Pesticides in Perspective Introduction In the Ærst article in this column Ian Shaw wrote about theUKsurveillance scheme for monitoring pesticide residues infoodwhichistheÆrstissuethatconcerns consumers in connection with pesticide use. However consumers are becoming increasingly aware of environmental issues particularly issues such as global warming and genetically modiÆed crops. With this heightened awareness of the environment and what affects it issues such as pesticides are becoming of increasing interest to the public and this interest is fuelled by pressure groups and the media. With that in mind and the fact that governments obviously recognise that they need to be aware of any potential environmentalrisksfrompesticideuse,the UKgovernmentestablished thePesticides in the Environment Working Group (PEWG) to evaluateUKenvironmental monitoring activities and to make recommendations for the future.The current article is co-authored by Monitoring of Pesticides in the UK Environment{ Summary from the report of the Pesticides in the Environment Working Group (PEWG)–Published by the Environment Agency Bristol UK. R&D Publication Number 69 Introduction The Pesticides in the Environment Working Group (PEWG) was established by the Environment Agency on behalf of the UK Government to look at the overall balance of monitoring activities on pesticides in the {The opinions expressed in the following article are entirely those of the authors and do not necessarily represent the views of either The Royal Society of Chemistry the Editor or Editorial Board of JEM Zeneca Agrochemicals or those of the Column Editor.This journal is # The Royal Society of Chemistry 2000 two members of the PEWG. Dr. Andre�e Carter is a Research Development Manager within the UK Agricultural Development Advisory Service (ADAS). She specialises in policy and research issues concerning the environmental fate of pesticides and their impact in the environment. Her current research interests include pesticide contamination of water with respect to diffuse and point sources the environmental impact of sheep dip and the linking of pesticide fate with exposure of non-target organisms. As an independent member of the UK's Advisory Committee on Pesticides for the last nine years she has advised government ministers on scientiÆc and policy matters concerned with the use and regulation of pesticides particularly with respect to soil and water issues.More recently she has been an ad hoc member of the EU's ScientiÆc Committee on Plants to provide expert advice on matters concerned with the environmental fate of plant protection products in the EU. Andre�e Carter is environment to identify gaps and to make recommendations for improvement. The Group was set up following a recommendation from The Working Party on the Incidence of Pesticides in Water (Department of the Environment 1996) who recognised that there were a number of critical deÆciencies in monitoring and research programmes.The Environment Agency also recognised that monitoring should address all potential uses and impacts of pesticidal products. All pesticides used in the UK must be approved for use by the relevant regulatory authority and Pesticides also Chairman of the UK Soil Management Initiative which promotes the adoption of sustainable soil management. Tim Pepper is a database manager also with ADAS and has over twelve years experience of Æeld monitoring for pesticide residues in the aquatic environment and manages the ADAS database of agrochemical leaching information. With a background in hydrology soils and drainage particularly relating to environmental/ pollution issues he has been responsible for the management of a number of UK government and industry funded studies concerned with strategies to reduce pesticide leaching/contamination from agricultural land and is a member of a steering group co-ordinating the UK research effort in this area.Dr Terry Clark Column Editor Zeneca Agrochemicals UK E-mail Terry.Clark@aguk.zeneca.com extensive environmental safety data are required to achieve this. In order to monitor the use of these pesticides their residues in the environment and their potential environmental impact a range of UK organisations carry out a number of detailed surveys and investigations. This surveillance enables an assessment of compliance with regulatory standards to be made and provides information of any potential adverse effects on the environment.This information has never been comprehensively collated to provide an overall assessment of the national situation for 83N J. Environ. Monit. 2000 2 Pesticides aquatic terrestrial and atmospheric systems and the associated uptake or transfer to food and drinking water. Copies of the full report available from alastair.ferguson@environmentagencyu. gov.uk or at Rio House Waterside Drive Aztec West Almondsbury Bristol BS32 4UD UK The use of pesticides and their residues in drinking water food terrestrial aquatic and atmospheric systems and their impact on non-target species are reported. Information from routine statutory and special surveys has been collated where available from published sources from the relevant monitoring organisation.SpeciÆc examples are used to illustrate the range of monitoring activities undertaken but it is acknowledged that this initial report was unable to consider all available material. This report does not include surveillance of pesticide impacts on human health e.g. operator exposure suspected adverse reactions and incidents reported to the Health and Safety Executive (HSE) with the exception of those that directly impact on the environment. The PEWG review has identiÆed that a wide range of monitoring activities are carried out or sponsored by government commercial and voluntary organisations. Examples of very comprehensive well targeted surveillance and associated enforcement actions were identiÆed for speciÆc areas of pesticide use and the associated residues or impact in the environment.However the overview found that a number of monitoring gaps or deÆciencies for pesticide inputs residues and impacts were identiÆed with few instances of duplication or overlap. This report has highlighted that due to the variety of different EU and UK legislation and other initiatives all which may have differing objectives there is no overall integrated approach to the assessment of use residues and impact of pesticides in the environment. Key issues The review has identiÆed a number of key issues relevant to the different monitoring schemes and these are presented for the different surveys of uses residues and impacts of pesticides.Plant protection products Data concerning the use of plant protection products are the most 84N J. Environ. Monit. 2000 2 comprehensive and are widely available. Long-term trends in use show that the weight of active substance applied (in the 10 year period 1986±1996) has decreased by 19% on average for all crops although over the same period there has been a 23% increase in the formulation treated area. This change in usage could be a function of the shift to using lower dose active substances more frequent applications using lower doses and complex tank mixing at reduced rates. Data also illustrate that there have been signiÆcant changes in the type of active substance used.For example organochlorine pesticide use has decreased due to revocation or restriction of use. Organophosphate insecticides have been extensively replaced by synthetic pyrethroids whose use increased fourfold in the period 1986±1996. Isoproturon the cereal herbicide showed an increase in use of 22% by weight during 1986±1996. Trend data illustrate year by year variation in use which is attributable to the inØuence of weather conditions on product use; for example a warm wet spring may causee fungicide use. The British Agrochemical Association (BAA) sales data for 1998 show that the amount of active substances applied in home and garden situations is 1 887 000 kg this being approximately 65% greater than the amount used in amenity situations however this Ægure includes ferrous sulfate which represents 80% of the reported weight of herbicides used.Although it is likely that the active substances used will be the same as some of those used in the agriculture and amenity sectors there is very little published information available about which active substances are applied or how waste and rinsings are disposed of or their fate in the environment. The most recent survey of pesticide usage in amenity situations (Produce studies Ltd. 1996) conÆrms that since the revocation of residual triazine herbicides for this use in 1993 the main herbicides applied are glyphosate and diuron. A signiÆcant deÆciency of the DoE survey report is the lack of information concerning the amount of individual active substances applied.Assessments are conÆned to chemical groups and therefore the impact of each pesticide cannot be determined. Biocidal products The scope of the EC Biocidal Products Directive is very broad and the types of products manufacturers and users are varied. The active substances used in biocidal products may also be used in many other types of products (e.g. plant protection products) and so speciÆc monitoring for effects of biocidal products will be difÆcult. Very little information is available through the regulatory agency HSE or the different industry associations concerning their use and therefore residue and impact assessments cannot easily be made.Data which does exist with the exception of the rodenticide survey are restricted to special one-off investigations which may in some cases no longer be valid. The HSE needs to prioritise its future approach to surveying the use of biocides. Veterinary products There are no data available in the public domain concerning the total amount of veterinary products used or trends in use with the exception of very limited data released from the National OfÆce of Animal Health (NOAH). Both the VeterinaryMedicinesDirectorate(VMD) andNOAHwill respond to speciÆc requests for usage information. Since 1998 tiered environmental risk assessments must be carried out for new active substances but little information concerning their potential pathways into the environment e.g.via manure or washoff is available in the public domain. Information supplied byVMDand NOAHfor sheep dip use indicates that the use of organophosphate products has reduced signiÆcantly during the period 1986±1998. Alternatives include the use of synthetic pyrethroids endectocides or non-dip products. Discharges Whilst sampling and analysis does take place for consented discharges there are limited data available concerning the loading of the pesticide to the environment. Some restricted data sets have been compiled under the requirements of the Oslo and Paris Commission (OSPAR) which use monitoring and modelling approaches to assess loadings from rivers and direct discharges to tidal waters.The signiÆcance of veterinary or biocide residues in animal wastes as discharges is not known. Analytical issues Analytical methods have changed and developed over time and therefore it is difÆcult to determine trends in data without Ærst investigating the analytical methodology used and the limit of detection. Routine methodology for some active substances may not be available and information concerning relevant metabolites is generally not available. Old data are often treated with suspicion as methods may not have been validated or concentrations conÆrmed. Current monitoring programmes may have lower limits of detection than previously used and different programmes may have different limits of detection due to the objectives of the individual programmes.The cost of analyses can restrict the scale and scope of monitoring programmes. Drinking water Installation of additional drinking water treatment processes together with implementation of additional regulatory and voluntary measures has led to continuing improvement in drinking water quality in respect of the number of breaches of the 0.1 mg L-1 standard for individual pesticides in drinking water. Whilst some stewardship incentives have been successful in reducing water contamination the majority of improvements in drinking water quality are not related to changes in pesticide use. Data reported in the aquatic systems section of this report illustrate continued contamination of environmental waters.Costs continue to be incurred by the water companies for pesticide removal in addition to those spent on the original capital investment. The small number of drinking water exceedences reported are mainly restricted to herbicides from the phenyl-urea triazine and phenoxy acid groups. A total of 147 pesticides are monitored in public supplies in England and Wales but since strategies tend to be ``risk based'' and depend on judgements of the likelihood of particular pesticides being used in the supply zone not all companies analyse for all pesticides. The Water Quality (Water Supply) Regulations deÆne pesticides as insecticides fungicides and herbicides. The revised EC Drinking Water Directive (98/83/EC) has a wider deÆnition and when the Directive is implemented into national legislation water companies will need to consider whether further active substances will need to be included in their strategies e.g.products registered under the Biocidal Products. Private water supply data is reported by the Northern Ireland Drinking Water Inspectorate (DWI) (EHS 1997) but is not collated centrally by the Drinking Water Inspectorate (DWI) for England and Wales nor the Water Service Unit of the Scottish Executive. Food The Working Party on Pesticide Residues (WPPR) and the VMD surveys provide very comprehensive information concerning plant protection product and veterinary pesticide residues in food. Trends in residues are difÆcult to establish due to the targeted nature of the sampling programme.However few samples exceed the maximum residue level (MRL) and this is supported by additional information from the food industry. There is no information concerning potential residues of some of the products covered by the EC Biocidal Products Directive e.g. poultry house treatments and any omissions need to be considered. Terrestrial systems The incidents reported by the Wildlife Incident Investigation Scheme (WIIS) are conÆned to those reported by the public the veterinary profession or other interested organisations. Reporting is likely to be biased to larger animals and therefore impacts on smaller species are probably under-recorded whilst several taxa (including plants and aquatic species) are not part of the scheme.Most reported incidents are due to abuse or misuse of pesticides. Incidents are mainly attributable to granular formulations of aldicarb carbofuran bromadialone and alphachloralose. Incidents of poisoning from the use of second generation rodenticides are of concern for several predatory species. Long-term monitoring shows that residues are widely found in barn owls but there is insufÆcient evidence currently available to determine whether this is impacting on population numbers. Long-term monitoring of organochlorines in selected bird species from 1963±1997 indicate a decline in residues of metabolites of DDT and dieldrin. There have been a number of studies concerning the potential impact of pesticides on terrestrial invertebrates but with the exception of the WIIS investigations on bee incidents there is no systematic recording of pesticide residue levels.There are a number of long-running surveys of invertebrates such as the Game Conservancy Trust Sussex study which indicate trends in invertebrate abundance on farmland. Pesticides Little monitoring information is available for assessing the indirect or offtarget effects of pesticides on terrestrial species. Long-term monitoring of farmland bird population has provided valuable insight into the role of farming intensiÆcation in their decline. SpeciÆc studies of grey partridge have provided convincing evidence for the role of indirect effects of pesticides in this species and there is evidence for such effects from autecological studies of other species such as the corn bunting.Numerous studies have been carried out on the effects of pesticides on invertebrates. Such studies have shown variable effects on invertebrate populations but long-term effects on various groups of invertebrates have been shown in one-off studies. Many studies concentrate on the impact of a pesticide but more recently the concept of ``ecologically acceptable concentrations'' has been proposed whereby the population recovery following impact becomes the focus. Monitoring surveys need to consider habitat biodiversity and ecological function to address this.The relevance of collating data on residues in soil or vegetation needs to be considered. No systematic surveys take place to investigate pesticide residues in soils or to determine the community structure and thus health of the soil. Aquatic systems A great deal of monitoring is carried out to determine levels of pesticides in environmental waters sediment and associated biota. Examples of structured monitoring programmes are discussed which have collated extensive data sets. The different monitoring organisations or schemes would beneÆt from liaison to improve the information obtained and its interpretation. For example water quality monitoring for pesticides is not currently co-ordinated with sites where aquatic organisms are monitored.The pesticides which cause exceedances of 0.1 mg L21 in surface and ground waters in England and Wales are mainly the herbicides isoproturon mecoprop diuron and MCPA. Other exceedances include the biocide PCSD/ eulan a moth prooÆng agent and cypermethrin and diazinon which are both used in sheep dip. The number of exceedances of 0.1 mg L21 indicate that contamination of surface waters does occur and where this water serves as a supply for drinking water the pesticides present must be removed by treatment 85N J. Environ. Monit. 2000 2 Pesticides processes. Pesticides which most frequently exceed Environmental Quality Standards (EQSs) originate mainly from the use and disposal of sheep dip and discharges from the textile industry i.e.permethrin cypermethrin diazinon cyØuthrin and propetamphos. Trend data from the harmonised monitoring sites in England and Wales indicate that the number of detections of isoproturon and cypermethrin have increased in line with their increased usage whereas detections of atrazine and simazine whose use in amenity situations was fully revoked in 1993 have signiÆcantly decreased. Notable reductions in the concentrations of other revoked or restricted pesticides in waters such as dieldrin DDT and lindane have also been observed. In Scotland and N. Ireland monitoring surveys have detected few pesticides in surface water and none of those monitored have exceeded any EQS. Groundwater concentrations are generally low in England and Wales but have not been monitored in Scotland or N.Ireland though there are plans to do so in the future. Herbicides were also prominent in samples taken from marine waters but diuron may also be used as an antifouling paint therefore its pathway to water may also be direct. TBT is the pesticide that most frequently exceeds its EQS but levels in some places are showing declines where the impact of revocation for use on small vessels is evident. Monitoring of certain species and diversity has shown some recovery which have been attributed to reductions in TBT levels. Surveys show that despite the reduction of pesticides like dieldrin and DDT in environmental waters they continue to be detected in sediment and biota indicating their continued persistance in some environmental compartments.The surveys of residues and impacts on aquatic species appear to have been prioritised according to known environmental problems but this potentially excludes many species and active substances. Most surveys have been concerned with monitoring impact. Consideration needs to be given to the monitoring of population recovery or determining whether the concept of ecologically acceptable concentrations of a pesticide can be supported. Atmospheric systems The review of pesticides in air and rainfall found limited information partly 86N J. Environ. Monit. 2000 2 because of the availability of analytical techniques. The scale of the problem is therefore difÆcult to quantify.In agricultural ecosystems impacts of pesticides via aerial deposition are negligible compared with that from their direct agricultural application. There are no data available to determine whether sensitive non-target plants or ecosystems might be affected. No assessments have been made for biocides or veterinary products. The current approvals system for agricultural pesticides only determines the likelihood of contamination and may determine the proportion of applied active substance lost to the atmosphere but it does not consider overall loadings of pesticides to air. From pesticide usage patterns and physico-chemical properties modelling techniques could be employed to predict which pesticides might occur in air and rainwater.Recommendations Inputs Plant protection products The relevant government departments should re-survey the amenity sector and include the use and disposal of home and garden products in order to assist in determining their potential impact on the environment. The relevant government departments should survey the products and active substances used in forestry in order to assist in determining their potential impact on the environment with particular reference to environmental fate pathways of contamination and disposal routes. Biocidal products The implementation of the Biocidal Products Regulations in the UK in 2000 requires that monitoring of inputs is carried out and therefore this deÆciency in data collection must be urgently addressed.Commodities should be prioritised with respect to their use and their potential environmental impact. Information concerning their mode of use fate and subsequent distribution in the environment is also required under the regulations. HSE should take the lead role in compiling the required information in conjunction with other relevant organisations. Veterinary products VMD should make available to those carrying out environmental monitoring programmes data on sales of veterinary pesticides and information they hold on where and when such products are used. Subject to the protection of conÆdentially sensitive material VMD should also provide data on the environmental impact of such products which have been provided by manufacturers in support of applications for marketing authorisations.Such information includes data on the fate and behaviour of active ingredients and their subsequent distribution in the environment. PEWG should explore avenues for collecting further data on the usage of veterinary medicines. Discharges Existing data on the monitoring of discharges and receiving waters should be reviewed by the relevant environment agencies and recommendations made as to whether sufÆcient information is available to determine loadings to the environment and potential toxicity. Recommendations Residues and impacts Drinking water The DWI and the Scottish Executive should consider the beneÆts and practicality of collating data on pesticides in private water supplies in England and Wales.Food Pesticides Safety Directorate (PSD) and VMD should consider whether the implementation of the biocides regulations requires that additional active substances be monitored. Terrestrial systems PEWG should carry out an investigation to prioritise which terrestrial biota should be investigated in order that a baseline of residue levels and their impact of pesticides can be established. Characterisation of residues in soil and vegetation is not considered to be a priority area. However it is recommended that PEWG reviews the existing data on residues in relation to priority habitats and species under the biodiversity action plan and evaluates them in the context of population dynamics and recovery.Aquatic systems PEWG should investigate which aquatic biota should be prioritised considering the variability in response the need for further information on habitat population dynamics and recovery. Environment agencies and other relevant organisations should include assessments of the impacts of pesticides on aquatic organisms. PEWG should carry out an integrated review of aquatic systems which links all monitoring data with information on biological effects. Atmospheric systems Relevant government departments should carry out a desk study to determine priority substances and then a survey of wet and dry deposition which employs current standards of analytical expertise and a wider range of active substances.Data should be interpreted with respect to impact on sensitive habitats. General points PEWG should seek to establish a mechanism for improving the availability of regulatory assessments and monitoring data and analytical methodologies (within the limits of conÆdentiality) between the different regulatory agencies and within the public domain. All monitoring organisations should review the substances monitored to ensure that they include appropriate relevant metabolites. Examples of the trends in pesticide use residues and impacts in the environment have been presented in this report. PEWG should consider whether more detailed interpretations of the existing survey data should be carried out particularly with respect to integrating data from different surveys in order to determine future priorities for monitoring of use residues and impacts.PEWG should develop a general framework using collated information and modelling to provide predictions of the fate residue and impact of pesticides in order to identify environmental compartments of concern and susceptible organisms to assist the prioritisation process. The implications of undertaking such an approach would require further investigation of the cost resources and possible time-scale. PEWG should determine whether the Pesticides monitoring surveys could include a wider remit such as assessment of offtarget impacts or the indirect effects of pesticide use waste minimisation techniques adopted adoption of best practices. PEWG should consider opportunities for using the resources and infrastructure of existing usage survey programmes to obtain information on the use of other pesticides or activities. National surveillance of pesticide residues and their impact may not be appropriate in all cases. PEWG should consider the establishment of intensively monitored representative locations where the most important processes biodiversity ecology of species of concern and impacts can be monitored. This approach could be considered in the context of the requirements of the proposed Water Framework Directive where a catchment is identiÆed as the fundamental management unit. Tim Pepper and Andre�e Carter ADAS Gleadthorpe Research MansÆeld UK 87N J. Environ. Monit. 2000