The state epidemiologist, after investigating a complaint about black mold festering in Orleans Parish Prison, has dismissed as “unconscionable” the claims of a deputy sheriff who wrote a letter to Gov. Bobby Jindal warning that inmates face urgent health risks from toxins growing in the aging lockup.

Dr. Raoult Ratard, of the state Department of Health and Hospitals, determined that chronically coughing Deputy Don Marshall Jr., who has filed suit against Sheriff Marlin Gusman, did not develop his respiratory illness from “direct toxicity” but instead developed an allergic reaction.

“An allergic reaction is different from a direct effect caused by a toxin,” Ratard wrote in his findings, adding that “there is currently a great deal of overblown fear and legal attention to environmental fungal toxins.”

“Almost all real episodes (of) human illness due to fungal toxins have followed ingestion of the toxin,” he wrote.

A team of state health inspectors, in a recent walk-through of the jail, noted “several black spots consistent with mold” and offered a series of recommendations on how the Sheriff’s Office can improve air quality at OPP, which is expected to close early next year.

Ratard wrote that “although there are professional companies that can come and culture air and walls for fungi, this is really not necessary” because these cultures “will always be positive.”

“Molds are simply everywhere,” he added, “and short of very specialized and highly filtered clean room environments, it is not possible to eliminate them.”

Marshall, who has said he intends to seek class-action status for his lawsuit to include other Sheriff’s Office employees, scoffed at the state’s findings in an interview Friday, saying Ratard’s report won’t deter him from pursuing his case.

“They wrote off my conditions as normal conditions when I never had those conditions prior to working in the jail after Hurricane Katrina,” said Marshall, who has been diagnosed with allergic hypersensitivity and reactive airway disease, illnesses he blames on two kinds of mold growing in OPP and the Orleans Parish Criminal District Courthouse.

“They observed mold in the facilities, yet did not bother to take a swab,” Marshall added. “If they had done a proper investigation, at minimum, when they saw the mold builds they would have taken samples and sent them in. They’re going through the motions.”

Marshall sent a letter to Jindal in late July saying an allergist had determined he had been exposed to the two kinds of molds.

According to Ratard’s report — which contained passages copied from, but not attributed to, Wikipedia and the Centers for Disease Control and Prevention website — state officials immediately began investigating Marshall’s complaint, contacting the deputy’s physician and collecting documents.

Inspectors visited OPP in early August and noted conditions in several areas conducive to mold growth.

“Areas of unconfirmed visible mold on the ceilings in multiple tiers were observed,” the inspectors wrote, noting “extensive variability in the temperature and humidity” within OPP.

Ratard, in his investigative summary, said it is “important to make a difference between an allergic reaction which is specific to one individual and a direct toxic effect which affects anyone exposed to the toxin.”

By way of illustration, he described a hypothetical serving of peanuts at a restaurant. If the peanuts are contaminated with arsenic, Ratard wrote, “the restaurant owner is exposing his customers to a toxic compound and he should immediately cease serving the dish.”

On the other hand, he wrote, someone allergic to peanuts “may be at risk of severe illness” if they consume a dish containing them despite a warning on the menu, “but in no way (can) the restaurant owner ... be held responsible for the customer’s illness.”

State health officials also reviewed OPP’s outpatient logs for a five-month period and determined that, out of 1,003 recorded visits to medical personnel by inmates, 38 stemmed from asthma, while six were categorized as either fungus- or mold-related.

Those data, Ratard concluded, did not support Marshall’s claim that inmates faced “urgent and hazardous conditions.” The epidemiologist allowed, however, that mold may cause health effects such as allergic illnesses.

To improve air quality at OPP, the state Health Department recommended the Sheriff’s Office, among other measures, mitigate “excessive air conditioning condensation pooling on the floor,” ensure the air conditioning is working properly, stop leaks and repair water damage.

It wasn’t clear whether the Sheriff’s Office, which is preparing to move inmates into a new 1,438-bed jail in early 2015, has acted on the advice. A Sheriff’s Office spokesman did not respond to a request for comment Friday.

Follow Jim Mustian on Twitter, @JimMustian.