Six months ago, dangerous levels of dioxin were discovered near two U.S. Department of Defense schools on Okinawa Island — but only now are many service members based there learning the full extent of the contamination.

Parents whose children attend the potentially poisoned facilities at Kadena Air Base claim the Pentagon has failed to inform them of the risks or investigate whether the pollution extends onto the school ground. Many are accusing the military authorities of endangering their children’s health and now they have formed a group to demand answers.

The focus of parents’ fears are the playing fields of Bob Hope Primary School and Amelia Earhart Intermediate School, facilities operated by the Department of Defense for the children of U.S. service members.

Last June, construction workers unearthed more than 20 chemical barrels on civilian land bordering the schools.

Following tests the following month, the barrels were found to contain high concentrations of dioxin, a substance that can cause cancer, immune system damage and developmental problems in children. In nearby soil, dioxin levels measured 8.4 times the legal limit, while water peaked at 280 times the level considered safe. The land had once belonged to the adjacent air base but was returned to civilian use in 1987.

“Knowing that the base has probably been aware of this situation for many months, I feel very angry. I cannot imagine what could justify their decision to withhold this information from us parents. I believe they were morally and ethically obliged to warn us of the possible threat to our children,” Jannine Myers, the mother of a 10-year old girl attending Amelia Earhart Intermediate School, told The Japan Times.

Myers first heard about the contamination after reading a letter that was published in The Japan Times on Dec. 24 titled “Demand answers about dioxin threat at Okinawa schools.” (www.japantimes.co.jp/community/2013/12/23/voices/demand-answers-about-dioxin-threat-at-okinawa-schools/#.UtkSbCj8820 )

Angered by the authorities’ failure to notify parents and local residents about the possible dangers, Myers created a Facebook group on Jan. 10 named “Bob Hope/AEIS — Protect Our Kids,” in the hopes of persuading base officials to hold a public meeting and explain what action has been taken.

The group currently has more than 130 members with more parents joining everyday.

“If there is a dioxin threat at the schools, it will take an enormous amount of public pressure to a) have the U.S. authorities admit that they are responsible, and b), cause them to clean up this mess and protect our children,” Myers said.

Correspondence between Kadena Air Base officials and the Okinawa Defense Bureau reveals the U.S. authorities were aware of the proximity of the school fields to the chemical dumpsite as early as June.

Documents obtained by The Japan Times detail the bureau’s inquiries to the base immediately following the discovery of the barrels.

In response to these questions into past usage of the land, Kadena officials replied, “Starting in 1980, the area adjacent to the site was used as baseball fields and playgrounds for a nearby elementary school on Kadena Air Base.”

On Tuesday, in response to questions from The Japan Times about whether teachers and parents had been informed of the potential dangers, David Honchul, U.S. Forces Japan director of public affairs, appeared to contradict parents’ claims that they had not been notified. “There have been notices about the excavated drums and leadership at Kadena Air Base have been tracking the issue very closely,” he said by email.

Honchul also sought to reassure worried parents. “Kadena leadership and USFJ will take appropriate measures in accordance with DOD policy should we become aware of any potential substantial impact to human health and safety,” he wrote.

But it seems for many parents, this is too little, too late.

“The moment the knowledge of the barrels being uncovered and the potential for any dioxins to be found were known, every parent of the schools, and every person on Kadena should have been notified. I feel outraged,” Tina Eaton told The Japan Times. Eaton, who often takes her 3-year-old daughter to play on the schools’ fields, worries about the health effects of possible dioxin exposure on her child.

Meanwhile, on the civilian side of the wire, Japanese authorities are continuing to examine the land for further contamination.

Recently they discovered seven more barrels but they have not yet been unearthed. Unlike the nearby on-base land where American children are still allowed to play, the civilian side remains strictly cordoned off to prevent public access.

Among the barrels initially unearthed last June were some marked with the logo of the Dow Chemical Company, one of the leading manufacturers of military defoliants — including Agent Orange — during the Vietnam War. Tests on the barrels revealed the presence of two of Agent Orange’s telltale ingredients: the herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), and 2,3,7,8-tetrachlorodiben-zop-dioxin (TCDD), the most lethal form of dioxin.

Commenting on the results, Katsuhisa Honda, the Ehime University scientist in charge of the study, likened the land to contaminated fields in Vietnam where the Pentagon sprayed millions of liters of Agent Orange in the 1960s.

Despite U.S. military records related to Agent Orange cataloguing a herbicide stockpile at Kadena in 1971, the Pentagon has repeatedly denied it stored such substances on Okinawa Island.

This is not the first time that Kadena Air Base schools have been the focus of public concern.

In 1983, a large quantity of live ammunition was discovered buried beneath the playground of Bob Hope Elementary School.

Recently, a number of high profile environmental concerns have come to light in Okinawa.

Last week, Kyodo published U.S. documents showing the Pentagon conducted dozens of biological weapons tests on the island between 1961 and 1962. Last summer, The Japan Times reported allegations from former U.S. service members that several tons of nerve gas were dumped off the island’s coast in 1969.

Under the current U.S.-Japan Status of Forces Agreement, the Pentagon is absolved of all responsibility for environmental damage caused by its bases. However, in December, Washington announced that it would soon negotiate a new Environmental Stewardship Pact with Japan to supplement the current SOFA.

The Pentagon claimed the deal will improve environmental standards on its installations, but skeptics dismissed it as an attempt to placate Okinawans’ anger over plans to build a massive new military complex in the city of Nago.

However, it seems concerns over military pollution at Kadena Air Base has united many on both sides of the fence.

“We need to find out if our kids are at risk. That is the least the U.S. government/military owes us — and owes the people of Okinawa. They do not deserve this lethargic attitude on such a potentially devastating discovery, and neither do we,” Eaton said.