Title: Crop%20Profiles%20for%20North%20Carolina%20Agriculture
1Environmental 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.
2What 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
3How 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
4How 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
5Environmentally-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
6Environmentally-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
7Environmentally-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
8Environmental 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
9Environmental 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
10Environmental 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
11Environmental Impact of Pesticides in Air
Number of pesticides detected in air, rain, snow
and fog. U. S. Geologic Survey (1995).
12Environmental 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
13Environmental 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
14Environmental 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
15Environmental 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
16Environmental 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
17Environmental 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
18Environmental 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
19Environmental 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
20Environmental 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
21Environmental 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
22Environmental 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
23Environmental 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
24Environmental 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
25Environmental 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
26Environmental 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
27Environmental 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
28Environmental 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
29Environmental 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
30Environmental 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
31Environmental 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
32Environmental 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
33Endangered 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
34Harmful 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
35References
- 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/)
36References
- 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)