Lethal and Sublethal Effects of Embryonic and Larval Exposure of Hyla versicolor to Stormwater Pond Sediments

Stormwater ponds are common features of modern stormwater management practices. Stormwater ponds often retain standing water for extended periods of time, develop vegetative characteristics similar to natural wetlands, and attract wildlife. However, because stormwater ponds are designed to capture pollutants, wildlife that utilize ponds might be exposed to pollutants and suffer toxicological effects. To investigate the toxicity of stormwater pond sediments to Hyla versicolor, an anuran commonly found using retention ponds for breeding, we exposed embryos and larvae to sediments in laboratory microcosms. Exposure to pond sediments reduced survival of embryos by ~50% but did not affect larval survival. Larvae exposed to stormwater pond sediment developed significantly faster ([`(x)] = 39 \bar{x} = 39 days compared to 42 days; p = 0.005) and were significantly larger at metamorphosis ([`(x)] =  0. 4 9 \bar{x} = \, 0. 4 9 g compared to 0.36 g; p < 0.001) than controls that were exposed to clean sand. Substantial amounts (712–2215 mg/l) of chloride leached from pond sediments into the water column of treatment microcosms; subsequently, survival of embryos was negatively correlated (r ² = 0.50; p < 0.001) with water conductivity during development. Our results, along with the limited number of other toxicological studies of stormwater ponds, suggest that road salt contributes to the degradation of stormwater pond habitat quality for amphibian reproduction and that future research should focus on understanding interactions among road salts and other pollutants and stressors characteristic of urban environments.     

Association of Glyphosate Exposure with Blood DNA Methylation in a Cross-Sectional Study of Postmenopausal Women

Background: Glyphosate is the most commonly used herbicide in the world and is purported to have a variety of health effects, including endocrine disruption and an elevated risk of several types of cancer. Blood DNA methylation has been shown to be associated with many other environmental exposures, but to our knowledge, no studies to date have examined the association between blood DNA methylation and glyphosate exposure.Objective: We conducted an epigenome-wide association study to identify DNA methylation loci associated with urinary glyphosate and its metabolite aminomethylphosphonic acid (AMPA) levels. Secondary goals were to determine the association of epigenetic age acceleration with glyphosate and AMPA and develop blood DNA methylation indices to predict urinary glyphosate and AMPA levels.Methods: For 392 postmenopausal women, white blood cell DNA methylation was measured using the Illumina Infinium MethylationEPIC BeadChip array. Glyphosate and AMPA were measured in two urine samples per participant using liquid chromatography–tandem mass spectrometry. Methylation differences at the probe and regional level associated with glyphosate and AMPA levels were assessed using a resampling-based approach. Probes and regions that had an false discovery rate q<0.1 in ≥90% of 1,000 subsamples of the study population were considered differentially methylated. Differentially methylated sites from the probe-specific analysis were combined into a methylation index. Epigenetic age acceleration from three epigenetic clocks and an epigenetic measure of pace of aging were examined for associations with glyphosate and AMPA.Results: We identified 24 CpG sites whose methylation level was associated with urinary glyphosate concentration and two associated with AMPA. Four regions, within the promoters of the MSH4, KCNA6, ABAT, and NDUFAF2/ERCC8 genes, were associated with glyphosate levels, along with an association between ESR1 promoter hypomethylation and AMPA. The methylation index accurately predicted glyphosate levels in an internal validation cohort. AMPA, but not glyphosate, was associated with greater epigenetic age acceleration.Discussion: Glyphosate and AMPA exposure were associated with DNA methylation differences that could promote the development of cancer and other diseases. Further studies are warranted to replicate our results, determine the functional impact of glyphosate- and AMPA-associated differential DNA methylation, and further explore whether DNA methylation could serve as a biomarker of glyphosate exposure. https://doi.org/10.1289/EHP10174     

Glyphosate in German adults – Time trend (2001 to 2015) of human exposure to a widely used herbicide

The broadband herbicide glyphosate (N-[phosphonomethyl]-glycine) and its main metabolite aminomethylphosphonic acid (AMPA) were analyzed by GC-MS-MS in 24 h-urine samples cryo-archived by the German Environmental Specimen Bank (ESB). Samples collected in 2001, 2003, 2005, 2007, 2009, 2011, 2012, 2013, 2014, and 2015 were chosen for this retrospective analysis. All urine samples had been provided by 20 to 29 years old individuals living in Greifswald, a city in north-eastern Germany. Out of the 399 analyzed urine samples, 127 (= 31.8%) contained glyphosate concentrations at or above the limit of quantification (LOQ) of 0.1 μg/L. For AMPA this was the case for 160 (= 40.1%) samples. The fraction of glyphosate levels at or above LOQ peaked in 2012 (57.5%) and 2013 (56.4%) after having discontinuously increased from 10.0% in 2001. Quantification rates were lower again in 2014 and 2015 with 32.5% and 40.0%, respectively. The overall trend for quantifiable AMPA levels was similar. Glyphosate and AMPA concentrations in urine were statistically significantly correlated (spearman rank correlation coefficient = 0.506, p ≤ 0.001). Urinary glyphosate and AMPA levels tended to be higher in males. The possible reduction in exposure since 2013 indicated by ESB data may be due to changes in glyphosate application in agricultural practice. The ESB will continue monitoring internal exposures to glyphosate and AMPA for following up the time trend, elucidating inter-individual differences, and contributing to the ongoing debate on the further regulation of glyphosate-based pesticides.     

Occurrence and fate of the herbicide glyphosate and its degradate aminomethylphosphonic acid in the atmosphere

This is the first report on the ambient levels of glyphosate, the most widely used herbicide in the United States, and its major degradation product, aminomethylphosphonic acid (AMPA), in air and rain. Concurrent, weekly integrated air particle and rain samples were collected during two growing seasons in agricultural areas in Mississippi and Iowa. Rain was also collected in Indiana in a preliminary phase of the study. The frequency of glyphosate detection ranged from 60 to 100% in both air and rain. The concentrations of glyphosate ranged from <0.01 to 9.1 ng/m(3) and from <0.1 to 2.5 μg/L in air and rain samples, respectively. The frequency of detection and median and maximum concentrations of glyphosate in air were similar or greater to those of the other high-use herbicides observed in the Mississippi River basin, whereas its concentration in rain was greater than the other herbicides. It is not known what percentage of the applied glyphosate is introduced into the air, but it was estimated that up to 0.7% of application is removed from the air in rainfall. Glyphosate is efficiently removed from the air; it is estimated that an average of 97% of the glyphosate in the air is removed by a weekly rainfall ≥ 30 mm.     

草甘膦的毒性研究

草甘膦是目前世界上用量最大、应用最广的农药之一,是一种内吸传导型除草剂,在环境中的主要降解产物为氨甲基膦酸和二氧化碳。由于草甘膦消耗量大,施用范围广,不仅会造成环境污染,也将侵害生物和人体。本文主要概述草甘膦的基本性质、作用机制、环境行为及其毒性方面的研究进展。     

Effectiveness of glyphosate and imazamox on the control of the invasive cordgrass Spartina densiflora

The south-American cordgrass, Spartina densiflora, has become the dominant plant species on recent tidal marsh restorations in the Doñana National Park (SW Spain). We examined the effect of different doses of glyphosate (720–7200 g a.i. ha⁻¹) and imazamox (20–68 g a.i. ha⁻¹) on growth and photosynthetic apparatus of S. densiflora. Imazamox had no effect on neither on growth nor photosynthetic apparatus of S. densiflora. On the contrary, glyphosate inhibited photochemical efficiency of photosynthesis from day one. Net photosynthetic rate, stomatal conductance and photosynthetic pigments and the number of new tillers were reduced. Glyphosate at high doses (ca. 7200 g a.i. ha⁻¹) could be an appropriate method of control, since it has a negative effect over the photosynthetic apparatus and growth of S. densiflora. Furthermore, glyphosate and its main metabolite, AMPA, were not extracted from the soil, since they were retained by the very high iron and aluminum oxide content of this soil.     

Persistence of three organophosphorus insecticides in artificial ponds and some biological implications

The persistence and biological impact of the organophosphorus insecticides, Abate^®, Reldan^®, and Dursban^®, were studied following the application of 10 ppb to a series of artificial polyethylene-lined ponds and a single natural pond inoculated with leaf litter. Disappearance of the insecticides from water could be described in terms of two phases: early posttreatment, in which rapid partitioning took place; and, a variable time period, characterized by slowly decreasing residues. Of the three pesticides, Dursban was the most persistent followed by Reldan and Abate in that order.The rapid initial disappearance of the pesticides from water was primarily attributable to adsorption on bottom sediments and polyethylene. Polyethylene appeared to have a greater affinity for the pesticides than did the sediments. However, desorption from the polyethylene contributed to residual concentrations in the water of artificial ponds for prolonged periods.Dursban was most toxic to cladoceran and copepod populations. Cladocerans were more sensitive to the three insecticides than were cyclopod and calanoid copepods or copepod nauplii.Chlorophyll concentrations as a measure of algal biomass were always greater in ponds treated with Abate or Dursban than in untreated ponds, supporting the conclusion that algal blooms result from the elimination of Zooplankton predation.It was concluded that in artificial polyethylene-lined ponds residues persisted for longer times than in natural ponds. The resulting prolonged period in which Zooplankton were absent leads to an increased probability of algal blooms.     

Effect of Glyphosate on the Development of Pseudosuccinea columella Snails

Glyphosate (Roundup) is one of the most commonly used broad-spectrum herbicides with little to no hazard to animals, man, or the environment. Due to its widespread use, there is continuous contamination of the environment in both soil and water with this herbicide. There is a paucity of long-term exposure studies with sublethal concentrations of glyphosate on aquatic snails. This study was developed to determine the effects of sublethal concentrations of glyphosate on development and survival of Pseudosuccinea columella (intermediate snail host of Fasciola hepatica). This was assessed by continuously exposing three successive generations of snails to varying concentrations (0.1–10 mg/L) of glyphosate. Glyphosate had little effect on the first- and second-generation snails. However, third-generation snail embryos exposed to 1.0 mg/L glyphosate developed much faster than other embryos exposed to 0.1 mg/L, 10 mg/L, and 0 mg/L (control). Hatching was inhibited at 10 mg/L and inhibited slightly at 0.1 mg/L. The egg-laying capacity was increased in snails exposed to 0.1 and 10 mg/L. Abnormalities and polyembryony were observed in snails exposed to 0.1 and 10 mg/L. These results indicate that glyphosate does affect snail reproduction and development. This, in turn, could possibly have an effect on the population dynamics of F. hepatica, which could result in increased infections in animals, including man. Received: 15 November 1996/Accepted: 15 July 1997     

Occurrence of Glyphosate in Surface Waters of Southern Ontario

Glyphosate in surface waters of southern Ontario (Canada) was studied over a 2-year period. A small percentage of samples exhibited glyphosate concentrations greater than the analytical limit of quantitation (17 microg a.e./L), and the maximum concentration of glyphosate measured was 40.8 microg/L. No samples of roughly 500 analyzed exceeded the Canadian Water Quality Guideline of 65 microg a.e./L considered protective of aquatic life. Typical concentrations of glyphosate in amphibian habitats were well below a range of toxicity thresholds for aquatic organisms, and were thus judged to be unlikely to pose a substantial risk to either sensitive amphibian larvae or other aquatic biota.     

Cancer incidence among glyphosate-exposed pesticide applicators in the Agricultural Health Study

Glyphosate is a broad-spectrum herbicide that is one of the most frequently applied pesticides in the world. Although there has been little consistent evidence of genotoxicity or carcinogenicity from in vitro and animal studies, a few epidemiologic reports have indicated potential health effects of glyphosate. We evaluated associations between glyphosate exposure and cancer incidence in the Agricultural Health Study (AHS), a prospective cohort study of 57,311 licensed pesticide applicators in Iowa and North Carolina. Detailed information on pesticide use and other factors was obtained from a self-administered questionnaire completed at time of enrollment (1993-1997). Among private and commercial applicators, 75.5% reported having ever used glyphosate, of which > 97% were men. In this analysis, glyphosate exposure was defined as a) ever personally mixed or applied products containing glyphosate; b) cumulative lifetime days of use, or "cumulative exposure days" (years of use times days/year); and c) intensity-weighted cumulative exposure days (years of use times days/year times estimated intensity level). Poisson regression was used to estimate exposure-response relations between glyphosate and incidence of all cancers combined and 12 relatively common cancer subtypes. Glyphosate exposure was not associated with cancer incidence overall or with most of the cancer subtypes we studied. There was a suggested association with multiple myeloma incidence that should be followed up as more cases occur in the AHS. Given the widespread use of glyphosate, future analyses of the AHS will allow further examination of long-term health effects, including less common cancers.     

Estimating maternal and prenatal exposure to glyphosate in the community setting

Glyphosate is a herbicide in common use, in both agricultural and residential settings. Controlled residue studies show that glyphosate persists in food crops, allowing for the potential of a large number of people to be exposed. Glyphosate is generally considered safe however there are a number of studies suggesting formulations or additives that may have adverse health effects. To assess the degree of exposure of pregnant women, this study measured glyphosate in composite food samples and estimated exposure based on food frequency questionnaire. 43 pregnant women were recruited and completed a self administered questionnaire with a food frequency component and provided a composite food sample. Twenty food samples were analysed with very low glyphosate concentrations (mean 0.08 mg/kg, range 0.002-0.5 mg/kg) with residues detected in more than 75% of the samples. Maternal dietary exposure was very low (0.001 mg/kg bw/day) and was considerably lower than the predicted National Estimated Daily Intake of glyphosate (0.02 mg/kg bw/day). The estimated exposure based on measured glyphosate in composite food samples corresponded to 0.4% of the acceptable daily intake for glyphosate, and the predicted concentration from dietary information was 4% which is comparable to the National Estimated Daily Intake of 5.5% of the Acceptable Daily Intake of glyphosate. Prenatal exposures were estimated to be significantly lower. While residues of glyphosate are present in food, this study demonstrates that exposure concentrations are low and confirms the current models used to estimate glyphosate exposure.     

Laboratory persistence and fate of fluoxetine in aquatic environments

The persistence and fate of fluoxetine, a selective serotonin reuptake inhibitor, has been investigated in laboratory-scale experiments, including studies with various aqueous solutions, water/sediment systems, and activated sludge-amended medium. The samples were placed in the dark and/or in a growth chamber fitted with fluorescent lamps simulating the ultraviolet output of sunlight. Over a period of 30 d, fluoxetine was hydrolytically and photolytically stable in all aqueous solutions except synthetic humic water (pH 7), in which the degradation rate was increased by approximately 13-fold in comparison with buffered solutions at the same pH. Fluoxetine rapidly dissipated from the aqueous phase in water/sediment systems, primarily because of distribution to sediments. The dissipation rate from the aqueous phase was similar between light and dark systems, indicating a low contribution of photodegradation to the dissipation of fluoxetine in this system. The potential impact of fluoxetine in aquatic environments would be decreased because of adsorption to sediments. Based on results of ready-biodegradability investigations, fluoxetine would not be expected to rapidly biodegrade in wastewater treatment plants. A photoproduct was detected only in a sample of synthetic humic water and was identified as norfluoxetine formed by demethylation. Results indicate that fluoxetine is relatively recalcitrant to hydrolysis, photolysis, and microbial degradation and that it is rapidly removed from surface waters by adsorption to sediment, where it appears to be persistent.     

Effects of Temperature and Exposure Duration on Transfer of Cadmium Between Naturally Contaminated Sediments and Burrowing Mayfly Nymphs (Hexagenia rigida)

Burrowing mayfly nymphs (Hexagenia rigida) were exposed to naturally contaminated sediments collected from two stations along a metallic pollution gradient on the Lot River (France) using indoor microcosms. Bioaccumulation kinetics (0, 20, 40, and 60 days) of cadmium (Cd) and the combined effects of temperature (12, 18, and 24°C) were evaluated by a complete experimental design, jointly with the analysis of growth rate of the nymphs, bioturbation, and total and dissolved Cd concentrations in the water column. Cadmium was transferred from the sediment to the organisms with uptake influenced by contamination levels of the sediments, exposure duration, and temperature. The two complementary criteria—Cd concentration and burden in the nymphs—clearly demonstrate the importance of the growth dilution on the quantification of Cd bioaccumulation at the whole organism level. Received: 24 July 1997/Accepted: 22 February 1998     

Microcystin Concentrations in the Nile River Sediments and Removal of Microcystin-LR by Sediments During Batch Experiments

During the present study, microcystin (MCYST) concentrations in the Nile River and irrigation canal sediments, Egypt, were investigated during the period January–December 2001. Batch experiments were also conducted to confirm the adsorption of MCYSTs on these sediments. The results of field study showed that MCYST concentrations in the sediments were correlated with total count of cyanobacteria, particularly Microcystis aeruginosa, and MCYST within phytoplankton cells in most sites. No detectable levels of MCYSTs were found in the cell-free water of all studied sites in the Nile River and irrigation canals during the entire study period. The data obtained from batch adsorption experiments confirmed the capability of the Nile River and irrigation canal sediments for MCYST adsorption; and that adsorption was sediment weight-dependent and thus fitted the Freundlich adsorption isotherm. The results also revealed that both adsorption capacity (K_f) and intensity (1/n) varied significantly with clay and organic matter contents of these sediments. The results of present study have two implications. First, the presence of cyanobacterial toxins in freshwater sediments can affect benthic organisms inhabiting these sediments, and thus it should be considered during biological monitoring of rivers and streams. Second, the ability of freshwater sediments to adsorb cyanobacterial toxins suggests that bank filtration could be used in developing countries (e.g., Egypt), which require an inexpensive and low-maintenance method for removing these toxins from drinking water.     

Effects of the Herbicides Roundup and Avans on Euglena gracilis

Glyphosate is the active ingredient in a range of widely used herbicides. The aim of this work is to evaluate the effects of two commercial herbicides, Roundup and Avans, on the motility, velocity, and gravitactic orientation of the aquatic flagellate Euglena gracilis. An early warning system, called ECOTOX, has been used for monitoring the different parameters of movement. The motility was not affected by Roundup and Avans after short period tests (0, 30, and 60 s). However, gravitactic orientation of the cells was affected at concentrations of 1.25 g l⁻¹ and above when treated with Avans, whereas treatments with Roundup showed no specific changes after short period tests. Velocity of the cells was affected by both herbicides, but the effects of Avans were shown to occur at lower concentrations in comparison to Roundup. Avans showed lower no observable effect concentration (NOEC) values in comparison to Roundup for the different parameters after short period tests. After long period (7 days) tests, NOEC values were similar except for the upward swimming, where Avans had a NOEC value of 100 μg l⁻¹ and Roundup 200 μg l⁻¹. The results demonstrate that Avans containing trimethylsulfonium salt of glyphosate is more toxic to E. gracilis than Roundup, which contained isopropylamine salt of glyphosate.     

Accumulation and food chain transfer of fluoranthene and benzo[a]pyrene in Chironomus riparius and Lepomis macrochirus

This research investigated the accumulation of polycyclic aromatic hydrocarbons (PAHs) by Chironomus riparius from sediments and transfer of these contaminants to bluegill, Lepomis macrochirus. Experiments were conducted in laboratory microcosms containing sediments spiked with either benzo[a]pyrene (BAP) or fluoranthene (FLU). Chironomids rapidly accumulated PAHs from sediments. Concentrations of BAP and FLU in chironomids increased with sediment concentration; however, FLU accumulated to a much greater extent. At sediment concentrations ranging from 47 to 4,040 g/kg, levels of FLU in chironomids ranged from below detection to 181,000 g/kg. In contrast, the maximum concentration of BAP measured in chironomids at similar sediment levels was 6,030 g/kg. Levels of FLU and BAP in bluegill that were fed contaminated chironomids were generally low, indicating either low uptake or rapid metabolism of these compounds.Bioturbation of sediments by chironomids decreased water clarity and released sediment-associated BAP to overlying water. BAP in water and in C. riparius increased significantly with chironomid density. In experiments where bluegill were exposed to BAP from water, direct contact with sediments, and chironomids, each source contributed to total body burden. The results of the experiments indicated that PAHs in sediments may be mobilized and made available to benthic invertebrates and fish.     

Insecticide toxicity to Hyalella curvispina in runoff and stream water within a soybean farm (Buenos Aires, Argentina)

Toxicity to the locally dominant amphipod Hyalella curvispina was assessed in a first-order stream running through a cultivated farm. Cypermethrin, chlorpyrifos, endosulfan and glyphosate were sprayed throughout the studied period. Toxicity was assayed under controlled laboratory conditions with runoff and stream water samples taken from the field under steady state and flood conditions. Ephemeral toxicity pulses were observed as a consequence of farm pesticide applications. After pesticide application, runoff water showed 100% mortality to H. curvispina for 1 month, but no mortality thereafter. Toxicity persistence was shortest in stream water, intermediate in stream sediments and longest in soil samples. Runoff had a more important toxicity effect than the exposure to direct aerial fumigation. The regional environmental features determining fast toxicity dissipation are discussed.     

气相色谱联用质谱法同时检测人体尿液中草甘膦及氨甲基膦酸含量

目的建立一种同时检测人尿样中草甘膦(PMG)和氨甲基膦酸(AMPA)含量的气相色谱联用质谱(GC/MS)分析方法。方法采用GC/MS法,EI检测器,色谱柱为DB-5MS毛细管色谱柱。进样前尿样经三氟乙酸酐(TFAA)和七氟丁醇(HFB)衍生化后用氮气吹干,0.2%柠檬醛乙酸乙酯溶液溶解混匀后供GC/MS分析。结果 PMG和AMPA在10~400 ng/ml范围内呈线性关系,最低检测限分别为4.66 ng/ml和1.77 ng/ml,最小检测浓度(LOQ)分别为15.52 ng/ml、5.91 ng/ml,回收率分别为85.2%~97.5%、89.2%~99.1%,精密度均小于10%。结论本实验可同时检测尿液中草甘膦及其代谢产物氨甲基膦酸,且最低检测限较单个检测方法灵敏。     

Effects of Water Contamination on Site Selection by Amphibians: Experiences from an Arena Approach With European Frogs and Newts

Pesticide residues in breeding ponds can cause avoidance by at least some amphibian species. So far, outdoor experiments have been performed only with artificial pools in areas where the focus species usually occur and new colonization has been observed. Results of this kind of study are potentially influenced by natural disturbances and therefore are of limited comparability. We used an easily manufactured and standardizable arena approach, in which animals in reproductive condition for some hours had a choice among pools with different concentrations of a contaminant. Because there has been much debate on the potential environmental impacts of glyphosate-based herbicides, we investigated the impact of glyphosate isopropylamine salt (GLY-IS), Roundup LB PLUS (RU-LB-PLUS), and glyphosate’s main metabolite aminomethylphosphonic acid (AMPA) on individual residence time in water. The following European amphibian species were tested: Common frog (Rana temporaria), Palmate newt (Lissotriton helveticus), and Alpine newt (Ichthyosaura alpestris). The residence time in water was not significantly affected by concentrations below or slightly above the European Environmental Quality Standards for AMPA or the German “worst-case” expected environmental concentrations for GLY-IS and RU-LB-PLUS. Occasionally, microclimatic cofactors (nightly minimum ground temperature, water temperature) apparently influenced the residence time. The major drawback of such quick behavior studies is that results can only be transferred to perception and avoidance of contaminated water but not easily to site selection by amphibians. For example, testing oviposition site selection requires more natural water bodies and more time. Hence, to develop a standard procedure in risk assessment, an intermediate design between an arena approach, as presented here, and previously performed field studies should be tested.     

Influence of climatic and edaphic factors on persistence of glyphosate and 2,4-D in forest soils

Persistence in soil of the two herbicides glyphosate and 2,4-D was investigated after application for brush control in conifer reforestation areas. Field experiments were carried out at five sites in southern Sweden and six in northern Sweden. Initially, glyphosate disappeared faster in northern soils than in southern soils. This was probably a result of the higher biological activity in the northern soils. However, small amounts of glyphosate were detected in the northern area long after all traces had disappeared in the south, presumably because of the long period during which the soil remained frozen in the northern area and because of the slow release of vegetation-bound herbicide. One metabolite of glyphosate, aminomethylphosphonic acid (AMPA), persisted longer than glyphosate itself. After 2 years, 8% of the theoretical amount was found in the northern area and, after 1 year, 1% in the southern area. 2,4-D disappeared rapidly from all sites, although minor amounts persisted for several years, probably because of slow release from vegetation-bound residues.