Atrazine Contamination Research Articles

Complexity of influences on atrazine phytoremediation of coexisting graphene oxide in water: Mitigating its phytotoxicity while decreasing plant removal contribution

Phytoremediation is an efficient technology for the removal of herbicide atrazine (ATZ) contamination in water bodies, but its ability to reduce ATZ under combined pollution remains unclear, especially ATZ co-existing with the emerging pollutant graphene oxide (GO) that may have potential effects on ATZ fate, plants and microbes. Herein, we investigated the phytoremediation potential of an emergent plant (Iris pseudacorus) for ATZ and the response of bacteria in a hydroponic system with and without GO. The results showed that plants enhanced ATZ dissipation in water with the increased removal rate by a factor of 1.7–4.0. GO restricted ATZ uptake by plants, but favored ATZ bioconcentration in cell walls. The plant contributed most to changes in the bacterial communities, decreasing the alpha diversity, while enriching the functional categories involving in amino acid and carbohydrate metabolisms. These findings indicated that I. pseudacorus can be employed as an effective candidate of phytoremediation for ATZ co-existing with GO at environmentally relevant concentrations, tending to recruit bacteria with plant stress tolerance and growth-promotion activities more than with ATZ degradation activities; GO exerted a mitigating effect on ATZ stress improving the barrier function of cell walls, but decreased the contribution of plants to ATZ removal.

A review of the potential adverse health impacts of atrazine in humans.

Atrazine is a widely used chlorinated triazine herbicide in agricultural settings, which has raised concerns over its potential adverse effects on human health. The extensive application of atrazine has resulted in its pervasive presence in the environment, contaminating soil, groundwater, and surface water. While earlier research suggested that atrazine is unlikely to pose a health concern, recent evidence has indicated the necessity to reassess this point of view. This review aims to assess the recent evidence on atrazine's adverse effects on human health, focusing on (i) Cancer, (ii) Metabolic Diseases, (iii) Reproductive System, (iv) Neural System, and (v) Epigenetic Effects. Strategies to mitigate atrazine contamination and limitations of previous studies are also discussed. We strongly believe that further investigation is necessary to determine the potential detrimental consequences of atrazine in humans, particularly in developing countries, where herbicides are widely used without stringent safety regulations. Therefore, the current review will be beneficial for guiding future research and regulatory measures concerning the use of atrazine.

Simulated climate change and atrazine contamination can synergistically impair zebrafish testicular function

Elements that interfere with reproductive processes can have profound impacts on population and the equilibrium of ecosystems. Global warming represents the major environmental challenge of the 21st century, as it will affect all forms of life in the coming decades. Another coexisting concern is the persistent pollution by pesticides, particularly the herbicide Atrazine (ATZ), which is responsible for a significant number of contamination incidents in surface waters worldwide. While it is hypothesized that climate changes will significantly enhance the toxic effects of pesticides, the actual impact of these phenomena remain largely unexplored. Here, we conducted a climate-controlled room experiment to assess the interactive effects of the projected 2100 climate scenario and environmentally realistic ATZ exposures on the reproductive function of male zebrafish. The gonadosomatic index significantly decreased in fish kept in the extreme scenario. Cellular alterations across spermatogenesis phases led to synergic decreased sperm production and increased germ cell sloughing and death. ATZ exposure alone or combined with climate change effects, disrupted the transcription levels of key genes involved in steroidogenesis, hormone signaling and spermatogenesis regulation. An additive modulation with decreased 11-KT production and increased E2 levels was also evidenced, intensifying the effects of androgen/estrogen imbalance. Moreover, climate change and ATZ independently induced oxidative stress, upregulation of proapoptotic gene and DNA damage in post-meiotic germ cell, but the negative effects of ATZ were greater at extreme scenario. Ultimately, exposure to simulated climate changes severely impaired fertilization capacity, due to a drastic reduction in sperm motility and/or viability. These findings indicate that the future climate conditions have the potential to considerably enhance the toxicity of ATZ at low concentrations, leading to significant deleterious consequences for fish reproductive function and fertility. These may provide relevant information to supporting healthcare and environmental managers in decision-making related to climate changes and herbicide regulation.

Assessment of atrazine contamination in the Sele River estuary: spatial distribution, human health risks, and ecological implications in Southern Europe

BackgroundOveruse of pesticides is a major worldwide problem for the environment and human health. Atrazine (ATR) is a synthetic triazine herbicide that is typically used to manage crops and although it was banned many years ago, it was detected frequently with a high persistence in the aquatic environments. This study assesses the human and environment health risks, temporal patterns and spatial distribution of ATR and its degradation products (DPs) in the Sele River estuary within the Southern European context.. It specifically investigates their occurrence in the water dissolved phase (WDP), suspended particulate matter (SPM), and sediment.ResultsSampling was conducted across 10 sites throughout the year’s four seasons. Amounts of ATR and its DPs detected ranged from 20.1 to 96.5 ng L−1 in WDP, from 5.4 to 60.2 ng L−1 in SPM, and from 4.7 to 19.8 ng g−1 in sediment samples, signifying some pollution levels. Spatial distribution mechanisms revealed a southward movement of ATR and its DPs pollution from the Sele River mouth, intensifying during the rainy season. In this study area, a risk evaluation was also carried out. No sample contained ATR or its DPs in concentrations above the recommended limits, which pose a Non-carcinogenic and Carcinogenic risk. The environmental risk was low. Additionally, the determined Incremental lifetime cancer risk (ILCR) value was within the allowable range.ConclusionDespite its long-standing prohibition, this study investigate ATR levels in the water and sediments of Sele River in Southern Europe. Beyond simply delineating the pollution status of Sele River, this research delineates its ecological repercussions on the Thyrrenian Sea, providing essential data for norms and laws related to water contamination.Graphical

A comparative evaluation of biochar and Paenarthrobacter sp. AT5 for reducing atrazine risks to soybeans and bacterial communities in black soil

Application of biochar and inoculation with specific microbial strains offer promising approaches for addressing atrazine contamination in agricultural soils. However, determining the optimal method necessitates a comprehensive understanding of their effects under similar conditions. This study aimed to evaluate the effectiveness of biochar and Paenarthrobacter sp. AT5, a bacterial strain known for its ability to degrade atrazine, in reducing atrazine-related risks to soybean crops and influencing bacterial communities. Both biochar and strain AT5 significantly improved atrazine degradation in both planted and unplanted soils, with the most substantial reduction observed in soils treated with strain AT5. Furthermore, bioaugmentation with strain AT5 outperformed biochar in enhancing soybean growth, photosynthetic pigments, and antioxidant defenses. While biochar promoted higher soil bacterial diversity compared to strain AT5, the latter selectively enriched specific bacterial populations. Additionally, soil inoculated with strain AT5 displayed a notable increase in the abundance of key genes associated with atrazine degradation (trzN, atzB, and atzC), surpassing the effects observed with biochar addition, thus highlighting its effectiveness in mitigating atrazine risks in soil.

Screening of Atrazine Tolerant Aquatic Plant and Roles of Plant Growth Regulators on Plant Growth and Atrazine Tolerance

The extensive use of atrazine to control weeds in agricultural areas has contaminated atrazine in surface water and groundwater. Atrazine contamination in water resources causes human health concerns. Thus, this study investigated the possible use of aquatic plants for removing atrazine from contaminated water. The experiment was performed under plant nursery conditions and divided into two parts: (1) the atrazine-tolerant plants were screened, and (2) the most atrazine-tolerant plant was used for atrazine phytoremediation stimulated by plant growth regulators. The results showed that atrazine was toxic to all aquatic plants, as the dry weight of the plants was significantly decreased when exposed to 20 mg/L of atrazine (P<0.05). Based on five aquatic plants grown under 2.5–20 mg/L atrazine-contaminated water, <i>Azolla microphylla</i> Kaulf. was the most tolerant aquatic plant and was more suitable for use in atrazine phytoremediation than the other aquatic plants (<i>Ceratophyllum demersum</i> L., <i>Eichhornia crassipes</i> (Mart.) Solms, <i>Hydrilla verticillata</i> (L. f.) Royle, and <i>Salvinia cucullata</i> Roxb. ex Bory). The total chlorophyll, carotenoid, and proline contents in the biomass of <i>A. microphylla</i> cultured in 2.5–20 mg/L of atrazine did not significantly differ between the atrazine concentrations (P>0.05). Meanwhile, the proline contents in the other four aquatic plants increased with increasing atrazine concentrations, and the chlorophyll content significantly decreased with an increase in the atrazine concentration. However, <i>A. microphylla</i> could not remove atrazine from contaminated water, and the application of plant growth regulators (6-benzyladenine, gibberellic acid, indole-3-butyric acid, and salicylic acid) did not improve the atrazine removal from water. Atrazine in the water was around 21–26 mg/L on day five of <i>A. microphylla</i> cultivation compared to the initial concentration (25 mg/L). Using a plant growth regulator was ineffective for stimulating growth and atrazine removal by <i>A. microphylla</i>. Future research should explore other potential mechanisms for enhancing atrazine removal by <i>A. microphylla</i>.

Potential of Bacillus stercoris B.PNR2 to stimulate growth of rice and waxy corn under atrazine-contaminated soil

The presence of atrazine residue in agricultural soil may affect crop growth and the activity of plant growth-promoting bacteria. Therefore, this study investigated the impact of atrazine contamination on indole-3-acetic acid (IAA) production by Bacillus stercoris B.PNR2. Subsequently, the ability of B. stercoris B.PNR2 to stimulate the seedling growth of rice cultivars RD6 and Leum Pua, as well as the waxy corn cultivar Muang Tam, under atrazine contamination, was determined. The results showed that B. stercoris B.PNR2 produced IAA under various atrazine concentrations, and atrazine was not toxic to B. stercoris B.PNR2 cells. Atrazine at 20 mg/kg of soil did not affect the shoot and root dry weight of rice cultivars RD6 and Leum Pua, as well as the waxy corn cultivar Muang Tam grown in atrazine-contaminated soil without receiving a bacterial inoculum. The application of B. stercoris B.PNR2 did not stimulate the germination and growth of any of the plants used in this study. The application of B. stercoris B.PNR2 decreased the shoot and root dry weight of waxy corn grown under atrazine-contaminated soil. Additionally, the chlorophyll b and total chlorophyll content in rice cultivar RD6, grown under atrazine-contaminated soil, decreased to only 162.6 ± 4.2 and 616.0 ± 55.8 μg/g fresh weight, which was related to the increase in proline content to 343.6 ± 41.6 μg/g fresh weight. In conclusion, it can be stated that soaking seeds with B. stercoris B.PNR2 was not an appropriate means of inoculation to stimulate the growth of plants in this study.

Assessment of pesticide contamination in groundwater bodies in the Jucar River Basin (Spain) and its spatial distribution

Exposure to the pesticides used in agriculture is a threat to human health and the environment. Nowadays, the world experiences a number of global changes, such as anthropogenic climate change and agricultural expansion which are associated to an increased consumption of water, fertilisers, and pesticides. This has increased the risk of soil and groundwater contamination. In this study, the model Pesticide Root Zone Model 5 (PRZM 5) has been applied to model the behaviour of pesticides in groundwater bodies within the Júcar River Basin (JRB) in Spain. We consider a groundwater body to be at risk of contamination if pesticide estimated concentrations exceed the Maximum Concentration Levels (MCL) and two additional indicators. We identified that Mancha Oriental groundwater body presents a high risk of Atrazine contamination. In the case of the Bromacil risk indicators, Castellón groundwater body was the most likely to be contaminated. Regarding Terbuthylazine risk maps, the probability of exceeding the threshold is low, thus posing a minimal risk in the studied area. Conversely Terbumeton risk maps, showed a high risk of contamination, detecting new areas of contamination that had not been studied for contamination for any pesticide. The spatial distribution of pesticides corresponds to areas mostly dedicated to irrigated agriculture which are associated to regular pesticide applications. Therefore, it can be concluded that the amount of pesticide applied on the field is the most important factor influencing pesticide concentration in groundwater bodies.

Using Plant Growth Regulators to Stimulate Growth of Napier Grass Under Atrazine Contamination

ABSTRACT Phytotoxic effects of herbicides have been reported on non-target plant species. This study was performed to investigate the growth of Napier grass cv. Pak Chong 1 in herbicide atrazine-contaminated soil; the effect of 1-naphthalene acetic acid, 6-benzyladenine and thidiazuron to stimulate the growth of grass grown in atrazine-contaminated soil; and to determine the remaining atrazine in the soil. The experiment was performed in a factorial completely randomized design with 2 × 10 factors. The first factor was atrazine concentration and the second factor was the application of plant growth regulator. The growth of the plants and atrazine remaining in the soil was analyzed at the end of the experiment (after 26 days). The results showed that Napier grass cv. Pak Chong 1 was tolerant to 6.8 mg/kg atrazine contamination in soil. The shoot growth and root growth of grass grown in atrazine-contaminated soil did not significantly differ from that grown in non-contaminated soil. Thidiazuron and 6-benzyladenine at 0.1 mg/l tended to increase the shoot dry weight of the grass grown in both atrazine-contaminated and non-contaminated soil. Additionally, 10 mg/l of thidiazuron and 1-naphthalene acetic acid tended to decrease the shoot growth of grass grown in both contaminated and non-contaminated soil. Moreover, decreases in atrazine were detected in soil planted with Napier grass cv. Pak Chong 1 by about 67.65% within 26 days.

Metabolic insights into how multifunctional microbial consortium enhances atrazine removal and phosphorus uptake at low temperature

Agricultural soils in the black soil region of northeast China often face negative stress due to low temperatures, pesticide contamination, and inadequate nutrient supply. In this study, a new cold-tolerant strain of Peribacillus simplex C1 (C1) was selectively isolated from atrazine contaminated soil. The artificially constructed microbial consortium (CPD) [C1, phosphorus-solubilizing bacterium Enterobacter sp. P1, and atrazine-degrading bacterium Acinetobacter lwoffii DNS32] demonstrated the most effective performance in enhancing atrazine degradation and phosphorus-solubilizing capacity when the initial inoculation ratio of 5:1:2 at 15 °C. CPD enhanced energy-related metabolic pathways and increased choline production to regulate bacterial adaptation to temperature decrease. Additionally, the strains could selectively utilize carbon sources (low molecular weight organic acids) or nitrogen sources (some metabolites of atrazine) provided by each other to enhance growth. Furthermore, strain C1 enhanced membrane fluidity through increased expression of the unsaturated fatty acids. Pot experiments demonstrated that CPD assisted soybean seedlings in resisting dual stresses of low temperature and atrazine contamination by inducing the expression of genes related to photosynthesis, membrane permeability, phosphorus response, and cold tolerance.

Atrazine decontamination by a newly screened psychrotroph Paenarthrobacter sp. KN0901 in an aquatic system: Metabolic pathway, kinetics, and hydroponics experiment

Atrazine residues running off the fields and entering water resources are a major threat to food security and the ecosystem. In this study, a psychrotrophic functional strain named KN0901 to remove atrazine residues was screened. KN0901 could degrade 30 mg·L−1 atrazine in 4 days at 15ºC with 105 CFU·mL−1 incubation. The phylogenetic results showed KN0901 belonged to Paenarthrobacter sp. PCR results showed that the functional genes consist of trzN, atzB, and atzC, suggesting atrazine was transformed to cyanuric acid by KN0901. KN0901 could degrade atrazine without adding exogenous carbon and nitrogen sources. What’s more, KN0901 could tolerate extreme low temperature (5ºC) and high atrazine concentration (100 mg·L−1). When growth and degradation curves were compared, the results indicated the length of lag time showed significant correlation to atrazine degradation rate. The hydroponic experiments showed that the toxicity of atrazine was significantly reduced with KN0901 treatment. The study provided an effective, economic, and eco-friendly bioremediation measure to address atrazine contamination.

Characterization of Arsenic and Atrazine Contaminations in Drinking Water in Iowa: A Public Health Concern.

Arsenic and atrazine are two water contaminants of high public health concern in Iowa. The occurrence of arsenic and atrazine in drinking water from Iowa's private wells and public water systems was investigated over several decades. In this study, the percentages of detection and violation of regulations were compared over region, season, and water source, and factors affecting the detection and concentration of arsenic and atrazine were analyzed using a mixed-effects model. Atrazine contamination in drinking water was found to vary by region, depending on agricultural usage patterns and hydrogeological features. The annual median atrazine levels of all public water systems were below the drinking water standard of 3 ppb in 2001-2014. Around 40% of public water systems contained arsenic at levels > 1 ppb in 2014, with 13.8% containing arsenic at levels of 5-10 ppb and 2.6% exceeding 10 ppb. This unexpected result highlights the ongoing public health threat posed by arsenic in drinking water in Iowa, emphasizing the need for continued monitoring and mitigation efforts to reduce exposure and associated health risks. Additionally, an atrazine metabolite, desethylatrazine, should be monitored to obtain a complete account of atrazine exposure and possible health effects.

Responses of Soil Microbial Community to Herbicide Atrazine Contamination

Responses of Soil Microbial Community to Herbicide Atrazine Contamination

Avaliação ambiental do uso de agrotóxicos na região do cerrado do Brasil

Abstract The Cerrado in Central Brazil is composed of unique vegetation types with a large source of bioactive compounds. The 1970s and 1980s were marked by the intensive incorporation of these forested areas into pastures and cropland, which increased the consumption of pesticides like glyphosate and atrazine. Today there continues to be a constant loss of native vegetation in this biome, and the pressure from land use is causing significant losses of native vegetation, driven mainly by agricultural expansion. This article offers a mapping of the estimated average consumption of pesticide per crop as well as an understanding of the risks associated with glyphosate and atrazine contamination in the state of Goiás. Both of these areas serve as a basis for understanding the challenges and opportunities for sustainability associated with agriculture in the Brazilian Cerrado.

Potential of Salvinia biloba Raddi for removing atrazine and carbendazim from aquatic environments

In this exploratory study, naturally occurring Salvinia biloba Raddi specimens were assessed for atrazine and carbendazim polluted water remediation. Experiments were carried out over 21 days in glass vessels containing deionized water artificially contaminated with 0, 5, 10, and 20 mg L−1 of atrazine or carbendazim. Atrazine had a pronounced detrimental impact on S. biloba, as no biomass development was observed in all macrophytes exposed to this herbicide in the entire concentration range. However, carbendazim-treated plants were able to grow and survive in the polluted medium even when subjected to the highest concentration of this fungicide (i.e., 20 mg L−1). In addition, increased chlorosis and necrosis were also detected in plants subjected to carbendazim as a result of the high phytotoxicity caused by atrazine. A maximal removal efficiency of ~ 30% was observed for both pesticides at 5 mg L−1 and decreased with increasing concentrations of the pollutants. The spectrum of the FTIR-ATR analysis revealed the existence of various functional groups (e.g., amide, carboxyl, hydroxyl, phosphate, sulfate) on the plants, which could be related to pesticide biosorption. In addition, at the end of the 21-day assay, seven carbendazim-resistant bacteria could be isolated from the roots of fungicide-treated plants. Therefore, the use of autochthonous free-floating S. biloba macrophytes for phytoremediation of aquatic environments contaminated with carbendazim shows great promise. Still, additional research is required to further elucidate the plant-mediated carbendazim elimination process and the role of the herbicide-resistant bacteria, and seek alternative species capable of mitigating atrazine contamination.

Atrazine pollution in groundwater and raw bovine milk: Water quality, bioaccumulation and human risk assessment

Atrazine herbicide can bioaccumulate over time and thus affect humans for generations to come. However, scarce studies have evaluated its bioaccumulation potential in bovine milk, a nutritional staple for children and the elderly both domestically and internationally. This study aimed to determine its concentration in groundwater and bovine milk, as well as the risks it is likely to pose for human health. Eighteen dairy farms in the Pampean plain of Argentina were analyzed. A strong correlation was found between the chemical composition and the geomorphological characteristics of the plain. In addition, increased salinity was observed in the groundwater at greater distances from the aquifer's recharge area. Atrazine was quantified in 50 % of the groundwater samples (at values ranging from 0.07 to 1.40 μg/L), and in 89 % of the bovine milk samples (from 2.51 to 20.97 μg/L). Moreover, atrazine levels in 44.4 % of the groundwater samples and 11.1 % of the bovine milk samples (n = 18) exceeded the limits internationally established as safe for human consumption. The hazard quotient (HQ) values of the compound were negligible for children and adults, both in groundwater (child = 9.7E-4, adult = 4.5E-4) and in milk (child = 1.0E-2, adult = 1.6E-3). The estimated cancer risk (CR) values need further evaluation (child = 7.8E-6, adult = 3.6E-6 in groundwater; child = 6.6E-5, adult = 1.3E-5 in milk). In both types of samples, the HQ and CR of residual atrazine were higher for children than for adults. Nevertheless, bioaccumulation factors suggest that dairy cows have a moderate capacity to incorporate atrazine from abiotic matrices. This is the first report on residual atrazine in bovine milk in Argentina. The results presented here indicate that the status of atrazine contamination in the area should continue to be monitored in order to assess its long-term impact on public health.

UV activated sodium percarbonate to accelerate degradation of atrazine: Mechanism, intermediates, and evaluation on residual toxicity by metabolomics.

Efficient and safe removal of widely used herbicides such as atrazine has become a recent hotspot. Herein, UV driven sodium percarbonate system (UV/SPC) was established to have many advantages in remediation of atrazine contamination. The mechanism and environmental risk of intermediates were explored, which provided information for the feasibility of UV/SPC. The degradation efficiency of atrazine was significantly enhanced as the increasing dosage of SPC. Quenching assay identified that •OH and CO3•- were committed to degrading atrazine. Humic acid and HPO42- remarkably inhibited atrazine degradation. Several intermediates were generated through the dealkylation, dechlorination-hydroxylation, alkylic-hydroxylation, alkyl oxidation and olefination reactions. Toxicity prediction proved that acute toxicity and bioaccumulation of intermediates were mitigated comparing with atrazine. Based on metabolomics results, the alteration of key metabolites such as citrate, L-kynurenine, malic acid, putrescine, glutamine, spermine, ethanolamine and phytosphingosine in various metabolic pathways of E.coli verified that the toxicity of atrazine was weakened after UV/SPC treatment. The application of UV/SPC on atrazine removal in real waters was influenced by environmental factors, and might be improved through coupling with other treatment technologies.

Physiochemical Characterization of Biochars from Six Feedstocks and Their Effects on the Sorption of Atrazine in an Organic Soil

Application of biochars in agricultural soils has the potential to reduce groundwater contamination of atrazine, a widely used herbicide in the US, therefore sustaining environmental quality and reducing human health issues. This study was conducted to characterize biochars produced from six feedstocks and investigate their ability to remove and retain atrazine in an organic-rich soil. Australian pine (AP), Brazilian pepper (BP), coconut husk (CH), cypress (Cy), loblolly pine (L), and pecan shell (P) feedstocks were pyrolyzed at 350 °C and 500 °C. Adsorption and desorption behaviors of atrazine were explained using Freundlich isotherms. Higher pyrolysis temperature increased specific surface area (5 times), total pore volume (2.5 times), and aromaticity (1.4 times) of the biochars. CH feedstock produced the most effective biochars (CH350 and CH500), which adsorb 8–12% more atrazine than unamended soils. CH350 biochar performed the best (Kd ads = 13.80, KOC = 153.63, Kd des = 16.98) and had significantly higher (p < 0.05) adsorption than unamended soil, possibly resulting from its highest cation exchange capacity (16.32 cmol kg−1). The Kd des values for atrazine desorption were greater than the Kd ads for adsorption, indicating retention of a considerable amount of atrazine by the biochar-amended soils following desorption.

Magnetic particles encoding a suspension probe for ultra-sensitive and quantitative determination of atrazine

As a highly toxic and widely used herbicide, atrazine poses a serious threat to food safety as well as overall environmental and human health. Due to complex matrix interference and the difficulty of signal enrichment, there is an urgent need for a convenient, fast, and ultrasensitive method that detects trace atrazine without concern for matrix effects. Here, we provide the first account of a sensitive and rapid suspension probe based on magnetic microspheres used to detect atrazine in herbs. The self-made magnetic beads featured -COOH groups and were used as the carrier to construct immunofluorescent probes. These probes then conjugated with the atrazine antigen through an activated ester method, ultimately binding to the antibody. Homogeneous detection was ensured using flow cytometry and the microflow optical channel along with allophycocyanin-conjugated goat-anti-mouse secondary antibody (APC-IgG-SecAb) as the fluorescent signal. The magnetic suspension probe allowed for high target enrichment and the inherent two-dimensional selective detection of flow cytometry effectively avoided any matrix interference. This method had good linearity across 1.69−23.19 ng mL−1. The IC50 and LOD values were 4.81 ng mL−1 and 0.95 ng mL−1, respectively; the sensitivity was increased three-fold relative to ELISA. After complete optimization, 2-N-morpholinoeth-anesulfonic acid was used as the coupling solution and maintained good mono-dispersity, stability, and reactivity for the labelled microspheres during the process. The entire experiment was simple, and effectively used reagents; moreover, both the labor required and detection time were greatly reduced. Critically, the strategy presented here greatly reduced interference from complex matrices, and saved preparation for matrix-matched solutions when different herbs were screened. Overall, this strategy was sensitive, rapid, eco-friendly, and labor-saving; collectively, these attributes make it well-suited for on-site screening of atrazine contamination and will allow for increased food safety.

Predicting atrazine concentrations in waterbodies across the contiguous United States: The importance of land use, hydrology, and water physicochemistry

AbstractAtrazine contamination is ubiquitous in North American surface waters, but the dependency of the herbicide's distribution on landscape and within‐lake processes is currently poorly known. We sought to identify novel predictors of atrazine and to build a coherent framework to model its concentration in waterbodies through the development of binomial‐gamma hurdle models and LASSO regression models. We constructed models for over 900 waterbodies in the contiguous United States using data from the 2012 U.S. EPA National Lake Assessment, the 2012 U.S. Department of Agriculture CropScape and the Global HydroLAB HydroLAKES databases. Atrazine was detected in 32% of U.S. waterbodies, with a mean concentration of 0.17 μg L−1 when detected. The two‐part hurdle model explained as much as 75% of the variance in atrazine across a spatially and temporally heterogeneous landscape. Three predictors explained 31% of the variability in atrazine detection in U.S. waterbodies, where the proportion of corn + soy cultures in the watershed was the most important variable. Once atrazine was detected, our models explained an additional 29% of the variability in atrazine concentrations, where the estimated areal weight of atrazine application (kg atrazine km2) in the watershed was the most important predictor. Spatially, water quality variables associated with eutrophication were linked to increased levels of atrazine contamination while cooler water temperatures and natural lakes and landscapes were associated with decreased levels of contamination. Our results suggest that changes in land‐use practices may be the most effective way to mitigate atrazine contamination in waterbodies.