Newcastle residents affected by the Orica chemical (hexavelent chromium) leak have been assured by health specialists that the leak does not pose much health risks.

NSW Health released a Final Health Risk Assessment into the August 8 leak yesterday and health specialists said it was very unlikely that even one person would develop cancer.

''We would not expect to see any health effects in the residents exposed downward of the plume,'' said NSW chief health officer Kerry Chant.

"Our detailed examination of all available data confirms that the initial advice given to the Stockton community was correct," Dr. Chant said in a statement.

"That is, the Orica chromium VI incident was not expected to produce acute health effects in the community."

Independent cancer epidemiologist Bruce Armstrong also gave a separate assessment of the health risk.

''It's very unlikely that even one person will develop cancer as a result of exposure to chromium VI from the release that occurred at the Orica plant,'' he said.

He said that the cancer risk was negligible with only a 1.8 in one million chance that a child aged zero to two might develop a cancer during their lifetime as a result of the hexavelent chromium exposure. An adult who was similarly exposed would have a 1.7 in 10 million chance of developing cancer.

''These are very small risks,'' he said.

A separate independent toxicology report from Orica-commissioned consultant Toxikos also found little risk of cancer to the residents of Stockton.

"There is no reason to suspect that cancers risks due to this incident would result in an increase above background levels in the general population," the report said.

But a resident spokesman from the community said the residents would not be satisfied until there is a full inquiry into last month's chemical spill.

''We won't be happy until there's a commission that looks into it,'' said Stockton resident and former Newcastle councilor Frank Rigby.