Humans and Pests: Pesticide Use on the Golf Course Part 1 of 3

(An except from a three-part series presented in a club newsletter)

Almost everyone has an opinion or assumption about pesticides and pesticide use in general. Whether one insists on killing the spiders around the porch and preventing damaging snow mold on putting green, or on insists on restricting all applications of “Round-up” and protecting pollinators— pesticide use triggers strong emotions.

Fundamentally we need to agree about “What is a pest?” A good way to think about pests is “a plant, insect, or animal that is not desirable in a given environment.” Consider our friend the “Milkweed”—it is essential for the miraculous life cycle of the monarch butterfly, but in grazing pastures or directly in front of or behind a golf ball Milkweed can be toxic…or at least a pest. Consider, also, mosquitoes and ticks. Most people would rather apply a pesticide (chemical or natural) directly to their skin than be attacked by these pests.

Similarly, we need to know, “What is a pesticide?” Basically, pesticides are products that have been developed to control pest populations. In almost every situation they cannot and do not eradicate species, as if that were even possible.  Proper use of pesticides aims to keep pest populations below unacceptable levels.

The term “pesticide” encompasses a number of different types of products—herbicides to control weeds, insecticides to control insects, fungicides, rodenticides…you get it. The goal to target a specific pest without causing adverse effects to the surrounding ecosystem—including humans—is the goal of any certified professional applicator.

People who apply pesticides on the golf course are trained and certified to do their job. These individuals understand the pests, the products they apply, and the ecosystem they are protecting. They also understand the principles of Integrated Pest Management (IPM), a five- step process of managing pests in the environment.

·       Step 1 is monitoring—Pesticides are not used indiscriminately on a routine schedule, but rather only if and when a pest is present in sufficient numbers to cause economic damage.

·       Step 2 is diagnosis—It is not assumed that observed damage is caused by a general condition, rather the pest or pests causing damage are identified by species and stage of life.

·       Step 3 is establishing action thresholds—A single dandelion does not trigger a broadcast spray over acres of turf, rather the stakeholders of any property determine the threshold for tolerating the levels of pests (which are always present) in the environment.

·       Step 4 is selection of management tactics—This step can include pesticide use, but it also includes mechanical and cultural tactics such as aerating greens to provide soil conditions that promote healthy turf, trimming trees to provide needed sunlight, or changing grass species that are less susceptible to disease.

·       Step 5 is recordkeeping and evaluation—Records must be kept for all pesticide applications by law, and staff evaluates the effectiveness of any pesticide treatment for current results and future planning.

After a pesticide is applied, human exposure is reduced. The concentrated product has been diluted in the spray tank and applied to a broad area. To further minimize human exposure following a pesticide application, products are applied according to specified re-entry intervals and allowed to dry (not be dislodged) prior to human contact. These are practices specified by law for all registered products for the sole purpose of protecting people from exposure to pesticides. State laws often require that golf course workers inform golfers about every pesticide application.

“But what about that smell?!” Chemical smells can be offensive and certainly out of place in a natural environment. Unusual odors can trigger an alert response for those who notice. Be appreciative for the “heads-up” that something has been sprayed. But remember, the odors themselves do not present a hazard. Odors are often the result of products added to pesticides to improve their effectiveness for controlling a target pest—products such as surfactants, stickers, emulsifiers, and the like.

Ultimately golfers want to know, “What are the human risks with respect to pesticides on the golf course?” From the preceding discussion, pesticides can indeed pose a risk to humans if they are improperly handled or mis-applied. The golf course staff must make sure this is not the case.

In conclusion, here are some thoughts to consider regarding human intersection with pesticides on the golf course.

First, if you do an internet search of “golf and cancer,” you will be overwhelmed with the amount of fundraising that golf outings contribute to cancer research. You will find much less about exposure on golf courses causing cancer—except, perhaps, for over exposure to the sun.

Second, consider the acute toxicity of direct exposure to a pesticide—that is, if you ingested a golf course pesticide straight out of the jug. Dr. Joseph Vargas from Michigan State University addresses this in his book, Management of Turfgrass Diseases. In the table below you can see a list of common chemicals a golfer might encounter and its acute oral toxicity expressed as LD50. (The term LD50 is the toxicity of a product that is sufficient to kill 50 percent of a population of animals measured in milligrams of active ingredient per kilogram of body weight—low numbers are more toxic, higher numbers are less toxic.)

A common product that is applied to greens is chlorothalonil—you will see it in the table. Remember, the table lists the oral dosage of the chemical, and a golfer’s exposure to this product is very low as it has been diluted and spread over a large area.

For perspective, Dr. Vargas likes to make this point about the risks of golf course pesticides to humans when he references the information above. He says, “Picture a golfer consuming a couple of beers (Ethyl alcohol) and a few hands full of pretzels (Salt) after a round of golf and taking a couple Aspirin with coffee (Caffein) the next morning to cure some body aches . That golfer has orally consumed more toxic chemicals than he could have possibly encountered with the diluted chlorothalonil spray on the golf course!”

All chemicals should be handled with awareness and care.