Multiyear monitoring of bird communities in chlorpyrifos-treated orchards in Spain and the United Kingdom: Spatial and temporal trends in species composition, abundance, and site fidelity.

The relationship between agricultural practices and the welfare of wild birds has gained increased attention over the last decades. To assess the potential effects of chlorpyrifos on the bird community, a multiyear, multisite monitoring program was carried out in treated cider orchards (in the United Kingdom) and treated citrus orchards (in Spain). Constant-effort mist netting was used over several consecutive years in the United Kingdom (2012-2014) and Spain (2010-2012). The general structure of the bird community and the presence of breeding species were analyzed. Twelve and 11 bird species (out of 81 and 45 trapped) in Spain and the United Kingdom, respectively, exceeded the 2% dominance value. For a selection of 6 species in citrus and 4 in cider orchards, N-mixture models were fitted to the number of trapped birds. The abundance of most species was strongly and significantly affected by seasonality. No species showed any indication of reduction in population size over the years. The results of this extensive field program support the indications that chlorpyrifos spray applications present a low risk to the bird community over the years. Environ Toxicol Chem 2019;38:616-629. © 2018 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC.

Modelling effects of time-variable exposure to the pyrethroid beta-cyfluthrin on rainbow trout early life stages.

BACKGROUND: Available literature and regulatory studies show that the severity of effects of beta-cyfluthrin (a synthetic pyrethroid) on fish is influenced by the magnitude and duration of exposure. To investigate how the exposure pattern to beta-cyfluthrin (constant vs peak) may influence the response of the fish, we used a mechanistic effect model to predict the survival and growth of the rainbow trout over its early life stages (i.e. egg, alevin and swim-up fry). We parameterized a toxicokinetic-toxicodynamic (TKTD) module in combination with a dynamic energy budget model enabling us to describe uptake and elimination, as well as to predict the threshold concentration for survival and sublethal effects (feeding behaviour and growth). This effect model was calibrated using data from an early life stage experiment where trout was exposed to a constant concentration of cyfluthrin. The model was validated by comparing model predictions to independent data from a pulsed-exposure study with early life stages of rainbow trout. RESULTS: The co-occurrence of effects on behaviour and growth raised the possibility that these were interrelated, i.e. impairment of feeding behaviour may have led to reduced food intake and slower growth. We, therefore, included 'effect on feeding' as mode of action in the TKTD module. At higher concentrations, the constant exposure led to death. The model was able to adequately capture this effect pattern in the calibration. The model was able to adequately predict the response of fish eggs, alevins and swim-up fry, from both the qualitative (response pattern) and quantitative points of view. CONCLUSIONS: Since the model was successfully validated, it can be used to predict survival and growth of early life stages under various realistic time-variable exposure profiles (e.g. profiles from FOCUS surface water modelling) of beta-cyfluthrin.

Why do women still develop cancer of the cervix despite the existence of a national screening programme?

The study looked at why women developed invasive cervical cancer during a 10-year period. It reviewed the hospital records of 66 patients with cervical cancer with an age range of 21-81 years. Screening non-attenders accounted for a disproportionate number of cases. The proportion of women who had never been screened did not vary during the study period. Attention needs to focus on reasons why these women do not attend.

Integrating ecosystem services into risk management decisions: case study with Spanish citrus and the insecticide chlorpyrifos.

The European regulatory system for the approval of pesticides includes a thorough evaluation of risks to the environment and is designed to be protective of ecosystems. However, a decision to ban an agrochemical could also potentially have a negative impact on the value of ecosystem services, if resulting changes in crop management are damaging to ecosystems or result in negative socio-economic impacts. To support regulatory decision-making, consideration of ecosystem services to identify best environmental management options could be a way forward. There is generally a growing trend for the consideration of ecosystem services in decision making. Ecosystems provide the conditions for growing food, regulate water and provide wildlife habitats; these, amongst others, are known as ecosystem services. The objectives of this case study were to bring a holistic approach to decision making by valuing the environmental, social and economic benefits derived from the use of chlorpyrifos in Valencian citrus production. Spanish growers harvest between 5 and 6 milliont of citrus annually, worth an estimated €5 to 7 billion in food markets throughout Europe. The approach highlighted the potential for unintended negative consequences of regulatory decisions if the full context is not considered. In this study, rather than a regulatory restriction, the best option was the continued use of chlorpyrifos together with vegetated conservation patches as refuges for non-target insects. The conservation patches offset potential insecticidal impacts to insects whilst maintaining citrus production, farm income and the amenity value of the citrus landscape of Valencia. This was an initial proof-of-concept study and illustrates the importance of a wider perspective; other cases may have different outcomes depending on policies, the pesticide, crop scenarios, farm economics and the region.

Comparing population recovery after insecticide exposure for four aquatic invertebrate species using models of different complexity.

Population models, in particular individual-based models (IBMs), are becoming increasingly important in chemical risk assessment. They can be used to assess recovery of spatially structured populations after chemical exposure that varies in time and space. The authors used an IBM coupled to a toxicokinetic-toxicodynamic model, the threshold damage model (TDM), to assess recovery times for 4 aquatic organisms, after insecticide application, in a nonseasonal environment and in 3 spatial settings (pond, stream, and ditch). The species had different life histories (e.g., voltinism, reproductive capacity, mobility). Exposure was derived from a pesticide fate model, following standard European Union scenarios. The results of the IBM-TDM were compared with results from simpler models: one in which exposure was linked to effects by means of concentration-effect relationships (IBM-CE) and one in which the IBM was replaced by a nonspatial, logistic growth model (logistic). For the first, exposure was based on peak concentrations only; for the second, exposure was spatially averaged as well. By using comparisons between models of different complexity and species with different life histories, the authors obtained an understanding of the role spatial processes play in recovery and the conditions under which the full time-varying exposure needs to be considered. The logistic model, which is amenable to an analytic approach, provided additional insights into the sensitivity of recovery times to density dependence and spatial dimensions.

Evaluating exposure and potential effects on honeybee brood (Apis mellifera) development using glyphosate as an example.

This study aimed to develop an approach to evaluate potential effects of plant protection products on honeybee brood with colonies at realistic worst-case exposure rates. The approach comprised 2 stages. In the first stage, honeybee colonies were exposed to a commercial formulation of glyphosate applied to flowering Phacelia tanacetifolia with glyphosate residues quantified in relevant matrices (pollen and nectar) collected by foraging bees on days 1, 2, 3, 4, and 7 postapplication and glyphosate levels in larvae were measured on days 4 and 7. Glyphosate levels in pollen were approximately 10 times higher than in nectar and glyphosate demonstrated rapid decline in both matrices. Residue data along with foraging rates and food requirements of the colony were then used to set dose rates in the effects study. In the second stage, the toxicity of technical glyphosate to developing honeybee larvae and pupae, and residues in larvae, were then determined by feeding treated sucrose directly to honeybee colonies at dose rates that reflect worst-case exposure scenarios. There were no significant effects from glyphosate observed in brood survival, development, and mean pupal weight. Additionally, there were no biologically significant levels of adult mortality observed in any glyphosate treatment group. Significant effects were observed only in the fenoxycarb toxic reference group and included increased brood mortality and a decline in the numbers of bees and brood. Mean glyphosate residues in larvae were comparable at 4 days after spray application in the exposure study and also following dosing at a level calculated from the mean measured levels in pollen and nectar, showing the applicability and robustness of the approach for dose setting with honeybee brood studies. This study has developed a versatile and predictive approach for use in higher tier honeybee toxicity studies. It can be used to realistically quantify exposure of colonies to pesticides to allow the appropriate dose rates to be determined, based on realistic worst-case residues in pollen and nectar and estimated intake by the colony, as shown by the residue analysis. Previous studies have used the standard methodology developed primarily to identify pesticides with insect-growth disrupting properties of pesticide formulations, which are less reliant on identifying realistic exposure scenarios. However, this adaptation of the method can be used to determine dose-response effects of colony level exposure to pesticides with a wide range of properties. This approach would limit the number of replicated tunnel or field-scale studies that need to be undertaken to assess effects on honeybee brood and may be of particular benefit where residues in pollen and nectar are crop- and/or formulation-specific, such as systemic seed treatments and granular applications.

Telemetry-based field studies for assessment of acute and short-term risk to birds from spray applications of chlorpyrifos.

In a program of avian field studies, radiotelemetry was combined with observations, carcass searches, residue analysis, and determination of brain acetylcholinesterase (AChE) activity to assess the acute and short-term risk posed by chlorpyrifos to birds. Studies were conducted in field crops (brassicas, Poland) and orchards (pome, Italy; citrus, Spain). In total, 25 individual applications of chlorpyrifos were studied on 13 sites. Before each application, birds were fitted with radio transmitters (with minimum stress to birds). Radiotagged birds were monitored and the avifauna observed before, during and for 7 d following each application. A total of 201 birds representing 19 species were radiotagged. In 80% of individual telemetric monitoring periods, birds remained at the study sites. No radiotagged birds showed any sign of intoxication. These included individuals who spent a major proportion of time within treated areas (some individuals located within treated area on >90% of occasions). A total of 7,238 bird sightings were recorded during constant observation during and immediately after application. An additional 4,017 sightings were recorded in 104 individual surveys during 7 d after each application. Two untagged birds (out of 11,255 bird sightings) exhibited atypical behavior for <1 min and 2 to 3 min, respectively, before flying away. This observation (for 0.02% of bird sightings) may or may not have been treatment related. Ten carcasses were recovered (none radiotagged). Residue analysis and brain AChE activity indicated that none was likely to have died from chlorpyrifos exposure. Radiotracking, supported by more traditional assessment methods, was effective for assessing impacts in the field. This extensive field program supports a conclusion that spray applications of chlorpyrifos present a low risk to birds.

Screening for esophageal luminal narrowing--a magnetic disc tablet as a bolus challenge: preliminary report.

Narrowing of the esophageal lumen often exists for months before being noted by the patient. Screening tests for such lesions would be useful, if applicable to office use. A magnetic disc tablet (14 mm in diameter and 5 mm thick) was fashioned by hand using dental acrylic material to enclose the magnet with a smooth watertight sheath. A magnetic detector was held on the anterior abdominal wall 2.5 cm below the xiphoid cartilage and 2.5 cm to its left. A significant change in reading indicated that the tablet had reached the cardia of the stomach. The magnetic tablet was readily detected in 11 patients without organic narrowing. Our method attempts to detect narrowing of the esophageal lumen by use of a magnetic disc tablet. Perhaps this will be of clinical usefulness in detecting esophageal disease before symptoms become apparent.