
A sample of potatoes from Mahi Pono’s recent donation to the Hawaii Foodbank on O‘ahu show insignificant amounts of the heavy metals cadmium and lead, a trace of the herbicide chlorpropham, and nothing else, according to the results of lab testing recently commissioned by MauiTime. The tests were conducted by Anresco Laboratories of San Francisco on a sample of potatoes acquired by South Maui State Representative Tina Wildberger, who provided them to MauiTime in late January.
Anresco conducted a general heavy metal scan on the potatoes, as well as testing for residues from 306 chemical compounds. The full results can be found by clicking here (heavy metal report) and here (pesticide report). Anresco’s pesticide tests no longer scan for the Restricted Use Pesticide (RUP) paraquat, the laboratory said. Mahi Pono recently announced that a different California lab, Environmental Micro Analysis, conducted tests for 400 pesticides – including paraquat, but not heavy metals – and found the test potatoes “clear” of all chemical residues.
Results of both lab tests were reviewed by Dr. Lorrin Pang, Maui County district health officer. Pang told MauiTime that although the Food and Drug Administration does not set limits on cadmium or lead, the amounts of those heavy metals found in the sample potatoes were below the standards set by the European Union. He found the level of the herbicide chlorpropham (.011 parts per million) to be minute as well. Chlorpropham is widely used in the potato industry as a sprout inhibitor during potato storage. The European Standing Committee on Plants, Animals, Food and Feed tried to ban the chemical last year, but did not have the votes.
“I am thrilled to learn that the potato test came back relatively clean, especially considering that Mahi Pono is a conventional farm that uses pesticides,” Tina Wildberger told MauiTime. “It is important for me to know our community is not ingesting harmful chemicals.”

On January 25, MauiTime first reported on allegations that Mahi Pono had failed to follow proper procedures while spraying Gramoxone, the brand name for a paraquat-containing herbicide product, on its potato fields. The incident is currently under investigation by the Hawai‘i Department of Agriculture. According to a recent Maui News article, Mahi Pono is one of “more than 10 paraquat licensees in the state.” However, a Department of Agriculture spokesperson told MauiTime that the state only certifies individuals who apply paraquat, not businesses. Mahi Pono, whose name means “to cultivate morally or properly,” has not addressed the specific incident, nor has it denied that it uses paraquat.
Mahi Pono’s use of the highly toxic and widely banned chemical (even China forbids its use) is ironic, given the company’s big announcement in January that it would not use glyphosate (RoundUp), a much weaker herbicide, in its 41,000-acre agricultural operation. Since then, Mahi Pono has issued all kinds of pronouncements about its farming, but continues to avoid any mention of “paraquat,” saying only that it employs “conventional” (read: chemical) farming techniques and follows instructions when using RUPs on its fields.
In the aftermath of the MauiTime story, social media filled with numerous allegations and speculation that Mahi Pono’s potatoes were tainted – an assertion not made in our report. However, the social media feedback led to MauiTime’s decision to have the potatoes tested.
Pang found the potato results to be misleading in the face of Mahi Pono’s use of “conventional” chemicals on its crops. He emphasized that he was speaking not on behalf of Maui County, but in his capacity as a chemist, physician, and public health expert who has advised the World Health Organization and currently serves as a consultant to the US Congress.
“I would not say that it’s OK because the chemicals and pesticides and heavy metals aren’t in the food,” Pang said. “I worry about the spraying. I would look at the drift.” Pang considers federal and state regulations regarding pesticide spraying to be inadequate and said pesticides and other sprayed chemicals drift in a far wider area than assumed.
“If the potatoes are clean, or if they are dirty, you still have a choice,” he said. “You can eat them, or choose not to.”
However, Pang added, “The spraying is different. It requires the consent of everyone affected. And everyone on Maui hasn’t given consent to inhaling drift from paraquat or other pesticides.” Pang said he didn’t bring up this matter when contacted for his opinion on Mahi Pono’s potato pesticide report, “because no one asked me.” He compared the issue to smoking.
“We assume that people who smoke are informed of the risks and have individually chosen to smoke,” Pang said. “But secondhand smoke exposure is prohibited because it affects people who have not chosen to smoke.”
Pang’s comments were echoed by Wildberger. “During pesticide application, Maui’s robust trade-winds carry fugitive dust for miles, affecting schools and neighborhoods,” she said. “South Maui residents reserve the right to breathe clean air. Residents should not be exposed to chemicals that were manufactured for the purpose of killing organic matter.”
Pang said, if asked, he would tell Mahi Pono, “Quit spraying stuff. Don’t put it on the ground when the dust is going to drift. Please stop trying to get 100 percent production 100 percent of the time. Stop trying for it.”
Wildberger added, “When I asked [Mahi Pono community farm manager] Darren Strand about this issue at a [January] gathering hosted by O‘ahu developers, his response was that the rainy season should help. Clearly there is no other plan to prevent exposure to pesticide drift. I want to make sure that our developing agricultural industry does business safely while contributing to food security in Hawai’i.”
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Image 1 courtesy Maui County Health Volunteers. Image 2 by MauiTime