On June 9, the South Hadley Board of Health passed a regulation banning application of second generation anticoagulant rodenticides [SGARs] on town-owned/-operated property. SGARs are environmentally harmful wherever they are applied, including to federally listed threatened and endangered species, household pets and even young children. Plus, low-income and minority populations tend to be financially least prepared to deal with the unintended consequences and health care costs of accidental rodenticide poisonings.
SGARs are rodent poisons (rodenticides) capable of killing rodents (typically rats and mice) after a single feeding; in practice however, rodents are able to feed repeatedly and can accumulate more than a lethal dose. These products tend to have a long biological half-life and can remain in a dead rodent’s body at toxic levels for many months. Thus, when poisoned rodents are consumed by a raptor (owls, bald eagles, red-tailed hawks, etc.); predator (bobcats, mountain lions, foxes, etc.); or household pets (dogs, cats, etc.) a lethal dose can be ingested (called “secondary poisoning”). Not only are these deaths destructive to natural ecosystems, but also lost are the valuable rodent management services that these wildlife species provide.
Such concerns are important in most rodent control efforts where the poison applicators (public or professional) may not be thoroughly trained and where monitoring may be incomplete and/or infrequent. And we must always consider the possibility of human error in handling, applying, and disposing of toxicants.
Antidotal therapies are costly and not a probable outcome for secondarily poisoned non-target wildlife. SGARs must be applied in a manner that renders them unavailable to non-target wildlife (and pet species); and a poison’s biological half-life must be short enough so that a hyper-lethal dose is not likely. Since these constraints for SGARs are unrealistic in principle and practice, and since non-target wildlife (and pets) are valuable environmental resources, SGARs are now banned from application by anyone on town-owned/-operated lands and in and around its buildings and structures. Integrated Pest Management (IPM) shall be the methodology of choice to understand, prevent and manage unwanted rodents on town-owned premises.
IPM is a decision-making process in which all necessary appropriate treatments (typically low-/non-toxic) are brought to bear on a pest problem with the goal of providing a remedy that is the most effective, safe, economical and sustainable. South Hadley residents are likewise encouraged to not use SGARs. Active ingredients of SGAR products include: brodifacoum; bromadiolone; difenacoum; or difethialone.
Dr. Stephen Frantz is a member of the South Hadley Board of Health and town resident.