Introduction to Pesticides: general environmental problems, regulations in US and Europe, toxic effects and environmental levels. Y.

Transcription

1 Analysis, fate and risks of organic contaminants in river basins under water scarcity Valencia, 7-8 February 2011 Introduction to Pesticides: general environmental problems, regulations in US and Europe, toxic effects and environmental levels Y. Picó SAMA-Food and Environmental Safety Research Group Facultat de Farmàcia Definition by FAO Any substance or mixture of substances intended for preventing, destroying or controlling any pest, including vectors of human or animal disease, unwanted species of plants or animals causing harm during or otherwise interfering with the production, processing, storage, transport or marketing of food, agricultural commodities, wood and wood products or animal feedstuffs, or substances which may be administered to animals for the control of insects, arachnids or other pests in or on their bodies. The term includes substances intended for use as a plant growth regulator, defoliant, desiccant or agent for thinning fruit or preventing the premature fall of fruit. Also used as substances applied to crops either before or after harvest to protect the commodity from deterioration during storage and transport.

2 Characteristics A pesticide is any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest. Pesticide includes herbicides, fungicides, insecticides, or any other substance used to control pests. Pesticides are carefully regulated by the Environmental Protection Agency (EPA) in United States and for the European Union (UE) which review studies to determine the risks posed by individual pesticides. History of pesticides Other Milestones Modern Chemistry Organic Chemistry World War I World War II Silent Spring published Vietnam war (Agent Organge) EPA Created DDT withdrawal

3 Classification of Organic Pesticides by Chemistry Insecticides Organochlorine Organophosphorus Carbamates Herbicides Phenoxy herbicides * Triazines * Imidazolinone * Sulfonylureas * Fungicides Alifatic nitrogen Amide Antibiotic Aromatic Benzimidazole Benzothiazole Conazole More than 1000 active ingredients

4 Organochlorine p,p -DDT Organophosphorus Chlorpyriphos Dinitrophenol Dinoprop Pyrethroid insecticides Cypermethrin Benzimidazole Carbendazim Carbamate Pirimicarb Nitroguanidine Imidachloprid World-wide pesticide sales in 2004 were $ billion Fungicides 25% Others 5% Herbicides 44% Insecticides 26% Rest of the World 10% Latin America 14% North America 27% Western Europe 24% Asia Pacific 25%

5 Crop surface and pesticide use

6 Environmental problem Over 98% of sprayed insecticides and 95% of herbicides reach a destination other than their target species, including non-target species, air, water and soil. What Happens after Application? When pesticides are applied the goal is that they will remain in the target area long enough to control a specific pest and then degrade into harmless compounds without contaminating the environment. Once applied, many pesticides are mobile in the environment (air, soil, water). This movement can be beneficial (moving pesticide to target area, such as roots) but can also reduce the effect on the target pest and injure non-target plants and animals.

7 Pesticide Movement &Degrade Runoff * Leaching * Degradation Microbial * Physical Hydrolysis * Photolysis * Pyrolysis * Volatilization * Factors influencing a pesticide s fate Properties of the pesticide Conditions where & when applied Application method

8 Properties of the pesticide Water Solubility/dissolvability - more soluble pesticides have lower sorption and are more mobile in the environment as they are leached or moved with runoff. Persistence the amount of time a pesticide remains in the environment, measured by halflife. Pesticides with longer half-lives pose a greater threat to the environment. Compound Soil Half-life K OC Water Sol. (ppm) DDT 3-10 yrs chlordane 2-4 yrs parathion (methyl) 5 days chlorpyrifos (Lorsban) days terbufos (Counter) days aldicarb (Temik) 70 days 28 6,000 carbofuran (Furadan) days carbaryl (Sevin) 10 days permethrin (Pounce, Ambush) 30 days 10, esfenvalerate (Asana) 35 days 5, atrazine 60 days alachlor 15 days

9 Metabolism & Degradation Pesticide metabolites can be as toxic as the parent compound European Legislation (I) Directive 91/414/EEC on the placing of plant protection products on the market. Plant protection products cannot be placed on the market or used without prior authorisation Maximum Residue Levels (MRLs) for pesticide residues in food and feed are covered by Regulation (EC) No 396/2005. Directive 1107/2009/EEC concerning the placing of plant protection products on the market has been published on 24 November 2009.

10 EFSA s Founding Regulation 178/2002, states that the Authority should collect and analyse data in its fields of expertise. EFSA carries out two different types of data collection activities: harmonised collection of EU-wide data required by EU regulations on an ongoing basis in order to assess and monitor trends over time and help inform risk management policies and measures; specific data collection to support risk assessments and other tasks. European Legislation (II) Directive 76/464/EEC: established two lists of priority pollutants Directive 78/659/EEC: regulates the quality of freshwaters in order to support fish life Directive 60/2000/EC (Water Framework Directive): established the framework for the protection of freshwaters, coastal waters and groundwaters Decision 2001/2455/EC: approved a list of 33 priority pollutants Directive 2008/105/EC: established the quality standards for the priority pollutants in water

11 Water Framework Directive (2000/60/EC) List of Priority substances (2455/2001/EC) Anthracene Atrazine Chlorpirifos Di(2-ethylhexyl)phthalate Diuron Endosulfan Isoproturon Lead and its compounds Naphthalene Octylphenol Pentachlorophenol Simazine Trichlorobenzenes Trifuralin Brominated diphenylethers Cadmium and its compounds C10-13-chloroalkanes Hexachlorobenzene Hexachlorobutadiene Hexachlorocyclohexane Mercury and its compounds Nonylphenol Pentachlorobenzene Polycyclic aromatic hydroc. Tributyltin compounds Alachlor Benzene Chlorfenvinphos 1,2-dichloroethane Dichloromethane Fluoranthene Nickel and its compounds Trichloromethane Subject to study for their identification as possible dangerous priority substances Identified as dangerous priority substances MRL future in EU FUTURE One Regulation where all MRLs will be established, monitored and controlled at EU level Rapid alert system in place Regular review of MRLs in force Establishement of tolerances and enforcement via River Basin Plans

12 Current status in EU NOW till 2011 Some harmonised EU MRLs Establishing temporary MRLs Default approach (LoD = 0.01 mg/kg or highest acceptable EU member MRL) For dringking water, maximum level of individual pesticide 0.1 µg/l, sum of various pesticides 0.5 µg/l Pesticide Laws and Regulations in the USA Federal Federal Insecticide, Fungicide, and Rodenticide Act (1972) Federal Food, Drug, and Cosmetic Act (1939) Worker Protection Standard (1992) Food Quality Protection Act (1996) State laws vary

13 Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Control of distribution, sale, use Gives US EPA authority to Study pesticide consequences Require pesticide purchase registration Requires Pesticide applicator certification Registration, proper labeling Federal Food, Drug, and Cosmetic Act (FFDCA) Allows US EPA to establish tolerances for pesticides in food Small fraction of marketed food tested for pesticide residue

14 Food Quality Protection Act (FQPA) Health-based standard for pesticides in foods Requires US EPA to review tolerances for pesticide tolerances in food Focus on children I I WANT A SPRAY THAT KILLS EVERYTHING BUT ISN T T DANGEROUS. Toxicity: the ability of a compound to cause injury or death Oral LD 50 values for: Toxic Effects Pesticide mg/kg DDT chlordane methyl parathion 14 chlorpyrifos terbufos 2-5 malathion aldicarb 1 carbaryl 850 carbofuran 8-14 permethrin 430-4,000 rotenone nicotine sabadilla 4,000 pyrethrins microbials NA

15 Toxic Effects LOW numbers indicate GREATER toxicity!! LD 50 values are not complete indicators even for acute toxicity. Toxicity is influenced by route of exposure, dilution, and combinations with other chemicals. Other types of injury (besides death) occur. Many individuals are more susceptible than average. Test animals may not accurately represent humans. Toxic Effects OBVIOUSLY Environmental toxicity is also an issue... toxicity to fish (pyrethroids, rotenone, many others), bees (carbaryl, many others), birds (DDT, now Furadan), and plants (lead arsenate, others) are all concerns.

16 Wiser Conclusions: Persistent pesticides have caused and continue to cause problems. We should not allow current and new compounds and use patterns to pose the same risks. Transport in water, on soil, etc. moves compounds to unwanted sites; at these sites the pesticides pose health risks or may be more persistent. Challenge: to identify environmental transport risks of specific compounds and select chemicals and use patterns that minimize risks. Most insecticides are broad-spectrum poisons that affect humans, other vertebrates, beneficial insects, etc. Challenge: to develop pesticides with selective toxicity. We do not know the answers to all the questions about the risks posed by pesticides. Environmental occurrence

17 Environmental occurrence Pesticides in surface waters by substance in England and Wales, 1998 to 2007 Environmental Levels Atrazine concentrations at Niagara-on-the-Lake, Wolfe Island and Quebec City sampling stations in 1995 and 2000 Atrazine concentrations in the St. Lawrence River,

18 Environmental Levels Metabolite concentrations for alachlor, as well as acetochlor and metolachlor (not shown), were greater than parent compounds for much of the year. Temporal variability in atrazine, diazinon, and norflurazon concentrations from lake and river samples collected September and November 2004, and May 2005, Lac du Flambeau Reservation and vicinity, Vilas County, Wis

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