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Risk assessment for bees is mainly based on data for honey bees; however, risk assessment is intended to protect all bee species. This raises the question of whether data for honey bees are a good proxy for other bee species. This issue is not new and has resulted in several publications in which the sensitivity of bee species is compared based on the values of the 48-h median lethal dose (LD50) from acute test results. When this approach is used, observed differences in sensitivity may result both from differences in kinetics and from inherent differences in species sensitivity. In addition, the physiology of the bee, like its overall size, the size of the honey stomach (for acute oral tests), and the physical appearance (for acute contact tests) also influences the sensitivity of the bee. The recently introduced Toxicokinetic-Toxicodynamic (TKTD) model that was developed for the interpretation of honey bee tests (Bee General Uniform Threshold Model for Survival [BeeGUTS]) could integrate the results of acute oral tests, acute contact tests, and chronic tests within one consistent framework. We show that the BeeGUTS model can be calibrated and validated for other bee species and also that the honey bee is among the more sensitive bee species. In addition, we found that differences in sensitivity between species are smaller than previously published comparisons based on 48-h LD50 values. The time-dependency of the LD50 and the specifics of the bee physiology are the main causes of the wider variation found in the published literature. Environ Toxicol Chem 2024;43:1431-1441. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC., (© 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.)

In Europe, the risk assessment for bees at the European Union or national level has always focussed on potential impacts on honeybees. During the revision of the European Food Safety Authority bee guidance it was explicitly stated that bumblebees and solitary bees should be considered as well and consequently concerns were raised regarding the representativeness of honeybees for these other bee species. These concerns originate from differences in size as well as differences in behavioral and life history traits of other bee species. In response to this concern, the non-Apis working group of the International Commission for Plant-Pollinator Relationships initiated a ring-test of a semifield tunnel study design using the bumblebee Bombus terrestris. Nine laboratories participated, validating and improving the proposed design over a 2-year period. The intention of the ring-test experiments was to develop and if possible, establish a test protocol to conduct more standardized semifield tests with bumblebees. In the present study, the results of the ring-tests are summarized and discussed to give recommendations for a promising experimental design. Environ Toxicol Chem 2022;41:2548-2564. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC., (© 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.)

Arbuscular mycorrhizal fungi (AMF) perform key soil ecosystem services and, because of their symbiotic relationship with plant roots, may be exposed to the plant protection products (PPPs) applied to soils and crops. In 2017, the European Food Safety Authority (EFSA) released a scientific opinion addressing the state of the science on risk assessment of PPPs for in-soil organisms, recommending the inclusion of AMF ecotoxicological testing in the PPP regulatory process. However, it is not clear how this can be implemented in a tiered, robust, and ecologically relevant manner. Through a critical review of current literature, we examine the recommendations made within the EFSA report and the methodologies available to integrate AMF into the PPP risk assessment and provide perspective and commentary on their agronomic and ecological relevance. We conclude that considerable research questions remain to be addressed prior to the inclusion of AMF into the in-soil organism risk assessment, many of which stem from the unique challenges associated with including an obligate symbiont within the PPP risk assessment. Finally, we highlight critical knowledge gaps and the further research required to enable development of relevant, reliable, and robust scientific tests alongside pragmatic and scientifically sound guidance to ensure that any future risk-assessment paradigm is adequately protective of the ecosystem services it aims to preserve. Environ Toxicol Chem 2022;41:1808-1823. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC., (© 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.)

The risk of honey bee (Apis mellifera L.) exposure to pesticide residues while foraging for nectar and pollen is commonly explored in the context of agroecosystems. However, pesticides are also used in urban and suburban areas for vegetation management, vector control, and the management of ornamental plants in public and private landscapes. The extent to which pesticides pose a health risk to honey bees in these settings remains unclear. We addressed this at a landscape scale by conducting pesticide residue screening analyses on 768 nectar and 862 pollen samples collected monthly over 2 years from honey bee colonies located in urban and suburban areas in eight medium to large cities in California, Florida, Michigan, and Texas (USA). A risk assessment was performed using the US Environmental Protection Agency's BeeREX model whenever an oral toxicity value was available for a compound. Chemical analyses detected 17 pesticides in nectar and 60 in pollen samples during the survey. Approximately 73% of all samples contained no detectable pesticide residues. Although the number of detections varied among the sampled regions, fewer pesticides were detected in nectar than in pollen. Per BeeREX, four insecticides showed a potential acute risk to honey bees: imidacloprid, chlorpyrifos, and esfenvalerate in nectar, and deltamethrin in nectar and pollen. In general, exposure of honey bees to pesticides via nectar and pollen collection was low in urban and suburban areas across the United States, and no seasonal or spatial trends were evident. Our data suggest that honey bees are exposed to fewer pesticides in developed areas than in agricultural ones. Environ Toxicol Chem 2022;41:991-1003. © 2022 SETAC., (© 2022 SETAC.)

Ecotoxicological profiles of the 3 insecticides imidacloprid, thiacloprid, and flupyradifurone in terms of acute and chronic effects were analyzed in Chironomus riparius. Toxicokinetic-toxicodynamic modeling revealed that chironomids would die from starvation as a result of prolonged feeding inhibition under chronic exposures. The starvation effect is an indirect cause for mortality, which, for the neonicotinoids, adds to the direct/acute mortality, although the results suggests that this additional effect is not relevant for flupyradifurone. Environ Toxicol Chem 2021;40:1706-1712. © 2021 Bayer Inc. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC., (© 2021 Bayer Inc.)

There are various differences in size, behavior, and life history traits of non-Apis bee species compared with honey bees (Apis mellifera; Linnaeus, 1758). Currently, the risk assessment for bees in the international and national process of authorizing plant protection products has been based on honey bee data as a surrogate organism for non-Apis bees. To evaluate the feasibility of a semifield tunnel test for Osmia bicornis (Linnaeus, 1758) and Osmia cornuta (Latreille, 1805), a protocol was developed by the non-Apis working group of the International Commission for Plant-Pollinator Relationships, consisting of experts from authorities, academia, and industry. A total of 25 studies were performed over a 2-yr period testing a replicated control against a replicated positive control using either a dimethoate or diflubenzuron treatment. Studies were regarded to be valid, if ≥30% of released females were found to occupy the nesting units in the night/morning before the application (establishment). Thirteen studies were regarded to be valid and were analyzed further. Parameters analyzed were nest occupation, flight activity, cell production (total and per female), cocoon production (total and per female), emergence success, sex ratio, and mean weight of females and males. Dimethoate was a reliable positive control at the tested rate of 75 g a.i./ha, once >30% females had established, displaying acute effects such as reduction in flight activity, increase in adult mortality (shown by nest occupation), and reproduction ability of the females (total cell and cocoon production). On the other hand, no effects on larval and pupal development were observed. The growth regulator diflubenzuron had statistically significant effects on brood development, causing mortality of eggs and larvae at a rate of approximately 200 g a.i./ha, whereas fenoxycarb did not cause any significant effects at the tested rates of 300 and 600 g a.i./ha. In conclusion, the ring-test protocol proved to be adequate once the study comprised a well-established population of female Osmia bees, and the results improved in the second year as the laboratories increased their experience with the test organism. It is noted that the success of a study strongly depends on the experience of the experimenter, the crop quality, the quality of the cocoons, and the weather conditions. Based on these finding, recommendations for a semifield study design with Osmia spp. are proposed. Environ Toxicol Chem 2021;40:236-250. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC., (© 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.)

The commercialization of RNA-based agricultural products requires robust ecological risk assessments. Ecological risk is operationally defined as a function of exposure and adverse effects. Information on the environmental fate of RNA-based plant-incorporated protectants is essential to define routes and duration of exposure to potentially sensitive nontarget organisms. Providing these details in problem formulation helps focus the ecological risk assessment on the relevant species of concern. Postharvest plant residue is often considered to be the most significant route of exposure for genetically modified crops to adjacent aquatic environments. Previous studies have shown that DvSnf7 RNA from SmartStax PRO maize dissipates rapidly in both terrestrial and aquatic environments. Although these studies suggest that direct exposure to DvSnf7 RNA is likely to be low, little is known regarding the fate of DvSnf7 RNA produced in plants after entering an aquatic environment. This exposure scenario is relevant to detritivorous aquatic invertebrates that process conditioned maize tissues that enter aquatic environments. To assess potential exposure to shredders, dissipation of DvSnf7 RNA expressed maize tissue was evaluated following immersion in microcosms containing sediment and water. Concentrations of DvSnf7 RNA in the tissue were measured over a duration of 21 d. The DvSnf7 RNA dissipated rapidly from immersed maize tissue and was undetectable in the tissues after 3 d. Concentrations of DvSnf7 RNA found in tissue as well as calculated water column concentrations were below levels known to elicit effects in a highly sensitive surrogate species, supporting the conclusion of minimal risk to aquatic nontarget organisms. Environ Toxicol Chem 2020;39:1032-1040. © 2020 SETAC., (© 2020 SETAC.)

Recent regulatory testing programs have been designed to evaluate whether a chemical has the potential to interact with the endocrine system and could cause adverse effects. Some endocrine pathways are highly conserved among vertebrates, providing a potential to extrapolate data generated for one vertebrate taxonomic group to others (i.e., biological read-across). To assess the potential for biological read-across, we reviewed tools and approaches that support species extrapolation for fish, amphibians, birds, and reptiles. For each of the estrogen, androgen, thyroid, and steroidogenesis (EATS) pathways, we considered the pathway conservation across species and the responses of endocrine-sensitive endpoints. The available data show a high degree of confidence in the conservation of the hypothalamus-pituitary-gonadal axis between fish and mammals and the hypothalamus-pituitary-thyroid axis between amphibians and mammals. Comparatively, there is less empirical evidence for the conservation of other EATS pathways between other taxonomic groups, but this may be due to limited data. Although more information on sensitive pathways and endpoints would be useful, current developments in the use of molecular target sequencing similarity tools and thoughtful application of the adverse outcome pathway concept show promise for further advancement of read-across approaches for testing EATS pathways in vertebrate ecological receptors. Environ Toxicol Chem 2020;39:739-753. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC., (© 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.)

Current herbicide risk assessment guidelines for nontarget terrestrial plants require testing effects on young, vulnerable life stages (i.e., seedling emergence [and subsequent growth] and vegetative vigor [growth and dry wt]) but not directly on the reproduction of plants. However, the European Food Safety Authority (EFSA) has proposed that effects on reproduction might be considered when evaluating the potential effects on plants. We adapted the plant community model for grassland (IBC-grass) to give insight into the current debate on the sensitivity of reproductive versus vegetative endpoints in ecological risk assessment. In an extensive sensitivity analysis of this model, we compared plant attributes potentially affected by herbicides and the consequences for long-term plant population dynamics and plant diversity. This evaluation was implemented by reducing reproductive as well as vegetative endpoints by certain percentages (e.g., 10-90%) as a theoretical assumption. Plant mortality and seed sterility (i.e., inability of seeds to germinate) were the most sensitive attributes. Our results indicated that effects on seed production at off-field exposure rates must be very strong to have an impact on the risk assessment. Otherwise, effects on seed production are compensated for by the soil seed bank. The present study highlights the usefulness of community level modeling studies to support regulators in their decisions on the appropriate risk assessment endpoints and provides confidence in their assessments. Environ Toxicol Chem 2018;37:1707-1722. © 2018 SETAC., (© 2018 SETAC.)

Environmental risk assessment of chemical mixtures is challenging because of the multitude of possible combinations that may occur. Aquatic risk from chemical mixtures in an agricultural landscape was evaluated prospectively in 2 exposure scenario case studies: at field scale for a program of 13 plant-protection products applied annually for 20 yr and at a watershed scale for a mixed land-use scenario over 30 yr with 12 plant-protection products and 2 veterinary pharmaceuticals used for beef cattle. Risk quotients were calculated from regulatory exposure models with typical real-world use patterns and regulatory acceptable concentrations for individual chemicals. The results could differentiate situations when there was concern associated with single chemicals from those when concern was associated with a mixture (based on concentration addition) with no single chemical triggering concern. Potential mixture risk was identified on 0.02 to 7.07% of the total days modeled, depending on the scenario, the taxa, and whether considering acute or chronic risk. Taxa at risk were influenced by receiving water body characteristics along with chemical use profiles and associated properties. The present study demonstrates that a scenario-based approach can be used to determine whether mixtures of chemicals pose risks over and above any identified using existing approaches for single chemicals, how often and to what magnitude, and ultimately which mixtures (and dominant chemicals) cause greatest concern. Environ Toxicol Chem 2018;37:674-689. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC., (© 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.)

Bisphenol A (BPA) is a high production volume compound primarily used to produce epoxy resins and polycarbonate plastic. Exposure to low concentrations of BPA occurs in freshwater and marine systems, primarily from wastewater treatment plant discharges. The dataset for chronic toxicity of BPA to freshwater organisms includes studies on fish, amphibians, invertebrates, algae, and aquatic plants. To broaden the dataset, a 1.5-generation test with sheepshead minnow (Cyprinodon variegatus) and a full life-cycle test with mysid shrimp (Americamysis bahia) were conducted. Testing focused on apical endpoints of survival, growth and development, and reproduction. The respective no-observed-effect concentration (NOEC) and lowest-observed-effect concentration (LOEC) values of 170 and 370 µg/L for mysid and 66 and 130 μg/L for sheepshead were based on reduced fecundity. The hazardous concentrations for 5% of the species (HC5) values of 18 μg/L were calculated from species sensitivity distributions (SSDs) with freshwater-only data and combined freshwater and marine data. Inclusion of marine data resulted in no apparent difference in SSD shape, R 2 values for the distributions, or HC5 values. Upper-bound 95th percentile concentrations of BPA measured in marine waters of North America and Europe (0.024 and 0.15 μg/L, respectively) are below the HC5 value of 18 μg/L. These results suggest that marine and freshwater species are of generally similar sensitivity and that chronic studies using a diverse set of species can be combined to assess the aquatic toxicity of BPA. Environ Toxicol Chem 2018;37:398-410. © 2017 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC., (© 2017 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC.)

A probabilistic ecological risk assessment (ERA) was conducted to determine the potential effects of acute and chronic exposure of aquatic invertebrate communities to imidacloprid arising from labeled agricultural and nonagricultural uses in the United States. Aquatic exposure estimates were derived using a higher-tier refined modeling approach that accounts for realistic variability in environmental and agronomic factors. Toxicity was assessed using refined acute and chronic community-level effect metrics for aquatic invertebrates (i.e., species or taxon sensitivity distributions) developed using the best available data. Acute and chronic probabilistic risk estimates were derived by integrating the exposure distributions for different use patterns with the applicable species or taxon sensitivity distributions to generate risk curves, which plot cumulative probability of exceedance versus the magnitude of effect. Overall, the results of this assessment indicated that the aquatic invertebrate community is unlikely to be adversely affected by acute or chronic exposure to imidacloprid resulting from currently registered uses of imidacloprid in the United States. Environ Toxicol Chem 2017;36:1375-1388. © 2016 SETAC., (© 2016 SETAC.)

The registration of pesticides follows guidance published by the European Food Safety Authority (EFSA). As a default, the EFSA guidance document on risk assessment for birds and mammals assumes that animals feed exclusively on pesticide-treated fields. However, the guidance document suggests refining the risk via the proportion of food animals obtain from a treated field or specific crop (expressed via the portion of diet obtained from a treated area [PT value]). The EFSA guidance equalizes the portion of food taken from a treated area per day with the portion of time spent potentially foraging over the course of a day within this area. Therefore, radiotracking is commonly used to gather species-, crop-, and season-specific PT data, and radio telemetry of continuously tracked farmland species can deliver individual PT values for a given day, crop, and species. In the present study the authors introduce a way of calculating long-term PT values based on empirically recorded data via telemetry field studies for the most appropriate use in wildlife risk assessment of pesticides. The novel aspect of the proposal is that the authors follow the prerequisite given by EFSA to cover the long-term risk by introducing 21-d PT values that aim to cover both intra- and inter-individual variability of foraging focal farmland species in cropped habitats. Currently, the intra-individual variability is not taken into account for PT calculations. The authors demonstrate this approach and discuss EFSA guidance input requirements for PT values recorded in field studies, based on a PT field study conducted with woodpigeons (Columba palumbus) radiotracked in an agricultural landscape in the United Kingdom. The results indicate that a 21-d PT value considering intra-individual variability gives a more appropriate PT value for long-term risk assessments. Environ Toxicol Chem 2017;36:1270-1277. © 2016 SETAC., (© 2016 SETAC.)

Interest in stream mesocosms has recently revived for higher tier aquatic macrophyte risk assessment of plant protection products mainly because 1) the highest predicted environmental concentrations for the assessment of effects are frequently derived from stream scenarios, and 2) they allow an effect assessment using stream-typical pulse exposures. Therefore, the present stream mesocosm study used an herbicide pulse exposure and evaluated the responses of Elodea canadensis and Myriophyllum spicatum. Macrophytes were exposed for 24 h to 1 μg/L, 3 μg/L, 10 μg/L, and 30 μg/L of the herbicide iofensulfuron-sodium with a subsequent recovery period of 42 d. Biological endpoints were growth rates of the main, side, and total shoot length, the shoot number, the maximum root length, and the dry weight. The total shoot length was identified as the most sensitive endpoint; the growth rate of the total shoot length was inhibited by up to 66% and 45% in M. spicatum and E. canadensis, respectively. The lowest no observed effect concentrations (NOECs) were observed at day 7 and/or day 14 after herbicide treatment and were 1 μg/L for M. spicatum and 3 μg/L for E. canadensis. The no-observed-ecologically-adverse-effect concentrations (NOEAECs) were 10 μg/L and 30 μg/L for M. spicatum and E. canadensis, respectively. Such or similar mesocosm designs are useful to simulate typical stream exposures and estimate herbicide effects on aquatic macrophytes in stream systems. Environ Toxicol Chem 2017;36:1090-1100. © 2016 SETAC., (© 2016 SETAC.)

Bisphenol A (BPA) is a high production volume chemical intermediate used primarily in the production of polycarbonate plastics and epoxy resins. It primarily enters surface water and sediment via effluent discharges during its manufacture and use. The physical properties of BPA suggest that sediment is a potential sink and may result in exposure to benthic organisms. Currently there are no studies measuring the chronic toxicity of BPA to benthic organisms via direct sediment exposure. The present study examined the chronic toxicity of BPA to 3 commonly used test organisms that are generally representative of invertebrates occupying the base of the benthic food web and for which standardized testing protocols are available: the oligochaete Lumbriculus variegatus (mean numbers and biomass), the midge Chironomus riparius (emergence and development rate), and the estuarine amphipod Leptocheirus plumulosus (survival, growth, and reproduction). No-observed-effect concentrations (NOECs) for the 3 species ranged from 12 mg/kg to 54 mg/kg dry weight. All NOEC values were higher than all measured concentrations of BPA in freshwater and marine sediments reported in reliable, fully reported studies from North America and Europe from the 1990s to the present. For the first time, there are studies with BPA measuring the chronic toxicity to 3 taxa of sediment dwelling invertebrates, which are suitable to support region-specific risk assessments., (© 2015 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC.)

Washoff of 17 pyrethroid products resulting from a 1-h, 25.4-mm rainfall occurring 24 h after application was measured in indoor studies with concrete slabs. These products included different pyrethroid active ingredients and a range of formulation types. Based on this replicated study, 5 product pairs with contrasting washoff behaviors were chosen for an outdoor study using 6 full-scale house fronts in central California. Products in 4 of these pairs were applied once to different rectangular areas on the driveway (1 product in each pair to 3 house lots and the other to the remaining 3 house lots). The products in the fifth pair were applied 3 times at 2-mo intervals to vertical stucco walls above the driveway. All house lots received natural and simulated rainfall over 7 mo. Indoor studies showed differences up to 170-fold between paired products, whereas the maximum difference between paired products in the field was only 5-fold. In the pair applied to the wall, 1 product had 91 times the washoff of the other in the indoor study, whereas in the field the same product had 15% lower washoff. These results show that, although the formulation may influence washoff under actual use conditions, its influence is complex and not always as predicted by indoor experiments. Because the formulation also affects insect control, washoff research needs to be conducted together with efficacy testing., (© 2015 The Authors. Published by Wiley Periodicals, Inc. on behalf of SETAC.)

Limited data are available on the fate of clothianidin under realistic agricultural production conditions. The present study is the first large-scale assessment of clothianidin residues in soil and bee-relevant matrices from corn and canola fields after multiple years of seed-treatment use. The average soil concentration from 50 Midwest US corn fields with 2 yr to 11 yr of planting clothianidin-treated seeds was 7.0 ng/g, similar to predicted concentrations from a single planting of Poncho 250-treated corn seeds (6.3 ng/g). The water-extractable (i.e., plant-bioavailable) clothianidin residues in soil were only 10% of total residues. Clothianidin concentrations in soil reached a plateau concentration (amount applied equals amount dissipated) in fields with 4 or more application years. Concentrations in corn pollen from these fields were low (mean: 1.8 ng/g) with no correlation to total years of use or soil concentrations. For canola, soil concentrations from 27 Canadian fields with 2 yr to 4 yr of seed treatment use (mean = 5.7 ng/g) were not correlated with use history, and plant bioavailability was 6% of clothianidin soil residues. Average canola nectar concentrations were 0.6 ng/g and not correlated to use history or soil concentrations. Under typical cropping practices, therefore, clothianidin residues are not accumulating significantly in soil, plant bioavailability of residues in soil is limited, and exposure to pollinators will not increase over time in fields receiving multiple applications of clothianidin., (© 2015 The Authors. Published by Wiley Periodicals, Inc. on behalf of SETAC.)

Kinetic parameters of environmental fate processes are usually inferred by fitting appropriate kinetic models to the data using standard nonlinear least squares (NLS) approaches. Although NLS is appropriate to estimate the optimum parameter values, it implies restrictive assumptions on data variances when the confidence limits of the parameters must also be determined. Particularly in the case of degradation and metabolite formation, the assumption of equal error variance is often not realistic because the parent data usually show higher variances than those of the metabolites. Conventionally, such problems would be tackled by weighted NLS regression, which requires prior knowledge about the data errors. Instead of implicitly assuming equal error variances or giving arbitrary weights decided by the researcher, we use an iteratively reweighted least squares (IRLS) algorithm to obtain the maximum likelihood estimates of the model parameters and the error variances specific for the different species in a model. A study with simulated data shows that IRLS gives reliable results in the case of both unequal and equal error variances. We also compared results obtained by NLS and IRLS, with probability distributions of the parameters inferred with a Markov-Chain Monte-Carlo (MCMC) approach for data from aerobic transformation of different chemicals in soil. Confidence intervals obtained by IRLS and MCMC are consistent, whereas NLS leads to very different results when the error variances are distinctly different between different species. Because the MCMC results can be assumed to reflect the real parameter distribution imposed by the observed data, we conclude that IRLS generally yields more realistic estimates of confidence intervals for model parameters than NLS., (Copyright © 2011 SETAC.)

Bisphenol A (BPA) is a high production volume substance primarily used to produce polycarbonate plastic and epoxy resins. During manufacture and use, BPA may enter wastewater treatment plants. During treatment, BPA may become adsorbed to activated sludge biosolids, which may expose soil organisms to BPA if added to soil as an amendment. To evaluate potential risks to organisms that make up the base of the terrestrial food web (i.e., invertebrates and plants) in accordance with international regulatory practice, toxicity tests were conducted with potworms (Enchytraeids) and springtails (Collembolans) in artificial soil, and six plant types using natural soil. No-observed-effect concentrations (NOEC) for potworms and springtails were equal to or greater than 100 and equal to or greater than 500 mg/kg (dry wt), respectively. The lowest organic matter-normalized NOEC among all tests (dry shoot weight of tomatoes) was 37 mg/kg-dry weight. Dividing by an assessment factor of 10, a predicted-no-effect concentration in soil (PNEC(soil)) of 3.7 mg/kg-dry weight was calculated. Following international regulatory guidance, BPA concentrations in soil hypothetically amended with biosolids were calculated using published BPA concentrations in biosolids. The upper 95th percentile BPA biosolids concentration in North America is 14.2 mg/kg-dry weight, and in Europe is 95 mg/kg-dry weight. Based on recommended biosolids application rates, predicted BPA concentrations in soil (PEC(soil)) would be 0.021 mg/kg-dry weight for North America and 0.14 mg/kg-dry weight for Europe. Hazard quotients (ratio of PEC(soil) and PNEC(soil)) for BPA were all equal to or less than 0.04. This indicates that risks to representative invertebrates and plants at the base of the terrestrial food web are low if exposed to BPA in soil amended with activated sludge biosolids., (Copyright 2009 SETAC.)

United States potable well monitoring in the Pacific Northwest, California, Texas, Mississippi delta, and the Southeast was conducted in 2005 to provide estimates of dietary exposure to aldicarb carbamate residues (aldicarb and its two carbamate metabolites) in potentially vulnerable potable wells. Samples were analyzed from 1,673 drinking water wells in nine major use areas that were within 300 m of fields treated at least once with aldicarb between 2002 and 2005. Analyses were performed with a high-performance liquid chromatography/tandem mass spectrometry analytical method with limits of quantitation of 0.021 microg/L for aldicarb and aldicarb sulfone and 0.027 microg/L for aldicarb sulfoxide. The method detection limits were 0.0070 microg/L for aldicarb and aldicarb sulfone and 0.0090 microg/L for aldicarb sulfoxide. Samples from 1,513 of the 1,673 wells contained no aldicarb carbamate residues. Only 10 wells had total aldicarb carbamate residues above 1 microg/L, the maximum being 2.9 microg/L. All residues were below the U.S. Environmental Protection Agency Health Advisory Limit (HAL) of 10 microg/L. Given the number of samples collected in this study, there is a 95% confidence level that the maximum concentration in this study exceeds the 99.8th percentile of concentrations of all potable wells located within 300 m of fields recently treated with aldicarb. Therefore, the data from this study show that the restrictions and management practices on the current product label continue to be effective in preventing residues in excess of the 10 microg/L HAL in potable wells in these use areas.

Field exposure of small mammals to fungicide-treated wheat seed was investigated over three weeks following drilling on fields near York, United Kingdom. Seed consumption by small mammals trapped on and immediately adjacent to the drilled fields was quantified by measuring the amount of seed in the stomach. In addition, exposure to one seed-treatment, fluquinconazole, was quantified by measuring residues of the fungicide in the stomach, liver, and intestine. The wood mouse, Apodemus sylvaticus, was the dominant species caught on the fields and the only species found to have consumed measurable quantities of seed. Voles, Microtus agrestis and Clethrionomys glareolus, were caught in small numbers, almost exclusively in the field hedge, and showed no evidence of having consumed seed. Stomach-contents analysis revealed that more than 80% of animals trapped in the hedge adjacent to the field had consumed no wheat seed, whereas 98% had consumed less than 10% (by stomach volume). Ninety percent of animals trapped on the field had consumed seed, although 90% of these animals had less than 20% seed in the stomach. Residues of the fungicide in the stomach, intestine, and liver were lower than would be expected for the amount of seed consumed, possibly because of dehusking of the seeds by mice. The relevance of these findings when assessing exposure (and risk) posed by seed treatments to wild mammals is discussed.