Friday, November 24, 2023

Open Letter to Boulder County Regarding the Proposed Integrated Weed Management Plan - 2023




Two Radishes


From the Office of Grass to Veggies



Contact: James Lissy | | | Longmont, CO

Re: Boulder County Proposed Integrated Weed Management Plan

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Earthrise from Moon
Earthrise from the moon – Apollo 8 – Photo by Bill Anders.  “The Earth from here is a grand oasis in the big vastness of space.” – Jim Lovell

As a resident of Boulder County, the county’s proposed integrated weed management proposal is appalling due to its emphasis on using, over-using and unchecked use of chemicals which pose a significant threat to human health, pollinators, water quality, aquatic life, soil and overall health of the environment.  The lack of pro-active notification to the community regarding this plan, lack of emphasis on indigenous / regenerative agriculture for weed control, lack of consideration of modern science and lack of scientific monitoring when chemicals are used make this proposed plan highly unacceptable.
I understand that the County wants the easy button when it comes to weed control.  The County wants to be able to suppress the undesirable weeds as easily and efficiently as possible.  However, the effects that the chemicals have on everything else in the environment is blatantly ignored in this proposed plan.  At the bottom of this letter, you will find a list of scientific articles that walk you through the actual effects that these chemicals have on the environment as a whole.  While a lot of these chemicals do effectively kill the targeted species and some are certainly more harmful than others, the majority of these chemicals have drastic and unknown consequences on the rest of the environment as a whole.  These are extremely important considerations since these chemicals can have negative effects on desirable plants species, pollinators, soil health, water quality, aquatic health, endangered species, and us humans.  Not to mention that the increasing resistance to chemicals in the targeted weed species has been noted in several studies which hints at chemicals that are currently effective will likely not be effective in the future.
As you read through the actual scientific and independent research a few things become abundantly clear.  Governing agencies and society as a whole generally consider these chemicals to be safe until proven otherwise.  Even after the chemicals have been proven to not be safe, the new peer reviewed scientific papers done by independent scientists with independent funding gets rejected and ignored by governing agencies within the US, such as the Environmental Protection Agency (EPA).  The only “science” that the EPA currently evaluates is what is submitted by the company that manufactures the chemical when they first submit an application to the EPA.  These companies stand to make billions of dollars in profit if their applications are approved by the EPA which is an obvious and clear conflict of interest.  Most governing bodies outside of the US peer review submitted research to either verify or dismiss the submitted research which makes governing bodies outside of the US currently much more reliable for determining harm levels of chemicals.  The majority of these chemicals have adverse effects on plants, worms, soil, fish, aquatic life, and seed production of desirable plants.  These negative effects of chemicals are normally not discovered until well after the wide use of the chemicals, making the damage already done.  Paper after paper cites lacks of research or notes that more research is needed into specific and potentially harmful aspects of chemical use.  When research is done on effects of pollinators, this research is usually limited to honey bees.  This limited research is absurd for a few notable reasons:  Bees in general are not the only pollinators and are only a portion of all overall pollinators.  Honey bees are not native to the US and there are a lot of native bee species in the US which are commonly referred to as native bees.  Native bees are extremely important to the ecosystem since they have adapted to live here naturally, without human assistance.  Chemical effects on native bees have not been researched.  A lot of these native bees are solitary, do not live in hives and live underground or in brush on the ground making them more susceptible to the potential effects of chemicals.  Furthermore, pollinators in general have a wide range of foraging which also makes them more susceptible to chemical use even if the chemicals are not sprayed directly on them.  Chemical effects on soil and water health are often overlooked and it is routinely discovered that chemicals once touted as safe have drastic negative effects on soil and water health.

 Based on the factual findings of actual modern scientific research done by independent scientists and the lack of adequate research into the potential negative environmental effects noted by the majority of the scientific papers I would like to propose the County adopt and implement the following into their proposed weed management plan.  The County emphasizes and prioritizes indigenous / regenerative agriculture practices above everything else.  This would include but would not be limited to: livestock grazing, reseeding native plants, and controlled burns.  The County hires and collaborates with local indigenous communities, ranchers, farmers, and local businesses who have vast and extensive knowledge in regenerative agriculture to come up with the best solutions possible with a priority and emphasis on community and environmental health.  The County does not implement the use of any chemical until the chemical is scientifically proven safe for every aspect of the environment, aside from the targeted species, by peer reviewed, independently funded research and scientists.  Notify the community via pro-active outreach at least 90 days before a new chemical is scheduled to be used by the County.  The County establish a way for community members to submit new research that has been done on chemicals that are currently in-use by the County and the County halts all use of the chemical in question until the concerns have been evaluated by an independent, 3rd party scientist that is in no way shape or form affiliated with the manufacturer of the chemical and is an expert in their field.  Aerial application is not allowed in any way, shape or form due to the uncontrolled and broad nature of aerial applications along with the large carbon footprint that aerial applications have.  Before any chemical use or application of any kind, the county takes comprehensive soil, water, and air samples of the direct and surrounding area that chemicals will be applied to.  After chemical application, routine soil, water and air samples of the direct and surrounding areas are routinely taken and changes monitored by an independent, 3rd party that is not affiliated with the chemical manufacturer in any way shape or form.  All samples, results, and analysis are property of the public and made public as soon as the sample results are available and public release is not to be delayed for any reason.  This routine sampling shall be done for a period of at least 2 years since the last chemical application on each parcel.  The County very clearly implement measures laid out in the Colorado Pesticides Act to ensure that state regulations on pesticide use is being followed by County employees and that proper labelling of the application area is occurring so the public is aware what chemicals have been applied and when and in what dosage along with the complete history of chemical use by the County being an easily accessible public record.  The County establish a new position or office of Ombudsman – the purpose of which is to receive, evaluate, and investigate complaints from the general public regarding County practices, procedures, implementation, etc.  This position or office would be an intermediary between the County and the public and they would take all points of view into consideration and would have legal authority to implement change at the highest level, if needed, to protect the health of the community and the environment.
In addition to implementing the measures listed above directly into the Integrated Weed Management plan the County needs to implement additional measures to protect the community.  Matters, proposals or issues that are deemed potential public health threats / issues should trigger the County to send pro-active outreach to every known citizen of the County to notify them of the potential public health issue and to illicit feedback.  This would include, but not be limited to, the County asking each City to put a notice in each city newsletter that already gets mailed out to each County resident each month.  The County should then hold several open houses at varying days and times, including weekends, do not require an RSVP and do not have attendance limitations for the purpose of having community conversations regarding the public health issue.  The open houses shall be run by the new position or office of the Ombudsman to ensure an unbiased and nonpartisan approach and conversation.  The Ombusdamn would also implement non-biased surveys to gather as much public feedback as possible without trying to steer the public towards a specific agenda.  Additionally, matters affecting public health should be required to be put to a public vote so the voice of each and every resident can be heard regarding the issue.
These measures would put an emphasis on protecting the health of the community and the environment which is of the utmost importance.  If we do not have our health or if the environment is not healthy from unintended consequences, then we as a community have nothing.
Without further ado, here are links to 46 scientific articles so you can read through them and come to your own conclusions which should ultimately lead to better overall conversations in the community that are focused on the health of the community and the health of the environment and how we can work with nature instead of against it.  In addition to the scientific articles below, the documentaries Into the Weeds and The People vs. Agent Orange do in-depth dives into glyphosate and 2-4-D respectively.  The County revamping the weed management plan has potential to be an unbelievable force for good and template for other communities that is based on community input / conversations, science, health, and environmental health.  I should hope that we can all agree that each of those aspects should be of the utmost importance to our society as a whole.

The industrialization of the agricultural sector has increased the chemical burden on natural ecosystems. Pesticides are agrochemicals used in agricultural lands, public health programs, and urban green areas in order to protect plants and humans from various diseases. However, due to their known ability to cause a large number of negative health and environmental effects, their side effects can be an important environmental health risk factor. The urgent need for a more sustainable and ecological approach has produced many innovative ideas, among them agriculture reforms and food production implementing sustainable practice evolving to food sovereignty. It is more obvious than ever that the society needs the implementation of a new agricultural concept regarding food production, which is safer for man and the environment, and to this end, steps such as the declaration of Nyéléni have been taken.
Many of the pesticides have been associated with health and environmental issues, and the agricultural use of certain pesticides has been abandoned.  Exposure to pesticides can be through contact with the skin, ingestion, or inhalation. The type of pesticide, the duration and route of exposure, and the individual health status (e.g., nutritional deficiencies and healthy/damaged skin) are determining factors in the possible health outcome. Within a human or animal body, pesticides may be metabolized, excreted, stored, or bioaccumulated in body fat. The numerous negative health effects that have been associated with chemical pesticides include, among other effects, dermatological, gastrointestinal, neurological, carcinogenic, respiratory, reproductive, and endocrine effects. Furthermore, high occupational, accidental, or intentional exposure to pesticides can result in hospitalization and death.
Current agriculture has to deal with important factors, such as population growth, food security, health risks from chemical pesticides, pesticide resistance, degradation of the natural environment, and climate change. In recent years, some new concepts regarding agriculture and food production have appeared. A concept as such is climate-smart agriculture that seeks solutions in the new context of climate change. Another major ongoing controversy exists between the advocates and the opponents of genetically engineered pesticide-resistant plants, regarding not only their safety but also their impact on pesticide use.
Furthermore, the real-life chronic exposure to mixture of pesticides with possible additive or synergistic effects requires an in depth research. The underlying scientific uncertainty, the exposure of vulnerable groups and the fact that there are numerous possible mixtures reveal the real complex character of the problem.  The combination of substances with probably carcinogenic or endocrine-disrupting effects may produce unknown adverse health effects. Therefore, the determination of “safe” levels of exposure to single pesticides may underestimate the real health effects, ignoring also the chronic exposure to multiple chemical substances.
Taking into consideration the health and environmental effects of chemical pesticides, it is clear that the need for a new concept in agriculture is urgent. This new concept must be based on a drastic reduction in the application of chemical pesticides, and can result in health, environmental, and economic benefits as it is also envisaged in European Common Agricultural Policy (CAP).
We believe in developing pesticide-free zones by implementing a total ban at local level and in urban green spaces is easily achievable.
Agricultural pesticide use and its associated environmental harms is widespread throughout much of the world. Efforts to mitigate this harm have largely been focused on reducing pesticide contamination of the water and air, as runoff and pesticide drift are the most significant sources of offsite pesticide movement. Yet pesticide contamination of the soil can also result in environmental harm. Pesticides are often applied directly to soil as drenches and granules and increasingly in the form of seed coatings, making it important to understand how pesticides impact soil ecosystems. Soils contain an abundance of biologically diverse organisms that perform many important functions such as nutrient cycling, soil structure maintenance, carbon transformation, and the regulation of pests and diseases. Many terrestrial invertebrates have declined in recent decades. Habitat loss and agrichemical pollution due to agricultural intensification have been identified as major driving factors.
Our review indicates that pesticides of all types pose a clear hazard to soil invertebrates. Negative effects are evident in both lab and field studies, across all studied pesticide classes, and in a wide variety of soil organisms and endpoints. The prevalence of negative effects in our results underscores the need for soil organisms to be represented in any risk analysis of a pesticide that has the potential to contaminate soil, and for any significant risk to be mitigated in a way that will specifically reduce harm to soil organisms and to the many important ecosystem services they provide.
Glyphosate is an extensively used herbicide globally. Its use dates back to 1970s with increasing numbers over the years. It is an effective weed killer but since it parallelly destroys non-target crops, its use during initial days was restricted.
Over years of extensive usage, many issues related to toxicity, carcinogenicity and GE varieties cropped up. Many researchers studied the toxicological characteristics, health impacts, environmental exposures and ecological impacts of glyphosate and Glyphosate-based herbicides. Many international agencies assessed its carcinogenic potential and grouped and regrouped it based on conclusions of various studies. As an outcome of many studies, an important aspect of toxicity of adjuvants used for technical formulations of glyphosate surfaced and gave a better understanding of its overall toxicity.
In interaction with water, glyphosate rapidly converts into its primary metabolite, i.e., AMPA, that holds most of its precursor's harmful properties and becomes far more persistent, such that its half-life lasts between 76 and 240 days
Glyphosate, as stated in the usage guidelines and the harmful clauses mentioned in the health data sheet, should not be released in the environment since it is harmful to marine organisms, with long-term impact studied the effect of glyphosate addition on plant tissues of Lemna minor (common duckweed) which resulted in reduced yield and growth, prevents the synthesis of carotenoids and chlorophyll a and b, and declines the photosystem II photochemical functions.
Glyphosate transforms into AMPA as soon as it comes into contact with water while maintaining toxic aspects of its precursor.
Glyphosate can interfere with water-soluble organic matter, clay particles, and colloidal iron oxides. This connection could therefore contribute to colloidal associated transportation of glyphosate.  Various concentrations of the residues were found in ground and surface waters. Usually, groundwater has been utilized as the essential source of drinking water supply. There are several reports which suggest that the water supplies in areas having intensive agricultural activities might be at high risk of glyphosate contamination
The study thus indicated that inhalation of the said herbicides may cause damage to DNA in exposed humans.
When examining the influence of Roundup containing glyphosate on aromatase, the enzyme involved in the development of oestrogen, at nontoxic levels, it was noted that glyphosate interferes with the levels of aromatase and mRNA and thus has both endocrinal and toxic effects The research suggests that Roundup containing glyphosate is lethal to placental cells of the human within 18 hours of exposure, at amounts lower than those for agricultural use
Plant communities in field edges, fallow fields, and other semi-natural habitats of agricultural landscapes may be at significant ecotoxicological risk from herbicides applied to nearby crop fields. In agricultural landscapes, field margins, fallow fields, and other semi-natural habitats are often the only remaining habitat for wild plant species and support diverse plant communities that help sustain pollinators, predators, and beneficial arthropods. Previous studies have indicated that herbicides, even at low concentrations, adversely affect plant communities, causing a decline in forb cover and reduced the flowering of key species and a reduction in the frequencies of certain species. Our data on plant species diversity and community composition of a fallow field support these findings.
Herbicides may not be an important factor in changing the functional composition of plant communities in the short term, but the long-term cumulative effects of herbicides on the functional composition and structure of plant communities in agricultural ecosystems need to be taken seriously
The herbicide glyphosate, N-(phosphonomethyl) glycine, has been used extensively in the past 40 years, under the assumption that side effects were minimal. However, in recent years, concerns have increased worldwide about the potential wide ranging direct and indirect health effects of the large scale use of glyphosate. In 2015, the World Health Organization reclassified glyphosate as probably carcinogenic to humans.
there are animal data raising the possibility of health effects associated with chronic, ultra-low doses related to accumulation of these compounds in the environment.
Intensive glyphosate use has led to the selection of glyphosate-resistant weeds and microorganisms. Shifts in microbial compositions due to selective pressure by glyphosate may have contributed to the proliferation of plant and animal pathogens.
It is scientifically proven that herbicides cause infertility, kidney problems, endocrine disruption, apoptosis, cytotoxicity, and neurotoxic effects. Such diseases impact the quality of those affected, and naturally the contaminated environment negatively affects human health.
Sixty percent of agrochemicals are used in the soil, and the others drain into the ground polluting the water supply; these chemicals are toxic for living organisms as they are absorbed by plants and successively accumulate in human tissue through biomagnifications of the food chain, causing human health and environment concerns. Chemical pollutants are a serious and growing global problem.
several studies have shown that herbicides and their derivative compounds contaminate natural resources such as water and soil, for example, aminomethylphosphonic acid (AMPA), a secondary compound of glyphosate, can persist for several years in the soil.
People who have been exposed to herbicides occupationally, or by eating foods or liquids containing herbicide residue, or for that matter inhaled herbicide-contaminated air, have experience a broad range of chronic health effects, including impaired neurobehavioral function (e.g., cognitive and behavioral disorders), Alzheimer’s and Parkinson’s diseases, hormone disruption, asthma, allergies, hypersensitivity, obesity, diabetes, hepatic lesions, kidney failure, multiple sclerosis, and cancer
One of the world’s most widely used glyphosate-based herbicides, Roundup, can trigger loss of biodiversity, making ecosystems more vulnerable to pollution and climate change
The widespread use of Roundup on farms has sparked concerns over potential health and environmental effects globally. Since the 1990s use of the herbicide boomed, as the farming industry adopted “Roundup Ready” genetically modified crop seeds that are resistant to the herbicide. “Farmers spray their corn and soy fields to eliminate weeds and boost production, but this has led to glyphosate leaching into the surrounding environment. In Quebec, for example, traces of glyphosate have been found in Montérégie rivers,” says Andrew Gonzalez, a McGill biology professor and Liber Ero Chair in Conservation Biology.
“We observed significant loss of biodiversity in communities contaminated with glyphosate. This could have a profound impact on the proper functioning of ecosystems and lower the chance that they can adapt to new pollutants or stressors. This is particularly concerning as many ecosystems are grappling with the increasing threat of pollution and climate change,” says Gonzalez.
the side effects caused by the wide and irrational use of herbicides threaten the environment and human health. Although herbicides are the least harmful among pesticides, many studies have shown the serious negative effects of herbicides on the environment and human health. Every year a list of herbicides that cause cancer or leave large residues in the soil and water are published. However, many herbicides have been banned, but only after they have been used in tons and causing environmental pollution. The chemical structure of herbicides degrades quite slowly in nature, which causes its accumulation in the soil and the environment. The effects of these herbicides have reached rivers, lakes, seas and oceans. Also, the effect of chemically degradation herbicides on living organisms under different environmental conditions is still unknown.
The effect of herbicides on non-target plants Herbicides, especially broad-spectrum herbicides, affect plant biological  diversity  and  damage  environmental  balance.  In addition to the possibility of killing crops, herbicides can reduce plant yield and increase susceptibility to diseases. For example, glyphosate significantly increases the severity of various plant diseases, and lead to weakening plant capacity to resist against pathogens, and immobilizes soil and plant nutrients
A University of Sydney led study published today in Nature has revealed the chemical odyssey pesticides embark upon after their initial agricultural application, with environmental consequences for a range of ecosystems.
A global study published today in Nature, which analysed the geographic distribution of 92 of the most commonly used agricultural pesticides, found that approximately 70,000 tonnes of potentially harmful chemicals leach into aquifers each year, impacting ecosystems and freshwater resources.
Associate Professor Federico Maggi, the study’s lead author from the University of Sydney’s School of Civil Engineering, said: “Our study has revealed that pesticides wander far from their original source. In many cases these chemicals end up a long way downstream and often, though in much smaller amounts, all the way to the ocean.”
The study showed that about 80 percent of applied pesticides degrade into daughter molecules – or byproducts – into soil surrounding crops.
This degradation of pesticides often occurs as a ‘cascade’ of molecules into the surrounding environment, which can persist in the environment for a long time and can be just as harmful as the parent molecule or applied pesticide. One such example is glyphosate. Although it is highly degradable, it breaks down into a molecule known as AMPA that is both highly persistent and toxic,” said Associate Professor Maggi.
Associate Professor Maggi last week co-authored a separate paper in Nature Ecology and Evolution that outlined recommendations to reduce pesticide use, including calling for a reliable set of indicators and improved monitoring.
He and the paper’s co-authors argue that targets for lowering pesticide pollution should be focused on decreasing risk, including reducing amounts and toxicity, because some organisms are at high risk from very toxic pesticides, even when used in low quantities.
Exposure to glyphosate — the world’s most widely used, broad-spectrum herbicide and the primary ingredient in the weedkiller Roundup — increases the risk of some cancers by more than 40 percent, according to new research from the University of Washington.
Various reviews and international assessments have come to different conclusions about whether glyphosate leads to cancer in humans.
The research team conducted an updated meta-analysis — a comprehensive review of existing literature — and focused on the most highly exposed groups in each study. They found that the link between glyphosate and Non-Hodgkin Lymphoma is stronger than previously reported.
“Our analysis focused on providing the best possible answer to the question of whether or not glyphosate is carcinogenic,” said senior author Lianne Sheppard, a professor in the UW departments of Environmental & Occupational Health Sciences and Biostatistics. “As a result of this research, I am even more convinced that it is.”
By examining epidemiologic studies published between 2001 and 2018, the team determined that exposure to glyphosate may increase the risk of Non-Hodgkin Lymphoma by as much as 41 percent. The authors focused their review on epidemiological research in humans but also considered the evidence from laboratory animals.
“This research provides the most up-to-date analysis of glyphosate and its link with Non-Hodgkin Lymphoma, incorporating a 2018 study of more than 54,000 people who work as licensed pesticide applicators,” said co-author Rachel Shaffer, a UW doctoral student in the Department of Environmental & Occupational Health Sciences.
“These findings are aligned with a prior assessment from the International Agency for Research on Cancer, which classified glyphosate as a ‘probable human carcinogen’ in 2015,” Shaffer said.
Glyphosate is the most widely used broad-spectrum systemic herbicide in the world. Recent evaluations of the carcinogenic potential of glyphosate-based herbicides (GBHs) by various regional, national, and international agencies have engendered controversy. We investigated whether there was an association between high cumulative exposures to GBHs and increased risk of non-Hodgkin lymphoma (NHL) in humans. We conducted a new meta-analysis that includes the most recent update of the Agricultural Health Study (AHS) cohort published in 2018 along with five case-control studies. Using the highest exposure groups when available in each study, we report the overall meta-relative risk (meta-RR) of NHL in GBH-exposed individuals was increased by 41% (meta-RR = 1.41, 95% confidence interval, CI: 1.13-1.75). For comparison, we also performed a secondary meta-analysis using high-exposure groups with the earlier AHS (2005), and we calculated a meta-RR for NHL of 1.45 (95% CI: 1.11-1.91), which was higher than the meta-RRs reported previously. Multiple sensitivity tests conducted to assess the validity of our findings did not reveal meaningful differences from our primary estimated meta-RR. To contextualize our findings of an increased NHL risk in individuals with high GBH exposure, we reviewed publicly available animal and mechanistic studies related to lymphoma. We documented further support from studies of malignant lymphoma incidence in mice treated with pure glyphosate, as well as potential links between glyphosate / GBH exposure and immunosuppression, endocrine disruption, and genetic alterations that are commonly associated with NHL or lymphomagenesis. Overall, in accordance with findings from experimental animal and mechanistic studies, our current meta-analysis of human epidemiological studies suggests a compelling link between exposures to GBHs and increased risk for NHL.
The herbicide glyphosate and the insecticides malathion and diazinon were classified as probably
carcinogenic to humans.
The herbicide 2,4-D was classified as possibly carcinogenic to humans (Group 2B), based on inadequate evidence in humans and limited evidence in experimental animals. There is strong evidence that 2,4-D induces oxidative stress, a mechanism that can operate in humans, and moderate evidence that 2,4-D causes immunosuppression, based on in vivo and in vitro studies
Once 2,4-D is applied directly on the soil or sprayed on the crops, it easily reaches water bodies.  Being a polar molecule, 2,4-D and its ester and amines are quite mobile in aqueous systems because of its acidic carboxyl group (pKa = 2.8) and low soil adsorption that may be the reason for its widespread occurrence in the environment.  In addition, it can reach the water bodies by surface runoff or through infiltration, leaching and soil percolation, becoming an environmental and human health problem.  It is also noteworthy that 2,4-D is a moderately persistent substance in the environment, with a half-life between 20 and 312 days, depending on environmental conditions.
Studies have demonstrated the bioaccumulation capacity of this herbicide in non-target organisms, exposed for a short period of time. Regarding the post-2,4-D exposure effects in different organisms, studies have shown endocrine disruption, reproductive disorders, genetic alterations and carcinogenic effects.  In humans, 2,4-D has been associated with the development of Parkinson’s neurodegenerative disease and autism.
The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) is applied directly to aquatic and conventional farming systems to control weeds, and is among the most widely distributed pollutants in the environment. Non-target organisms are exposed to 2,4-D via several ways, which could produce toxic effects depending on the dose, frequency of exposure, and the host factors that influence susceptibility and sensitivity. An increasing number of experimental evidences have shown concerns about its presence/detection in the environment, because several investigations have pointed out its potential lethal effects on non-target organisms.
The salt and ester formulations of 2,4-D are derived from the parent acid molecule. The dimethyl-amine salt (DMA) and 2-ethlhexyl ester (EHE) are most commonly used formulations accounts of approximately 90 to 95% of the total use across the world. Additionally, over 1500 herbicide products contain 2,4-D as an active ingredient and it was also a part of Agent Orange, the herbicide widely used during the Vietnam war.
2,4-D is a moderately persistent chemical with a half-life (t1/2) between 20 and 312 days depending upon the environmental conditions.  The herbicide is directly applied onto soil or sprayed over crops, and from there, often reaches superficial waters and sediments.  Due to low adsorption coefficients and high solubility in water, 2,4-D has often been detected in surface and ground water, which means an important environmental problem and health hazard.  About 91.7% of 2,4-D eventually end up in water. This contamination threatens the life of exposed vegetation and animals. Additionally, herbicides are also carried by runoff into the local river systems, thereby threatening the health of aquatic life as well. Unfortunately, 2,4-D has non-specific weed targets. It can reduce growth rates, induce reproductive problems, and produce changes in appearance or behavior, or could cause death of non-target species, including plants, animals and microorganisms. It is also known as endocrine disruptors, affecting developmental processes even at low concentrations
Of the 14,395 participants included in the study, 4681 (32.5%) had urine 2,4-D levels above the dichotomization threshold. The frequency of participants with high 2,4-D levels increased significantly (p < .0001), from a low of 17.1% in 2001–2002 to a high of 39.6% in 2011–2012. The adjusted odds of high urinary 2,4-D concentrations associated with 2,4-D agricultural use (per ten million pounds applied) was 2.268 (95% CI: 1.709, 3.009). Children ages 6–11 years (n = 2288) had 2.1 times higher odds of having high 2,4-D urinary concentrations compared to participants aged 20–59 years. Women of childbearing age (age 20–44 years) (n = 2172) had 1.85 times higher odds than men of the same age.
Agricultural use of 2,4-D has increased substantially from a low point in 2002 and it is predicted to increase further in the coming decade. Because increasing use is likely to increase population level exposures, the associations seen here between 2,4-D crop application and biomonitoring levels require focused biomonitoring and epidemiological evaluation to determine the extent to which rising use and exposures cause adverse health outcomes among vulnerable populations (particularly children and women of childbearing age) and highly exposed individuals (farmers, other herbicide applicators, and their families).
The herbicide aminopyralid provides foliar and soil residual weed control and increases forage production in bahiagrass pastures; however, the soil residual activity of aminopyralid makes carryover injury likely in subsequent sensitive vegetable crops.
The crops included in this research were negatively affected by aminopyralid at soil concentrations less than the limit of quantitation (0.2 µg kg(-1) )
Microbial community diversity was moderately impacted by herbicide treatment
Currently, the European Commission has decided to withdraw this substance from the market as a result of the European Green Deal and due to chlorsulfuron's risk analysis assessment.
The compound IN-A40972 was concluded to be a relevant groundwater metabolite and a relevant impurity. Based on the available information, there is no sufficient evidence demonstrating the absence of carcinogenic properties.
The metabolite IN-A4097 which was found in the metabolism studies was regarded as toxicologically relevant.
Based on the results of laboratory degradation studies published in the scientific literature, the  applicant also claimed that a strong positive correlation was found between soil pH and half life of chlorsulfuron in soil.
The formulated product (“Chlorsulfuron 75 WG”) was tested on algae and aquatic plants, showing a similar toxicity as the active substance, based on the content of the active substance.,of%20up%20to%2020%20years.
In a large (n = 49 922) prospective US cohort of pesticide applicators, dicamba was associated with increased risk of liver and intrahepatic bile duct cancer.  This association was robust to exposure lags of up to 20 years.
In a large prospective cohort, use of the herbicide dicamba was associated with increased risk of liver and intrahepatic bile duct cancers. Dicamba use was also inversely associated with myeloid leukaemia. Elevated risk of CLL was associated with high dicamba exposure, but this association was only observed in unlagged analyses. We additionally observed associations with tonsil cancer, lymphocytic leukaemia and MCL
However, because it can pollute water, especially in the case of permeable soils and near-surface groundwater levels, it can be applied only at a certain distance (buffer zone) from lakes and streams.
These compounds decompose partly by photodegradation and partly by microbial pathways, but much more slowly than phenoxyacetic acids and benzoic acids. Their half-lives in soil are 30–90 days. The degradation product of triclopyr is persistent in soil for up to a year.
Solubility in water and thus susceptibility to water erosion or leaching is high for atrazinefluroxypyr, glyphosate, and metamitron,
Few long-term studies on the fate of herbicides in soil have been done. 
Besides a herbicide’s chemical properties, its fate in soil depends on several parameters. It can interact strongly with soil components by forming complexes with metal ions in solution, and by being adsorbed on soil particles, including clay minerals.  An early laboratory study found that the rate of degradation for three dinitroanilines was directly correlated with soil temperature and moisture content.  A compound may adsorb onto clay particles and soil organic matter and remain unchanged for varying lengths of time
The half-life of fluroxypyr in soil samples ranged between 28 and 78 d. An estimated mean 48.6 ± 20% of the fluroxypyr was converted into F-P and 8.0 ± 2% into F-MP. The main metabolite, F-P, was rapidly degraded, with an average half-life of 10 ± 5 d. However, F-MP was not degraded to a significant degree in any sample, resulting in slowly increasing concentrations throughout the experiment. This pattern of relatively rapid degradation of F-P and slow accumulation of F-MP was also observed in the field. The persistent nature of F-MP may be of concern if fluroxypyr is used repeatedly at the same location. Fluroxypyr was detected in the groundwater beneath the track at all three locations studied in concentrations exceeding the EU limit of 0.1 μg L for pesticides in drinking water, and F-P was detected in the groundwater at two of three locations. The most important factor controlling fluroxypyr degradation rate in soil was the soil water content, which modulated microbial activity and presumably also fluroxypyr availability to microorganisms.
However, it is possible that exposure to imazamox at low doses, via contaminated water, over a prolonged period of time may cause a change in cellular structure and function, even if it is not toxic at high doses.
Imazapyr has a high potential for leaching into groundwater because it is highly water-soluble, persistent in soil, and only weakly sorbed by soils.
Indaziflam, a broad-spectrum, pre-emergence herbicide was the focus of a field investigation conducted after the identification of sporadic injury symptoms on the pecan trees a few months after the application.
Indaziflam is classified as moderately mobile in the soil, however its breakdown products (indaziflam-carboxylic acid, fluoroethyldiaminotriazine and fluoroethyltriazinanedione) are more mobile [2]. The water solubility of indaziflam is 0.0028 g/L at 20°C and its organic carbon sorption coefficient (Koc) is <1,000 mL/g [2, 4].
Based on the observed injuries of the ryegrass (Lolium multiflorum) planted in the columns, indaziflam was reported to leach to 30 cm depth. Jhala et al. [8] reported that the leaching depth of indaziflam is positively correlated with the application rate and the amount of rainfall.
the extensive application of quinclorac has resulted in the evolution of resistant plants, the frequent detection in the environment, and the hazard to non-target organisms.
Accompanied with the extensive use of herbicides, weed control has become difficult owing to the evolution of herbicide resistance
As one of the most important model organism, fish has long been employed for examining the toxicity of pollutants in the aquatic environment (Fig. 5). For silver catfish, 395 mg/L of quinclorac could lead to the deaths of 50% population in the 96 h short term
The potential hazard of quinclorac is originated from not only its toxicity to non-target organisms but also its slow degradation in the environment
Worldwide, more than 30 weed species have evolved resistance to auxinic herbicides. Not much is known about the mechanisms of resistance for most of these. The fact that a significant number of the resistant weed biotypes have multiple resistances to unrelated herbicides suggests that metabolic degradation is a common mechanism of resistance.
Pesticides are one of the highly persistent group of chemicals in the soil environment. The excessive usage of pesticides leads to the formation of pesticide-based soil contaminants.
No published data exist on the effect of aminocyclopyrachlor on seed production of desirable perennial grasses in natural ecosystems, thereby suggesting the need for further research.
How aminocyclopyrachlor will affect plant community composition may be difficult to predict, because this herbicide also affects native forbs and shrubs, and may reduce seed production of desired, perennial grasses. Further field testing is needed to assess the effects of aminocyclopyrachlor on long-term changes in plant community composition.
Aminocyclopyrachlor is an herbicide that belongs to the new class of chemicals known as the pyrimidine carboxylic acids, which are used to control broadleaf weeds and brush. However, the environmental behavior and fate of aminocyclopyrachlor are not fully understood. The aim of the present study was thus to evaluate the mineralization, extractable residue and bound residue formation of aminocyclopyrachlor in three tropical soils with different physico-chemical properties. 14C-labeled [pyrimidine-2-14C] aminocyclopyrachlor was used to assess the fate of this herbicide in soil placed in biometer culture flasks. Total mineralization (accumulated 14CO2) of aminocyclopyrachlor was found to be <10% in all soils, decreasing in the following order: Oxisol—Typic Hapludox (clay) > Oxisol—Typic Hapludox (loamy sand) > Plinthosol—Petric (sandy clay). Overall, constant rate of mineralization (k) values for all soils were very low (0.00050% to 0.00079% 14CO2 day−1), with mineralization half-life times (MT50) consequently very high (877 to 1376 days), suggesting potential long persistence in soil. The amount of extractable residues decreased from ~31% to 50% in all soils after 126 days of incubation, indicating an increase in bound residue formation from ~5.0- to 7.5-fold compared to evaluation immediately after herbicide application, suggesting that degradation herbicide is involved in the formation of bound residues. Extractable residues are important factors that control mineralization and bound residue formation from aminocyclopyrachlor in the soil. The present study is the first to assess the fate, distribution, and formation of bound residues of aminocyclopyrachlor in soils. Aminocyclopyrachlor residues were predominantly associated with the OM and clay contents of soil. This effect of soil physico-chemical properties should be considered in environmental risk assessment of aminocyclopyrachlor and its application in the field for weed control.,observed%20adverse%20effect%20level%20(LOAEL)
The data available on environmental fate and behaviour are sufficient to carry out the required environmental exposure assessments at EU level for the representative uses, with the notable exception that information is missing regarding the effect of the water treatment process chlorination on the nature of the residues that might be present in surface water, when surface water is abstracted for drinking water. Consequently, the consumer risk assessment from the consumption of drinking water could not be finalised. The potential for groundwater exposure by the active substance clopyralid above the parametric drinking water limit of 0.1 μg/L consequent to the uses assessed, was indicated to be high in up to six out of nine FOCUS groundwater scenarios for the representative use on winter cereals and up to three out of nine of these scenarios for the representative use on grassland.
The risk to aquatic organisms, earthworms and non-target plants was assessed as low for exposure to clopyralid, but needs to be further assessed at Member State level for the formulation.
data gaps for description and validation data for the analytical method used in developmental toxicity study in rats and for validation data for the methods used in water solubility, solubility in organic solvents and octanol/water partition coefficient studies were identified. Methods of analysis are available for the determination of the active substance in the technical material and in the representative formulation and for the determination of the respective impurities in the technical material.
These results confirm the cytotoxic and genotoxic effects of clopyralid on non-target organism.
Flumioxazin has developmental toxicity in rats, causing embryonic lethality, teratogenicity (mainly ventricular septal defects, VSD, and wavy ribs), and growth retardation. The mechanism of this developmental toxicity in rats has already been shown to be embryonic anemia resulting from PPO inhibition and following the elimination of heme biosynthesis. Even though all mammals have PPO for heme biosynthesis, which is essential for vital activity, a remarkable species difference in the toxicity caused by flumioxazin-induced PPO inhibition has been reported.
Flumioxazin is a preemergence, N-phenylpththalimide herbicide that can be applied to control a broad spectrum of weeds in a variety of cropping systems. Limited information exists concerning the environmental fate of flumioxazin
The assessment of the endocrine-disrupting properties of flumioxazin for humans and non-target organisms could not be finalised due to the incomplete data sets.
Regarding non-target organisms other than wild mammals, the available evidence is not considered sufficient to conclude either on EATS-mediated endocrine activity or on EATS-mediated adversity.
more information is needed on its effects on desirable species.
imazapic control decreased sharply with time
mitigation of the effects to native seeds will depend on herbicide specifics such as mode of action and soil mobility.
Reinvasion of areas treated with imazapic occurred quickly
the characteristics of indaziflam that lead to longer downy brome control than imazapic, also make it difficult to reduce injury to species seeded concurrently with herbicide efforts. In contrast, imazapic injury to seeded species can be limited, but downy brome control is short, resulting in eventual reinvasion.
Our results suggest that indaziflam applications strongly limit restoration of a native species
The exposure to metsulfuron methyl possibly induced a leakage of nutrients from the macrophyte leaves, which promoted an increased algal growth.
thus this study shows that aquatic ecosystems, in particular those which are macrophyte-dominated, may be affected by metsulfuron methyl at concentrations that may well occur in water bodies adjacent to agricultural land.
An unintended consequence of the application of the herbicides could be the influence on the microbial ecological balance of the soil, leading to a significant change of the quality of the population. This could end up affecting the productivity of crops negatively.
All species exhibited marked effects on the vegetative growth and reproductive performance when sprayed at 10% label rate. Less pronounced but significant effects were shown at 1% label rate. Seed weight was reduced for B. cernua and S. arvensis. The seedling stage was the most sensitive period for all species tested, although surviving plants sprayed at later stages showed considerable effects on the reproductive parts. All species tested would be at risk from small doses of metsulfuron methyl drifting away from the sprayed areas. This study highlights the shortcomings of the current testing schemes required prior to pesticide registration.
Knowledge about the negative effects and mechanism of sulfentrazone (SUL) on aquatic early life stages is still limited.
The results inferred the environmental concentration of SUL might cause potential cardiac and endocrine health risk in zebrafish later life stages, also facilitated a better understanding of the sub-lethal effects and molecular mechanism of SUL on aquatic organism.
Bees and the pollination services they deliver are beneficial to both food crop production, and for reproduction of many wild plant species. Bee decline has stimulated widespread interest in assessing hazards and risks to bees from the environment in which they live. While there is increasing knowledge on how the use of broad-spectrum insecticides in agricultural systems may impact bees, little is known about effects of other pesticides (or plant protection products; PPPs) such as herbicides and fungicides, which are used more widely than insecticides at a global scale.
We suggest a number of areas for further research to improve the knowledge base on potential effects. This will allow better assessment of risks to bees from herbicides and fungicides, which is important to inform future management decisions around the sustainable use of PPPs.
As herbicides and fungicides are not designed to target insects, little is known as to whether they pose a risk to bees and other insect pollinators. However, emerging evidence has suggested that herbicides can affect factors such as bee navigation, learning and larval development whereas fungicides can affect food consumption, metabolism and the immune response.  Bees may be exposed to these compounds directly via contact exposure during or after application, or via oral exposure through contaminated nectar and pollen. In order to minimise impacts on non-target pollinating insects such as bees, it is important to understand any potential effects these compounds may have, to determine the risks they pose and to mitigate against them.
With a growing global population and increasing environmental concerns, it is crucial to sustainably manage our agricultural systems. It is important to understand both the benefits and risks of PPP use to humans and the environment in order to make decisions around agricultural management. Pesticide use has been linked with pollinator declines globally. Understanding what has been studied in terms of different pesticide classes and substance groups and potential impacts on bees and other insect pollinators is vital to determine the role of PPPs in bee decline.
Although herbicides and fungicides are not designed to target insects, the current declines in both diversity and abundance of some bee species and attempts to resolve the factors driving these declines warrant the scrutiny on the potential effects of non-insecticide PPPs on pollinators.
For herbicides, we found that most studies examined the impacts of active ingredients rather than formulations, whereas for fungicides this was much more compound specific. Using active ingredients allows the investigation of the impacts of that compound alone. However, commercially, most PPPs are supplied as formulations and so this may be a more likely exposure route to bees in the environment. Formulations contain a variety of substances other than the active ingredients (e.g. adjuvants), and it could be that some of these other substances may also interact with bees. A number of different PPPs can be applied to any piece of land in close temporal proximity, and so there is a vast number of possible PPP combinations applied to land across the globe with differing persistence’s in pollen, nectar and soil, and boundless possible interactions between them. Realistically, the number of possible PPP combinations bees could be exposed to is too large for any one study. However, it’s important that the role of single compounds versus mixtures of compounds (alone and in formulation) in terms of effects on bees and other pollinators continues to be investigated in future studies.
With an increasing interest in the sustainable use of PPPs, and public scrutiny over the non-target effects of herbicides and fungicides in a range of areas including human health, water contamination and pest resistance, it is likely that there will be more interest in the impacts of herbicides and fungicides on bees in the future with new research emerging over time. Neonicotinoids were first released in the 1990s and their use has increased exponentially in the last 20+ years. However, during this time, pollinators were exposed to a variety of these insecticides. After decades of scientific research into the negative effects of neonicotinoids on pollinators, the outdoor use of three commercially used neonicotinoids were banned in 2018 in the European Union. Therefore, it is important to avoid the prolonged and unsustainable use of PPPs if further pollinator declines are to be prevented. In order to ensure safe pesticide use, it is important to determine the effects of commercially used PPPs on multiple bee species using methodology that accurately reflects all possible exposure routes. Although there is an increasing amount of scientific literature regarding herbicide and fungicide effects on bees, several key knowledge gaps in our current understanding remain. These include a lack of studies on bumblebee and solitary bee species, the low number of studies considering contact and internal exposures and the lack of attention to certain compounds over others. To fully understand the potential risks of herbicides and fungicides to bees and to mitigate against them more research is required, specifically diversifying the type of research (i.e. exposure route, study species and type of exposure) and the range of compounds investigated. It is important to address these gaps in the future if we are to build a body of research capable of contributing towards future policy and ensure the sustainable management of agricultural systems and continued provision of pollination services to both crops and wild plants.
Wild and managed pollinators are essential to food production and the function of natural ecosystems; however, their populations are threatened by multiple stressors including pesticide use. Because pollinator species can travel hundreds to thousands of meters to forage, recent research has stressed the importance of evaluating pollinator decline at the landscape scale. However, scientists’ and conservationists’ ability to do this has been limited by a lack of accessible data on pesticide use at relevant spatial scales and in toxicological units meaningful to pollinators.

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