Unit 5. Pesticides in Our Environment Flashcards
Which of the following are parts of “the environment?”
1. Gables Shopping Center.
2. The New River.
3. Chicken Hill.
4. Dolly Parton.
5. All of the above.
5. All of the above.
The Virginia Core Manual defines the environment as “everything that surrounds us. It includes not only natural elements such as forests and rivers but also people and the manmade components of our world.”
Name the federal government agency whose mission it is to protect human health and the environment.
The Environmental Protection Agency (EPA).
Before you choose and apply a pesticide, you should identify sensitive areas within the treatment area. Give three examples of sensitive areas.
- Schools and playgrounds.
- Hospitals and nursing homes.
- Seeps and swamps where groundwater is at or near the ground surface.
- Surface waters such as ponds, lakes, streams, and oceans.
- Near the habitats of endangered species.
- Near apiaries (bee hives).
- Near ornamental gardens or food crops.
- In food-preparation areas such as exist in restaurants and food packing houses.
- Where domestic animals are confined.
- Where people work.
Pesticide contamination is the result of either point source or nonpoint source pollution. The following are examples of which?
* Over-the-rate broadcast applications of pesticides in farm fields.
* Overapplying weed-and-feed fertilizers on lawns.
* Erosion of pesticide-contaminated soil.
These are examples of nonpoint source pollution because the most likely source of contamination is a wide area (many lawns, many farm fields).
Pesticide contamination is the result of either point source or nonpoint source pollution. The following are examples of which?
- Contamination of a pond that is near a spray equipment clean-up site.
- Contaminated soil beside an old pesticide storage facility that has many leaking barrels.
- Contamination of groundwater in the area of a large pesticide spill.
These are examples of point source pollution because the contamination comes from a nearby, easily-identified source (equipment cleanup site, poorly maintained chemical storage facility, etc.).
List three (3) ways in which pesticides can move off site.
- In air, through wind or air currents generated by ventilation systems.
- In water, through runoff or leaching.
- On objects, soil particles, animals, plants or humans that travel or are moved offsite.
To protect consumers and the environment, the law establishes legal limits (tolerances) for how much pestcide residue may safely remain on crops or animal products sold for food or feed. List top reasons why pesticide residues might exceed legal limits.
- Too much pesticide was applied.
- The days-to-harvest, days-to-grazing, or days-to-market directions on the pesticide label were ignored.
- A pesticide is applied “off label.” That is, the pesticide was used in a way that was not permitted by the label.
- Pesticides moved off of the release site on air or water currents.
Pesticide drift is a major concern. List the three (3) forms in which pesticides may drift off of the target area.
- As dry particles (ex. dusts).
- As liquid spray droplets.
- As vapors.
Some pesticides are volatile. This means that the active ingredient can change from a liquid to a gas (vapor) after it is applied. When this happens, a pesticide can travel great distances, leave illegal residues and may spoil nearby food crops.
How can you avoid problems of pesticide volatility?
- Choose nonvolatile pesticide formulations.
- Spray during the coolest part of the day.
- Avoid making applications when the air is hot and dry.
Which of the following can increase pesticide drift?
1. Small droplet or particle size.
2. Height of spray boom.
3. Strong winds or wind gusts.
4. Low humidity.
5. High temperatures.
6. Temperature inversions.
7. All of the above.
7. All of the above.
What things can you do to decrease the chance of spray drift?
1. Choose a spray tip (nozzle) that forms larger droplets.
2. Lower your spray boom as much as possible.
3. Do not spray on windy days or days when the temperature is high and the humidity is low.
4. Do not spray when you suspect a temperature inversion (note that you can set off a smoke canister to confirm that an inversion exists).
5. All of the above.
5. All of the above.
Pesticides can also move offsite in water. When they do, they have the potential to contaminate both surface waters and groundwater.
Name two (2) things that might increase runoff and leaching.
- Too much liquid is applied, leaked or spilled onto a surface.
- Too much rainwater, irrigation water, or other water gets onto a surface.
Note that the “surface” can be a leaf surface, a soil surface, a place where soil is contaminated by spills, etc. In other words, this “surface” can be anywhere a pesticide residue exists, whether it has been deposited intentionally or unintentionally.
What is the difference between runoff and leaching?
- Runoff is the movement of water across a treated surface.
- Leaching is the movement of water downward from a treated surface.
Both runoff and leaching threaten water resources. Runoff is more likely to contaminate surface waters (ponds, streams, etc.). Leaching is more likely to contaminate groundwater.
Explain how solubility, adsorption and persistence of a pestcide affect its ability to move offsite in water.
- Solubility. Many pesticides dissolve easily in water and can then move, in solution, into water systems.
- Adsorption. Some pesticides become tightly attached to soil particles but they can then move offsite through soil erosion. If eroded soil moves into water, the adsorbed pesticide may be released into the water.
- Persistence. Some pesticides break down slowly and can remain in the environment for a long time. The longer a pesticide remains in the environment, the more likely it is to move into surface or groundwaters.
What do we call water that is located beneath the earth’s surface?
Groundwater
