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Protecting Source Water fromPesticides
Lyn GarlingPenn State University
PA Integrated Pest Management Programhttp://paipm.cas.psu.edu
Overview of Presentation
• Pesticides - background information• Extent of pesticide contamination of water• Pesticide characteristics
– relating to potential for water contamination• Environmental characteristics
– relating to potential for water contamination• Making pest management decisions - IPM• Educating water customers (“consumers”)
Pesticides: What are they?
• Common definition:– A chemical that kills a pest– Insects, weeds, fungi, rodents, slugs– ____ - cide
• EPA definition:– Any substance or mixture of substances
intended for preventing, destroying, repelling ormitigating any pest.
Pesticides in perspective
• There are ~ 87,000+ industrial chemicals• Pesticides = 900+ different active ingredients• Formulated into ~20,000 different commercial products in
many different physical forms• What makes pesticides different?
– made on purpose to be toxic– made to be handled by people– “use” implies “spread in the environment”
What are the components?
•• Active ingredients (a.i)Small percentage; “known” toxic chemicals
• Inert ingredientsLarge percentage; ~ 1,800 “unknown”compounds of variable toxicity
• SynergistsVary in %; toxicity
• Other components (solvents, propellants,adjuvants)
Regulation: EPA
• EPA translates pesticide legislation (laws) into regulatorypolicies/actions (interpretation of law)
• EPA requires companies to submit certain experimental dataon a.i. (but not inert ingredients)
• Does not require efficacy data of products
• EPA approves pesticide label information and formulationsubmitted by the company
• EPA Registration number on each product– Can be looked up on pesticide database, get labels, MSDS
The pesticide label is a “legal document”
• Specifies targeted pests• Conditions & locations of use• Known “Hazards”required to be disclosed
–(personal, non-target, environmental)• Poisoning emergency contact• Disposal instructions
What’s in a pesticide name?
• Brand names (e.g. “Ortho Ant Stop”)– Have no useful information about contents
• Active ingredient (a.i.) is the key to information– “trade name” (e.g. “Dursban”)– “common chemical name” (e.g. chlorpyrifos)– “technical chemical name” (long, hyphenated thing)
• Both can be looked up on a pesticide database
What is pesticide toxicity?
• EPA requires tests of each active ingredient(a.i)
• Acute vs. Chronic effects =• Immediate sickening vs. Long term effects
– Acute “measured” by LD50 / LC50 oral / dermal– Many are nerve toxins– Chronic effects?
• Hard to measure• Hard to attribute to any one source
Acute Toxicity (LD 50) oral(mammalian)
Least acutely toxic• Herbicides**• Some insecticides
* Microbials* Ins Growth Regs* Soaps* Some botanicals* Pyrethroids
Most acutely toxic• Rodenticides
*Anticoagulants
• Some insecticides*Organophosphates*Carbamates
• Some fungicides
Chronic Toxicity
• Cancer (carcinogenic)• Mutations (mutagenic)• Birth defects (teratogenic)• Reproductive effects (e.g. low sperm count)• Endocrine disruption (hormonal changes)• Other? (organ damage, nerve damage)
Chronic Health Effects
• Long-term, delayed effects• Hard to measure• Hard to attribute to any one source• Hard to factor in (no info on label**)• Our exposure is to multiple chemicals
– Continuous, low-level– Intermittent, higher-level
Endocrine Disruption
• Interfere w. natural hormones in the body• Show effects at very low-level exposure• Prenatal / early childhood effects• Linked to cancer development later in life• Many chemicals not yet screened• Commonly used a.i.s implicated
– (atrazine, 2-4-D; carbaryl, permethrin)
Key Issues with Pesticides
• Herbicides- Effects on aquatic plants- Endocrine disruption
Specific a.i. implicated (fish, amphibians, reptiles, humans?)- Unknown
• Insecticides*Acute Toxicity can be high - nerve poisons– Organophosphates (e.g diazinon) & Carbamates (e.g. carbaryl)
*Persistence - Can move up food chain and/or persist in sediments)*Endocrine disruption*Unknown
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are needed to see this picture.
Pesticides: How much of what kinds?
US Home & Garden Pesticide Use
Widespread Water Contaminationby Pesticides
• Air - volatilization, deposition by rain, dust• Water - dissolved; leaching, surface runoff• Soil - adhered to soil particles; erosion
• Agriculture uses the most pesticide overall (~80%)– Herbicides
• Homeowner and non-ag commercial uses– Herbicides– Insecticides
1.2 billion # a.i./yr
USGS National Water Quality AssessmentProgram (NAWQA)
• Study of 51 major river basins in US (see map)• Surface water samples = 186 stream sites• Bed sediment samples = 1,052 sites• Fish samples = 700 sites• Ground water samples = 5,047 wells including
2,356 domestic & 364 public wells
• Water sampled for 75 pesticide a.i., 8 degrds• Including:
– 16 of the 25 most heavily used insecticides– 20 of the 25 most heavily used herbicides
• Sediment/fish sampled for 32 organochlorines+ degradation products (DDT and relatives)
Integrated Pest Management
• IPM is . . . a scientific approach to effectivelymanaging pests while minimizing negativeimpacts on the environment.
• IPM uses . .knowledge about pest biologycombined with use of multiple, least-toxictactics for pest suppression.
• IPM emphasizes . . early prevention of pestsrather than intervention.
6 Steps of IPM
• Proper identification (problem/pest)• Learn pest and host biology• Sample environment for pests• Decide on action threshold• Choose tactics• Evaluate results
What exactly is the problem?
Positive ID: Termites or Ants?
• Termites are social insects, but not related to ants• Winged females mate, drop wings, establish new colonies consisting of males &
females. Usually white, stay underground• Incomplete metamorphosis• Potentially sexual “workers”
Friend or Foe? Make sure you know!Coccinellid or Chrysomelid?
Choose Tactics of IPM
• Cultural• Physical• Genetic• Biological• Chemical• Regulatory
Pesticide characteristics:Behavior in the environment
• Persistence vs Partitioning– Persistence = how long it stays in original form vs. is
transformed into “degradates”– Transformation expressed in “half-life”of the original
compound (hours to decades)– These dynamics in turn depend
• structure of compound• environmental conditions
– Both persistent compounds & degradates can betransported long distances and /or accumulate in soils,sediment or biota
• Partitioning - how a compound becomes distributedamong different environmental media (water -soil/sediment - biota - air)
• Measures of tendencies to partition & where (nextslide)
• Measures of “simple” water solubility
Chemical properties determine partitioning
• Air vs water– (KH) high = high volatility– Tends to reside in air– If get into ground water, tend to stay there
• Organic carbon in soil/sediment vs. water– (Koc) < 300 mL/g = hydrophilic, transported with water– (Koc) higher = hydrophobic, transported with soil OM
• Octanol vs water = indirect measure of lipid solubility– (Kow)
Chemical “behavior”
• Combination of partitioning, water solubility andpersistence determines the pattern ofcontamination by a chemical
• Tendency to “bioaccumulate” related topersistence (>30 days) and hydrophobicity (Kow
>1000)
• Tendency to move w. water related to watersolubility (< 1mg/L = ~insoluble)
Environmental characteristics
• Geology• Topography• Soil type• Vegetative cover• Local/regional climate & seasonal trends• Flow patterns above and below ground
Making decisions -consider before acting
• Is pest management part of an overallmanagement plan? Where does it fit in?
• It is always conditional (“If… Then….” )• Have the pest problem in 360 degrees perspective• Have an IPM plan in place & use IPM approach• Know the characteristics of pesticides under
consideration• Timing (pest biology & environmental conditions)• Key characteristics of your environment
Conventional vs. Biorational
– Conventional = synthetic, usually kill orinactivate pest on contact, broadly toxic, manyact as nerve poisons, may be long-lasting
– Biorational = usually naturally derived, shortlived, more narrowly targeted at the biology ofa pest, tend to be less toxic
Biocontrol Agents of Weeds
• Specific to one plant species• Insects feed on roots, seeds, flowers, leaves and stems• May transmit plant pathogens (good)• Fungal products available to attack milkweed,
sicklepod, and others
Galerucella calmariensisGalerucella pusilla
Purple Loosestrife Biocontrol Agents
Cornell Experiments
• Galerucella sp. impact on Purple Loosestrife
Microbial Pathogens of Insects
Advantages:
• Very low toxicity• Targets specific insect groups (flies, grubs, etc)
and specific stages (larvae)• Easy to use• Relatively fast working• Commercially available in various formulations• Break down quickly in environment
Microbials: continued
• Disadvantages– Break down quickly– Only work on certain stages/spcs
Most common: Bacillus thuringiensis (Bt)
–Mosquito & fly larvae ( Bt israelensis)–Beetle larvae (Bt tenebrionis & San Diego)–Caterpillars (Bt kurstaki)
Other Bacteria
– Baccillus aizawai (wax moth)– Baccillus sphaericus (mosquitoes)– Baccillus popillae & B. lentimorbus
• (Japanese beetle)
Pathogens: Fungi
• Most effective in moist environs,soft insects
• Only target insects• Slow to act• Exempt from EPA regs
• 2 Most common commerciallyavailable– Beauveria bassiana– Metarrhizum anisopliae
Fungi• Entomophaga species
promising• Used on Gypsy moth
Pathogens: Nematodes• Nematodes
– Free living in the soil– 3 main species that vary by behavior– Effective against hidden or soil dwellers– Can be bought and applied– Exempt from EPA regs
Entomopathogenic Nematodes
Commercially availablein sprayable mix
• Keep moist and cool
• Active “infectivejuveniles” (Ijs)
• Use on high valuecrops - nurseries,citrus, turf, soil &vine dwelling pests
Signs andsymptomsofnematodeinfection
Black Vine WeevilWax Worm
Fungus Gnat White Grub
The Challenge
of…..
Public Education!
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Home & Garden Use Significant
Of 94 million households surveyed:• 85% had at least one pesticide at home• Most had between 1-5 pesticides stored• 27% had more than 6 products on hand• 76% treated their own homes for insects• 20% hired a commercial applicator• 77% got information from a retail sales person
Lawns and the Environment
• If lawns were a crop,they’d be the 5th
largest crop in the US• 10x the amount of
pesticides used onlawns/acre v. crops
• 60% homeowners uselawn pesticides
Where DO People Get Info?
Survey of Residential PesticideUse and Sales in the San Diego
Creek Watershed of OrangeCounty, California
“Homeowner” behavior
• Homeowners vs renters tend to apply their ownpesticides; weed & feed, insecticides etc.
• Many also hire lawn care companies or“exterminators”
• Buy primarily from “big boxes” (Home Depot)• “Read the label” ? Not exactly - “front” vs “back”
– If mixing, did not actually measure
Major Outdoor Pest Problems
0
10
20
30
40
50
60
70
Insects Snails andslugs
Animals Plantdiseases
Weeds79% ants
31% misidentified GWF as a disease
Storage• 81% had 1-5 pesticides stored in/around
house• 10% had more than 6• 71% had pesticides 1-3years old• 24% had pesticides older than 3 years
Indicates storage anddisposal may be aproblem
Also indicates that whatis sold does not predictwhat is used
How to influence choices?
Where do they get information? Go there.– Advertising & sales promotions– Websites– Each other– Articles in magazines/newspapers– Point-of-purchase
What do they care about?Go there.
• Solving pest problems (the driving force)– Aesthetics (weeds, landscape plants)– “Getting rid of” insects
• Health of kids and pets– Awareness issue– Their role?
• Clean water– Awareness issue– Their role?
Our Water, Our WorldPromotion of Less-Toxic Pest Control
Contra Costa County, CA
• Public education partnership response to contamination• Organophosphate pesticide runoff from urban areas of
use• Diazinon and chlorphyrifos contamination at high levels
of concern• Urban & suburban creeks (1991)• Wastewater effluent (1993)
Response - Water Quality Regulators
In 1998, using Clean Water Act authority:
• listed waterbodies in virtually every urbanizedarea of California as impaired by pesticides andtoxicity
• required that TMDLs (Total Maximum DailyLoads) be calculated and that dischargers (localgovernments) reduce the amount of these pesticidesin the waterbodies to the TMDL targets (max.allowable amount)
Educational Response
• Outreach - Printed materials (brochures, factsheets, etc.) and events
• Advertising (Print, Radio, TV)• Media Relations• Point-of-Purchase - IPM Partnership
(or Our Water, Our World Promotion)
OWOW IPM Partnership – Goals
• Educate consumers about less-toxicapproaches & proper use & disposal
• Develop partnership with retailers– Stores can help spread the word about water
quality problems related to residential pesticideuse
• Create a program that will have broadappeal to stores
Promotional Materials
• Fact sheets – 24 (15 – English / 9 – Spanish)– Bug/pest-based (Ants, aphids, fleas, weeds,
mosquitoes)– Plant care-based (Lawns, roses)– Methods (Healthy garden, Use and disposal,
Finding a PCO that can prevent pest problems)– Issue-based (Water quality & pesticides)
• Less-toxic product list• Shelf talkers• Special displays (e.g., end caps, tablings)
Want to Reduce Negative Environmental Effects?
Avoid broad spectrum insecticides“Kills 65 different kind of insects!!”
Avoid long-lasting products“Protect your lawn for 6 months!!”
Avoid granules/pelletsoutside (birds eat them)inside (kids eat them)
Be careful with systemics
Read the label for water and wildlife concerns