May 5, 2009      

Secretary Richardson
Maryland Department of Agriculture
Annapolis, Maryland

Dear Secretary Richardson,

I am here to suggest a way your department can save at least $1 million annually in its budget while at the same time improving the health of Maryland residents, race horses, farm animals, family pets, and crabs. It will also keep Maryland’s berries and leafy vegetables safe to eat. The way to do all this is to suspend the gypsy moth suppression program in Maryland. As you probably know, three pesticides are currently used in Maryland to suppress gypsy moths; BTK, Dimilin, and Confirm. The Department of Agriculture only uses BTK and Dimilin but is planning to add Confirm next year. These pesticides pose a variety of health problems.

BTK, an irritant with no clear threshold, can cause adverse effects in asthmatics taking steroids. It can cause adverse health effects in celiacs and people with gluten intolerance because its formulations contain flours. The BTK formulations also contain yeast and mold that will trigger allergic reactions in susceptible people. Furthermore, anyone with a respiratory viral infection (and that means anything from a simple cold to AIDS) could develop a super infection when exposed to BTK. Super infections are usually fatal. The 2008 USDA Environmental Impact Statement (EIS) for the Gypsy Moth Suppression Program says that the occurrence of super infections “should be monitored by groups involved in the use of BTK.” So is the Department of Agriculture or the State prepared to spend even more money to set up a monitoring program?

Dimilin and Confirm both cause methemoglobinemia, a condition that decreases the blood’s ability to carry oxygen. This impairment can result in serious adverse effects equivalent to suffocation. Infants under three months of age and people with sickle cell anemia are more susceptible to adverse effects from this condition. Dimilin and Confirm will cause this condition not only in humans but all mammals. Cats and dogs are most susceptible to developing this condition upon exposure. Since the condition interferes with the body’s ability to carry oxygen, I wonder about the advisability of racing horses in its proximity. As an aside I would add that people with chemical sensitivity usually have reactions within five miles of a spray block. The California Department of Food and Agriculture has documented pesticide drifts of up to 3.3 miles outside the designated treatment area for Checkmate, a pheromone delivered in a polyurea microcapsule. This finding was contrary to agency claims that precision spray technology would assure avoidance of rivers, streams, schools, and other sensitive areas. Similar claims are being made for Maryland’s gypsy moth spray program. If racing a horse with methemoglobinemia does not kill the horse, at the very least the condition could take away the exposed horse’s competitive edge. What race horse owner would want to risk putting his horse at a disadvantage? This year the Laurel Racecourse is within five miles of an Anne Arundel spray block being treated with Dimilin, AA003.

Furthermore the USDA EIS says that “at the upper ranges of exposure, the hazard quotient exceeds a level of concern for the consumption of contaminated vegetation on site by a large mammal after either a single application or two applications…and suggests a high likelihood of adverse effects in the blood.” These effects are compounded when Confirm’s half life of three to six months is considered. So the adverse effects can persist in horses, cows and other herbivores, including humans, for a long time. In fact, the EIS states that with respect to Confirm, the greatest threat to human health involved long-term consumption of contaminated vegetation. There is no apparent dose duration relationship for Confirm so even short-term exposures are likely to lead to methemoglobinemia. Additionally, Dimilin and Confirm are likely to have an additive effect on methemoglobinemia, so people or animals that travel through or near areas sprayed with these two pesticides are at an increased risk.

Dimilin poses an additional threat. One of its metabolites is a carcinogen. According to the EIS the consumption of water that is contaminated with the metabolite is “the greatest source of concern for members of the general public in the application of Dimilin to control gypsy moths.” The other cancer concern is the consumption of vegetation sprayed with Dimilin. Both Dimilin and Confirm can be absorbed through the skin.

Dimilin kills blue crabs by inhibiting the molting process. Dimilin also affects crab escape behavior and may thus influence the ability of juvenile crabs to avoid predation and feed.

There are many natural controls for gypsy moths: several fungal pathogens, a virus (LdNVP), some mammals (specifically mice and shrews), birds (some birds even prey on egg masses), various flies and wasps that act as parasites, ground beetles and ants. Many of these natural pathogens are adversely affected by the gypsy moth pesticides. Places from New England to New Zealand have found that moths can be effectively controlled by restoring beneficial insects and other predators and have abandoned spray programs altogether. In areas of heavy infestation like Frederick County, the state should study ways to enhance natural controls. Prince George’s County dropped out of the state’s gypsy moth suppression program a few years ago and so far only a few homeowners have resorted to hiring a helicopter to conduct their own spray program. This year no private helicopter sprayings for gypsy moths are scheduled for Prince George’s County. I live in Prince George’s County and in 2002 I watched the fungus wipe out a gypsy moth infestation in my forested back yard. The Department of Agriculture should follow Prince George’s County’s example and save itself a lot of time and money.

Respectfully submitted,

CSDA Maryland Coordinator


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