder Friday night.
The resident feared the substance was a contaminant and called 911. Police arrived at the scene and dispatched the regional Hazardous Material Incident Response Team, Chapel Hill police spokeswoman Jane Cousins said Sunday.
Officials, who still are not releasing information about the location or the identity of the resident, secured the residence as a crime scene late Friday.
Lou Turner, director of the N.C. laboratory, said preliminary test results indicate that the substance received in Chapel Hill is probably not anthrax.
According to a press release from the Centers for Disease Control, anthrax is an illness caused by the anthrax bacteria that is noncommunicable and is treatable with antibiotics.
The CDC stated that the disease can be contracted through direct skin contact, inhalation or ingestion of the anthrax bacteria.
Turner confirmed that the substance received in Chapel Hill has been under extreme scrutiny because of the recent anthrax scares nationwide. "We run it through a battery of five to six tests including microscopic observation where we just look at the colonies under a microscope," she said.
Turner said laboratory officials also are exposing the substance to a stimulus that typically would promote growth in anthrax bacteria, a move she said has not shown any alarming results. "We're not seeing any growth in the colonies so far," Turner said. "If it was (anthrax), we probably would have seen growth by now, but we can't say yea or nay."
Cousins, who said police have no new information on the case, said a letter found with the suspicious powder is an important part of the investigation. She had no further information to give regarding the letter.
The incident comes days after a similar incident in Durham where preliminary tests of a powder found in an envelope also have returned with negative results.
A Durham lab technician received a suspicious letter containing a tan powder while he was at work, the Durham Herald-Sun reported Monday.
Nationally, at least 13 people recently have tested positive for the presence of the anthrax bacteria.
The anthrax scare began Oct. 4 when a Florida photojournalist died from the disease. It was the first anthrax death in the United States since 1976.
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