Are there “safe levels” of pesticide exposure?

The Hawaii State Department of Agriculture (HDOA)’s Pesticide Branch recently released a 2013 report conducted on its behalf by University of Hawaii at Manoa researchers analyzing chemicals in the air near Kauai schools.

Several incidents of chemical odors affecting students and teachers at Waimea Canyon Middle School on Kauai occurred between November 2006 and April 2008. Unidentified odors caused students to be evacuated from the school and seek medical treatment for flu-like symptoms including dizziness, headaches and nausea. Symptoms experienced by the students were consistent with exposure to volatile chemicals.

Ambient air studies were conducted on Kauai in response to community concerns regarding potential pesticide exposure. The primary finding of the report, which was conducted by Qing X. Li, Jun Wang and Robert Boesch, all of the Department of Molecular Biosciences and Bioengineering, is that the concentrations of the chemicals consistent with pesticide use were “well below health concern exposure limits or applicable screening levels.”

The report also found that, although the symptoms experienced by students and faculty could be consistent with exposure to certain pesticides, they could also be caused by “exposure to volatile chemicals emitted from natural sources, such as stinkweed. At the time of these occurrences, stinkweed was growing in the fields near the school and was considered by some county emergency response officials to be the potential cause of the students’ symptoms.”

The Hawaii Crop Improvement Association (HCIA), a trade union representing the seed crop agribusiness industry, wasted no time in claiming victory. “It is critical that the public know the truth regarding agriculture use of pesticides in Hawaii,” said Bennette Misalucha, HCIA’s executive director. “There are too many extreme voices slandering the responsible work by Hawaii’s farmers. We want to help residents and lawmakers know that children in schools are not being evacuated or exposed to pesticides from seed crop farming.”

“I am unaware of stinkweed ever causing the evacuation of a school anywhere in the world, ever. For HDOA to claim definitive knowledge of the cause of the Waimea School incidents is disingenuous,” said Kauai County Councilman Gary Hooser. “No comprehensive testing or evaluation of possible pesticide drift occurred until four years after the 2008 incident at Waimea Canyon School. Syngenta had, by that time, stopped applying pesticides near the school and was aware the testing was taking place, yet pesticide drift was still detected on the school grounds.”

“That HDOA is denying any pesticide drift problems in relation to the GE chemical test fields, in alignment again with the chemical company lobbying group HCIA, is indicative of the failure of the state to address our concerns,” said Nomi Carmona, the executive director of Babes Against Biotech. “HDOA recently stated there are 129 vacancies in their department and we are still understaffed with pesticide inspectors. The fact that only seven of 72 investigations of pesticide misuse have been completed on Kauai speaks of failure to thoroughly and accurately investigate the situation.”

The report says that HDOA conducted regulatory compliance investigations, including the collection of environmental samples from the school and surrounding areas, of the odor and health complaints from the school and determined that there was no evidence to indicate that pesticides had been used improperly. But it doesn’t specify when those initial investigations took place.

As for the stinkweed, prior to conducting air monitoring at the school and at other locations, samples of the plant were collected, extracted and analyzed for chemical compounds in the laboratory. Stinkweed was found to produce 29 chemicals during these studies. Methyl isothiocyanate (MITC) was one of those 29 chemicals. According to the report, “MITC is a highly foul-smelling, noxious chemical at high concentrations, and is cited as a potent lachrymator and nose and throat irritant.”

But MITC is also a degradation product of metam-sodium, a pesticide that can be used to treat utility poles for wood rot, as well as in agriculture.

“Metam-sodium is classified as a restricted-use product that can only be sold in conjunction with strict record keeping, and no sales of metam-sodium were recorded on Kauai for 2012,” the report states. But again, the report fails to mention if sales of the pesticide were reported in 2008 or before.

“Because we found MITC in stinkweed plant tissue, air emissions from stinkweed plants, and in passive sampling near stinkweed plants, we believe the MITC detected through high volume air sampling was from plant sources,” reads the report.

Approximately half of the 29 chemicals produced by stinkweed were detected both in indoor and outdoor air samples collected from the passive and high volume air samplers positioned at Waimea Canyon Middle School and other Kauai schools. Trace amounts of five pesticides were also detected in both the passive and high volume samples collected at Waimea Canyon Middle School. Two of the five pesticides, dichlorodiphenyltrichloroethanes (DDTs) and benzene hexachlorides (BHCs), were widely used historically for mosquito and other insect control and are no longer in use. They have no odor in low concentrations.

Because these pesticides do not break down quickly, they can still be detected throughout the islands, and in fact, throughout the world. And that’s really the point. Are there any safe levels of these pesticides when they can break down and enter the water table and the food chain?

One of the other five pesticides found in “trace amounts” in the air surrounding Waimea Middle School, Chlorpyrifos, belongs to a class of pesticides known as organophosphates, which are designed to interfere with the way insect brains operate. But they can also affect human brains. In fact, Chlorpyrifos is so toxic that the Environmental Protection Agency (EPA) forced the removal of all Chlorpyrifos-containing home-use products in 2000, including Dursban, Raid, Black Flag Liquid Roach and Ant Killer and Hartz Mountain Flea and Tick Collar.

But that was after 35 years of exposure for the American public and more than 7,000 cases of Chlorpyrifos-related poisoning cases. Approximately 21 to 24 million pounds were used annually in the U.S., of which about 11 million pounds were applied in the home, where the chemical’s main job was to kill termites. Because of its extensive use in the home before the ban in 2000, the vast majority of the U.S. population during that time was exposed to chlorpyrifos or its environmental breakdown product, trichloropyridinol (TCP). Chlorpyrifos can cause severe brain damage, especially in children, as Paul Koberstein reports in his piece, “The ghost in the GMO machine.”

“We know through the Maui County interviews with the EPA that pesticide testing combinations are both untested and used in high volumes by chemical companies performing outdoor experiments across the state,” said Carmona. “We also know that the EPA performs zero health or environmental impact studies of pesticides before registering them for use, instead relying on data provided by pesticide manufacturers.”

Currently, lawmakers are considering SB1037 (SD2), a bill which requires HDOA to establish a mandatory disclosure program for pesticide use under circumstances consistent with commercial agricultural use.

But Misalucha and HCIA say the bill is dangerous and “not clearly defined.”

“HCIA continues to lobby against pesticide buffer zones around schools and has, for years, sought to pre-empt the rights of the counties on these issues, while arguing against common sense state policies like pesticide disclosure and notification,” countered Carmona. “HCIA lobbied to strike county rights to enact ordinances which protect the lives and health of citizens. We need to prioritize children’s health over pesticide manufacturer profits.”