Protecting Source Water from Pesticideswren.palwv.org/documents/GarlingonPesticidesWREN61709.pdf ·...

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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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

cawilen@ucdavis.edu858-694-2846

“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