Crop%20Profiles%20for%20North%20Carolina%20Agriculture

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Environmental Effects of Pesticides
Stephen J. Toth, Jr. Wayne G. Buhler Department
of Entomology Department of Horticultural
Science North Carolina State University North
Carolina State University
Photograph by Ken Hammond.
2
What is theEnvironment?

• The environment is everything around us natural
  and manmade not limited to the outdoors, but
  including indoor areas in which we live and work.

Erwin W. Cole
Ken Hammond
3
How do Pesticides Effectthe Environment?

• Point-Source Pollution contamination that comes
  from a specific, identifiable place (a point)
• Includes pesticide
  spills, wash water
  
  from cleanup sites,
  leaks from storage
  sites,
  and improper
  disposal of pesticides
  and their
  containers

Tim McCabe
4
How do Pesticides Effectthe Environment?

• Nonpoint-Source Pollution
  contamination that comes
  from a wide area
• Includes the drift of
  pesticides through
  the air,
  pesticide run-
  off into waterways,
  pesticide
  movement
  into ground water, etc.

Bob Nichols
5
Environmentally-Sensitive Areas
Sensitive areas include sites or living things
that are easily injured by pesticides, including

• areas where ground water is near surface or
  easily accessed through wells, sinkholes, etc.
• areas near surface waters (oceans, lakes, streams)

NCSU Communication Services
6
Environmentally-Sensitive Areas
Sensitive areas include sites or living things
that are easily injured by pesticides, including

• areas heavily populated with people (schools,
  playgrounds, hospitals, nursing homes, etc.)
• areas populated with livestock and pets

Ken Hammond
7
Environmentally-Sensitive Areas
Sensitive areas include sites or living things
that are easily injured by pesticides, including

• areas near the habitats of endangered species and
  other wildlife
• areas near honey bees
• areas near food crops and ornamental plants

Steve Bambara
8
Environmental Impact of Pesticides in Air

• The atmosphere is an important part of the
  hydrologic cycle
• Pesticides enter the
  atmosphere
  through
  drift, wind erosion
  
  and evaporation
• Pesticides can move
  great distances in
  the
  atmosphere
• Pesticides reach the
  earths surface via
  
  dry deposition and
  precipitation

U. S Geological Survey
9
Environmental Impact of Pesticides in Air
Long-range movement of long-lived pesticides
documented

• DDT and other organochlorine pesticides detected
  in Arctic and Antarctic fish and mammals used in
  1960s and 1970s
• Toxaphene is still transported
  into Great Lakes region
  by
  winds from the Gulf of
  Mexico used on cotton in
  
  the South, banned in 1982

USDA/ARS
10
Environmental Impact of Pesticides in Air
Pesticides frequently detected in the atmosphere

• Organochlorine insecticides (DDT, dieldrin and
  lindane) widespread use in 1960s and 1970s
  resistant to environmental degradation
• Organophosphate insecticides (chlorpyrifos,
  diazinon, malathion and methyl parathion) not
  long-lived in environment used heavily in the
  past and at present
• Triazine herbicides (atrazine) heavily-used
  herbicides, persistant in environment
• Acetanilide herbicides (alachlor and
  metolachlor) used heavily, but not as persistant
  as triazine herbicides

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Environmental Impact of Pesticides in Air
Number of pesticides detected in air, rain, snow
and fog. U. S. Geologic Survey (1995).
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Environmental Impact of Pesticides in Air
Hazards of atmospheric pesticides to humans and
environment

• Source of exposure to pesticides through
  inhalation (lungs have surface area equal to
  tennis court)
• Source of contamination of surface waters and
  ground water through dry deposition and
  precipitation
• Transport of pesticides from application sites to
  sensitive areas
• Accumulation of pesticides in the environment
  (soil, wildlife, etc.)

Gene Alexander
13
Environmental Impact of Pesticides in Soil

• Pesticides can move in the environment via the
  soil by two methods erosion and leaching
• Erosion soil particles
  which are transported
  
  by wind and water
  pesticides attached
  
  to soil particles
• Leaching downward
  movement of pesticides
  in the
  soil through
  cracks and pores

USDA Photograph
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Environmental Impact of Pesticides in
SoilLeaching
USDA Photograph

• Soil normally filters water as it moves
  downward, removing contaminants such as
  pesticides
• Soil and pesticide properties, geography and
  weather can influence the movement of pesticides
  (leaching)
• Pesticides that leach through soils may reach
  ground water

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Environmental Impact of Pesticides in SoilSoil
Properties That Affect Leaching

• Organic matter plant and animal material
  decomposing in the soil organic matter binds
  pesticides the more organic matter in the soil,
  the less likely pesticides will leach
• Soil texture determined by the percentage of
  sand, silt and clay the higher percentage of
  sand, the more likely pesticides will leach

USDA Photograph
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Environmental Impact of Pesticides in SoilSoil
Properties That Affect Leaching

• Soil acidity (pH) the acidity of the soil
  affects chemical properties of pesticides as
  the soil pH decreases (becomes more acidic),
  pesticides bind more to the clay in the soil
  making the pesticides less likely to reach the
  ground water

Scott Bauer
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Environmental Impact of Pesticides in
SoilPesticide Properties That Affect Leaching

• Solubility ability to dissolve in water the
  more soluble the pesticide, the more likely it
  will leach
• Adsorption the ability of the pesticide to bind
  tightly and quickly to organic matter in the soil
  affects leaching the greater the ability to bind
  to organic matter, the less likely pesticides
  will leach
• Persistence how long the pesticide remains in
  the soil pesticides degraded primarily by
  sunlight, soil microbes and chemicals in the
  soil the more persistent a pesticide, the more
  likely it will leach into ground water

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Environmental Impact of Pesticides in Soil
Effects of Pesticide Application on Leaching

• Rate of application the higher the rate (amount)
  of pesticide applied, the greater the chance the
  pesticides will leach
• Application method pesticides applied to growing
  plants can be absorbed by the plants or broken
  down by sunlight before reaching soil soil
  incorporated pesticides are not exposed to
  sunlight and have greatest chance of leaching
  into ground water

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Environmental Impact of Pesticides in
SoilEffects of Geography Weather on Leaching

• Geography depth from soil surface to ground
  water (closer ground water is to soil surface,
  the more pesticide leaches into ground water)
• Weather pesticides
  break down faster
  
  in warm, moist soil
  therefore, less
  likely
  to leach

Gene Alexander
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Environmental Impact of Pesticides in Ground Water

• Ground water is water located beneath the earths
  surface, usually in rock or soil
• Ground water is the primary source of drinking
  water for 50 of population, 95 of rural
  residents in the United States

Ron Nichols
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Environmental Impact of Pesticides in Ground Water

• At least 143 pesticides and 21 of their
  transformation products have been found in ground
  water, from every major chemical class
• Pesticides commonly
  found at low levels
  
  in agricultural areas
  (seldom exceed
  water-
  quality standards)
• Pesticides also found in
  non-agricultural setting
  
  such as golf courses and
  residential areas

Ken Hammond
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Environmental Impact of Pesticides in Ground Water
Pesticides most frequently detected in ground
water

• Triazine (atrazine) and acetanilide (alachlor and
  metolachlor) herbicides used extensively on corn
  and soybeans in Midwest
• Carbamate insecticide aldicarb (Temik) ground
  water contamination problems, sampled for
  extensively

Bill Tarpenning
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Environmental Impact of Pesticides in Ground Water
Factors strongly associated with pesticide
contamination of of ground water are

• High pesticide usage in the area
• High recharge of ground water by precipitation or
  irrigation
• High soil permeability
• Well contamination is greatest in shallow,
  inadequately sealed wells

Tim McCabe
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Environmental Impact of Pesticides in Surface
Waters

• Surface waters include streams, rivers, lakes,
  reservoirs and oceans
• Streams and reservoirs supply approximately 50
  of the drinking water in United States

Ken Hammond
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Environmental Impact of Pesticides in Surface
Waters

• Pesticides enter surface waters through run-off,
  wastewater discharges, atmospheric deposition
  (dry and precipitation), spills and ground water
• Pesticide concentrations in surface waters
  follow the seasonal patterns of pesticide
  application and run-off

U. S Geological Survey
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Environmental Impact of Pesticides in Surface
Waters

• Low levels of pesticides are widespread in
  surface waters in the United States
• Herbicides are detected
  more frequently than
  
  insecticides, due to their
  greater use
• Some pesticides exceed
  water-quality standards
  
  during certain seasons,
  but the annual
  average
  concentrations seldom
  exceed standards

Doug Wilson
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Environmental Impact of Pesticides in Surface
Waters
Pesticides most frequently detected in surface
waters

• Triazine (atrazine) and acetanilide (alachlor and
  metolachlor) and 2,4-D herbicides widely used
  in agriculture
• Carbofuran and diazinon were the most frequently
  detected insecticides in current use

Bill Tarpenning
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Environmental Impact of Pesticides on Plants

• Pesticides can move from the intended target and
  damage nearby plants, including crops, forests
  and ornamental plants
• Phytotoxicity plant injury resulting from
  contact with pesticides and/or inert ingredients
  in pesticide formulations

Scott Bauer
Bruce Fritz
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Environmental Impact of Pesticides on Wildlife
Acute Poisoning short exposures to some
pesticides may kill or sicken wildlife

• Fish kills caused by pesticide residues carried
  into waterways by run-off, drift, etc. (e.g.,
  fish kills in Mississippi River resulting from
  Guthion use in Louisiana)
• Bird kills caused by birds
  consuming
  pesticide-treated
  vegetation/insects, pesticide
  granules,
  bait or treated seed
  (e.g., birds poisoned by
  eating
  granular carbofuran)

Ken Hammond
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Environmental Impact of Pesticides on Wildlife
Chronic Poisoning exposure to non-lethal levels
of pesticides over extended periods can cause
reproductive effects, etc.

• Populations of bald eagles and other birds of
  prey were reduced by the widespread use of
  organochlorine insecticides (DDT) in 1950s and
  1960s
• These compounds and metabolites
  caused reproductive effects in
  birds
• Reduction in use of organochlorine
  insecticides in the 1970s and early
  1980s
  resulted in greatly improved
  reproduction and increasing bird
  populations

Tim McCabe
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Environmental Impact of Pesticides on Wildlife
Secondary Poisoning occurs when animals consume
prey that contain pesticide residues and
concentrate the pesticide in their bodies (i.e.,
bioaccumulation) resulting in their poisoning

• Predators become sick after feeding on dead or
  dying animals poisoned by pesticides
• Pesticide residues move up the food chain (plants
  eaten by plant feeding animals which in turn are
  eaten by predators)

USDA Photograph
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Environmental Impact of Pesticides on Wildlife
Indirect Effects adverse effects caused by the
modification or elimination of wildlife habitat
or food supply

• Herbicides can reduce food, cover and nesting
  sites for wildlife
• Insecticides can reduce insects that serve as
  food supply for other animals
• Plant pollination can be effected by reductions
  in populations of bees and other plant pollinators

Ken Hammond
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Endangered and Threatened Speciesof Plants and
Animals

• Endangered species any species which is in
  danger of extinction throughout all or a
  significant portion of its range
• Threatened species any species which is likely
  to become an endangered species within the
  foreseeable future
• Endangered / threatened species of plants and
  animals protected by the U. S. EPA under the
  federal Endangered Species Act

Tim McCabe
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Harmful Effects of Pesticides on Surfaces

• Pesticides can leave a visible deposit on
  surfaces (i.e., clothes, carpets, walls, etc.)
• Pesticides can corrode metal surfaces (i.e.,
  paint on automobiles)
• Pesticides can short-circuit electrical
  equipment

N. C. Pesticide Applicator Training Program
35
References

• Applying Pesticides Correctly A Guide for
  Private and Commercial Applicators. Unit 4
  Pesticides in the Environment. pp. 39-48.
• Applying Pesticides Correctly A Guide for
  Private and Commercial Applicators. Unit 5
  Special Environmental Concerns. pp. 49-59.
• McLaughlin, R. A., J. B. Weber, and R. L. Warren.
  1994. Protecting Groundwater in North Carolina
  A Pesticide and Soil Ranking System. AG-439-31.
  N. C. Cooperative Extension Service, Raleigh. 6
  pp. (http//ces.soil.ncsu.edu/soilscie
  nce/publications/Soilfacts/AG-439-31/)
• U. S. Geologic Survey. 1995. Pesticides in the
  Atmosphere Current Understanding of Distribution
  and Major Influences. Fact Sheet FS-152-95. U.
  S. Geologic Survey, U. S. Dept. of the Interior.
  4 pp. (http//water.wr.usgs.gov/pnsp/atmos/)

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References

• U. S. Geologic Survey. 1995. Pesticides in
  Ground Water Current Understanding of
  Distribution and Major Influences. Fact Sheet
  FS-244-95. U. S. Geologic Survey, U. S. Dept.
  of the Interior. 4 pp. (http//water.wr.usgs.go
  v/pnsp/gw/)
• U. S. Geologic Survey. 1997. Pesticides in
  Surface Waters Current Understanding of
  Distribution and Major Influences. Fact Sheet
  FS-039-97. U. S. Geologic Survey, U. S. Dept.
  of the Interior. 4 pp. (http//water.wr.usgs.go
  v/pnsp/gw/)
• Whitford, F., Miller, B., Bennett, R., Jones, M.,
  and Blesoe, L. 1994. Pesticides and Wildlife
  An Introduction to Testing, Registration, and
  Risk Management. Publication PP-30. Purdue
  University Cooperative Extension Service, West
  Lafayette, Indiana. pp. 6-7.
  (http//www.agcom.purdue.edu/AgCom/Pubs/PPP/PPP-30
  .html)