Does Roundup contribute to algae blooms, and should Martin County ban it?

Gil Smart | Treasure Coast Newspapers

Show Caption Hide Caption Popular breakfast cereals, oatmeal may contain cancer-linked pesticide Your favorite cereal, instant oatmeal or granola bar might also contain the main ingredient for weed killer.

Could Roundup be contributing to the slimy green goo once again fouling our waterways this summer?

A group of protesters outside Martin County offices Tuesday thought so, saying it's one of many reasons the Martin County Board of Commissioners should ban the ubiquitous — and controversial — weed killer.

The group of about 20 protesters were unsuccessful in one respect: County commissioners said they'd need to conduct more research before considering a ban. But I suspect the protesters weren't too surprised; after all, the county was unlikely to pass a ban on the spot.

The real goal might have been public awareness — or more of it.

After all, Roundup has been much in the news lately.

On Aug. 10, a California jury delivered a hammer blow to Roundup maker Monsanto, awarding $289 million to a school groundskeeper who claimed repeated exposure to glyphosate, the active ingredient in Roundup, caused him to develop cancer.

Monsanto said the jury got it wrong and the company — recently acquired by pharmaceutical giant Bayer — will appeal.

Then, on Aug. 15, the Environmental Working Group reported that traces of glyphosate were found in a variety of popular oat cereals, oatmeal, granola and snack bars, in some cases at levels higher than what some scientists consider safe.

Turns out, Roundup is sometimes used as a "dessicant" — basically, it's sprayed on some crops near the end of the growing season to expedite the usual process whereby the crop dies and dries in the field. That allows farmers to clear the fields before the onset of unfavorable weather, and reduces the moisture in grain crops to enable them to be more easily stored without getting moldy.

Inevitably, the Environmental Working Group claims, the chemical makes its way to your dining room table. Glyphosate with a side of toast and orange juice: Bottoms up!

Does Roundup cause cancer? Maybe, maybe not. In 2015 the International Agency for Research on Cancer, part of the World Health Organization, classified it as "probably carcinogenic to humans." But the next year a report from WHO and the United Nations' Food and Agriculture Organization concluded that exposure through diet probably didn't pose a cancer risk.

Whichever's correct, the bottom line is you don't want to go bathing in the stuff.

But what of other things that do bathe in it? And here I'm talking about cyanobacteria — that is, blue-green algae.

Glyphosate doesn't cause blue-green algae blooms, but some researchers have suggested it may feed existing blooms, making them worse.

A 2009 Ohio Sea Grant study concluded Roundup "may be contributing to the growth of harmful algal blooms in Lake Erie."

Glyphosate is a "phosphonate" — an organic molecule based on phosphorus. Phosphorus feeds blue-green algae blooms; there's evidence, the Ohio researchers concluded, that "many cyanobacteria present in Lake Erie have the genes allowing the uptake of phosphonates, and these cyanobacteria can grow using glyphosate and other phosphonates as a sole source of phosphorus."

Geoff Norris, an emeritus professor with the University of Toronto's Department of Earth Sciences — and a Stuart snowbird — shares that view. He wrote a paper in 2016 for his condo association on Hutchinson Island (later shared by former Sewall's Point commissioner Jacqui Thurlow-Lippisch on her blog) reaching a similar conclusion.

Glyphosate, he wrote, "has been used heavily in the agricultural areas around Lake Okeechobee and upstream in the Kissimmee River watershed for at least 25 years. Glyphosate provides a source of phosphorus for blue-green bacteria and recent research by others suggest that glyphosate enhances the growth of blue-green bacteria, which become tolerant and absorb glyphosate directly."

And that's when your bloom can go "boom."

Far more research on this question is needed. And the possibility that Roundup might contribute to blooms in Lake Okeechobee in and of itself isn't a reason for Martin County to ban the chemical, which is likely used by every landscaping company in the region, not to mention individual homeowner.

The stuff works, after all.

But given the California verdict and what it might portend, given recent revelations about how much of the stuff we're all ingesting, and given the possibility it could be a contributor to our algae problem — county officials might be wise to see the big picture here.

And one, at least, did: Before the commission meeting Tuesday, Commission Chairman Ed Ciampi stopped to chat with protesters and even brought along his own sign: "I support a ban on glyphosate," said the sign, which also advocated extending the county's fertilizer ban from four to six months, and banning offshore drilling.

"I'm a Republican," said Ciampi. But Florida's ecological problems have gotten so bad it's no longer possible to be "pro-business" if that's ultimately detrimental to the environment.

A ban would surely inconvenience landscapers, backyard botanists and even the county itself, which spends a reported $2.4 million annually to eradicate weeds.

But given what's going on in our waters, given the potential impact on human health, maybe it's better to be safe than even sorrier.

Gil Smart is a columnist for Treasure Coast Newspapers and a member of the Editorial Board. His columns reflect his opinion. Readers may reach him at gil.smart@tcpalm.com, by phone at 772-223-4741 or via Twitter at @TCPalmGilSmart.