FLINT, MI -- State officials found evidence of rising blood lead levels in Flint two months before the problem was exposed by a Flint pediatrician, but didn't immediately inform the public, according to documents released by a water researcher.

Michigan public health officials said today, Dec. 22, that they did not sound an alarm about the spike, which coincided with use of the Flint River for drinking water, because they initially believed the numbers represented a "seasonal fluctuation."

As a result of what happened in Flint, state officials now say that the way the state analyzes the data they collect needs to be "thoroughly reviewed."

Virginia Tech Professor Marc Edwards, a key figure in the Flint water crisis, released 159 pages of public records on his Web site this week, documents received in response to a Freedom of Information Act request to the state.

The records are a collection of emails and attachments, primarily from officials at the Michigan Department of Health & Human Services, about Flint water.

The documents show:

Emails about blood lead levels in Flint date back to at least July 23 and by July 28, inner-office correspondence says the city's rising numbers warrant further investigation and that "there does appear to be a higher proportion of (elevated blood lead levels) last summer (2014) than usual."

A report prepared by the state DHHS's Child Health Epidemiology Section, which included data up to July 27, concluded "positive tests for (elevated blood lead levels) were higher than usual for children under age 16 living in the city of Flint during the months of July, August and September 2014."

A Sept. 11 email from Robert L. Scott of DHHS' Childhood Lead Poisoning Program tells others in the department that he has received a request for information about blood lead levels in Flint. "Sounds like there might be more to this than what we learned previously. Yikes," the email says.

Edwards said today, Dec. 22, that the documents show the state had evidence of elevated blood lead levels in Flint while the Michigan Department of Environmental Quality and the city of Flint denied a public health problem with lead in the city's water supply.

After Edwards reported his testing showed a serious problem with lead in Flint water, a DEQ spokesman questioned the credibility of his research and former Flint mayor Dayne Walling assured residents it was safe to drink until September when a Flint pediatrician reported her findings.

Those denials would not have continued as long as they did had state health officials told the public what it had discovered, the professor said.

"Everything they looked at, they found a problem, and they never told anyone," Edwards said of the agency.

Dr. Eden Wells, chief medical executive for the DHHS, said today that the documents do show missed opportunities for the state to have addressed Flint's lead in water crisis earlier, but do not show an effort to withhold information.

"I have done this a lot after (disease) outbreaks ... You always go back, and learn from them, (including whether evidence) could have allowed for an earlier response," she said.

Wells, who was named by Gov. Rick Snyder to be Flint's drinking water public health adviser, said state health officials initially concluded that spikes in blood lead lead levels immediately after the city changed its water source to the Flint River were seasonal and not related to water.

DHHS officials initially questioned the findings by a Hurley Medical Center pediatrician, Dr. Mona Hanna-Attisha, who on Sept. 24 showed blood lead levels of children in some parts of the city tripled after the switch to Flint River water.

The released emails show that on Sept. 28, in preparation for a news conference on Hanna-Attisha's findings, the director of the state health department said he needed an analysis of the Flint doctor's data and her conclusions.

"I would like to make a strong statement with a demonstration of proof that the lead blood levels seen are not out of the ordinary and are attributable to seasonal fluctuations," the email from DHHS Director Nick Lyon said.

Blood lead levels above 5 micrograms per deciliter are considered elevated by the Center for Disease Control and Prevention.

Wells said only after reviewing the state's own data further, examining it based on zip codes and focusing on young children, who are most susceptible to lead poisoning, could she conclude blood lead levels were rising among Flint children under 5 years old.

Jennifer Eisner, a spokeswoman for DHHS, said the department initially believed higher blood lead levels were due to seasonal fluctuations.

"As a result of this process, we have determined that the way we analyze data collected needs to be thoroughly reviewed," Eisner said in an email to The Flint Journal-MLive.

Wells was involved in a follow-up examination of state data after Hanna-Attisha made her research public in late September. Wells eventually agreed with the Flint doctor.

Edwards said he spent weeks in an effort to get access to state blood lead level data after testing of Flint water by Virginia Tech found lead levels in water rising as well.

The professor said he encountered resistance from state agencies in releasing blood lead data, delaying efforts to address the problem.

Edwards' experiments on the river water found it was far more corrosive than Lake Huron water that had been purchased from the Detroit water system and used in Flint for decades.

Flint reconnected to the Detroit system in October, using state, local and grant funds to end its use of the Flint River after 17 months.

State and federal reviews of how the Flint's water crisis was allowed to happen are ongoing.