(Except for pesticides, September 24, 2020) A new report from the United States Geological Survey (USGS) “National Water Quality Assessment (NAWQA) Project” shows that pesticides are widely distributed in American rivers and streams, of which nearly 90% A water sample containing at least five or more different pesticides. Since the analysis of the United States Geological Survey (USGS) in 1998 showed that pesticides are widespread in all waterways in the United States, pesticide pollution in waterways is common in history, and at least one pesticide can be detected. Thousands of tons of pesticides enter American rivers and streams from agricultural and non-agricultural sources, polluting basic drinking water sources such as surface water and groundwater. With the increase in the amount of pesticides in waterways, it has an adverse effect on the health of aquatic ecosystems, especially the synergistic effect of certain pesticides with other pesticides to increase the severity of this effect. Such reports are an important tool for determining appropriate regulatory actions to protect human, animal and environmental health. The USGS concluded that “identifying major contributors to toxicity can help improve rivers and streams to support the quality of aquatic life.”
Water is the most abundant and important compound on the earth, vital to survival, and the main component of all living things. Less than three percent of fresh water is fresh water, and only a small portion of fresh water is groundwater (30.1%) or surface water (0.3%) for consumption. However, the ubiquitous use of pesticides threatens to reduce the amount of fresh water available, because pesticide runoff, replenishment and improper disposal can contaminate nearby waterways, such as rivers, streams, lakes or underground catchments. Since rivers and streams account for only 2% of surface water, these fragile ecosystems must be protected from further damage, including loss of aquatic biodiversity and decline in water quality/potability. The researchers in the research report said, “[The main purpose of this research is to characterize the characteristics of the pesticide mixtures found in water samples of the watersheds in the United States with agricultural, developed and mixed land uses from 2013 to 2017″ (2017 In addition, the researchers aim to understand “the potential toxicity of pesticide mixtures to aquatic organisms, and to evaluate the occurrence of potential drivers of toxicity of the mixture.”
In order to assess the national water quality, researchers collected water samples from sampling points in the basin established by the National Water Quality Network (NWQN)-Rivers and Streams in 1992. These land types are based on land use types (agricultural, developed/urban and mixed). From 2013 to 2017, researchers collected water samples from each river basin site every month. Within a few months, as in the rainy season, as the amount of pesticide runoff increases, the frequency of collection will increase. Researchers used tandem mass spectrometry coupled with direct water injection liquid chromatography to assess the levels of pesticides in water samples to analyze a total of 221 pesticide compounds in filtered (0.7μm) water samples at the USGS National Water Quality Laboratory. In order to assess the toxicity of pesticides, the researchers applied the Pesticide Toxicity Index (PTI) to measure the potential toxicity of pesticide mixtures to three classification groups-fish, cladocerans (small freshwater crustaceans) and benthic invertebrates. The PTI score classification includes three levels to represent the approximate screening level of predicted toxicity: low (PTI≥0.1), chronic (0.1 1).
It was found that during the period 2013-2017, at least five or more pesticides were present in 88% of the water samples from NWQN sampling points. Only 2.2% of the water samples did not exceed the detectable level of pesticide concentration. In each environment, the median pesticide content in water samples of each land use type was the highest, 24 pesticides in agricultural environments, and 7 pesticides in mixed (agricultural and developed land), the lowest. Developed areas are located in the middle, and each water sample accumulates 18 kinds of pesticides. Pesticides in water samples have potential acute to chronic toxicity to aquatic invertebrates, and chronic toxicity to fish. Among the 221 pesticide compounds analyzed, 17 (13 insecticides, 2 herbicides, 1 fungicide and 1 synergist) are the main drivers of toxicity in the Aquatic Taxonomy. According to PTI analysis, a pesticide compound contributes more than 50% to the toxicity of the sample, while other current pesticides contribute little to the toxicity. For cladocerans, the main pesticide compounds that cause toxicity are the insecticides bifenthrin, carbaryl, toxic rif, diazinon, dichlorvos, dichlorvos, tridifenuron, fluphthalamide, and tebupirine phosphorus. The herbicide attriazine and the insecticides bifenthrin, carbaryl, carbofuran, toxic rif, diazinon, dichlorvos, fipronil, imidacloprid and methamidophos are potential pesticides to benthic invertebrates The main driver of toxicity. The pesticides that have the greatest impact on fish include the herbicide acetochlor, the fungicide to degrade carbendazim, and the synergistic piperonyl butoxide.
The United States Geological Survey (USGS) passed its National Water Quality Assessment (“Assessing the occurrence and behavior of pesticides in streams, lakes and groundwater and the potential of pesticides to contaminate our drinking water supply or damage aquatic ecosystems”) (NAWQA) report. Previous USGS reports indicate that pesticides are ubiquitous in the aquatic environment and are common pollutants in freshwater ecosystems. In the United States, many of the most commonly used pesticides can be detected in surface water and groundwater, which are the drinking water source for half of the American population. In addition, rivers and streams contaminated by pesticides can discharge sewage into oceans and lagoons such as the Great Barrier Reef (GBR). Among them, 99.8% of GBR samples are mixed with more than 20 different pesticides. However, these chemicals not only have harmful health effects on aquatic organisms, but also have adverse health effects on terrestrial organisms that depend on surface water or groundwater. Many of these chemicals can cause endocrine disorders, reproductive defects, neurotoxicity and cancer in humans and animals, and most of them are highly toxic to aquatic organisms. In addition, water quality surveys often reveal the presence of more than one pesticide compound in the watercourse and the potential toxicity to marine life. However, neither the USGS-NAWQA nor the EPA’s aquatic risk assessment assesses the possible risks of pesticide mixtures to the aquatic environment.
Pesticide contamination on the surface and groundwater has caused another problem, that is, the lack of effective waterway monitoring and regulations, preventing pesticides from accumulating in waterways. One of the methods of the US Environmental Protection Agency (EPA) to protect human and environmental health is to control pesticides in accordance with the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and in accordance with the provisions of the Clean Water Act Pollution of point sources in waterways. However, the EPA’s recent rollback of waterway regulations has little effect on protecting the health of aquatic ecosystems, and marine and terrestrial species (including humans) need to do so. Previously, USGS-NAWQA criticized the EPA for not establishing sufficient pesticide water quality standards. According to NAWQA, “Current standards and guidelines do not completely eliminate the risks caused by pesticides in watercourses because: (1) the value of many pesticides has not been determined, (2) mixtures and decomposition products have not been considered, and (3) seasonality has not been assessed. The high concentration of exposure, and (4) certain types of potential effects have not been assessed, such as endocrine disruption and unique responses of sensitive individuals.
The results of the study indicate that 17 different pesticides are the main drivers of aquatic toxicity. Organophosphate insecticides play a major role in chronic Cladran toxicity, while imidacloprid insecticides cause chronic toxicity to benthic invertebrates. Organophosphates are a class of insecticides that have an adverse effect on the nervous system, and their mode of action is the same as that of nerve agents in chemical warfare. Exposure to imidacloprid insecticides can adversely affect the reproductive system and is highly toxic to various aquatic species. Although dichlorvos, bifenthrin and methamidophos are rarely present in the samples, when these chemicals are present, they exceed the chronic and acute toxicity thresholds for aquatic invertebrates. However, the researchers pointed out that the toxicity index may underestimate the potential impact on aquatic organisms, because past studies have found that “weekly discrete sampling often misses short-term, potential toxic peaks in pesticides”.
Aquatic invertebrates, including benthic organisms and cladocerans, are an important part of the food web, consume too much nutrients in the water, and are also a food source for large carnivores. However, the impact of pesticide pollution in waterways may have a bottom-up impact on aquatic invertebrates, killing beneficial invertebrates whose nervous system is similar to the target of terrestrial insects. In addition, many benthic invertebrates are larvae of terrestrial insects. They are not only indicators of waterway quality and biodiversity, but also provide various ecosystem services such as bio-irrigation, decomposition and nutrition. The input of pesticides must be adjusted to reduce the impact of potentially toxic pesticides in rivers and streams on aquatic organisms, especially in areas where agrochemicals are more widely used.
The report shows that the number of pesticides in the sample varies from place to place every year, with agricultural land using the highest amount of pesticides, including herbicides, insecticides and fungicides, and a large influx from May to July. Due to the abundance of agricultural land, the median pesticides in each water sample in the central and southern regions are the highest. These findings are consistent with previous studies showing that water sources near agricultural areas tend to have higher levels of pollutants, especially in spring, when agrochemicals runoff is more rampant. In February 2020, the U.S. Geological Survey reported on the Pesticide Cooperative Sampling Project in Waterways (conducted by EPA). 141 pesticides were detected in 7 rivers in the Midwest and 73 pesticides were detected in 7 rivers in the southeast. The Trump administration has abandoned the requirement of the multinational chemical company Syngenta-ChemChina to continue to monitor the presence of herbicides in the waterways of the Midwest by 2020. In addition, the Trump administration has replaced the rules in the 2015 WOTUS “Navigable Waters Protection Rules”, which will greatly weaken the protection of several waterways and wetlands in the United States, and by abandoning various pollution hazards that threaten waterways. Prohibition of activities. As the impact of climate change intensifies, rainfall increases, runoff increases, and glacier ice melts, leading to the capture of traditional pesticides that are no longer produced. The lack of specialized pesticide monitoring will lead to the accumulation and synergy of toxic chemicals in the aquatic environment. , Further polluting water sources.
The use of pesticides should be phased out and eventually eliminated to protect the waterways of the country and the world and reduce the amount of pesticides entering drinking water. In addition, in addition to pesticides, the federal government has long advocated protective federal regulations that consider the potential synergistic threats of pesticide mixtures (whether formulated products or actual pesticides in the environment) to ecosystems and organisms. Unfortunately, current administrative regulations fail to consider the environment as a whole, creating a blind spot that limits our ability to make extensive changes that can truly improve ecosystem health. However, promoting local and state pesticide reform policies can protect you and your family from pesticide-contaminated water. In addition, organic/renewable systems can save water, promote fertility, reduce surface runoff and erosion, reduce the demand for nutrients, and can eliminate toxic chemicals that threaten many aspects of human and ecosystem life, including water resources. For more information about pesticide contamination in water, please refer to the “Threat Waters” program page and the “Articles Beyond Pesticides” “Pesticides in my drinking water?” Personal preventive measures and community actions. Tell the U.S. Environmental Protection Agency that it must work hard to protect health and the environment.
This entry was posted at 12:01 AM on September 24, 2020 (Thursday) and is classified under Aquatic Organisms, Pollution, Imidacloprid, Organophosphate, Pesticide Mixtures, Water. You can track any response to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Ping is currently not allowed.
document.getElementById(“comment”). setAttribute(“id”, “a6fa6fae56585c62d3679797e6958578″); document.getElementById(“gf61a37dce”). setAttribute(“id”,”comment”);