San Joaquin Valley Residents Breathe Chemical Pesticides
Research from UC Davis Health found that 22 percent of adults and 10 percent of children who took part in an air-quality study in California’s San Joaquin Valley were breathing detectable levels of pesticides, including one chemical, chlorpyrifos, that is no longer permitted in California. The new findings are published in the Journal of Exposure Science and Environmental Epidemiology.
“Although the cohort in our study was small, the findings are significant because they show children and adults in agricultural regions of the San Joaquin Valley of California continue to be exposed to pesticides and herbicides. This is despite efforts to decrease their use,” said Deborah H. Bennett, professor of environmental health at UC Davis.
The researchers recruited 31 adults and 11 children who lived in three small agricultural towns in the San Joaquin Valley. They gave them backpacks with two special air-collection tubes on the shoulder straps. The location of the tubes allowed researchers to sample the air the participants were breathing.
Each participant wore the backpacks for 1-3 days, eight to 14 hours per day. The combined air sampling took place over a total of 92 days. When the researchers analyzed the results, they found that seven adults (22 percent of adult participants) and one school-aged child were exposed to detectable levels of at least one pesticide.
The pesticides found by the sensors on the backpacks include:
- 1,3-dichloropropene, a pesticide used to eradicate parasitic worms
- Chlorpyrifos, a pesticide in use since the 1960s that has been linked to neurologic damage in children
- Pyrimethanil, a fungicide used to prevent mold and mildew, an insecticide used to prevent insects
- Penthiopyrad, a fungicide to prevent mold and mildew
- Trifluralin, an herbicide used to control grasses and weeds
When the samples were collected, chlorpyrifos was no longer approved for use in California. Previous research showed that chlorpyrifos has numerous adverse health effects, including acting as a developmental neurotoxin in children and sensitive populations.
“Many people in agricultural communities are very concerned about pesticide exposure,” said Jane Sellen from Californians for Pesticide Reform; Sellen was a co-author of the study. “They were happy to work with the scientists to collect this much needed data. Even with a small sample size, the results were alarming but not surprising.”
No Surprise: Pesticides Harm Wild Bee Pollinators
Native wild bees play a crucial ecological role, ensuring the survival and reproduction of countless plant species — including many agricultural crops — by spreading pollen as they forage for food. Unfortunately, their numbers seem to be declining.
A new study in Nature Sustainability sheds light on one potential cause: pesticide use. The research reveals a stark decline in the number of wild bee sightings, with appearances of some species dropping as much as 56 percent in areas of high pesticide use compared to areas with no pesticide use. Wild bees, alongside honeybees, play a crucial role in pollinating three-quarters of food crops and nearly 90 percent of flowering plant species.
The team inspected museum records, ecological surveys and community science data collected between 1996 and 2015 from across the contiguous United States. Using advanced computational methods, they sifted through more than 200,000 unique observations of over 1,000 species — representing one-third of all known bee species in the U.S. — to assess how frequently different species were observed in various locations.
In addition, they analyzed data from several government sources, such as the U.S. Geological Survey’s National Land Cover Database and Pesticide National Synthesis Project. The former tracks U.S. land cover types (crop, urban, forest, wetland, etc.) with snapshots taken every two to three years from 2001 to 2016, while the latter provides detailed data on pesticide use by county from 1992 to 2021.
By integrating these resources, the researchers correlated factors such as land use, pesticide application, honeybee colony presence, and types of agricultural crops with wild bee sightings over the past two to three decades.
The research provides compelling evidence that pesticide use is a major contributor to the declining numbers of wild bees. The study found a strong correlation between pesticide use and fewer wild bee sightings, suggesting a direct link between pesticide exposure and bee population declines.
Some scientists have speculated that certain crops might adversely affect wild bees. However, Guzman and the team uncovered evidence to the contrary. Among crops frequented by pollinators, they found just as many wild bees in counties with a lot of agriculture versus a little.
Interestingly, the study hinted that the presence of colonies of honeybees, an invasive species, had almost no effect on wild bee populations, despite some evidence to the contrary. The researchers caution, however, that they need more detailed data and further study to confirm this conclusion.
The current study builds on work published earlier this year that found that ecological risk assessments (ERAs) underestimate pesticide threats to wild bees and other pollinators. Currently, ERAs measure pesticide effects on honeybees, often in lab studies, then extrapolate those findings to native bee species. However, the new study revealed that current ERAs vary wildly — as much as a million-fold — when estimating how lethal pesticides are just to honeybees. And many wild bees are even more sensitive to pesticides, compounding the problem.
New Tests Created to Find Fake Honey
There is growing consumer demand for honey; £89.8 million worth was imported to the U.K. in 2023. But as a high-value product it is vulnerable to fraud, with syrups often added to dilute the pure honey. A report from the European Commission in 2023 found that 46 percent of 147 honey samples tested were likely to have been adulterated with cheap plant syrups.
Because honey’s characteristics vary due to sources of nectar, season of harvest and geography, it can be very difficult and complex to detect adulterated products. Authentication methods are costly and time consuming. But scientists at Cranfield University have successfully tested two new methods to authenticate U.K. honey quickly and accurately.
A research project led by Dr. Maria Anastasiadi of the U.K.’s Science and Technology Facilities Council (STFC) used a special light analysis technique — Spatial Offset Raman Spectroscopy (SORS) — to detect fake honey without opening the jar. SORS rapidly identified the “fingerprint” of each ingredient in the product, and the scientists combined this technique with machine learning to successfully detect and identify sugar syrups from various plant sources.
The analysis method is portable and easy to implement, making it an ideal screening tool for testing honey along the supply chain. The results were published in Foods.
DNA barcoding was used in a second study to detect rice and corn syrups in U.K. honey samples. Scientists used 17 honey samples collected from bee farmers around the country, representing different seasons and floral nectar sources, and bought four samples of from supermarkets and online retailers. The samples were then spiked with corn and rice syrups produced in a range of countries.
DNA barcoding — a method already used in food authentication to identify plant species in products — was effective in breaking down the composition of each sample, to successfully detect syrups even at 1 percent adulteration level.
The two methods developed can work together to increase chances of detecting exogenous sugar adulteration in honey.
Nature Always Wins: Giant Ragweed Becomes Herbicide-Resistant in Wisconsin
When giant ragweed takes hold in a crop field, the towering weed reduces yield and sends plumes of its famously allergy-inducing pollen into the air. There are few tools available to thwart the menace, especially for farmers growing non-GMO soybeans. Now, some Wisconsin farmers are left with even fewer options.
New research from the University of Wisconsin-Madison and the University of Illinois Urbana-Champaign shows that some giant ragweed populations in Wisconsin have evolved resistance to a class of post-emergence herbicides known as protoporphyrinogen oxidase (PPO) inhibitors (Group 14 herbicides).
“It’s hard to control giant ragweed with pre-emergence herbicides, in part because it’s a larger seed and can emerge from greater depths. So farmers depend on post-emergence products. For folks growing non-GMO soybean, those post products are ALS and PPO, and we already have fairly widespread ALS resistance in giant ragweed,” said study co-author Pat Tranel. “Losing PPOs means you’re basically out of chemical options.”
The Wisconsin team also tested for resistance to acetolactate synthase (ALS) inhibitors and glyphosate, finding four populations with resistance to ALS and two populations with resistance to glyphosate. These types of resistance had already been documented in giant ragweed, but the team also found one population with resistance to both.
Resistance to glyphosate affects GMO soybean growers, who turn to PPO and ALS herbicides in those cases. Similarly, non-GMO growers who can’t use glyphosate rely on these chemistries. The authors say with ALS and PPO resistance — essentially, zero chemical options — more non-GMO growers may switch to GMO soybeans.
AI Boosts Indoor Food Production’s Energy Sustainability
Integrating artificial intelligence into today’s environmental control systems could reduce energy consumption for indoor agriculture by 25 percent, according to a new study from Cornell published in Nature Food.
“If we incorporate AI into agricultural plant factories — large-scale indoor farms with complete lighting and climate control — all around the world, we can facilitate crop photosynthesis, transpiration and respiration in these buildings,” said researcher Benjamin Decardi-Nelson. “We can expect to see substantial energy reduction while amplifying efficiency and a savings of precious resources.”
Indoor farming methods, such as plant factories with artificial lighting, are less vulnerable to climate change, but they’re energy intensive and require careful resource management to be sustainable. Ventilation can reduce energy use, but its use complicates plant growth by affecting carbon dioxide levels and moisture balance.
By using AI techniques like deep reinforcement learning and computational optimization, the scientists analyzed lettuce cultivated in indoor agriculture facilities throughout the U.S. and in Iceland and Dubai. AI reduces energy use by optimizing lighting and climate regulation systems. In temperate zones, energy use dropped to from 9.5 to 6.42 kilowatt hours per kilogram fresh weight (the energy needed or used to produce one kilogram of indoor-grown lettuce). For warmer areas, such as Dubai or the southern U.S., AI reduced energy usage to 7.26 kilowatt hours per kilogram fresh weight, down from 10.5 kilowatt hours per kilogram fresh weight.
Low ventilation during light periods (16 hours of simulated sunlight) and high ventilation during dark periods provided an energy-efficient solution for optimal indoor carbon dioxide levels for photosynthesis and for oxygen for respiration and plant growth.
By streamlining operations using AI to reduce energy consumption, indoor farms become viable, Decardi-Nelson said, even in regions with limited energy-saving opportunities. “By strategically aligning environmental control system technology with plant biology,” Decardi-Nelson said, “energy can be conserved using ventilation while minimizing carbon dioxide waste and maintaining ideal growing conditions.”
Researchers Develop Index to Quantify Circular Bioeconomy
As the world faces the challenges of mitigating climate change and providing resources for a growing population, there is increasing focus on developing circular economies for sustainable production. But to evaluate strategies and impacts, it is necessary to have reliable metrics. Researchers at the University of Illinois Urbana-Champaign have developed a Circularity Index that provides a comprehensive method to quantify circularity in bioeconomic systems.
“The traditional economic system is linear — we produce, distribute, use and dispose of products. To increase sustainability, we need to develop a circular economy. Rather than just using natural resources, we must recover, reuse and recycle waste materials,” said lead author Yuanhui Zhang.
“Circular bioeconomy has become a hot topic in research, but most studies are merely descriptive and there’s no way to measure impacts. To move the technology forward, we need measurements to quantify effects, establish benchmarks, compare approaches, and identify weak spots,” he said.
In the paper, the researchers provide a step-by-step outline of the Circularity Index (CI), which measures circularity on a scale from 0 to 1. Zero means the system is completely linear, and 1 means it is completely circular. The index includes eight categories: take, make, distribute, use, dispose, recover, remake and reuse. The CI is computed by entering available data into each of these categories.
Zhang and his colleagues demonstrate how to use the CI in two case studies. The first examines nitrogen cycling in a corn-soybean farm in the Midwestern United States. The researchers entered production and output data for a period of eight years and compared the effect of two different fertilizer treatments: urea versus manure. They calculated the CI to be 0.687 for urea and 0.86 for manure, indicating the use of manure fertilizer provides a more circular economy.
In the second case study, the team looked at the U.S. food and agriculture system, focusing on energy use. Drawing on national data from the USDA, EPA, and DOE, they compared the current system with an approach based on the Environment-Enhancing Food Energy and Water System framework, which involves recovery, remake and reuse of organic waste. They find the existing system has a CI of 0.179, while the EE-FEWS approach would lead to a CI of 0.84.
“We know it’s important to reduce fossil fuel use, increase renewable resources, and minimize our water consumption. But to do so effectively, we need to know how much, and what the weak links and tradeoffs are. The CI provides a single number that allows you to establish a baseline, compare systems, and determine best strategies for action,” Zhang said.
The CI can serve as an indicator to support policy initiatives such as the United Nations’ Sustainable Development Goals. It also has potential commercial value; for example, food companies can demonstrate their production circularity to consumers.
Pilot Study Uses Recycled Glass to Grow Plants Faster and with Less Disease
Researchers report that plants can be cultivated in recycled glass from discarded, pulverized bottles like those from beer or soda. And the pilot study found that partially substituting soil in a planter with recycled glass fragments speeds up plant development and reduces unwanted fungal growth.
The researchers got recycled glass particles from a company that diverts bottles from landfills, crushed them into particles, and tumbled the pieces to round off the edges. The final product is smooth enough that people can handle the glass bits without getting cut, and plant roots can easily grow around the glass pieces without being harmed.
In initial tests, the researchers assessed the soil-like qualities, such as compaction and water retention, of three different-sized glass fragments. They found that a size similar to coarse sand grains had characteristics ideal for plant cultivation, such as allowing oxygen to reach the roots and maintaining sufficient moisture levels.
In a greenhouse, the team grew cilantro, bell pepper and jalapeño plants in a variety of pots containing anywhere from 100 percent commercial potting soil to 100 percent recycled glass. Pots with more soil had higher levels of nutrients compared to those with more glass. But there was little variation in pH level among the pots.
Early results suggest that the plants grown in recyclable glass have faster growth rates and retain more water compared to those grown in 100 percent traditional soil, with a 50-50 weight ratio appearing best for plant growth.
Another noteworthy result was that pots with 100 percent potting soil developed a fungus that stunted plant growth. However, the pots that included any amount of recyclable glass didn’t have any fungal growth.
| Depressing Joke of the Month What did the large-scale farmer say when considering options for maximizing profitability under the current commodity and crop insurance policy regime?“I know I should be cover cropping, but I’ll make more money if instead I cover my crops with an insurance premium subsidy funded by the American taxpayer!”  Courtesy of the National Sustainable Agriculture Coalition Weekly Round Up email. |
