(Beyond pesticides, September 23, 2022) According to a September 15 Environment California press release, California Department of Pesticide Regulation (CDPR) data confirms more bad news about neonicotinoid (neonic) contamination: nearly all waterways samples from three counties show the presence of the neonicotinoid imidacloprid. at levels above the U.S. Environmental Protection Agency (EPA) chronic benchmark for damage to aquatic ecosystems; in five other counties, well over half showed its presence at similar levels. The use of neonics is strongly correlated with mass mortalities and other damage to a variety of bees and pollinators, as well as other beneficial organisms. These surprising measures will make the state’s efforts to protect these organisms even more difficult, according to Environment California (EC). See beyond pesticides’ Poisoned Waterways report for a deep dive into neonics and their impacts in US rivers, lakes and streams.
The data represents 405 surface water samples collected between 2000 and 2020; those of urban waterways in Los Angeles, Orange, and San Diego counties showed nearly 92 percent contaminated at EPA baseline levels; in Alameda, Contra Costa, Placer, Sacramento and Santa Clara counties, 58% of streams had such levels. Many heavily contaminated counties are in the central and southern coast regions of the state. Some of this contamination undoubtedly comes from heavy agricultural use of imidacloprid, causing the compound to migrate into waterways, but some may also come from non-agricultural uses – such as flea prevention for pets and building pest control products – common in developed urban areas. . According to the CDPR, there are 253 pesticide products containing imidacloprid registered for use in California.
The Environment California webpage hosts an interactive map of the sampling sites (across much of the state) that are represented in these imidacloprid measurements. The percentage of samples from each location containing the compound ranges from 0 to 91.67. The CE page notes that “very few samples were tested for imidacloprid before 2010. . . . [and that] the percentage of samples that detect imidacloprid remains fairly constant over time. Detailed results can be found in the CDPR Surface Water Database.
The 2017 Beyond Pesticides report mentioned above cited similarly alarming findings in other state waterways a decade ago: [CDPR] A study using 2010 and 2011 surface water monitoring data from three agricultural regions in the state found imidacloprid in 89% of samples taken. . . . In the three agricultural regions studied, imidacloprid was detected in 85% of the samples in Salinas, 93% in Imperial Valley and 100% in Santa Maria Valley. These levels exceed currently established chronic aquatic benchmarks.
Neonicotinoids (such as imidacloprid, acetamiprid, thiamethoxam, clothianidin and dinotefuran) are a family of insecticides that damage the central nervous system of insects and can paralyze or kill them, as well as have effects deleterious to the brains of baby bees. They are used as foliar sprays, plant root dips and granules to kill or suppress a variety of pests – especially sap-feeding insects such as aphids and root-feeding larvae. But a very important carrier for these compounds is the seed coating, often for staple crops (eg corn, soybeans, cotton). Ironically, years ago the EPA released a report concluding that neonic seed coating offers little or no overall benefit for controlling insects or improving yield or quality in soybean production.
Regardless of how they are deployed, neonics are systemic pesticides, meaning that plants germinate from coated seeds and/or absorb the applied compound through their roots, after which it permeates the entire plant. This makes the pollen, nectar, guttation droplets, and fruits of the plant poisonous to creatures that feed on them. Non-target organisms, such as birds, bees, butterflies and bats, are poisoned when they feed among these contaminated plants. In addition to insect exposure through foraging, it turns out that soil contaminated with neonics can also harm ground-nesting bees.
Neonicotinoids can persist for long periods in soils and are highly soluble in water; thus, they can be transported via rainfall and/or irrigation systems into groundwater and streams. They are routinely detected in sampling of waterways nationwide at concentrations that exceed acute and chronic toxicity values for susceptible organisms (as reported in Beyond Pesticides’ “deep dive” report). Through a 2017 risk assessment, the EPA found that “[C]he concentrations of imidacloprid detected in streams, rivers, lakes and drains regularly exceed acute and chronic endpoints derived for freshwater invertebrates. Imidacloprid, one of the oldest neonicotinoids in commercial use, is particularly persistent in aquatic environments and does not readily biodegrade. its half-life in water is generally greater than 30 days.
Neon contamination of waterways – in California and across the country – is of great concern because these compounds pose a serious threat to key aquatic organisms and can have a complex cascading impact on ecosystems. Aquatic insects and crustaceans are very sensitive to neonicotinoids; the mayfly, keystone species, was identified as the most sensitive.
Beyond pesticides’ Poisoned Waterways notes the report: “Impacts on aquatic invertebrates can have cascading effects on food webs and healthy ecosystem functioning. [Even] low-level sublethal exposures can result in decreased species abundance, altered predator-prey relationships, [and] reduced water filtration and nutrient cycling. In addition, he points out that the current federal aquatic life benchmarks for neonicotinoids may underestimate the risks: the standard test organisms used by the EPA to establish these benchmarks are, by orders of magnitude, more tolerant to neonicotinoid exposure than other susceptible species.
Beyond the impacts on aquatic life, terrestrial insects, pollinators, birds and bats, neonics – presented by the agrochemical industry as being safe for mammals – are nevertheless associated with a multitude of problems. human health, including damage to the reproductive and endocrine system; possible kidney, liver, developmental and neurological damage; and possibly, indirect carcinogenic impacts linked to the endocrine system.
In response to this new CDPR dataset, Environment America Conservation Program Manager Steve Blackledge said, “Every Californian knows the importance of having access to safe, clean water. Neonics like imidacloprid not only harm our pollinators and land birds, but also our aquatic wildlife. Neonics are also present in our bodies and although they are considered “safe for mammals”, recent research suggests that exposures to neonics can increase the risk of developmental and neurological damage.
The EPA has been grossly negligent in taking protective action against the neonic family of insecticides. Indeed, in March 2022, Beyond Pesticides covered its draft decisions on the review of registration of five neonics: imidacloprid, dinotefuran, clothianidin, thiamethoxam and acetamiprid. We wrote then: “Despite the agency’s own conclusions on evidence of serious threats to pollinators, aquatic invertebrates and other wildlife, it has made interim decisions on these neonicotinoids. . . that ignore the science on the impacts of pesticides. The EPA appears to be ready to finalize these registrations. . . . [T]its willingness, failing other measures, to extend the use of these harmful compounds for 15 years.” The schedule of review processes for these compounds can be viewed here.
California lawmakers passed a “Save the Bees Bill,” Assembly Bill 2146, which is currently awaiting the governor’s signature. The bill aims to end non-agricultural uses of neonics on lawns, golf courses and home gardens, starting in 2024. Media outlet KSBW8 opined that if signed into law, the enacted law “could have a significant impact on the central coast and its agriculture”. Undoubtedly, this would also be true for other regions, watersheds, and waterways in the state.
Environment California encourages Governor Gavin Newsom to sign the bill as soon as possible. The organization’s state director, Laura Deehan, said, “We want to make California the next, and largest, state to take this important step. The bill has already passed the Legislative Assembly, so we are now urging Governor Newsom to sign the bill into law. We must prioritize the preservation of our pollinators over the short-term convenience of heavy pesticide use.
Beyond Pesticide agrees that Governor Newsom should sign this bill, which would enact certain protections in the state against the ravages of neonics use. We encourage readers who live in California to contact the governor to defend his signature: 916.445.2841 or through the state’s website. Other states, localities and entities have taken steps to restrict the use of this class of pesticides, including Maine, Maryland, Massachusetts, Vermont, New York, New Jersey, Portland, Oregon and Emory University. At the federal level, it is imperative that the EPA create much stricter neon regulations – with a ban being the most protective of organisms, ecosystems, public health, and water resources.
Source: https://environmentamerica.org/california/media-center/pesticide-linked-to-bee-die-offs-found-in-californias-urban-waterways/
All unattributed positions and opinions in this article are those of Beyond Pesticides.
