If you think dust is trivial, talk to Hagerman National Wildlife Refuge manager Kathy Whaley or U.S. Geological Survey biologist Bethany Kunz. Last summer, they oversaw the first of at least three new studies about dust suppression on refuge roads.
As an ecologist, I have always been interested in conservation biology and questions of how wildlife populations persist in areas that are used by humans, says Kunz. In five years with the USGS in Missouri, Kunz has studied the effects of chemicals introduced into the environment for management purposesherbicides, fire retardants and, now, dust suppressants.
Dust seems inconsequential, but its actually a safety concern and a money concern, she says.
Kunz will tell you that there are more than 150 road dust control products of various chemical compositions on the marketeven Elmers Gluelike products. "Millions of gallons are being applied, she says, and we dont always have an idea of what they are doing to the environment.
Kunz will also tell you that dust costs road managers money, and that proper dust control can reduce maintenance expenses by minimizing gravel loss, cutting new gravel cost and decreasing roadblading frequency.
Whaley, the manager at Hagerman Refuge in droughtprone north Texas, will tell you that dust control is important to improve visibility and, therefore, safety for visitors.
To ensure a highquality experience, it is imperative that visitors are able to drive and stop their vehicle on wildlife drives to observe birds and wildlife or take photographs without being subjected to severe dust from passing vehicles, she says.
Whaley will also tell you that dust can damage oftenexpensive binoculars and cameras, and that bicycles and dusty roads do not go together well.
Both Whaley and Kunz will tell you that heavy dust can harm vegetation. It can inhibit photosynthesis. It can affect the health and appearance of trees, grasses, wetlands and wildflowers. Limestone dust can increase soil pH levels and, thus, foster invasive species.
So last summer, they conducted a study on two stretches of road at the 11,300acre Hagerman Refugeone an auto tour route and the other frequented by heavy equipment used in oil and gas extraction. Because environmental safety is of vital importance to National Wildlife Refuge System dust control programs, the study tested three nontoxic products: Dust Stop (a cellulosebased powder); Durablend (magnesium chloride with a bonding polymer added); and EnviroKleen (a biodegradable synthetic fluid with binder).
The goal was to learn which would be the most effective, environmentally safe product for refuge dust control. Other factors, Whaley says, were ease of application, sustainability of the road surface after application, length of time the product remains effective, impact of precipitation on effectiveness, and product cost related to longevity and overall success rate.
From Whaleys practical perspective, the Durablendtreated sections of road consistently produced the least dust with passing traffic. From just a dust standpoint, there was a clear winner. However, the results become more complicated when you take into consideration surface condition after traffic use and cost.
From Kunzs research perspective, all three were successful, but she stresses that were not trying to identify one magicbullet productbecause it doesnt exist.
Instead, Kunz says, the USGS studieswhich are scheduled to continue at Squaw Creek and Swan Lake Refuges in Missouri this year and perhaps at Hart Mountain Refuge in Oregon after thatare trying to identify an approach to environmentally friendly dust control on refuges nationwide.
For more information about dust suppression, contact BKunz@usgs.gov or Kathy_Whaley@fws.gov
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