Pesticides Background

Pests are living organisms that are either harmful or a cause of concern to humans and their surrounding environment.  Pests may also have a negative economic impact.  They come in all shapes and sizes.  For instance, they can range from insects (e.g. cockroach) to plants (e.g. dandelion) to mammals (e.g. rats) to fungus (e.g. mold).  As a result of this diversity, there are different types of pesticides that target them such as insecticides, herbicides, rodenticides, and fungicides

The term pesticide defines a chemical substance mixture of chemical substances used to prevent, eliminate, or repel pests.  There are different types of pesticides with different uses.  The general pest control categories include: 1) chemical pesticides, 2) biopesticides, and 3) pest control devices (Table 1). 

Humans can be exposed to pesticides via: 1) ingestion, 2) skin contact, 3) eye contact, or 4) inhalation.  The risks associated with pesticides and the effects to human health vary based on age and lifestyle as well as dose, duration, and toxicity of the substance.  The US Environmental Protection Agency (US EPA) uses a four-step process to assess risk.  This process consists of: 1) identification of the health affects from exposure (hazard identification), 2) dose of the pesticide and the effects that develop (dose-response assessment), 3) how the exposure occurred (exposure assessment), and 4) a combination of the last three steps to describe the overall risk (risk characterization).

Table 1: Pesticide categories and respective descriptions.

Pesticide

Description

Chemical Pesticides

Chemically synthesized and related.  The main families include: 1) organochlorines (DDT or Anofex®), 2) organophosphates (parathion or Blandan M®), 3) pyrethroid (allethrin an active ingredient in Raid®), and 4) carbamates (carbofurancarbofuram or Furadan®).

Biopesticides

Pesticides derived from animals, plants, bacteria, and minerals. They usually fall under three categories: 1) microbial pesticides (contain microorganisms), 2) plant incorporated protectants (toxic plant substance produced when genetic material is introduced), and 3) biochemical pesticides (natural substances).

Pest Control Devices

Instruments that are used to trap, kill, or repel pests. There are no chemicals associated (mousetrap).

People that are sick, the elderly, those with asthma and allergies, and young children can be especially sensitive to toxic substances.   Chronic effects potentially caused by pesticides include: 1) damage to the nervous system, 2) development of cancer, 3) harm to the reproductive system, 4) changes in hormone function, 5) impairment of fertility, and 6) effects to the immune system.

The use of pesticides in the home can be risky and therefore caution should be taken.  First and foremost, it is extremely important to follow the directions and precautions indicated on the label (Figure 1).  Understanding this information increases safety and effectiveness.  Look for such words as “caution” or “warning” that signify that the product can be toxic to humans or pets.  Make sure that the pesticide that you are using is appropriate to kill the targeted pest.  Keep the product in the original bottle since it contains important information such as first aid instructions, assistant phone number, and product handling instructions.

It is also extremely dangerous to place pesticides in food or beverage containers since those that are not aware may think that what is inside can be consumed.  Puncture used pesticide containers in order to prevent reuse.  It is also important to keep pesticide containers out of the reach of children and pets.  Use locked cabinets, store out of reach, and make sure tamper proof caps are secure. Remember, the safety of a pesticide has to do with how you use and store it.  In the U.S., approximately 87 people die per day as a result of unintentional pesticide poisoning, and another 2,277 per day are treated in emergency departments (Centers for Disease Control and Prevention, 2012).

Precautions should be taken when dappling pesticides inside and outside of the home.  If it is being applied indoors, open windows to promote good ventilation.  Always, wear gloves and eye protection to avoid exposure (especially on a windy day).  It is also important to wear protective clothing.  Remember, if a pesticide falls on the protective clothing, wash separately from your other clothes.  Do not eat, chew gum, or smoke when applying pesticides or near a recently treated area.  Keep children or pets away from any spills and promptly clean-up as indicated in the product instructions.  Dispose of any rags or containers properly that have been used to clean up the spill.

Always apply only what you need. The product effectiveness might have an expiration date; therefore a larger size might not be a better value after all.  If you have pesticide left over, you can pass them on to someone else who use them or dispose of them properly (e.g. designated hazardous waste drop off locations).  Do not apply these products near rain or storm sewers so they do not enter drainages or waterways.  Never pour pesticides down the household drain.

Within agriculture fields, pesticides are applied to large areas.  Therefore, workers that apply pesticides and those living near agricultural fields are the most at risk to exposure of these substances.  If you live adjacent to a field, make sure that you close the windows in your home when they are spraying or during a windy day.  Dust and air that may enter your home may contain pesticides. Research studies suggest that the amount of pesticide dust found in the home is related to how close the home is to agriculture fields (Beamer, 2011).

If you or a family member works in agriculture fields, it is important to take certain steps to decrease exposure.  Before leaving the work site, either shower or wash body parts that have been exposed to pesticides in addition to changing your clothes. Studies show that a likely pathway that introduces pesticides into the home is the family car (Beamer, 2011).  Therefore, it is important to decontaminate at the work site before entering the vehicle. Lastly, be sure to practice safe handling of pesticides at work since it can decrease exposures at home.   

Integrated pest management (IPM) is a management philosophy that combines various practices to minimize pests.  It combines knowledge about the lifecycle and tendencies of pests, application of the proper pest control methods, and common sense prevention techniques.  It has been applied both in and around the home as well as agricultural sites.  It is considered effective and environmental friendly. This management approach may be more time consuming, but in the end it is safer and less costly.  The following are the general steps (Table 2):

Table 2: Integrated pest management steps and actions.

Steps

Actions

Monitor and Identify

  • Identify and monitor pests accurately.
  • Locate all areas where the pest has been seen and take samples for identification.
  • If you spot a pest, find out what it is by either looking up information online or consulting an expert (best way).

Action Threshold

  • Once a pest is identified, establish an action threshold (level at which the pest population indicates that a solution or action must be taken).
  • Everyone will have a different action threshold, or in other words, the amount of pests that they can tolerate.
  • Information about the pest is important in order to develop a realistic action threshold.

Prevention

  • Inspect both indoor and outdoor to prevent pests from becoming a problem.  For example, properly caulk around windows and cover door gaps.

Control

  • When a pest has been identified and the population considered a nuisance, the proper control method should be evaluated and applied.
  • It should be the most effective with the less risk to humans and pets.

An important part of IPM is the prevention of pest infestation in the home and garden.  There are precautionary steps that can be taken to decrease the likelihood of pest problems. The following are less harmful suggestions to prevent pests in your home (Table 3):

Table 3: Suggested actions on how to prevent pests.

Eliminate

Actions

Food Sources

  • Store perishable food in the refrigerator.
  • Do not leave dirty dishes in the sink overnight.
  • Secure leftovers or food scraps in a sealed container.
  • Avoid keeping food scraps in the garbage inside your home.
  • Use a garbage bin with a lid inside and outside of your home.
  • Keep an eye on the expiration dates of flour or cereals.
  • If you leave your pet’s dish with food, set it inside a bigger dish with water and a drop of dish soap.
  • Clean your pet’s waste frequently.
  • Keep your kitchen clean from cooking grease and oil.
  • Mix crop types in garden or field (mixed cropping).

Water Sources

  • Repair any leaking faucets or drips.
  • Keep an eye out for accumulation of water.
  • Frequently change your pet’s water.
  • Dry or remove any water damaged or wet materials.
  • Do not let water standing too long in garden or fields.

Hiding Places

  • Do not accumulate paper or paper products.
  • Repair any holes or crevices in and around your home.
  • Clean frequently areas where food or paper is stored; do not let dirt and debris accumulate.
  • Vegetation and shrubs should be trimmed at least one foot away from your home.
  • Bathe pets or animals frequently along with their bedding or mats.
  • Remove piles of old or diseased plant debris.
  • Sink and bath tub drains should be covered when not in use.
  • Check for any pests in boxes, packages, or luggage that you bring into your home.

When it comes to gardening or agriculture, additional steps can be taken in order to decrease pest invasions than those already presented.  It is important to properly care for flowers, trees, and vegetables.  A healthy plant resists pests much better than a weak plant.  Make sure you have healthy soil, which promotes healthy plants.  Different types of crops should be planted in the garden, since a pest might prefer one type and cannot easily spread to others.  Have a realistic goal when it comes to weeds.  It is impossible to get rid of all weeds, so keep them to a minimum.  Lastly, make sure that all water is drained in order to prevent plant disease as well as insect reproduction. 

Pesticide alternatives can decrease exposure and are considered less toxic than conventional methods.  When using pesticide alternatives around the home, it is important to identify where the pests are entering and the time of day they seem most active. The following chart summarizes some of the alternatives to common pesticides used around the home:

Table 4: Alternatives to pesticides.

Alternative

Pests

Suggested Use*

Glue Traps or Tapes

Cockroaches, scorpions, rodents, flies, and spiders

Place glue traps near entrances or where pests are frequently seen.

Traps

Cockroaches, flies, bees/wasps, rodents

Place traps near areas where pests are seen.

Beneficial Predators

Variety of pests

Ladybugs eat the larvae of aphids, mites, and white flies. Cats hunt and eat mice and other pests.

Canola Oil and Baking Soda

Fungi

One teaspoon of baking soda to 1/4 gallon of water, add 1/4 teaspoon of canola oil.  Spray all over your plants.

Boric Acid

Cockroaches and ants

Apply directly to cracks, crevices, and behind appliances or furniture.  Keep out of reach from children and pets (moderately toxic).

Citronella Oil

Insects

Candles, lamp oil, skin lotions, and sprays.

Soap and Water Solution

Insects

Mix water and soap solution and apply to plant or area were insects are found.  Use soaps that are low in salts (e.g. potassium salts) or do not contain antibacterial chemicals.

Vacuuming

Insects

Vacuum various areas around the home.  You can vacuum pests, nests, or eggs.  Remember to dispose of the vacuum bag after use.

Neem Derivatives

Scabies, ticks, fleas, lice, and mites

Oil, infusion, or premade products.

*Follow products instructions; these are only general use suggestions.