Does eating organic reduce pesticide exposure?

Kale at Pescadero Farmer's Market

Veggies for sale at the Pescadero Farmer’s Market. (Photo credit: Kristine Wong)

Civil Eats | Nov. 3, 2015

When parents spend the extra money to feed their children organic food, it’s often in hope of keeping the overall amount of pesticides in their bodies to a minimum. (If you’ve seen this popular video of the Swedish family that made the switch, you know what we’re talking about.) But a new study by a team of scientists at the University of California, Berkeley suggests that diet is only part of the equation, especially for kids who might be exposed to insecticides at home or pesticides from agricultural fields nearby.

Researchers fed 40 Mexican-American children in Salinas (a rural agricultural area) and in Oakland, California a diet of conventional fruits and vegetables for four days. Then they fed the kids (between the ages of three and six and 20 in each group) a week-long diet of organic produce before returning them to a conventional diet for the last five days. The researchers tested the children’s urine daily for the presence of insecticides and herbicides.

Overall, the results showed that the presence of two kinds of pesticides (organophosphate insecticides and the herbicide 2,4-D) in the children’s bodies decreased after eating organic produce (by 40 and 49 percent in the insecticides and by 25 percent in the herbicide).

But researchers didn’t detect any decrease in the levels of other pesticides (such as pyrethroid insecticides like home bug sprays), according to the paper published recently in the journal Environmental Health Perspectives.

“That could mean that the diet wasn’t an important source of exposure for those pesticides,” Asa Bradman, a researcher at Berkeley’s Center for Environmental Research and Children’s Health who led the study, told Civil Eats.

The study results, he emphasized, point to the importance of considering the cumulative amount of pesticide exposure levels in children from other sources when considering the greater health risks (such as lower IQs or delayed development) to this population—especially those living in areas where pesticides could be applied to farm fields or to areas nearby their schools or homes.

“The Salinas children generally had higher concentrations of pesticides than those living in Oakland,” said Bradman.

Pesticide use near California schools could be a significant factor, as documented by a state health department report last year. It found that Latino children were 46 percent more likely to attend schools with “pesticides of concern” applied nearby than other kids in the state.

Bradman’s previous research found that because several farmworker families often live together in one apartment or house, crowding occurs that can lead to pest infestations and increased pesticide use at home.

The Berkeley study is the first to look at the effects of an organic diet among a Mexican immigrant population and test the effect on insecticide levels. Other studies at Harvard looked at the effect of an organic diet on organophosphate pesticide exposure and found similar results.

“Any results like this are really valuable because there’s so little known when it comes to dietary exposure and pesticide residues,” said Emily Marquez, a scientist at the nonprofit advocacy group Pesticide Action Network. “We also don’t know about how exposure changes due to cultural differences in diet.”

While the Centers for Disease Control asks a sample of the U.S. population about exposure to chemicals in the environment ever year, Marquez says, it’s not clear whether respondents live in urban or agricultural areas. And though FDA and USDA test pesticide levels in food annually, she added, much of the focus is on imported produce.

California is the only state in the U.S. that requires the reporting of pesticide use (though the island of Kauai in Hawaii has a voluntary reporting system that could be expanded statewide later this year). Now the state is moving forward to regulate the application of pesticides near schools. The California Department of Pesticide Regulation, which gathered input this past summer from the public on how it might approach setting these limits, is planning to release draft regulations in December.

Parents and community groups are pushing for a one-mile buffer zone around schools, as well as two-day notice before any pesticides are applied, the Los Angeles Times reports.

And in Iowa, a coalition of farmers and the Pesticide Action Network are trying to get laws introduced that would improve reporting and regulations around pesticide drift.

Despite all of the talk regarding children’s health and safety when it comes to pesticide exposure, both Bradman and Marquez are quick to say that they don’t want to discourage children from eating conventional produce if their families can’t afford organic fruits and vegetables.

“When considering risk from exposure, I wouldn’t say that conventional foods are unsafe,” he added. “If you look at the American diet, there’s definitely great need for more fruits and vegetables and less refined carbohydrates.”

But that doesn’t mean it’s not worth reducing pesticide exposure overall. And Marquez says her organization is working toward that end.

“We can change the agricultural system so that it’s no longer dependent on pesticides,” she said. “One way to do this would be to subsidize farmers to help them convert their land—by improving biodiversity and creating a conservation wetland, for example. That will help them begin to transition away from pesticides.”

Farms without wildlife don’t produce safer food

Civil Eats | Aug. 11, 2015

Lettuce crops

Lettuce crops. (Photo credit: Suzie’s Farm courtesy of Creative Commons)


Most leafy green lovers probably remember the moment when they became suspicious of spinach.

In 2006, an E. coli outbreak that killed three people and sickened about 200 more was traced to the cool-weather crop growing along California’s Central Coast. Despite the fact that federal and state investigators claimed it was not possible to determine exactly how the dangerous E. coli strain spread to the farm, cattle and wild pig manure were implicated as the sources of the bacteria.

The following year, the state’s farming industry pushed out the California Leafy Greens Marketing Agreement, a set of recommended practices based on previous guidelines issued by to U.S. Food and Drug Administration (FDA) to promote food safety on farms. Though voluntary, it covers over a dozen salad fixings (think spinach, arugula, kale, and several types of lettuce) and has since become widespread throughout the nation.

Simultaneously, many produce buyers began asking growers to clear areas near fields of any vegetation. As a result, the farm fields along the California coast changed radically after the outbreak, as farmers did away with wooded areas, medians, and hedgerows, and most farms became relatively sterile landscapes, aside from the crops.

Now a new study [PDF] is calling the efficacy of that practice into question.

“The bottom line is that removing habitat around farm fields is ineffective at making food safer from pathogens,” said Daniel Karp, a U.C. Berkeley postdoctoral researcher whose work is funded by The Nature Conservancy. “It has been shown in this region that there are a lot of benefits to surrounding vegetation as well, such as providing a home for pollinators, which are declining across the nation.”

The research—which was published yesterday in the journal Proceedings of the National Academy of Sciences (PNAS)—used three sets of industry data from 2007 to 2013 and mapped the results of 236,000 tests for E. coli and Salmonella on leafy greens, irrigation water, and rodents on Central Coast farms.

Karp and his collaborators found that among 57 farms in Salinas, Monterey, San Benito, Santa Clara, and Santa Cruz counties—the source of three-quarters of the the country’s leafy greens—the overall frequency of disease-causing strains of E. coli increased in the six-year period. But it turned out the prevalence increased the most where surrounding wildlife vegetation had been cleared away.

In areas that had kept some natural vegetation intact—a fact the researchers verified using aerial imagery—the team also found that the overall presence of disease-causing strains of E. coli and Salmonella did not go up.

Karp says that by looking to California as an example, the study results could have implications for all of America’s 4.5 million acres of farmland where foods eaten raw are grown, and the wildlife habitat that surrounds this land.

“Federal legislation [enacted] in 2011 will give the FDA the ability to regulate farming practices,” he said, referring to the controversial Food Safety Modernization Act that has yet to be implemented. “While it doesn’t require farmers to remove habitat, my worry is that these practices will spread across the nation as buyers will put pressure on their growers and won’t buy from them unless they remove wildlife habitat.”

Screen Shot 2015-08-10 at 9.53.09 PM

The Wild Farm Alliance, a nonprofit organization that advocates for the importance of protecting native species through sustainable agriculture has expressed concern about the dangers of removing wildlife habitat near leafy green crops all along.

Karp points to ways that conservation, agriculture, and livestock can flourish side by side, such as maintaining natural habitat (like trees) as a buffer between livestock and leafy green fields. The vegetation could filter runoff from grazed lands in the soil, he said.

“Or you could plant crops that need to be cooked, like artichokes, corn or wheat,” as buffer between livestock and leafy greens, Karp said.

Another option that could possibly work, he said, is to fence off waterways upstream from leafy green fields in order to prevent wildlife and cattle from defecating in the stream, which might eventually transport the feces downstream.

“We need to talk about how we can manage farming systems that both produce food and livestock and conserve nature at the same time,” Karp said. “We need to think creatively.”

Figure from study: Promising practices include (1) planting low-risk crops between leafy green vegetables and pathogen sources (e.g., grazeable lands); (2) buffering farm fields with noncrop vegetation to filter pathogens from runoff; (3) fencing upstream waterways from cattle and wildlife; (4) attracting livestock away from upstream waterways with water troughs, food supplements, and feed; (5) vaccinating cattle against foodborne pathogens; (6) creating secondary treatment wetlands near feedlots and high-intensity grazing operations; (7) reducing agrichemical applications to bolster bacteria that depredate and compete with E. coli; (8) exposing compost heaps to high temperatures through regular turning to enhance soil fertility without compromising food safety; and (9) maintaining diverse wildlife communities with fewer competent disease hosts.

Why saving lemurs will save this country’s rainforests

TakePart | November 6, 2014

Lemur in MadagascarMore than 90 percent of Madagascar’s lemur population faces extinction. Now scientist say that could threaten the future of the African island’s rainforests.

What do lemurs do for rainforests? Poop in them. Because lemur droppings contain tree seeds, they’re one of Madagascar’s best tree farmers, according to a new study published in the journal Ecology.

The study tracked the seed dispersal behavior of the island nation’s largest lemurs and followed the growth of a rainforest tree called Cryptocarya crassifolia. The findings revealed that seeds dispersed via lemurs were 300 percent more likely to grow into saplings than seeds that just dropped onto the ground.

“Lemurs may play an important role as gardeners of Madagascar’s rainforest, but they are at risk of extinction across the island,” said Amy Dunham, an assistant professor of biosciences at Rice University.

Onja Razafindratsima, a graduate student of Dunham’s, was the lead researcher in the study. “Only by understanding what role they play in the ecosystem can we hope to understand what the consequences of their loss may be,” she said.

A Malagasy native, Razafindratsima conducted the study in Ranomafana National Park in Madagascar’s southeast region. She spent a year following 24 groups of lemurs to figure out where they were dispersing seeds in the rainforest and noted the amount of sunlight that fell through the rainforest canopy. She then studied how those habitats affected the probability of seeds sprouting and thriving.

“One particular lemur species—the red-fronted brown lemur—tended to drop seeds away from parent trees in places where there’s opening in the rainforest canopy,” Razafindratsima said. The red-fronted brown lemur also tended to eat more seeds than its lemur brethren, making the species the most effective at seed dispersal, she said.

The other two lemur species studied, the southern black-and-white ruffed lemur and the red-bellied lemur, also promoted rainforest growth by moving seeds away from the parent tree—where competition for sapling resources is fierce, and chances of seedling development are lower.

“These two lemur species greatly enhance the recruitment of this tree species and its ability to regenerate,” Dunham said.

But knowledge of how important the species is to Madagascar’s rainforests doesn’t change the grim prognosis for the declining lemur population, which faces habitat loss from slash-and-burn agriculture and hunting.

“Some of the actions that need to be done would be to protect more forest habitat, to increase regulations on mining and wood extraction, and to provide alternatives to slash-and-burn agriculture,” said Razafindratsima.

In February, a group of lemur conservationists published an article in the journal Science recommending local actions to address the population decline. Those included increasing protected areas managed by local communities, promoting greater ecotourism in Madagascar, and increasing the presence of field researchers.

While conservation is key, Razafindratsima and Dunham believe there needs to be a balance between lemurs and the needs of local villagers, who they say use slash-and-burn techniques on the rainforest to grow food to feed their children.

“It’s a difficult problem, because we have to consider not just the animals but the people who live around the rainforest,” Dunham said. “We need to be sensitive with both people and animals while we figure out ways to conserve there as well.”

Photo of lemur in Ramonafana National Park by Yves Picq via Wikimedia Commons

The bugs that can save the bees

TakePart | October 29, 2014

honeybee_combHow do you stop deadly bacteria from decimating beehives? Sic a self-replicating, bacteria-devouring virus on it.

That’s what a Brigham Young University research study claims, bringing hope that a natural cure for one of the honeybees’ deadliest killers is possible.

The disease, called American foulbrood, has infected between 3 percent and 15 percent of all honeybee colonies worldwide. The bacteria attack bee larvae, wiping out hives in the process.

Beekeepers have tried antibiotics on infected hives, but the disease can come back stronger and more resistant to the treatment. Some end up burning entire hives to keep the disease from spreading through a colony.

But BYU undergraduate student Bryan Merrill may be responsible for finding a new microscopic savior to swoop in and save the bees.

The natural treatment Merrill discovered involves unleashing a phage, or bacteria-eating virus, on the bee larvae. Once established, the virus attacks bacteria and self-replicates until the job is done.

Merrill took his phage research to BYU microbiology professor Sandra Burnett, who oversaw his work over the past three years. The results were published in the journal BMC Genomics.

“Phages are the most abundant life form on the planet, and each phage has a unique bacteria that it will attack,” Burnett said in a statement. “This makes phage an ideal treatment for bacterial disease because it can target specific bacteria while leaving all other cells alone.”

To date, they’ve identified five types of phages as good candidates for fighting American foulbrood. A “phage cocktail,” which combines four or five strains, is being considered by the United States Food and Drug Administration to prevent infection in beehives.

If commercialized, the product could save the honey industry hundreds of millions of dollars a year and keep antibiotic-ridden honey off the shelves.

“Right now for American foulbrood, we only have antibiotics to treat them, and they’re not working well,” Burnett said in an interview.

So far, the disease has shown resistance to oxytetracycline, the standard antibiotic treatment, and oxytetracycline’s replacement, Tylan, Burnett said. Both antibiotics are unsafe for human consumption, meaning children and pregnant women can’t eat honey from treated hives, she noted.

What makes phages unique is their ability to modify their structure in response to bacteria that try to survive by changing over time.

A phage can multiply itself, so there are more of them to hunt down the bacteria, Burnett explained, and as soon as the host bacteria are gone, the phages vanish from the hive.

She’d like to see a commercialized solution available for home beekeepers as well as for the industry.

“If you look at beehives, it’s a 50-50 split from hobbyist small-scale beekeepers and large-industry beekeepers,” Burnett said.

The researchers are in talks with some companies about putting a single-phage product on the market, but they said more research must be done to determine if using different combinations of phages in a cocktail could also be effective.

Photo of honey bee comb by Waugsberg via Wikimedia Commons

Space lasers could help count the carbon for the trees

TakePart | September 10, 2014

redwood_forestLasers, 3-D imagery and outer-space surveillance sounds like cutting room floor fodder of a scrapped Austin Powers film, but it’s all part of NASA’s latest effort to map the Earth’s forests and gain a better understanding on climate change.

Dubbed Global Ecosystem Dynamics Investigation lidar—the nod to Star Wars may be entirely coincidental—the laser instrument will be designed to hitch a ride aboard the International Space Station. Once aboard, it will pump out large-scale 3-D imagery of forests. Lidar—the type of laser mapping tool that Google uses to guide its self-driving cars—will be deployed to measure the height and configuration of a forest’s canopy and undergrowth.

NASA and the University of Maryland hope the technology will give scientists a better picture of just how much carbon is stored in the Earth’s forests and the impact of logging on climate change.

“There’s an open question of what is the net balance between the amount of deforestation taking place and subsequent regrowth,” said Ralph Dubayah, a University of Maryland professor who is leading the GEDI project. “If we don’t know what that is, we don’t know what future atmospheric levels of CO2 are and it becomes hard to run climate models.”

With a 3-D picture—or fingerprint—of a forest, experts would be able to calculate the weight of its trees and figure out how much carbon they contain. About half of a tree’s biomass is carbon, according to Dubayah.

Armed with the new data, policy makers should be able to quantify the potential amount of carbon that could be released into the atmosphere by deforestation or forest fires. They then could determine what it would take to offset that release, such as by planting more trees.

Deploying lidar from space will be an improvement over the way forests are currently monitored.

Airplanes currently are used to shoot lidar lasers down into forests, thereby mapping the height and configuration of a forest’s canopy and undergrowth.

But the plane’s limited range restricts the amount of data that can be collected.

“From space, you can get access to essentially all the world’s forests,” Dubayah said. “Aircraft is expensive and if you’re in the middle of a rainforest, there are a lot of logistics involved in doing that. If you use lasers in space, you acquire much more data much more rapidly at cheaper cost.”

The GEDI system is still in development at NASA’s Goddard Space Flight Center and is slated for deployment in mid-2018. Dubayah hopes that the first batch of data will be available by 2019, with the program running continuously from the International Space Station.

“If we’re going to make any kind of policy changes in the U.S., one way to do that is by planting trees and running climate and land use models to look at potential scenarios,” Dubayah said. “It’s hard to run models forward in time that evaluate alternative policy scenarios if we don’t know what we’re starting with.”

Photo of Northern California redwood forest by Kirt Edblom via flickr/Creative Commons

Are you ready for a 35-year drought?

TakePart | August 29, 2014

drought_utahWith the American West losing an estimated 63 trillion gallons of groundwater over the past 18 months, it’s hard to imagine that the drought could get any worse.

But it just might.

A new study estimates that the possibility of a decade-long drought hitting the Southwest sometime this century could be as high as 90 percent. And there’s as much as a 50 percent chance of a mega-drought that lasts for 35 years or more, according to Toby Ault, a professor of earth and atmospheric sciences at Cornell University.

“This is only the beginning,” said Ault, whose research will be published next month in the Journal of Climate. “The further south you go, the drier the average conditions really are, and the risk is greater.”

It’s the first research that quantifies the risk of drought from reduced precipitation and drier conditions caused by climate change. Scientists conducted their analysis by incorporating historical data of past mega-droughts in the Southwest—such as the series of long-running droughts that struck the region between 900 and 1400—into computer models of contemporary climate observations.

The drought forecast in the Southwest—which the researchers define as Central to Southern California, Nevada, Southern Arizona, Southern Utah, New Mexico, Southern Colorado, and Western Texas—compares starkly with predictions for the northern states. Ault’s computer models indicate that Washington, Montana, and Idaho, for instance, face a decreased risk for drought over this century.

“Dry regions get drier, wet regions get wetter, and places on the edge are uncertain,” Ault said.

Making global predictions about drought is harder as less data is available for many regions outside the United States. “But even so, we saw that the Southwestern U.S. looks like it’s exposed to risks that are comparable to other parts of the world, such as parts of Africa, Northern Mexico, and parts of Brazil,” said Ault.

Researchers at Scripps Institute of Oceanography recently found that the earth’s surface in the West has risen 0.16 inches over the last year and a half as a result of losing 63 trillion gallons of water. Another report estimates that water levels in California’s three largest reservoirs have fallen 70 percent.

So what would a drought prolonged for 35 years or longer look like?

“Take the current drought and double it,” Ault said. “In Arizona, there’s been a drought that’s gone on and off for the last 10 years. Doubling that, it looks very challenging.”

Next up for Ault is to calculate how much snowpack and groundwater would be lost in a mega-drought. He also plans to determine how much water the Colorado River would lose during a decades-long drought.

Though his predictions focus on the risk of drought brought on by drier conditions from climate change, Ault says he’s still not sure if the West’s current drought is a result of global warming.

But regardless of the relationship, he emphasizes that people should pay attention to how drought is affecting the region.

“It’s a glimpse and preview of what we expect to happen from climate change—and a picture and window into the future,” he said.

Photo of drought in Utah by Anthony Quintano via flickr/Creative Commons

The link between dying wildlife, slavery and terrorism

TakePart | July 24, 2014

Rhino Action Day 2010The decimation of the planet’s wildlife is extracting a high cost on humans as it drives child slavery, human trafficking, and terrorism, according to a special report published Thursday in the journal Science.

Take poaching. Beyond the horrific impact on vanishing species, the slaughter of rhinoceroses and elephants for their valuable horns and tusks has bankrolled terrorist attacks in Africa by the extremist group Boko Haram.

The severe depletion of fish stocks around the world, meanwhile, has prompted an increased demand for cheap labor in the form of child slavery. That’s because it takes more time, workers, and money to catch fish that are less abundant, according to Justin Brashares, an ecology professor at the University of California, Berkeley, and the lead author of the Science paper.

“Millions of dollars are being spent by the European Union and the United Nations in anti-wildlife trafficking efforts—China started doing this as well—but almost all of [the efforts] are enforcement based,” he said. “They overlook that more than a billion people rely on natural resources for their livelihoods and don’t have any alternatives.”

Brashares wrote in the report that diminished fish stocks can push foreign fishing boats to travel farther for their catch, which puts more pressure on local fish populations. Such competition for scarce resources can lead to violent incidents, such as when Somali pirates attack foreign fishing boats that enter their waters.

Local, national, and international laws that recognize communities’ fishing and hunting rights—also known as tenure rights—are needed to address the underlying poverty driving such illegal actions, Brashares said.

“Fiji is a popular example where local fishing communities were given tenure rights,” Brashares said. “It seems to have worked very well in regulating harvesting and sustainability and allowed communities to be more connected to economic markets. In Namibia, local communities have secured tenure rights to wildlife and have had really positive outcomes in sustainability.”

So what can you do?

Brashares believes the most effective action individuals can take is to use resources such as GoodGuide—which rates the environmental health and safety of consumer products—or the Monterey Bay Aquarium’s Seafood Watch recommendations to identify responsible purchases. Economic decisions have more impact than emails to members of Congress, he said.

“If you say, ‘I can’t find out if my fish comes from slave labor,’ then I say that’s a great role for our nonprofits,” Brashares said. “We can push the Monterey Bay Aquarium to tell us what fish is socially sustainable.”

Photo of Rhino Action Day 2010 protest in South Africa by Stefan Möhl via fickr/Creative Commons