Farm Chemical Hazards Exposure Risks Rise Over Season

REGINA - Jun 27/05 - SNS -- Farmers need to take special care to avoid escalating exposure to toxins from the wide range of pest control products or pesticides applied during the growing season, according to Saskatchewan Provincial Pest Control Specialist Cameron Wilk.

"Intensified growth means more crop management concerns. Pesticides are an umbrella category that can be further broken down according to the end use for which they are developed. Herbicides are the most common pesticide in Saskatchewan —helping crop producers manage weed populations."

Foliar fungicides target fungal pathogens. Seed treatments are another type where the seed itself is treated to prevent plant diseases. Rodenticides manage rodent populations, while insecticides target insect infestations. Pesticide users should bear in mind that variety in the range of pesticide applications is accompanied by a corresponding range of safety concerns, Wilk points out.

"In general terms, herbicides are a relatively safe, low risk type of pesticide, while certain rodenticides and insecticides are higher risk pesticides. Compounding these risks, the amount of insecticides applied in any one season is highly variable, depending on a number of conditions that influence insect outbreaks."

For instance, orange wheat blossom midge, bertha armyworm, diamondback moth, grasshoppers and aphids all have the potential to become a concern every year. Correspondingly, Lorsban, Pyrinex, Monitor and Eco Bran are common trade names of insecticides that may then be applied to eliminate these insects. These are organophosphorus and/or carbamate insecticides. Exposure to these chemical substances can cause adverse effects on the cardiovascular (heart and blood vessels) or hematopoietic (blood) systems.

Decis and Ripcord are common pyrethroid insecticides with their own unique safety concerns. Exposure to these chemical substances can affect the endocrine system, which is comprised of the organs and glands that secrete hormones.

"Each of these insecticides may be rapidly absorbed through the skin, lungs and gut," explains Wilk. "Their acute toxic affects may be noticed within minutes or hours, depending on the exposure. Farmers or commercial pesticide applicators who are exposed to a number of small doses over the course of a growing season may quickly develop toxic symptoms due to the cumulative effect of each exposure."

The organophosphorus and carbamate insecticides will influence the nervous system by inhibiting the enzyme cholinesterase, which is necessary for the proper functioning of the central nervous system. Signs and symptoms from overexposure are similar and may vary in severity for products in the same chemical family.

"Organophosphorus and carbamate insecticide symptoms may resemble influenza, while pyrethroid insecticide symptoms may cause asthmatic reactions, eye or respiratory tract irritation, along with skin sensitization.

"It is very important to be informed before undertaking the application of insecticides or entering into areas treated with insecticides for monitoring purposes. There are easy ways to learn about the safe use of any insecticide or other agricultural chemical," adds Wilk.

Users should read the product or container label, as it shows the name of the product and the company that manufactured it, along with a mention that a Material Safety Data Sheet (MSDS) is available. It will also include hazard symbols; brief risk information; precautionary and first aid measures.

Chemical suppliers are required by law to provide the MSDS information sheet upon request for any product they sell. An MSDS gives detailed information about the chemical and its ingredients, health hazards, first aid measures, fire-fighting measures, accidental release measures, handling and storage instructions, and recommended personal protective equipment.

The use of personal protective equipment plays a significant role in mitigating the risks associated with insecticide application. Local farm supply dealers stock some personal protective equipment. Suppliers are always listed under "Industrial Equipment and Supplies" or "Safety" in the yellow pages of your telephone directory. To search on-line, enter "Canadian suppliers of personal protective equipment " into your search engine’s subject box.

"Applicators who are buying a chemical cartridge respirator should shop around to be sure they get a good facial fit and the right cartridge for the job," Wilk recommends. "The use of gauntlet-style PVC gloves; goggles; chemical-resistant hard hats and PVC aprons; disposable Tyvek coveralls and tractor cab-filter may also be advisable."

The best safety tool when working with pesticides is water. Keep a tank of clean water available in the field or on your equipment when applying pesticides. Use it for handwashing or for washing yourself in the case of a spill or a splash. If chemicals get on your skin or in your eyes, flush immediately with water.