Late each winter, when fresh green grass begins to sprout on the East Bay hills, Livermore grape grower and winemaker Aaron Taylor notices something about the vineyards surrounding his own 12-acre plot. While new vegetation is sprouting beneath his vines, the earth remains brown and bare on the adjacent properties.

"This is prior to the new season's first application of herbicide," he explained. That tells Taylor that the weed killers' effects are neither temporary nor seasonal.

In fact, popular herbicides can linger in soil for months after application — or even years.

"They don't necessarily just go away like they tell you," said Taylor, who operates Retzlaff Vineyards. "So you have to wonder what the long-term effect is on our ecosystems and ultimately on us."A multitude of researchers are now studying the long-term health effects of pesticides, and what they're finding isn't good. Widely used agricultural poisons seem to be causing a plague of human health problems.

Taylor's small vineyard is certified organic, which means that he can't use synthetic fertilizers and pesticides, such as Roundup, the infamous herbicide. Roundup's active ingredient is glyphosate, a controversial chemical that many experts believe causes cancer and other illnesses in humans. The U.S. Environmental Protection Agency does not classify glyphosate as carcinogenic, but the World Health Organization does, as does the State of California.

Nonetheless, many U.S. farmers use glyphosate — perhaps most of them. And since Monsanto first brought it to market in the 1970s, they've been using more, and more, and more. In the United States, farmers use more than 250 million pounds of the poison each year. Globally, about 20 billion pounds have been applied in the past 45 years. Statewide, farmers and landscapers used 11 million pounds of glyphosate in 2017, according to the California's Department of Pesticide Regulation. The state's wine industry alone applied about 300,000 pounds of glyphosate-based herbicides. In Alameda County, farmers and landscapers used 30,000 pounds, of which wine grape growers used 1,634 pounds.

It would be a miracle if this didn't contaminate our food supply. In fact, research has shown that glyphosate essentially now lingers in virtually every nook and cranny of our environment, including our food, soil, tap water, and human urine.

A study released early this year found glyphosate in 19 of 20 beer and wine samples tested, including some made from organically farmed ingredients.

The California Wine Institute dedicates a page on its website to glyphosate — chiefly downplaying the results of the study, which came from U.S. PIRG. The institute argues that the trace amounts of glyphosate found in California wines are far less than the daily intake levels allowed by the EPA.

East Oakland resident and UCSF doctor Rupa Marya cited the same beer and wine study as evidence of an environment clogged with residual chemicals.

"You can't even buy organic wine that's truly organic," she said. "All the organic wines tested contained glyphosate. It's in our water table."

Round Up the Usual Suspects

Glyphosate is just one item in a long list of routinely used chemicals that research has connected to cancers, autism, birth defects, and developmental disorders. In the United States each year, farmers and public groundskeepers apply upward of one billion pounds of pesticides, including more than 1,000 registered chemicals and tens of thousands of formulated products. In California, farmers and landscapers applied more than a million pounds of reproductive toxins and 2.5 million pounds of carcinogens in 2017, according to the state's pesticide agency.

"It's a chemical onslaught," said Michelle Perro, a Fairfax pediatrician who has studied child chemical exposure for decades.

Perro believes chemicals used to help grow food are sickening millions of people, especially children, who increasingly are diagnosed with developmental and attention deficit disorders. The chemical war waged on weeds and pests also is having dire ecological effects, like crashing populations of wildlife, especially bugs and birds.

Conveniently for pesticide manufacturers, proving that certain chemicals are harmful is an inherently tricky task.

"Part of the problem with understanding pesticides is that we live in a toxic soup, and it's often hard to isolate the individual chemical that may be causing a problem," said Jay Feldman, director of the Washington D.C. watchdog group Beyond Pesticides. "Not only that, pesticide products are formulations of multiple chemicals."

Years may pass between alleged exposure to a chemical and the onset of disease or chronic condition. If exposure victims pursue legal action, identifying and holding accountable a human culprit, or even a corporation, is next to impossible.

But a lawsuit filed against Monsanto last year broke through this barrier when a San Francisco jury awarded a former school groundskeeper stricken with cancer almost $300 million in damages from Monsanto, the maker of Roundup. Monsanto — now owned by the chemical colossus Bayer — allegedly sold a product that company executives knew was dangerous. Monsanto officials "acted with malice and oppression," the jury found. Bayer now faces thousands of similar lawsuits.

In fact, the wheels of revolution may be turning. In 2015, the southern California city of Irvine passed an ordinance prioritizing the use of organic pesticides on public properties and specifically discouraging synthetic ones after a spike of child cancer cases caught the attention of activists. And in July of this year, Sonoma County passed regulations all but banning glyphosate use on public lands. Several dozen other cities and counties in California have passed similar regulations, as have local governments in at least 22 other states.

Globally, many nations have banned specific synthetic pesticides shown by research to harm humans.

But in Alameda County, public groundskeepers still rely on Roundup to fight weeds.

"It's a cost-benefit assessment — what is the cost of using these pesticides, and what are the benefits?" said Ed Duarte, the integrated pest management expert for the Alameda County Department of Agriculture. He said the county's prevailing policy on pesticides is to use them only when necessary.

Perro thinks glyphosate is never necessary and should be banned.

"But not only that, we need to ban chemical farming," she said. "We have to transition to organic solutions."

Beyond Organic

About forty years ago, shortly after Kristie and Rick Knoll moved from Orange County to Brentwood and planted a large garden and dozens of fig trees, the young couple were sleeping in on a lazy weekend morning.

"Suddenly there was this barrage of noise, like we were being attacked by another country," Kristie recently recalled.

The din, she said, was a helicopter, which hovered low as it moved over a neighbor's fields, deploying pesticides — which Knoll blithely refers to as "poison."

She and her husband quickly learned that chemical warfare on animal and plant pests was standard in the business of farming, to which they were then brand new.

"Everybody was spraying everything with poison, and it was freaking us out," Knoll said. In response to the aerial dousings, she and her husband planted a line of trees along their property line — a sort of pesticide break. Still, she said, their neighbors occasionally "drift" on them.

"I don't know what it is, but we can smell it," she said.

Today, Knoll Farms is one of the few farms in Alameda County that strives to be completely chemical-free. The 10-acre farm was once but is no longer certified organic, as paying for the organic stamp eventually seemed a waste of time and money, said Knoll, who likes to say her farm is "beyond organic." She said they still don't use any synthetic pesticides on their orchards and vegetables.

"Why would you spray poison on something you're going to eat?" she said.

But Knoll's attitude is the exception and not the rule. After all, chemical use is the agricultural standard in much of the world. In Alameda County, for example, less than 200 acres of the county's 2,600 acres of fruit trees and grapevines is certified organic.

Organic remains the preferred purity indicator among activists for identifying ostensibly safe-to-eat food. While even organic foods sometimes carry measurable pesticide residues, the levels are relatively low. On the other hand, marketing terms like "sustainable" and "green" too-often denote little that is truly meaningful.

Consider California's wine industry, which is currently promoting environmentally friendly farming practices and neighborly manners in communities increasingly lashing out against vineyard conversions. Earlier this year, the Sonoma County Winegrowers organization applauded itself for certifying 99 percent of the county's vineyards as sustainable. The organization aligns its standards with those set by the California Sustainable Winegrowing Alliance's statewide certification program.

But much to the chagrin of organic farmers and chemical-free advocates, these and other sustainability programs don't restrict the use of many pesticides, including glyphosate. The California Sustainable Winegrowing Alliance requires that growers abstain from using certain chemicals compiled on a "red list" and at least attempt to do so with other products on a "yellow list." Glyphosate is not on either list.

"These lists were developed very intentionally, and the red list chemicals are barely used by anyone, anyway, and on the yellow list, very few of those chemicals are used," said Megan Kaun, a board member of Sonoma County Conservation Action and the director of a campaign to ban or heavily restrict the use of dangerous pesticides, including fungicides and herbicides. Kaun, like many activists, blames the county's wine industry as a major source of toxic chemical use.

While vineyard managers ostensibly mitigate impacts to the environment by applying chemicals only when little or no wind is blowing — often at night — this tactic only works in theory. Even on the stillest of mornings, a bystander can watch as a tractor sprays vines with chemicals that plume over the vineyard in a towering cloud, disappearing into the air.

"They're drifty," Kaun said. "All spray pesticides can drift a mile or more."

Senior scientist Margaret Reeves of the Pesticide Action Network in Berkeley said it's dangerous to assume pesticides don't drift. "Fumigant pesticides drift by design," she pointed out.

Chemical drift threatens other farmers' crops, animals, wildlife, and water sources. Of course, it also affects humans, especially farmworkers.

Kaun said the state's wine industry's sustainable campaign "is a huge farce — the farmers don't actually have to do anything to be sustainable."

Similar sustainability programs, with names such as "Lodi Rules" and "Fish Friendly Farming," place few restrictions on the use of potent chemical toxins — just guidelines suggesting limited use.

"Sustainable Sonoma is a little disingenuous because it allows the use of Roundup," said farmer Lou Preston, who grows certified organic grapes and a variety of food crops near Healdsburg.

Karissa Kruse, the president of the Sonoma County Winegrowers, declined a request for an interview.

The EPA's Dubious Data

The Wine Institute's glyphosate page makes no mention of the World Health Organization's opinion on the wine industry's favorite herbicide. In 2015, the WHO's International Agency on Research of Cancer, or IARC, classified glyphosate as a probable carcinogen. In 2017, California's Safe Drinking Water and Toxic Enforcement Act of 1986, better known as Proposition 65, added glyphosate to the list of known chemicals known to cause cancer.

What United States regulators consider safe in terms of glyphosate intake is six times higher than the level set by the European Union. Researchers have recommended that these levels be drastically cut. Moreover, new research has found that even ultra-low intake levels of glyphosate — 0.1 parts per billion — could have health consequences for humans. A 2013 study from researchers in Thailand concluded that "the use of glyphosate-contaminated soybean products as dietary supplements may pose a risk of breast cancer." That research, published in Food and Chemical Toxicology, focused on intake concentration levels as low as parts per trillion.

The U.S. PIRG study found as many as 51 parts per billion of glyphosate in the wines they tested. Sutter Home, Beringer, and Barefoot contained the highest concentrations, topping out at 51 parts per billion, while even the organic brands Inkarri and Frey contained 5.3 and 4.8 parts per billion, respectively.

Another study, from the Environmental Working Group, found staggering glyphosate levels in Cheerios and Quaker oat products. The results, released late last year, found more than 2,700 parts per billion of Bayer's potent week killer in samples of Quaker Oatmeal Squares and hundreds of parts per billion in nearly every other sample tested — concentrations that could affect the small bodies of children more potently than larger adults. These results make glyphosate-tainted wine look like a health nut's preferred cleansing tonic.

While the EPA considers the compound safe for human use — and, in fact, little more than a mild skin and eye irritant — many experts distrust the agency's chemical evaluation process. In a published analysis, scientist Charles Benbrook broke down the EPA's and the IARC's opposite assessments of the chemical. He found that the EPA came to a conclusion favorable to glyphosate because the agency relied on unpublished studies from chemical companies themselves. Nearly 100 percent of those studies showed negative results for carcinogenicity. The IARC, however, made its assessment after reviewing 118 peer-reviewed studies, of which 70 percent found a causal link between glyphosate and cancer.

In recent court rulings, juries have essentially ignored the EPA's opinion on glyphosate. In 2018, a terminally ill man named DeWayne Johnson sued Monsanto after Johnson was diagnosed with non-Hodgkins lymphoma, a rare form of cancer. A San Francisco jury ruled in his favor and awarded Johnson $289 million, a sum that was later reduced to $78 million. The ruling held that his physical exposure to Roundup as a school groundskeeper caused his cancer and that Monsanto knew of the dangers of its product for years and chose not to disclose this information to the public.

The ruling also opened the floodgates to many more similar lawsuits. The news group Reuters has reported that Bayer now faces 11,000 similar lawsuits in the United States. Already, juries have awarded billions to plaintiffs seeking compensation for damages caused by Roundup.

Benbrook reports that annual global glyphosate use has exploded by 15-fold since 1996 — the year that Monsanto began introducing genetically modified crops like corn, soy, and cotton that can withstand dousings of Roundup. That technological leap allowed Monsanto's flagship herbicide to be sprayed with abandon across vast fields of grains and legumes. Today, much of the world's staple foods are grown from "Roundup Ready" seeds.

Meanwhile, the scientific evidence implicating glyphosate as a culprit in serious health issues has accumulated in volumes. Dozens of studies indicating the chemical as carcinogenic led to IARC's classification, and researchers continue to find strong evidence linking glyphosate-based herbicides to non-Hodgkins lymphoma. One such study was just published this summer by Luoping Zhang, with U.C. Berkeley's School of Public Health. She and her coauthors found a 41 percent increased risk of non-Hodgkins lymphoma in people exposed to high levels of glyphosate-based herbicides.

Other peer-reviewed research and case studies suggest that glyphosate and other chemicals associated with conventional agriculture are shortening human lives. After researchers tracked almost 70,000 people for four-and-a-half years in France, they concluded that eating a diet of primarily organically farmed food reduced the odds of developing cancer by 25 percent. They published their findings in JAMA Internal Medicine in 2018.

In Sri Lanka, an epidemic of chronic kidney disease has killed thousands and afflicted tens, and maybe hundreds, of thousand since the 1990s. Its causes remain unidentified, but scientists believe pesticide exposure to be a factor. One hypothesis holds that glyphosate has leached into groundwater, bonding with heavy metals already in the water and creating new and dangerous compounds.

Glyphosate has been implicated in rising rates of non-alcoholic fatty liver disease, miscarriages and premature births, reduced gut microflora, and kidney diseases. At least one study found that intake of glyphosate at levels considered safe by the EPA had negative effects on sexual development and intestinal microbiota in rats. There is even speculation that the weed killer is responsible for the plague of cancer in domestic dogs

"It's a simple link — they run in the grass and lick their paws," Perro said.

She added that livestock are showing signs of a variety of chronic health effects suggestive of herbicide exposure.

Perro rejects the notion, often floated by skeptics, that higher rates of diseases are simply a result of more efficient diagnosing. Children, for instance, are increasingly diagnosed with attention deficit disorder.

"I am so offended by this idea that we're just better at diagnosing," she said. "When you walk into a classroom, the kids are spinning off the walls. Ten percent of kids in America now have a diagnosis of ADHD."

Research from UC Davis scientist Janie Shelton, published in 2014 in the journal Environmental Health Perspectives, identified pre-birth exposure to pesticides as the likely source of autism in children. In a 2006 paper in the journal The Lancet, Harvard researcher Philippe Grandjean said pesticides are causing a "silent pandemic of developmental neurotoxicity."

The American Academy of Pediatrics warned in a 2013 paper that pesticide exposure is the cause of "pediatric cancers, decreased cognitive function, and behavioral problems." The paper discussed the difficulties in identifying pesticide exposure as a source of illness. The authors also recommended a shift toward non-chemical pesticide alternatives.

Preston, the organic farmer in Healdsburg, believes that people everywhere are ignoring the dangers of living in a world saturated with toxins.

"As a society, we're way too glib about the presence and impact on our lives of chemicals, whether it's plastics, pesticides, the burning of fuels," Preston said. "They're everywhere, and we ignore it, and in the long run, it's going to get us."

Big Brother is Not Watching Them

Marya of UCSF thinks it's time that state leaders took aggressive legislative action on agricultural toxins.

"We need a statewide synthetic pesticide and fertilizer ban, and Gavin Newsom is the guy to do it," she said.

The idea isn't crazy. Many nations have implemented bans and restrictive use policies on glyphosate and other chemicals, thanks largely to research demonstrating their hazards.

But in terms of restricting chemicals connected to human health problems, the United States lags far behind other nations. According to research published in the journal Environmental Health in June, American farmers in 2016 used 322 million pounds of 85 different pesticides that are banned in the European Union. The paper explained that the European Union's chemical licensing process places the burden of proof on chemical manufacturers to conclusively demonstrate that use of a chemical will not harm humans or the immediate surrounding environment.

This, observed the paper's author Nathan Donley, a senior scientist with the Center for Biological Diversity, is nearly the opposite of the United States EPA's approach, in which "harm to plants, animals, the broader environment, and harm to humans from occupational exposures remains solely a cost-benefit analysis."

"EPA approval simply means that the agency has determined that the economic benefits to the pesticide company and corporate agriculture outweigh the harms to people and the environment," Donley said in an interview. "They approach their job saying, 'This chemical needs to be approved, so how do we do that?'" Industry reports, rather than peer-reviewed independent studies, tend to guide assessment and licensing.

Donley said that improved practices have lessened the problem of outright fraud, for which the EPA's pesticide branch was once notorious.

"But better practices don't necessarily do anything about bias," he said. "We need to put a really thick wall between the industry and the EPA to them separated."

Many chemical-free advocates criticize the EPA's chemical testing and assessment process. Not only is it driven by industry interests, they argue, but it's dangerously flimsy in design. Formal testing is conducted on individual, isolated chemical ingredients but not usually on the final formulation of a product — a shortcoming in pesticide regulation, since chemicals can change radically when they encounter and sometimes bond with other chemicals. According to information published by Beyond Pesticides, research has found that product formulations of glyphosate are more toxic than glyphosate alone.

There is another area of concern that the EPA also overlooks: the so-called breakdown products of an active ingredient. As a registered chemical biodegrades, it results in various new particles. Sometimes, these breakdown products are more hazardous than the original chemical. For example, the organophosphate naled, used to kill insects like mosquitoes, breaks down into several chemicals including dichlorvos, which is believed to cause cancer. In California, public mosquito control agencies applied 282,000 pounds of naled in 2017. Glyphosate, meanwhile, breaks down into a compound called aminomethylphosphonic acid, usually termed AMPA, which some experts say is just as toxic as glyphosate itself.

The impacts of lenient chemical restrictions have shown up in marked patterns among agricultural workers, whom Reeves of the Pesticide Action Network believes have been more or less sidelined in the call for safer foods. She said consumers tend to worry more about residues on foods they bring home than about farm laborers' exposure to the same chemicals.

"The vast majority of people hoping to reduce pesticide use are concerned about the impacts to the consumers, and very few people are thinking about the farmworkers," Reeves said.

Lawmakers explicitly left farmworkers and food service workers out of 1935's National Labor Relations Act — an omission that has not been corrected. In a 2011 report titled "Inventory of Farmworkers Issues and Protections in the United States," researchers found that agricultural employees are denied protections offered to other worker groups by that act, the Fair Labor Standards Act, and many state laws. These exemptions and loopholes have made farmworkers particularly vulnerable to heat stress and pesticide exposure.

A team of U.C. Berkeley researchers has studied childhood and prenatal exposure to pesticides in Salinas Valley farm communities. They've concluded that a chemical group called organophosphates causes extreme developmental disorders in children, including lower IQ, attention deficit disorders, and neurodevelopmental delays. Asa Bradman, an environmental health scientist who contributed to the research, has published a paper with his colleagues encouraging a phaseout of such organophosphates.

"But I worry that we might phase out one class of neurotoxins and replace them with others," he said.

UCSF doctor Marya said she has personally seen rising rates of lymphoma; inflammatory bowel disease; and colon, thyroid, and nasopharyngeal cancers, often in patients from agricultural communities.

"They're often either living in direct proximity to farms or they're farmworkers themselves," said Marya, who believes a wholesale ban on synthetic pesticides and fertilizers is overdue.

Feldman, at Beyond Pesticides, believes a global transition to organic, mostly chemical-free farming could be implemented, but it must happen through farmer education — not by failed systems of assessing and licensing chemicals, supposedly as safe. "You could spend half a lifetime trying to ban a single chemical," he said.

Perro warns that the American government cannot be trusted to protect us from chemical poisoning.

"People need to wake up about what's going on," she said. "This idea that government agencies are regulating these companies is erroneous. People are under this perception that they are being protected somehow in this fairy tale, and that is not the reality."

The Insect Apocalypse

The California Almond Sustainability Program — reminiscent of the wine grape growers' certification system — calls for an "ecosystem-based approach" to managing pests. This manual of guidelines suggests a balance between chemical and non-chemical tactics.

But growers of the state's most lucrative nut crop seem to be skewing toward the chemical approach. In 2017, they sprayed a staggering 3 million pounds of glyphosate-based herbicides, according to the Department of Pesticide Regulation's records.

That's ten times what wine grape growers applied on roughly one half the acreage.

In an emailed comment, the Almond Board of California said its growers "follow the strictest laws in the nation when using pesticides" and only use compounds approved by the U.S. EPA and the state's pesticide department.

The irony of spraying glyphosate around almond trees is that almond farmers rely heavily on on bees for pollination. New research from Nancy Moran at the University of Texas in Austin shows that contact with glyphosate is detrimental to bees' health and may lower survival rates.

Worse, pesticide applications are probably contributing to a phenomenon writers and scientists have dubbed the "insect apocalypse." Thousands of species of small arthropods — mostly, but not all, insects — are now plunging in abundance.

"Our work reveals dramatic rates of decline that may lead to the extinction of 40 percent of the world's insect species over the next few decades," wrote Francisco Sanchez-Bayo and Kris Wyckhuys, the authors of a paper published in February that blamed the die-offs on intensive pesticide use and agricultural land conversions, among other factors.

One of the most shocking studies analyzed in their review came from Puerto Rico, where researchers had observed biomass declines of between 98 and 78 percent of ground-foraging and canopy-dwelling arthropods over a period of 36 years. That's virtually everything, gone.

"The conclusion is clear," the authors wrote. "Unless we change our ways of producing food, insects as a whole will go down the path of extinction in a few decades."

Insect losses seem to be cascading into other tiers of the food web. A new study from researchers at the Cornell Laboratory of Ornithology describes freefalling populations of hundreds of bird species. Published in the journal Science, the paper reviewed citizen bird counting data from 2006 to 2015. They compared this period to data from as far back as 1970. They concluded that, among 529 species of birds in the United States and Canada, total numbers were down 29 percent — about 3 billion birds.

Is the Revolution Beginning?

Organic grape farmer Phil LaRocca, who owns LaRocca Vineyard near Chico, is rallying for an organic revolution — and leading by example. He said he has farmed without chemicals for 42 years.

"I've never used any herbicides on any of my production," said LaRocca, the chairman of the board of the California Certified Organic Farmers, a major certification group. "It's less convenient, it's more labor intensive, but it can be done."

He believes the organic revolution is underway.

"We're in a new era," LaRocca said. "That lawsuit [against Monsanto] is making people open their eyes."

He said interest in organic foods is growing, as is the acreage of organic production in California. Currently, he said, about 4 percent of the state's agricultural land is certified organic.

"But we have a goal of having 30 percent of our land certified organic by 2030," LaRocca said.

Already, he added, 28 percent of the state's leafy green production is certified organic, and between 12 and 15 percent of carrots are grown organically.

"A few years ago, we were at about two percent," he said.

But incredibly, in spite of negative publicity, glyphosate-based weed killers remain popular, and economic projections show glyphosate sales will continue to grow rapidly.

"I just can't believe people keep using Roundup," Preston said. "We know it gets into the water table; we know it affects wildlife."

Inertia in various forms prevents many food producers from transforming their ways. Simple habit surely keeps many farmers using herbicides that they've used for decades.

There's also a phenomenon referred to as the pesticide treadmill that has locked many farmers into growing systems that rely on pest-killing poisons. These poisons kill most targets, but not all. Those survivors perpetuate their species with ever-stronger genetic resistance to the pesticides designed to kill them — and the chemical war on weeds and bugs continues, ad nauseum.

Reeves of the Pesticide Action Network said shifting to a chemical-free future "would certainly be possible to do. The question is whether we have the political will."

In Livermore, while Taylor's neighbors apply potent poisons to their land to zap pestilent grasses, he remains baffled by the underlying motivation that drives this controversy — sickening children, killing adults, causing immeasurable health impacts in millions of people, tainting water supplies and wiping species off the planet.

"I just don't understand the big concern over weeds in the vineyard," he said. "A few weeds are not the end of the world."