CTHS0306
Future Environmental Effects of Non-Synthetic Chemical Use
CTHS0306
Report to the Horizon Scanning Programme Manager,
Defra - Science Advice and Liaison Team,
Cromwell House, Dean Stanley Street,
London SW1P 3JH
Project Leader: Dr Helen Thompson, CSL, Sand Hutton, York YO41 1LZ, UK
Tel 01904 462515, Fax 01904 462240, email
Authors:
Helen Thompson and Richard Watkins
CSL
Sand Hutton
York, YO41 1LZ
Laura Mongan, Ed Stutt, Alex Capleton, Philip Holmes and Paul Harrison
MRC Institute for Environment and Health
University of Leicester
94 Regent Road
Leicester, LE1 7DD
Alastair Boxall and Chris Sinclair
Cranfield Centre for EcoChemistry
Cranfield University
Silsoe
Beds MK45 4DT
Christopher Stopes
EcoS
Wood End
Garden Close Lane
Newbury
Berks RG14 6PP
31 July 2004
Contents
Contents 2
Executive Summary 6
1. Introduction 9
1.1 Complementary and alternative medicines (CAMs) 10
1.2 Pesticides and biocides 11
1.2.1 Semiochemicals 12
1.2.2 Antifeedants / feeding deterrents 12
1.2.3 Plant extracts (Botanicals) 12
1.2.4 Commodity chemicals 13
2. Methods 15
2.1 Complementary and Alternative Medicines 15
2.1.1 Identification of CAMs 15
2.1.2 Identification of additional data 16
2.1.3 Selection of CAMs of concern 18
2.1.4 Identification of the nature of use and dosimetry of CAMs in the UK 18
2.1.5 Identification of synthetic pharmaceuticals 18
2.1.6 ‘Case Studies’ 18
2.2 Pesticides and Biocides 19
2.2.1 Identification of pesticides and biocides 19
2.2.2 Identification of additional data 19
2.2.3 Selection of pesticides/biocides of concern 19
2.2.4 Identification of the uses of non-synthetic pesticides and biocides in the UK 19
2.2.5 Identification of synthetic pesticide equivalents 20
2.2.6 Case studies 20
2.3 Prediction of properties and effects 20
2.3.1 Prediction of Physico-chemical Properties 20
2.3.2 Prediction of persistence 20
2.3.3 Prediction of ecotoxicity 20
3. Results 23
3.1 Complementary and Alternative Medicines 23
3.1.1 Identification of CAMs 23
3.1.2 Selection of CAMs of concern 34
3.1.3 Synthetic pharmaceuticals 36
3.2 Pesticides and Biocides 37
3.2.1 Identification of non-synthetic pesticides and biocides 37
3.2.2. Selection of pesticides/biocides of concern 42
3.3 Filling data gaps 49
3.3.1 Data manipulation and assessment of predictions 49
3.3.2 Hazard characteristics of non-synthetic substances 50
3.3.3 Conclusion from predictive modelling work 52
3.4 Case studies of CAMs 53
3.4.1 Estimated future pattern of human use of herbal products in the UK 53
3.4.2 Estimated future pattern of human and veterinary use of essential oils in the UK 53
3.4.3 Environmental risk assessment of priority substances 55
3.4.4 Predicted no-effect concentrations and risk characterisation 58
3.5 Case studies on pesticides/biocides 70
3.5.1 Estimated future patterns of use of non-synthetics pesticides and biocides in the UK 70
3.5.2.Environmental risk assessment of priority substances 79
4 Stakeholder opinions 83
4.1. Scenarios 83
4.2 Risk assessment 85
4.3. Regulatory 86
5. Discussion 91
5.1 CAMs 91
5.2 Pesticides/biocides 93
5.3 Filling the data gaps 95
5.4 Future requirements 95
Usage data 95
Risk assessment 96
Improved understanding 97
Improved communication 97
6. Conclusions 99
7. Future work examples 101
Design of a database for collated data on non-synthetic CAMs and pesticides/biocides 101
Assessment of the potential of indirect effects on the ecosystem due to use of pheromone fogging, e.g. effects of mating disrupting pheromones. 101
Usage of the non-synthetic chemicals, particularly the CAMs but also “plant strengtheners”, both regulated and unregulated. 101
Current and future environmental impacts of essential oils 101
8. References 104
Tables and Figures
Table 1.1. Commercial and developmental status of non-synthetic chemical control strategies in the UK. Categories of development are ‘commercial’ – i.e. registered for use, ‘near market’ i.e. registration being sought (after ACP 2003) 14
Table 2.1 Summary of QSARs used in the current study to determine the ecotoxicity of the non-synthetic chemicals. The n value is the number of substances used to generate the relationship and the r2 value is the correlation coefficient for the relationship (this is only indicative where n<10). 22
Table 3.1: CAMs identified through various search strategies 23
Table 3.2: Availability of information on Herbal medicines and selected ‘active ingredients’ 25
Table 3.3: Availability of information on Essential Oils 28
Table 3.4: Uses, dosimetry and corresponding conventional pharmaceutical for Herbal medicines (for a glossary of terms see Appendix 1.5) 30
Table 3.5: Uses, dosimetry and corresponding conventional pharmaceuticals for Essential Oils 33
Table 3.6 Estimated annual usage of herbal products in the UK. 35
Table 3.7: Priority list for first round of predictive analysis 36
Table 3.8. Natural organic pesticides and biocides identified 38
Table 3.9. Natural inorganic pesticides and biocides identified 38
Table 3.10 Summary of data available for non-synthetic pesticides and biocides (x- data available) 39
Table 3.11 Availability of Substances permitted for plant protection in organic production in the EU 43
Table 3.12: Notifications by member states under 4th stage Review of EU Pesticides Directive (91/414) of substances permitted for use in the EU Organic Regulation (2092/91). Adapted from SANCO (2003). 46
Table 3.17 Classification approach used to classify substances based on their predicted data 49
Figure 3.1 Results of the comparison of prediction-based hazard classifications with experimentally based classification for non-synthetic pesticides and medicines (Toxicity (I) comparison of classification to class non-toxic, harmful, toxic or very toxic; Toxicity (II) comparison to combined classes non-toxic/harmful and toxic/very toxic). 50
Figure 3.2 Hazard classifications for the CAMs (PBT- persistent, bioaccumulative and toxic, PPBT potentially persistent, bioaccumulative and toxic) 51
Figure 3.3 Hazard classifications for the non-synthetic pesticides (open bars) and corresponding synthetic pesticides (cross-hatched bars). (PBT- persistent, bioaccumulative and toxic, PNT –practically non-toxic) 51
Table 3.18 Summary of projected use of herbal medicines in the UK 53
Table 3.19 Summary of projected (10 years) usage of essential oils in the UK 55
Table 3.20 Concentrations of ‘active ingredients’ and other major components in CAMs for human use 56
Table 3.21 Survey of herbal medicine usage of pre-operative patients in the UK 58
Table 3.22 Usage scenarios used in the exposure modelling for CAMs and essential oils in human use. 60
Table 3.23 Predicted concentrations (ng/L), predicted no-effect concentrations (ng/L) and risk characterisation ratios for active ingredients and major constituents of priority CAMs in surface waters 61
Table 3.24 Doses of CAMs used in veterinary medicines 64
Table 3.25 Concentrations of active ingredients and other major constituents in CAMs used in veterinary medicine 64
Table 3.26 Maximum stocking densities for animals at pasture (taken from Montforts, 1997) 66
Table 3.27 Predicted concentrations and predicted no-effect concentrations and aquatic risk characterisation ratios for active substances and major constituents of veterinary CAMs used to treat horses, cattle and sheep 67
Table 3.28 Pests and diseases on organic crops where non-synthetic chemical control methods might provide control 71
Figure 3.4 Increase in area of land in organic production or under conversion 1997-2002. 72
Table 3.29: Organic land use in England - 2002, % organic and conventional in England and UK 72
Table 3.30: Area of organic fruit and vegetable crops in England - April 2002 74
Figure 3.5 Insecticide use on top fruit and hops 75
Figure 3.6 Classes of pesticide used on top fruit and hops in 2002. 76
Figure 3.7 Fungicide use on top fruit and hops 77
Figure 3.8 Classes of fungicide used on top fruit and hops in 2002 77
Figure 3.9 Fungicide usage on potatoes 78
Table 3.31 Insecticide and fungicide usage on top fruit and hops and fungicide usage on potatoes in 2002 79
Table 3.32 Synthetic insecticide and fungicide usage and effect of increasing non-synthetic usage 80
Table 3.33 Information used in the modelling for the priority non-synthetic pesticides 81
Table 3.34 Information used in the modelling for the major usage synthetic substances 81
Table 3.35 PNECs for non-synthetic pesticides and their synthetic equivalents 82
Executive Summary
1. This work was undertaken as part of a larger project funded under the Environmental Constraints Theme of Defra’s Horizon Scanning Programme. For the purpose of this project, non-synthetic chemicals were defined as those that are naturally available either as unmodified natural products, chemicals extracted from natural materials, commercially produced “nature-identicals” or the product of simple inorganic chemistry. This project did not address the indirect effects of land use changes in relation to the production of chemicals or the impact of production processes.
2. Changes in patterns of use of synthetic and non-synthetic chemicals may cause detrimental effects in the environment, and possibly man. As with synthetic substances, non-synthetic chemicals can enter the environment through different routes; following application to crops or livestock for pest and disease control; disposal of waste products and packaging; excretion (both human and animal) and disposal via the sewerage system. Many non-synthetic chemicals, owing to their historical use, have not undergone a standard risk assessment to current protocols. Thus, there is uncertainty over the possible threat to human and environmental health. This project investigated the potential environmental effects of changing use patterns for two major applications: Non-synthetics as complementary & alternative medicines and as pesticides and biocides.
3. Complementary and alternative medicines (CAMs): During the past several decades the use of alternative and complementary medicines has increased in westernised countries. Indeed, millions of Europeans and Americans have sought ‘natural’ remedies for self-medication. The reasons for this are many; there is a perception that ‘natural’ substances are synonymous with health and safety; faith in natural remedies; belief in a holistic approach to health. CAMs can include treatments for microbial and parasitic infections as well as chronic illnesses caused by physiological changes such as the menopause (e.g. osteoporosis). CAMs are also used as replacements for veterinary products in conventional animal medicine e.g. see the NOAH compendium (NOAH, 2004).
4. Pesticides and biocides: There has been a movement towards the use of natural products in horticulture and agriculture for pest control and as biocides. Such natural or non-synthetic chemical pesticides can be divided by source: those extracted or derived from natural sources such as plants (e.g. pyrethrum, azadirachtin and nicotine), animals (e.g. semiochemicals from insects) and bacteria or fungi (e.g. Spinosad); those that are simple mineral products or the product of simple inorganic chemical reactions (e.g. sulphur, copper sulphate).
5. The purpose of this project was to identify and rank those non-synthetic substances that could potentially pose an environmental hazard once they are released through intended use or careless disposal. In addition, future scenarios for the use of a selected sub-set of priority chemicals have been identified, based on incremental changes in usage and radical replacement of currently-used classes of synthetics. These tasks were achieved through a review of published literature, predictive modelling, review of the current legislation and a workshop held with stakeholders (lobby-groups, industry and regulatory authorities) to review the draft output from the project, and advise on potential knowledge gaps and the priority of future R&D.
6. The approach taken involved development of a list of candidate chemicals in each class, based on an assessment of their market volumes, applications, the likelihood of environmental exposure, biological activities and toxicological profiles. This was achieved through in-depth literature searches (including “grey” literature and industry sources) and consultations with potential stakeholders. The current state of knowledge on environmental chemistry and toxicology for each of the identified substances was then collated and assessed. Particular attention was given to identifying weaknesses in the dataset (e.g. poor chemical characterisation of the CAMs). Incomplete datasets were anticipated from the outset, and therefore predictive analysis techniques, such as quantitative structure-activity relationships (QSARs), quantitative structure-property relationships (QSPRs) and quantitative structure-degradability relationships (QSDRs), were incorporated into the study design to fill data gaps. Consequently, a prioritised list ranked on available use and toxicity data was produced by computational modelling.
7. Synthetic equivalents were identified to enable comparison of environmental effects. Conventional medicines currently used for those ailments popularly treated by CAMs were briefly considered, to identify the potential for changes in use-patterns of CAMs and their consequent impact on the synthetic pharmaceutical sectors. For agricultural pesticides current usage data were used to identify the highest usage products for equivalent uses.
8. Subsequently, a series of ‘Case Studies’ were undertaken for a number of the priority chemicals. In these, the potential impacts of a number of future use scenarios were evaluated. Finally, gaps in knowledge and recommendations for future research were identified.
9. There is a clear lack of data on usage, composition of products, and their variability, and toxicity profiles for these substances. There is a need for wider international collaboration to prioritise gap filling on environmental impacts where non-synthetics are currently used. The vast amount of data generated and collated as part of this study should be made available through a web- based database system.
10. There is a public perception that non-synthetic chemicals are generically less harmful than synthetic chemicals, but there is no evidence to support this assumption. Improved access to unbiased information is required to promote public awareness.
11. Only very limited data are available on usage, composition and variability in composition of products containing non-synthetic chemicals, and the toxicity profiles for these substances. This should be addressed through international collaboration to prioritise and undertake gap-filling on the environmental impacts of the non-synthetics currently used.
12. Consideration of the environmental impacts of non-synthetic chemicals should not be limited to the obvious direct effects relating to toxicity; there is also a need to assess indirect effects, such as might arise from ecosystems impacts following use of mating disrupting pheromones.
13. Approximately 1 in 5 CAMs assessed in this study have properties that raise environmental concerns (relating to their potential classification as persistent, bioaccumulative or toxic). A similar situation exists with regard to non-synthetic pesticides. (These estimates do not allow for differences in usage patterns between synthetic and non-synthetics, which may in fact heighten concerns about non-synthetics).