Safe Use of Pesticides NATIONAL POISONS INFORMATION CENTER

Safe Use of Pesticides NATIONAL POISONS INFORMATION CENTER NATIONAL HOSPITAL – SRI LANKA

What is a Pesticide? • A pesticide is any substance or mixture of substances used to kill , destroy , repel or prevent the growth and development of a living organism. (a pest). • Pesticides can be classified according to the function. Eg. Algicide, Antimicrobial, Bactericides, Biocides, Disinfectants, Fumigants, Fungicides, Herbicides, Insecticides

What is a pest? • Pests are living organisms that compete with people for food supply, damage structures of personal property, injure plants, damage livestock or pets, or transmit diseases to people or animals. • Pests include animals such as insects, mites, rats, snails, nematodes or plants such as weeds and fungi. Microorganisms such as bacteria and viruses can be pests as well.

Use and Health Effects of Pesticides • Pesticides are chemicals used in agriculture to protect crops against insects, fungi, weeds and other pests. In addition to their use in agriculture , pesticides are also used to protect public health in controlling the vectors of tropical diseases, such as mosquitoes. • Pesticides are also potentially toxic to humans. They may include adverse health effects including cancer, effects on reproduction , immune or nervous systems. Before they can be authorized for use, pesticides should be tested for all possible health effects and the results should be analysed by experts to assess any risks to humans.

Before using a pesticide • Read the label thoroughly • Be familiar with all precautions • Be familiar with first aid information • Put on the proper Personal Protective Equipment (PPE)

Pesticide Exposure • Pesticides can enter the body through inhalation , ingestion, or absorption by the skin and eyes. The skin usually receives the most exposure, so it is important to cover as much of the body as possible. Make sure you wear the required protective clothing before opening the pesticide container.

Safe use of pesticides • Follow the “Directions for Use” on the label carefully * Use only for the purpose listed *Use only the amount directed, at the time and under the conditions specified • Special precautions must be taken during transport, storage and handling. Spray equipment should be regularly cleaned and maintained to prevent leaks. People who work with pesticides should receive proper training in their safe use.

Storage • Store pesticides in a place that can be locked and is not accessible to unauthorized people or children. Never put pesticides into food containers such as empty soft drinks or milk bottles. Keep pesticides in their original containers. Also keep them dry but away from fires and out of direct sunlight.

Transport Do not carry pesticide containers in a vehicle that is also used to transport food.

When Mixing a pesticide contd.

• Do not stir liquids or scoop pesticides with bare hands. • Never smoke or eat while mixing or applying pesticides. You could easily carry traces of the pesticide from your hands to your mouth. • Always mix or dilute the pesticide outdoors or in a well ventilated area. Only use the amount listed in the label and measure the pesticide carefully. Use suitable equipment for measuring out and mixing. • Mix the amount that you need for each application. Do not prepare larger amounts to store for possible future use. The pesticide will degrade and ineffective over time. • People who mix and pack pesticides in bags must take special precautions. It is recommended that gloves, an apron eye protection such as goggles be worn.

When applying a pesticide • Spray workers should wear shirts with long sleeves and trousers, a hat, non-absorbent gloves (not leather or fabric) and boots. The mouth and nose should be covered with a disposable or washable mask, or any clean piece of cotton. The cotton should be changed if it becomes wet. The clothing should be of cotton for ease washing and drying. It should cover the body without leaving any openings. In hot and humid climates the wearing of additional protective clothing may be uncomfortable, and pesticides should therefore be applied during the cooler hours of the day. • Keep children, pets (including birds and fish) away from areas where you mix and apply pesticides for at least the length of time required on the label. If no time is listed on the label, wait until the pesticide has dried before reentering the area. contd.

The discharge from the sprayer should be directed away from the body. Leaking equipment should be repaired.

After applying a pesticide • Wash all protective equipment as soon as possible following each use. • Wash non-absorbent gloves and rubber boots thoroughly with hot soapy water. * To prevent exposure to the hands, wash your gloves prior to removing them. * To prevent tracking pesticides inside, remove and rinse your boots before entering your home. • Dispose of clothing saturated with diluted spray solution or heavily contaminated with the concentrated pesticides. • Wash any parts of your body that may have come in contact with the pesticide. • Take a shower or bath at the end of the day.

Disposal • Left over pesticide suspension can be disposed of safely by pouring it into a specially dug hole in the ground or a pit. • It should not be disposed of where it may enter water used for drinking or washing. Dig the hole at least 100 metres away from streams , wells and houses. • Pour run-off water from hand washings and spray washings into the hole, and bury containers and bottles used for pesticides in it. • close the hole as soon as possible.

First aid for pesticide poisoning • All pesticide handlers should know and thoroughly understand first aid treatment for pesticide poisoning. • Skin contamination * Remove shoes first and then remove other contaminated clothing so shoes will not trap chemicals and be absorbed into the skin. * Wash the skin with large quantities of running water for 15 -20 minutes or more, using soap if possible. * Immediately cover the victim with a loosely applied clean cloth. * Avoid use of ointments or powders. contd.

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• Eye contamination * Eye membranes absorb pesticides faster than any other external part of the body, eye damage can occur in a few minutes with some types of pesticides. * If a pesticide splashes into an eye , hold the eyelid open and wash quickly and gently with clean running water from the tap or a gentle stream from a hose for 15 -20 minutes or more. Tilt head so poison does not run from one eye into the other. * Avoid use of drugs and ointments. contd.

• Inhalation * Remove the patient from the contaminated area. * Carry or drag the patient to fresh air. * Loosen all tight clothing. * Apply artificial respiration if the patient is not breathing or breathing is extremely shallow. Assist respiration by giving a breath once every five seconds. contd.

Ingestion * Most of the pesticides contain petroleum products as solvent to dissolve the active ingredient , so do not induce vomiting in pesticide poisoning. Petroleum products will cause more damage if the person is made to vomit. * Place an unconscious or semiconscious patient on his or her left side and tilt the head back. contd.

Patients requiring further medical treatment should be referred to the nearest medical facility.

Maximum Residue Limit • Pesticide residues on crops are monitored through the use of maximum residue limits (MRLs). MRLs are enforced by national authorities to ensure that the amount of pesticide residues consumers are exposed to through eating food over a lifetime will not have adverse health effects. MRLs are established to ensure that the total amount of pesticide residues absorb through food consumption will not exceed the acceptable daily intake (quantity of a pesticide humans can ingest in one day without any harmful effects). • MRLs are based on the maximum amount of residues that could be on the crop at harvest after a pesticide was applied in accordance with the use instructions found on the product s label. These limits are included in the Food and Drug Regulations and must not be exceeded.

Pre-harvest Interval • The pre-harvest interval (PHI) is the interval of time between the last application of pesticide and the safe harvesting of edible crops for immediate consumption (amount of pesticide residues allowed on the crop at harvest. ) Residue levels on a crop are affected by the crop’s growth, by environmental conditions (such as rain or UV radiation) and by the microorganisms on the plant s and in the soil. The PHI must therefore be long enough to allow for the pesticide residues in the harvested crop to degrade to a level that is acceptable. contd.

• It is important to respect the PHI so that the MRL for a given crop is not exceeded. Residues found in excess of the MRL on food would constitute a violation of the Food and Drug Regulations and could also pose a risk to consumers’ health. In such situations, the harvested crop could be seized, destroyed or forbidden for export. Use pesticides only for the crops and pests listed on the product’ s label and make sure to follow the application rates, number of applications and PHI stated on the label.

Restricted Entry Interval • A restricted entry interval (REI) is the amount of time after a pesticide is applied during which access to a treated area must be restricted. This time allows for the degradation of pesticide residues to levels that do not pose a risk to the health of workers going back into the treated area. contd.

An REI is required when the potential daily exposure to pesticide residues is expected to be above the levels deemed as safe. The potential daily exposure is calculated from the amount of residue that can be removed from the foliage of the plant , the amount of treated plant surface in contact with workers’ skin and the duration exposure. An REI can range from several hours to a few days.

Pesticide Residues in Food • The Food and Drug Administration (FDA) monitors and enforces pesticide tolerances in raw agricultural commodities and processed foods. • Pesticide residues on the food we eat are highly regulated. Although some residues may remain at the time of harvest, residues tend to decline as the pesticide breaks down over time. In addition, as the commodities are washed and processed prior to sale the residues often diminish further. There are several steps consumers can take to further reduce any pesticide residue that may remain on your food after purchase. • Consumers may also choose to purchase organic foods, which are grown and processed without synthetic pesticides and fertilizers.