LIHUE — Over the last seven decades, the use of atrazine in Hawaii has declined significantly, from about 400,000 pounds in 1964 to 77,403 pounds in 2012, according to a recent study by the state Department of Health. And much
LIHUE — Over the last seven decades, the use of atrazine in Hawaii has declined significantly, from about 400,000 pounds in 1964 to 77,403 pounds in 2012, according to a recent study by the state Department of Health.
And much of that drop is the result of the state’s dying sugar industry.
For anyone concerned about atrazine and its potential health and environmental impacts, DOH supervisor Fenix Grange said the report should be “extraordinarily comforting.”
“The hazard is going down, not going up,” she said. “But to be sure, we’re going out and collecting samples.”
The legislative report — as well as the DOH’s current sampling effort — is the fruit of House Concurrent Resolution 129. Adopted in April, it called for the DOH to head up a task force to address the potential data gaps on air, surface water and near-shore effects of the chemical herbicide.
“Last spring they asked for an atrazine study, because atrazine was kind of the flavor of the month,” said Grange, who prepared the report along with DOH toxicologist Barbara Brooks.
The report, completed in November and recently posted online, found that the sugar industry “was and is the largest user of atrazine in Hawaii.”
“The drop in atrazine usage over time reflects the decline of sugarcane cultivation, cancellation of some uses and more restrictive label application rates,” according to the report.
HCR 129 states “it is in the best interest of the state to be at the forefront of a monitoring and regulatory effort to protect Hawaii residents from the potential adverse effects of chronic atrazine exposure.”
Grange said the 63-page report is the first of its kind, a compilation of historical atrazine use data throughout the state.
Manufactured by Syngenta, Atrazine is a pre- or post-emergence herbicide used for weed control. Registered in the U.S. since 1958, it is one of the most widely used herbicides, with 76.5 million pounds of the active ingredient used domestically each year.
Use in Hawaii
As of 2012, 20 atrazine products were registered in Hawaii. And from 2010 to 2012, seven of those products were used — all for agriculture.
“Seed corn, sugarcane, sweet corn and macadamia nuts are the only crops currently using atrazine in Hawaii,” states the report.
From 2010 to 2012, an average 80,912 pounds of atrazine were sold annually in Hawaii. About 94 percent of the herbicide sold here is used for weed control on sugarcane, while seed corn production accounts for 6 percent (an average of 4,771 pounds per year), according to the report.
On Kauai, an average 3,457 pounds were sold annually between 2010 and 2012, representing about 4 percent of the total sales statewide and 72 percent of the atrazine used on seed corn statewide.
Grange said all of the atrazine purchased on Kauai is done by the seed corn industry. She also pointed out that the maximum rate of application per year on seed corn is 2.5 pounds per acre — one-quarter the maximum rate for sugarcane, at 10 pounds per acre.
In 2010, 3,520 pounds of the chemical were sold on Kauai. In 2011, that number dropped to 2,242 pounds, but more than doubled to 4,609 pounds the following year.
As part of the study, Don Heacock, a biologist with the state Department of Land and Natural Resources, provided the DOH with information on citizen water sampling for pesticides on Kauai.
On Friday, Heacock said a reduction in use of anything toxic, including atrazine, is a good thing.
“The thing about atrazine is it’s a hormone mimicking compound,” he said. “Any time you have something that mimics hormones in a human being and it’s an artificial compound it puts up a big red flag for possible human health effects.”
While certainly a move in the right direction, Heacock said the decline in use is somewhat irrelevant.
“The fact that we still use it is unbelievable,” he said. “Even the country that produces it (Switzerland) banned it.”
Although the Environmental Protection Agency approved atrazine’s continued use in October 2003, that same month the European Union announced a ban of atrazine because of “ubiquitous and unpreventable water contamination,” according to a publication on the National Center for Biotechnology Information website.
“Atrazine is a common agricultural herbicide with endocrine disrupter activity,” the website states. “There is evidence that it interferes with reproduction and development, and may cause cancer.”
Syngenta spokesman Paul Minehart said even though atrazine is not used in Europe, it “received favorable safety reviews from European Union regulators who found that, properly used, atrazine ‘will not have any harmful effects on human or animal health or any unacceptable effects on the environment.’”
“In fact, European farmers control their weeds with a herbicide almost identical to atrazine called terbuthylazine,” Minehart said.
During the month of December, Syngenta applied 244.75 pounds of atrazine to 306.5 acres, while Dow AgroSciences used 23.66 pounds on 18.5 acres and DuPont Pioneer 7.6 pounds to 12.17 acres, according to post-application pesticide summaries submitted to the Hawaii Department of Agriculture.
Mark Phillipson, spokesman for Syngenta on Kauai, said the December numbers are only “a snapshot,” and that this is the time of year when Syngenta uses larger amounts of atrazine as part of its integrated pest management plan.
“It all depends where a company is at in its planting cycle, when and where they’re using atrazine,” he said. “Some herbicides work better than others depending on the weed type.”
Phillipson said atrazine, like all pesticides used, is an important tool — one that is often misunderstood. Much like prescription medication, he said pesticides can be used and abused.
However, when used properly, both are effective, Phillipson said.
“I think the EPA has done a good job with atrazine in continuing to look at the data when they register the product,” he said. “In the case of atrazine, it’s really stood the test of time.”
Complaints and concentrations
The DOH report also provides details about the number of pesticide and fugitive dust related complaints received by the Hawaii Department of Agriculture each year.
Between 2010 and 2013, HDOA received 293 pesticide complaints, including 127 on Oahu, 73 on Big Island and 42 on Kauai. No cases of atrazine exposure were confirmed, according to the report.
During the same three-year period, HDOA received 70 fugitive dust complaints from agriculture, with Kauai accounting for 35, or 50 percent.
While agricultural dust accounted for just 5 percent of all dust-related complaints statewide, it accounted for 13 percent of the 271 complaints on Kauai.
“In contrast to pesticide complaints made to HDOA, Kauai and Maui had the highest number of agricultural dust complaints,” states the report.
In the past three years, the HDOH issued two violations for fugitive dust — one to Monsanto Company on Molokai and the other to Hawaii Commercial & Sugar Company on Maui.
Environmental data for groundwater, surface water and air in Hawaii were also evaluated as part of the study. Since 1993, atrazine concentrations have not exceeded the maximum contaminant level of 3 parts per billion, it states.
Grange said there is not a threat to drinking water from historical use, and the likelihood of any future threat from atrazine at present regulatory levels “do not seem to be a concern.”
“The worst-case conditions have come and gone already,” she said, referring to heavy use during Hawaii’s sugar cane era.
To provide some perspective, 16 of 39 water systems on Hawaii Island had historic detections of atrazine, compared to only 3 of 33 on Oahu, 2 of 18 on Kauai and 1 of 34 on Maui, the report states.
Statewide sampling nearly complete
In their executive summary, Grange and Brooks recommend additional stream and near-shore water sampling for atrazine and other commonly used pesticides.
“Limited data exist as there is no regulatory program requiring surface water monitoring,” the report states.
In September, the HDOH received $75,000 to begin testing for pesticides, including atrazine, in streams and other waterways around the state.
Once complete, the results of the stream sampling will be made available to the Legislature and general public.
While she could not confirm specific locations, Grange said the testing will include eight sites on Kauai, eight on Oahu, six on Big Island and two on Maui. The study will look at how pesticides may be impacting four specific land uses, including monoculture ag (those likely to be using restricted use pesticides), small mixed-use ag areas, turf uses (including golf courses and resorts) and urban and residential, according to Grange.
“This is a snapshot in time,” she said of the testing. “It won’t answer all the questions.”
• Chris D’Angelo, environmental reporter, can be reached at 245-0441 or cdangelo@thegardenisland.com.
