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Many pesticides can antagonize the androgen receptor (AR) or inhibit androgen synthesis but their potential to cause reproductive toxicity related to disruption of androgen action during fetal life is difficult to predict. Currently no approaches for using data to anticipate such effects exist. Prioritization schemes that limit unnecessary testing are urgently needed. The aim was to develop a quantitative to extrapolation (QIVIVE) approach for predicting anti-androgenicity arising from gestational exposures and manifesting as a shortened anogenital distance (AGD) in male rats. We built a physiologically based pharmacokinetic (PBK) model to simulate concentrations of chemicals in the fetus resulting from maternal dosing. The predicted fetal levels were compared with analytically determined concentrations, and these were judged against active concentrations for AR antagonism and androgen synthesis suppression. We first evaluated our model by using and anti-androgenic data for procymidone, vinclozolin, and linuron. Our PBK model described the measured fetal concentrations of parent compounds and metabolites quite accurately (within a factor of five). We applied the model to nine current-use pesticides, all with evidence for anti-androgenicity but missing data. Seven pesticides (fludioxonil, cyprodinil, dimethomorph, imazalil, quinoxyfen, fenhexamid, -phenylphenol) were predicted to produce a shortened AGD in male pups, whereas two ( , pyrimethanil) were anticipated to be inactive. We tested these expectations for fludioxonil, cyprodinil, and dimethomorph and observed shortened AGD in male pups after gestational exposure. The measured fetal concentrations agreed well with PBK-modeled predictions. Our QIVIVE model newly identified fludioxonil, cyprodinil, and dimethomorph as anti-androgens. With the examples investigated, our approach shows great promise for predicting anti-androgenicity (i.e., AGD shortening) for chemicals with activity and for minimizing unnecessary testing. https://doi.org/10.1289/EHP6774.

On-farm biopurification systems (BPSs) treat pesticide-contaminated wastewater at farms through biodegradation and sorption processes. However, information on the microbiota involved in pesticide removal in BPSs is scarce. Here we report on the response of BPS bacterial communities to the herbicide linuron (BPS+) compared with the control (BPS−) in a microcosm experiment. Both denaturing gradient gel electrophoresis (DGGE) and pyrosequencing of 16S rRNA gene fragments amplified from community DNA indicated shifts in the bacterial community after linuron application. Responding populations belonged to taxa that were previously reported from linuron degrading consortia cultivated from soil (Hyphomicrobiaceae, Comamonadaceae, Micrococcaceae). In addition, numerous taxa with increased relative abundance were identified that were previously not associated with linuron degradation. The relative abundance of IncP-1 korB copies increased in response to linuron application. Amplicon pyrosequencing of IncP-1 trfA genes revealed a high IncP-1 plasmid diversity and suggested that populations carrying IncP-1β plasmids increased in relative abundance. Transferable mercury resistance plasmids were exogenously captured from BPS+/BPS−, and in three transconjugants from BPS+ the gene hylA was detected. Our data suggest the existence of a multispecies linuron degrading bacterial food web and an involvement of IncP-1 plasmids in the adaptation of bacterial communities to pesticide pollution in BPSs. Exploring the complex response to linuron of bacterial communities from biopurification systems by means of cultivation-independent methods. Graphical Abstract Figure. Exploring the complex response to linuron of bacterial communities from biopurification systems by means of cultivation-independent methods.

On-farm biopurification systems (BPSs) represent an efficient technology for treating pesticide-contaminated wastewater. Biodegradation by genetically adapted bacteria has been suggested to perform a major contribution to the removal of pesticides in BPSs. Recently, several studies pointed to the role of IncP-1 plasmids in the degradation of pesticides in BPSs but this was never linked with catabolic markers. Therefore, a microcosm experiment was conducted in order to examine whether changes in mobile genetic element (MGE) abundances in response to the application of phenylurea herbicide linuron are linked with changes in catabolic genes. Denaturing gradient gel electrophoresis (DGGE) fingerprints of 16S ribosomal RNA gene fragments amplified from total community (TC)-DNA suggested significant shifts in the bacterial community composition. PCR-Southern blot-based detection of genes involved in linuron hydrolysis ( libA and hylA ) or degradation of its metabolite 3,4-dichloroaniline ( dcaQ I , dcaQ II , and ccdC ) in TC-DNA showed that the abundance of the hylA gene was increased faster and stronger in response to linuron application than that of the libA gene, and that the dcaQ II gene was more abundant than the isofunctional gene dcaQ I 20 and 60 days after linuron addition. Furthermore, a significant increase in the relative abundance of the IncP-1-specific korB gene in response to linuron was recorded. Our data suggest that different bacterial populations bearing isofunctional genes coding for enzymes degrading linuron seemed to be enriched in BPSs in response to linuron and that IncP-1 plasmids might be involved in their dissemination.

The effects of endocrine-disrupting chemicals (EDCs) on fertility and reproductive development represent a rising concern in modern societies. Although the neuroendocrine control of sexual maturation is a major target of EDCs, little is known about the potential role of the hypothalamus in puberty and ovulation disruption transmitted across generations. We hypothesized that developmental exposure to an environmentally relevant dose of EDC mixture could induce multi- and/or transgenerational alterations of sexual maturation and maternal care in female rats through epigenetic reprograming of the hypothalamus. We investigated the transmission of a disrupted reproductive phenotype via the maternal germline or via nongenomic mechanisms involving maternal care. Adult female Wistar rats were exposed prior to and during gestation and until the end of lactation to a mixture of the following 13 EDCs: di- -butyl phthalate (DnBP), di(2-ethylhexyl) phthalate (DEHP), bisphenol A (BPA), vinclozolin, prochloraz, procymidone, linuron, epoxynaxole, dichlorodiphenyldichloroethylene, octyl methoxynimmate, 4-methylbenzylidene camphor (4-MBC), butylparaben, and acetaminophen. Perinatally exposed offspring (F1) were mated with unexposed males to generate germ cell (F2) and transgenerationally exposed (F3 and F4) females. Sexual maturation, maternal behavior, and hypothalamic targets of exposure were studied across generations. Germ cell (F2) and transgenerationally (F3) EDC-exposed females, but not F1, displayed delayed pubertal onset and altered folliculogenesis. We reported a transgenerational alteration of key hypothalamic genes controlling puberty and ovulation ( , , and ), and we identified the hypothalamic polycomb group of epigenetic repressors as actors of this mechanism. Furthermore, we found a multigenerational reduction of maternal behavior (F1-F3) induced by a loss in hypothalamic dopaminergic signaling. Using a cross-fostering paradigm, we identified that the reduction in maternal phenotype was normalized in EDC-exposed pups raised by unexposed dams, but no reversal of the pubertal phenotype was achieved. Rats developmentally exposed to an EDC mixture exhibited multi- and transgenerational disruption of sexual maturation and maternal care via hypothalamic epigenetic reprogramming. These results raise concerns about the impact of EDC mixtures on future generations. https://doi.org/10.1289/EHP8795.

A study of 16 streams in eastern North America shows that riparian deforestation causes channel narrowing, which reduces the total amount of stream habitat and ecosystem per unit channel length and compromises in-stream processing of pollutants. Wide forest reaches had more macroinvertebrates, total ecosystem processing of organic matter, and nitrogen uptake per unit channel length than contiguous narrow deforested reaches. Stream narrowing nullified any potential advantages of deforestation regarding abundance of fish, quality of dissolved organic matter, and pesticide degradation. These findings show that forested stream channels have a wider and more natural configuration, which significantly affects the total in-stream amount and activity of the ecosystem, including the processing of pollutants. The results reinforce both current policy of the United States that endorses riparian forest buffers as best management practice and federal and state programs that subsidize riparian reforestation for stream restoration and water quality. Not only do forest buffers prevent nonpoint source pollutants from entering small streams, they also enhance the in-stream processing of both nonpoint and point source pollutants, thereby reducing their impact on downstream rivers and estuaries.

The increasing presence of pesticide residues in aquatic environments poses a significant threat to ecosystems and human health, necessitating the development of effective removal technologies. In this study, Zeolitic Imidazolate Framework-8 (ZIF-8) was investigated as adsorbent for Linuron, a widely used herbicide. The material was synthesized via a hydrothermal method and underwent thorough physico-chemical characterization, confirming its intrinsic properties. Adsorption experiments were conducted under systematically varied conditions using a Central Composite Face-Centered (CFC) experimental design, evaluating the effects of temperature, Linuron concentration, ionic strength on adsorption efficiency. The Response Surface Methodology (RSM) revealed that temperature and Linuron concentration were the most influential variables. A quadratic effect of ionic strength and a significant interaction between Linuron concentration and ionic strength were also observed. The fitted quadratic regression model exhibited excellent predictive performance (R2 = 0.909; Q2 = 0.755), and analysis of variance (ANOVA) confirmed its significance (p < 0.001) with a non-significant lack of fit. Maximum Linuron removal (>95%) was achieved at elevated temperature, moderate concentration, and intermediate ionic strength. These findings highlight the potential of ZIF-8 as a tunable and high-efficiency adsorbent for the remediation of pesticide-contaminated water, demonstrating the value of RSM-based optimization in designing adsorption processes.

Soil microorganisms and their activities are essential for maintaining soil health and fertility. Microorganisms can be negatively affected by application of herbicides. Although effects of herbicides on microorganisms are widely studied, there is a lack of information for chloroacetamide herbicide dimethachlor. Thus, dimethachlor and well known linuron were applied to silty-loam luvisol and their effects on microorganisms were evaluated during112 days long laboratory assay. Dimethachlor and linuron were applied in doses 1.0 kg ha −1 and 0.8 kg ha −1 corresponding to 3.33 mg kg −1 and 2.66 mg kg −1 respectively. Also 100-fold doses were used for magnification of impacts. Linuron in 100-fold dose caused minor increase of respiration, temporal increase of soil microbial biomass, decrease of soil dehydrogenase activity, and altered microbial community. Dimethachlor in 100-fold dose significantly increased respiration; microbial biomass and decreased soil enzymatic activities. Microbial composition changed significantly, Proteobacteria abundance, particularly Pseudomonas and Achromobacter genera increased from 7 to 28th day. In-silico prediction of microbial gene expression by PICRUSt2 software revealed increased expression of genes related to xenobiotic degradation pathways. Evaluated characteristics of microbial community and activity were not affected by herbicides in recommended doses and the responsible use of both herbicides will not harm soil microbial community.

Field studies were conducted to evaluate linuron for POST control of Palmer amaranth in sweetpotato to minimize reliance on protoporphyrinogen oxidase (PPO)-inhibiting herbicides. Treatments were arranged in a two by four factorial in which the first factor consisted of two rates of linuron (420 and 700 g ai ha-1), and the second factor consisted of linuron applied alone or in combinations of linuron plus a nonionic surfactant (NIS; 0.5% vol/vol), linuron plus S-metolachlor (800 g ai ha-1), or linuron plus NIS plus S-metolachlor. In addition, S-metolachlor alone and nontreated weedy and weed-free checks were included for comparison. Treatments were applied to ‘Covington’ sweetpotato 8 d after transplanting (DAP). S-metolachlor alone provided poor Palmer amaranth control because emergence had occurred at applications. All treatments that included linuron resulted in at least 98% and 91% Palmer amaranth control 1 and 2 wk after treatment (WAT), respectively. Including NIS with linuron did not increase Palmer amaranth control compared to linuron alone, but it resulted in greater sweetpotato injury and subsequently decreased total sweetpotato yield by 25%. Including S-metolachlor with linuron resulted in the greatest Palmer amaranth control 4 WAT, but increased crop foliar injury to 36% 1 WAT compared to 17% foliar injury from linuron alone. Marketable and total sweetpotato yields were similar between linuron alone and linuron plus S-metolachlor or S-metolachlor plus NIS treatments, though all treatments resulted in at least 39% less total yield than the weed-free check resulting from herbicide injury and/or Palmer amaranth competition. Because of the excellent POST Palmer amaranth control from linuron 1 WAT, a system that includes linuron applied 7 DAP followed by S-metolachlor applied 14 DAP could help to extend residual Palmer amaranth control further into the critical period of weed control while minimizing sweetpotato injury. Nomenclature: Linuron; S-metolachlor; Palmer amaranth; Amaranthus palmeri S. Wats AMAPA; Ipomoea batatas (L.) Lam. ‘Covington ‘

This paper summarises the results of voltammetric studies on the herbicide 3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea (Linuron), using a carbon paste electrode containing tricresyl phosphate (TCP-CPE) as liquid binder. The principal experimental conditions, such as the pH effect, investigated in Britton-Robinson buffer solutions (pH 2.0–7.0), the peak characteristics for the analyte of interest, or instrumental parameters for the differential pulse voltammetric mode were optimized for the method. As found out, the best electroanalytical performance of the TCP-CPE was achieved at pH 2.0, whereby the oxidation peak of Linuron appeared at ca. +1.3 V vs. SCE. The analytical procedure developed offers good linearity in the concentration range of 1.25–44.20 μg mL−1 (1.77 × 10−4–5.05 × 10−6 mol L−1), showing - for the first time - the applicability of the TCP-CPE for anodic oxidations in direct voltammetry (without accumulation). The method was then verified by determining Linuron in a spiked river water sample and a commercial formulation and the results obtained agreed well with those obtained by the reference HPLC/UV determination.

An increasing cost of controlling herbicide‐resistant weeds necessitates the development of cost‐effective weed control strategies in the semi‐arid U.S. Great Plains. Two separate field studies were conducted in 2013 and 2014 at the Montana State University Southern Agricultural Research Center near Huntley, MT to (1) evaluate a light‐activated sensor‐controlled (LASC) sprayer compared to a broadcast sprayer for effectiveness and cost savings for weed control in postharvest wheat (Triticum aestivum) stubble, and (2) determine the efficacy of LASC sprayer operated at two different speeds for weed control in fallow fields. Results indicated that both LASC and broadcast sprayers performed similarly for the effectiveness of a majority of herbicides tested on kochia [Bassia scoparia (L.) A.J. Scott] and prickly lettuce (Lactuca serriola L.). Paraquat alone or in tank‐mixture with linuron, and saflufenacil + 2,4‐D provided 93%–100% control of kochia, 98%–100% control of prickly lettuce, and reduced the total weed biomass by 75%–80% at 28 days after treatment (DAT), regardless of the sprayer used. A simple comparative economic analysis revealed that LASC sprayer reduced the overall chemical use by 23%–55% and resulted in cost savings of $5.83–$30.83 ha−1 across herbicide treatments. Herbicide efficacy was reduced up to 20% for kochia and prickly lettuce control when applied with LASC sprayer at a speed of 16 versus 8 km h−1. Altogether, these results indicate that the LASC sprayer can provide cost‐effective, site‐specific weed control in no‐tillage chemical fallow or postharvest wheat stubble. Core Ideas Both light‐activated sensor‐controlled (LASC) and broadcast sprayers provided similar efficacy of tested herbicides. Paraquat alone or in tank‐mixtures with linuron, and saflufenacil + 2,4‐D provided 93% to complete control of kochia and prickly lettuce. LASC sprayer reduced the chemical use by 23%–55% across all tested herbicides. Reduced efficacy of herbicides was noted with LASC sprayer operated at speed of 16 versus 8 km h−1.