Pesticide indicators

INDICATORS PESTICIDE INDICATORS Vincent Van Bol1, Sara Claeys2, Philippe Debongnie1, Jordan Godfriaux3, Luc Pussemier1, Walter Steurbaut2 and Henri Maraite3 describe the development of indicators for use by public authorities in their pesticide assessment with a view to reductions in such use Introduction In its communication No. 349 (1 July 2002), the European Commission put forward a proposal for a thematic strategy on the sustainable use of pesticides. The proposal focuses on reducing the risk associated with pesticide use and the amounts used. It was expected that a decrease in pesticide use will reduce the risk to human health and the environment. Numerous indicators reflect pesticides characteristics, including chemical and physical properties, toxicological effects, hazard categories, effectiveness, importance in use, etc. Among the available indicators, a major distinction is to be made between two different types : ● ● Pesticide Use Indicators (PUIs): total amounts of pesticide used or total number of sprayings ; Pesticide Risk Indicators (PRIs): a combination of hazard and exposure characteristics for one or several environmental compartments (e.g. farm worker, air, birds, earthworms) that are assessed separately. About 100 different indicators have been developed untill now (Van Bol et al., 2002). Pesticide Use Indicators (PUIs) The first indicators used by public authorities were PUIs, where the annual sales of pesticides give an indication of the amount of chemicals released into the environment (Table 1). However, a PUI based only on sales data does not Table 1: Pesticide use indicators used by public authorities Use indicators Country Survey period OECD pesticide use indicator (OECD, 1999) Frequency of application (Gravesen, 2000) Hectare doses OECD 1985– Denmark, Sweden 1986– Denmark, Sweden 1991– Veterinary and Agrochemical Research Centre. FPS Health, Food Chain Safety and Environment. Leuvensesteenweg, 17. B-3080 Tervuren. Website: http://www.var.fgov.be/index.php 2 Crop Protection Chemistry Laboratory, Faculty of Agricultural and Applied Biological Sciences, Ghent University, Coupure links 1 DOI: 10.1039/b308507b distinguish between high-toxicity and low-toxicity pesticides. It gives an undue weight to relatively harmless herbicides (e.g., glyphosate), compared with highly toxic insecticides (e.g., some carbamate or organophosphorous insecticides). In theory, annual sales comparisons could be correlated to the risk for humans and the environment if there are no important modifications in either the pesticide characteristics or the exposed environment. The environment will probably not change significantly over the next decade, but the pesticide characteristics certainly will, as a result both of scientific progress and of the re-registration process imposed by the EU Directive 91/414. Even if it can be assumed that the future pesticide use will be based on less toxic and more selective active substances, this does not necessary imply that the amount required to control pests will be reduced. In order to better control pesticide use, Danish authorities have developed the concept of Frequency of Application (FA) (Gravesen, 2000), also known as Pesticide Treatment Frequency (PTF), Treatment Frequency (TF) or Treatment Frequency Index (TFI). This indicator is regarded as an indicator of the spraying intensity as well as an overall indicator of the environmental impact of pesticides. It is assumed that there is a link between dose rates (and therefore the effects on target organisms) and the effects on non-target organisms, but this is not always true. These facts are illustrated in Table 2, where the potencies and toxicities of 15 active substances are compared (a low dose rate implies a high potency, just as a low MPC, LD50 or LC50 value means a high toxicity). In general, fungicides and herbicides are, as could be expected, much less toxic than insecticides. Even within each of these categories, increased potency does not necessarily mean increased risk for non-targets (for example, compare the insecticide pirimicarb with esfenvalerate, much more potent but much less toxic for non-target organisms). The FA approach therefore leads to a misinterpretaion of the situation by considering the unwanted side-effect of any two treatments as equivalent, whatever the nature and toxicity of the a.s. used. In order to compare all these 15 a.s. at a glance, we have plotted their relative potencies and toxicities (Figure 1) (the 653, B-9000 Ghent. Website: http://allserv.ugent.be/~hvanbost/labo/index.htm 3 Phytopathology Unit, Catholic University of Louvain, Croix du Sud, 2 bte 3, B-1348 Louvain-la-Neuve. Website: http://www.fymy.ucl.ac.be Pe s t i c i d e O u t l o o k – A u g u s t 2 0 0 3 This journal is © The Royal Society of Chemistry 2003 159 INDICATORS Table 2: Recommended rate of application and toxicity data for 15 active substances used in European agriculture Active substance Dose rate g.ha-1 Aquatic Mammals organisms (MPC) (LD50 oral) mg.l-1 mg.kg-1 Birds (LD50) mg.kg-1 Bees (LD50) µg.bee-1 Earthworms (LC50) mg.kg soil-1 Fungicides epoxiconazole kresoxim-methyl tolylfluanid chlorothalonil mancozeb 125 125 750 1500 1500 1.0E-03 3.0E-04 5.0E-05 7.0E-05 1.6E-04 5000 5000 250 1000 3420 2000 2150 5000 4640 700 100 20 43 181 193 1000 937 1780 1000 455 Herbicides rimsulfuron metribuzin MCPA isoproturon glyphosate 13 750 800 1500 2200 6.3E-02 3.6E-05 1.0E+00 3.2E-04 1.3E-01 5000 250 650 2000 2000 2000 168 377 3042 2000 100 35 100 50 100 1000 332 234 1000 360 Insecticides esfenvalerate imidacloprid diflubenzuron dimethoate pirimicarb 5 60 100 200 400 1.0E-06 3.6E-02 8.0E-07 3.2E-03 3.8E-04 89 131 4640 30 25 381 31 2000 15 8 0.02 0.0037 30 0.12 51 11 11 367 18 60 Note: active substances, recommended dosage and aquatic organisms MPC (Maximum Permissible Concentration) were obtained from the CAPER database (Reus et al., 1999). Mammals toxicity was based on AGRITOX (Mercier, 2001). Toxicity parameters for birds, bees and earthworms were obtained from the POCER-1 database (Vercruysse and Steurbaut, 2002). Lowest values (i.e. highest potencies and toxicities) are indicated in bold. relative potency of a.s. “i” was defined as dose rate esfen/ dose rate i , and the relative toxicity of “i” e.g.for mammals was define as LD50 pirimicarb /LD50 i ). The FA assumption that the effects on target and non-target organisms are proportional to each other would be verified only if there was a clear positive correlation between potency and toxicity, and this is obviously not the case. In addition, the objective of reducing pesticide use in terms of risk to humans and the environment can not be assessed by the former indicators in the following situations: valerate 1 comparison of regions where the pesticides dosage is different due to different registration status ; 2 comparison of regions where the pesticides use pattern is different because the major crops differ ; 3 comparison of regions where the major crops are similar but where the environment is not comparable in terms of sensitivity to pesticides ; 4 when, for socio-economic reasons, pesticides are stockpiled by end-users. Figure 1. Toxicity parameters of a selection of 15 active substanecs: target effect vs. non-target effect 160 Pe s t i c i d e O u t l o o k – A u g u s t 2 0 0 3 Hence PUIs are inappropriate for assessing risk reduction, mainly because the recommended dose does not correlate with the (eco)toxicity profiles of the active substances. PUIs are also inappropriate for risk comparisons between countries and regions where the environment and/or the use pattern are not similar. Inter-annual comparisons of pesticide use in a same region can produce some gross information on the risk evolution provided that there is no INDICATORS Table 3: Pesticide risk indicators used by public authorities Risk indicator Level of complexity Country Survey period Acute Aquatic Risk Index – NL (Luttik, 2000) Acute Toxicity Equivalent (Ekstrom et al., 1996) Acute Toxicity Persistence Units (Barnard, 2000) Chronic Toxicity Persistence Units (Barnard, 2000) Collective Health Risk Indicator (Spikkerud, 2000) Swedish Environmental Risk Indicator (Ekstrom et al., 1996) Swedish Human Health Risk Indicator (Ekstrom et al., 1996) Collective Environmental Risk Indicator (Spikkerud, 2000) Index of Load (Gravesen, 2000) POCER-1 (Vercruysse and Steurbaut, 2002) SYNOPS-1 (Gutsche and Rossberg, 1999) * * * * * * * ** ** *** *** The Netherlands Sweden USA USA Norway Sweden Sweden Norway Denmark Belgium Germany 1984– 1981–1985, 1991–1995 1964, 1966, 1971, 1992 1964, 1966, 1971, 1992 1990–1994, 1998– 1986–2001 1986–2001 1990–1994, 1998– 1986– 2002 1987, 1995 Note:. complexity range is defined by the function of the number of parameters required for the calculation, ≤ 5, 6-20, ≥ 21 is represented by *, **, ***, respectively. major modification in the environment or in the pesticides characteristics. This situation is not likely to occur in Europe over the next decade due to the rapid changes in the list of authorized a.s. Pesticide Risk Indicators (PRIs) Numerous risk indicators have been developed throughout the world. Eleven of the most commonly used PRIs are listed in Table 3, ranked by order of complexity. Indicators increase considerably in complexity when the risk assessment is applied to multiple environmental compartments in multiple contexts and with multiple pesticide applications. The number of required parameters then may be so large that it becomes difficult to manage them all. This is the reason why risk assessment at global level is usually based on assessement of a limited number of “representative” compartments that vary in function of the environmental context, for example: Non-target animal impacts ● ● ● ● ● ● Acute Aquatic Risk Index (Netherlands) – fish, crustaceans and algae Acute Toxicity Equivalent (Sweden) – honeybees, fish, crustaceans, algae and earthworms Index of Load (Denmark) – mammals, birds, earthworms, fish, crustaceans and algae SYNOPS-1 (Germany) – earthworms, algae, crustaceans and fish Collective Environmental Risk Indicator (Norway) – earthworms, honeybees, birds, fish, crustaceans and algae POCER-1 (Belgium) – fish, crustaceans, algae, birds, bees and beneficial arthropods Human impacts ● ● Acute Toxicity Equivalent (Sweden) – Risk phrases on product labels (that concern de facto the pesticide applicators, the farm workers and the bystanders) Acute/Chronic Toxicity Persistence Units (USA) – mammal toxicity parameters multiplied by a safety factor PRIs complexity is also linked to the way the risk is aggregated from a particular to a general context both in term of time scale than in term of surface scale. Aggregation procedures vary from a single sum of risks to very sophisticated GIS approach coupled with fugacity model including degradation kinetic of pesticides. An idea of the range of complexities involved is given by the comparison of the relatively simple indicator ATE with the more complex SYNOPS-1. ● ATE : Acute Toxicity Equivalent (Ekstrom et al., 1996) SQi SQ = sold quantity, ————————— Σ i = summ over i a.s. LD 50 oral mam.i i SYNOPS-1 : SYNOPtisches Bewertungsmodell für PlanzenSchutzmittel (Gutsche and Rossberg, 1999) Graphical representation of short- and long-term risk for earthworms, algae, crustaceans and fish Short term PRI = ABR for each taxa; ABR: Acute Biological Risk index = Exp/Tox Exp = PECst: PEC short term for soil : PECst = VDTsoil . AR .d for surface water : PECst = VDTdrift . AR . d VDTdrift: Value from Distribution Table (%) according to the crop and its growth stage AR: Applied Rate d: dilution factor depending the context Tox = LC50 Long-term PRI are obtained from calculations based on exposure diminution related to DT50 and long-term toxicity values (NOEC, NOEL, etc.) For an assessment at national level, SYNOPS-1 values are weighted by the application probability and the national sales data 1000* ● Σ The challenge for a good pesticide risk assessment is to work with indicators that are “easy” to calculate with a small number parameters and precise enough to obtain Pe s t i c i d e O u t l o o k – A u g u s t 2 0 0 3 161 INDICATORS information on the risk to human health and the environment. The input data required by ATE are relatively easy to obtain, but critical differencies between use patterns and envirenmental fates of different a.s. are overlooked. SYNOPS-1 takes more account of theses aspects, but requires far more input data which increases the difficulties and uncertainties. This has proved a real problem, for example, in the case of the Danish “Index of Load” and the Norwegian “Collective Environmental Risk Indicator”. Proposal for an adequate pesticide risk outlook Obviously the adequacy of a PRI for a global assessment increases in proportion to the reduction of its adequacy for a specific assessment. Consequently, for a pesticide risk assessment at regional level, it could be interesting to work with both a “global” indicator, for the over-all impact, and a “specific” indicator for the most relevant combinations of a.s., use pattern, and environmental compartment. The “global” indicator would have the following characteristics: ● ● ● it would include parameters only on the amount of active substances used (based on active substances sales), persistence and chronic toxicity (e.g., the American CTPU or the Belgian SEQglobal (Spread EQuivalent) (De Smet and Steurbaut, 2002); it would be used at regional level for inter-annual and inter-regional comparisons, mainly for policy purposes ; precautions would be taken to avoid using this indicator at local level (farm, field), as is unfortunately the case for the FA indicator in Denmark. The “specific” indicator would have the following characteristics: ● ● ● it would be based on several (10–15) pesticide risk indicators specific for particular aspects (farm worker risk, consumer risk, water organisms, resistance induction of target organisms, etc.), as in the case of the Danish IL, the Norwegian CERI or the Belgian POCER-1 indicators ; risk assessment of the particular aspects should be aggregated in a traceable procedure in order to determine the implications for human health, farmer interest and environment, as in the case of POCER-2 developed in Belgium (Maraite, 2002) ; it would be used mainly at farm or field level to support any IPM improvement for sustainable development or quality label evaluation purposes. Of course, one of the problems encountered in the use of all pesticide indicators is the large number of pesticide active substances and the even larger number of pesticide formulations. It is anticipated that these numbers will be significantly reduced by the on-going re-registration process in the framework of EU Directive 91/414. 162 Pe s t i c i d e O u t l o o k – A u g u s t 2 0 0 3 Acknowledgement This paper was produced within the framework of a research project financed by the Belgian Science Policy Office (Research Contract No. CP-AA-20). References Barnard, C. 2000. OECD Survey of National Pesticide Risk Indicators, 1999–2000 / USA. Washington, USA: Economic Research Service USDA. De Smet, B., and W. Steurbaut. 2002. Verfijning van de SEQindicator voor de evaluatie van het bestrijdingsmiddelengebruik in Vlanderen. Gent: Universiteit Gent. Ekstrom, G., H. Hemming, and M. Palmborg. 1996. Swedish pesticide risk reduction 1981-1995: food residues, health hazard, and reported poisonings. Reviews of Environmental Contamination & Toxicology, 147, 119-139. Gravesen, L. 2000. OECD Survey of National Pesticide Risk Indicators, 1999-2000 / Denmark. Copenhagen, DK: Danish Environmental Protection Agency. Gutsche, V., and D. Rossberg. 1999. Synoptisches Bewertungsmodell für Planzenschutzmittel (SYNOPS). In Comparing environmental risk indicators for pesticides, edited by J. Reus, P. Leendertse, C. Bockstaller, I. Fomsgaard, V. Gutsche, K. Lewis, C. Nilsson, L. Pussemier, M. Trevisan, H. van der Werf, F. Alfarroba, S. Blümel, J. Isart, D. McGrath and T. Seppälä. Utrecht, The Netherlands: CLM. Luttik, R. 2000. OECD Survey of National Pesticide Risk Indicators, 1999-2000 / The Netherlands. Bilthoven, NL: Centre for Substances and Risk Assessment. Maraite, H. 2002. Development of awareness tools for a sustainable use of pesticides. Paper read at Stakeholders Conference on the Development of Thematic Strategy on Sustainable Use of Pesticides, November 4, 2002, at Brussels. Mercier, T. 2002. AGRITOX [Database]. INRA, 2002 October,14 2001 [cited 2002]. Available from http://www.inra.fr/agritox/listesa/listesa.html. OECD. 1999. Environmental indicators for agriculture : methods and results - The stocktaking report. Pesticide use and Risk. Paris: OECD, OCDE. Reus, J., P. Leendertse, C. Bockstaller, I. Fomsgaard, V. Gutsche, K. Lewis, C. Nilsson, L. Pussemier, M. Trevisan, H. van der Werf, F. Alfarroba, S. Blümel, J. Isart, D. McGrath, and T Sepälä. 1999. Comparing environmental risk indicators for pesticides. Utrecht, The Netherlands: Centre for Agriculture & Environment (CLM). Reus, J., P. Leendertse, C. Bockstaller, I. Fomsgaard, V. Gutsche, K. Lewis, C. Nilsson, L. Pussemier, M. Trevisan, H. van der Werf, F. Alfarroba, S. Blümel, J. Isart, D. McGrath, and T. Seppälä. 2002. Comparison and evaluation of eight pesticide environmental risk indicators developed in Europe and recommendations for future use. Agriculture, Ecosystems & Environment 90(2),177–187. Spikkerud, E. 2000. OECD Survey of National Pesticide Risk Indicators, 1999-2000 / Norway. Aas, Norway: Norwegian Agricultural Inspection Service. Van Bol, V., Ph. Debongnie, L Pussemier, H. Maraite, and W. Steurbaut. 2002. Study and Analysis of Existing Pesticide Risk Indicators. Tervuren: Veterinary and Agrochemical Research Center (VAR). Vercruysse, F., and W. Steurbaut. 2002. POCER, the pesticide occupational and environmental risk indicator. Crop Protection, 21(4),307–315. INDICATORS The authors of the article are engaged in a research at the Belgian level aiming to develop a pesticide risk indicator to help public authorities, extensionists and farmers to manage the pesticide use in a more sustainable manner. working on the development of crop protection strategies aiming to high quality and yield while respecting the environment. He is the chairman of “Comité regional PHYTO”, a service of the Walloon region for advice on environmental responsible use of pesticides. Dr Vincent Van Bol, Dr Philippe Debongnie and Dr Luc Pussemier (Head of the Department of Quality and Safety) work at the Veterinary and Agrochemical Research centre (VAR) on various pesticide topics such as environmental fate, residue analyses, indicators. Concerning this last aspect, it worth to mention the participation of VAR to the CAPER European research (Reus et al., 2002) with SyPEP (System for Predicting the Environmental impact of Pesticides) and the development of the SEPTWA model (System for the Evaluation of Pesticides Transport to Surface Waters). Ir Jordan Godfriaux (Agronomist) is a researcher at the UCL Phytopathology Unit. He is currently president of the “Fédération des Jeunes Agriculteurs” in Belgium. Prof Dr Henri Maraite, head of the Phytopathology Unit at Université catholique de Louvain (UCL) since 1985, supervises research teams Prof Dr Walter Steurbaut, head of the Faculty of Agricultural and Applied Biological Sciences, Department of Crop Protection at Ghent University supervises studies on pesticide residues, formulation techniques and environmental impact assessment. Ir. Sara Claeys is working as researcher in this Department. She is BioEngineer in Environmental Technology (Ghent University, 2002). She is engaged on PhD-thesis on the pesticide impact on environment. Green Chemistry An Introductory Text by m lancaster University of York, UK -- The challenge for today’s new chemistry graduates is to meet society’s demand for new products that have increased benefits, but without detrimental effects on the environment. Green Chemistry: An Introductory Text outlines the basic concepts of the subject in simple language, looking at the role of catalysts and solvents, waste minimisation, feedstocks, green metrics and the design of safer, more efficient, processes. The inclusion of industrially relevant examples throughout demonstrates the importance of green chemistry in many industry sectors. Intended primarily for use by students and lecturers, this book will also appeal to industrial chemists, engineers, managers or anyone wishing to know more about green chemistry. Softcover |  | viii +  pages |      | £. RSC members’ price £. advancing the chemical sciences Orders & further details Sales  Customer Care Dept Royal Society of Chemistry · Thomas Graham House Science Park · Milton Road · Cambridge ·   ·  t +()  · f +()  · e [email protected] Or visit our websites: www.rsc.org and www.chemsoc.org Registered Charity No.  Pe s t i c i d e O u t l o o k – A u g u s t 2 0 0 3 163