Bifenthrin Study
New study considers Lyme disease, pesticides
STAFF REPORTER
Wednesday, March 30, 2011
Hopping ticks and Lyme disease are the focus of a new collaborative study led in Connecticut by the Yale Emerging Infections Program, a joint effort between the Connecticut state public health department and the Centers for Disease Control and Prevention.
Funded by the Centers for Disease Control and Prevention, the study is attempting to determine whether a more sparse approach to common pesticide spraying techniques, which involve several annual sprays of insecticide across large areas, can reduce the prevalence of Lyme disease and other tickborne diseases in Connecticut, New York, and Maryland.
While it is known that the proposed pesticide technique, a single strategically-placed springtime spray of bifenthrin, can effectively reduce tick populations, there have been no studies that identified whether this reduction would trigger a similar change in the occurrence of Lyme disease and other tickborne diseases, Julie Ray, the Connecticut program coordinator, said.
“There has been a steady increase in Lyme disease cases in the past few decades,” Brian Fallon, director of the Lyme and Tick-Borne Diseases Research Center at Columbia, said, adding that the rise in cases is a “failure” of the public health system.
According to a Connecticut State Department of Public Health study, there were 4,156 cases of Lyme disease in Connecticut in 2009, with 460 in New Haven County alone.
If her study proves that the incidence of Lyme disease will diminish even with the more conservative approach to pesticide administration, Ray said she hopes it will encourage people to ask their pesticide companies to spray less bifenthrin than they normally would. Most pesticide companies currently spray the chemical throughout people’s properties several times a year, she said.
Ray added that while the spraying of bifenthrin as a pesticide is not harmful to humans, the chemical is toxic to aquatic invertebrates, who come into contact with the spray through water runoff. The researchers are taking extra precautions to avoid this contamination, including not enrolling households with water on the property within 100 feet of where the pesticide will be sprayed.
But two scholars interviewed questioned the need to use the insecticide in the first place.
School of Forestry and Environmental Sciences professor John Wargo GRD ’84 said bifenthrin, which is part of a family of insecticides that typically affect insects’ nervous systems, might have long-term consequences for humans.
“I’m always a skeptic of spraying persistent chemicals, especially where children might be playing,” Wargo said. “It’s really important not to trade Lyme disease with another health threat.”
Jay Feldman, executive director of the nonprofit Beyond Pesticides, said pests like ticks are better managed by personal efforts like applying insect repellent and tucking pants into socks when walking through areas that could contain ticks. He added that another way of dealing with pests is to alter their habitats or breeding areas.
But Ray said people are often unlikely to actively pursue the personal efforts Feldman mentions.
Connecticut State Entomologist Kirby Stafford, who has studied ticks and the spread of Lyme disease extensively, said that landscape management could fight, but not eliminate, the presence of ticks. Still, he said that while pesticides are more effective in controlling tick populations, other alternatives should be considered.
The Yale study is being conducted in 1500 households across three states, Ray said. Half the study’s participants will have parts of their lawns sprayed with bifenthrin, while the other half will receive a harmless water spray, in order to test the assumption that people most often contract Lyme disease and other tick-borne illnesses from their own backyards rather than from elsewhere. The study’s method of control will allow for strong comparisons to be drawn from the two groups of households, she said.
The study will begin administering the pesticide in May, and expects to publish its results in April 2012.
Link Here- http://yaledailynews.com/blog/2011/03/30/new-study-considers-lyme-disease-pesticides/
(Beyond Pesticides, May 31, 2012) The Centers for Disease Control and Prevention (CDC) and the Maryland Department of Health and Mental Hygiene have enrolled Maryland households in a study that involves spraying the controversial pesticide bifenthrinon their property to determine the efficacy of this approach in controlling Lyme disease. Now in the beginning of its second year, the study found no evidence in the first year that the spraying works to reduce the transmission of Lyme disease. Beyond Pesticides is concerned that study participants have not been provided complete information about bifenthrin’s potential health risks to people.
According to the Baltimore Sun, the study is an effort to find new ways to combat the disease, which infected 1,600 people in Maryland in 2010. Half of the 185 families that have volunteered for the study will have water sprayed on their lawns to serve as a control group, while the other half will receive the bifenthrin treatment. The 185 families that have signed up so far this year get a $25 gift card, lowered from $40 given to the 440 participants last year.
Last year, while the pesticide reduced the amount of ticks on treated lawns compared to the control group, there was a negligible difference in both the numbers of ticks that volunteers reported on their bodies and the number of Lyme disease cases. State officials have declared that they will not advise residents to use pesticides to combat Lyme disease if this second year of testing shows similar inconclusive results in the number of tick bites and Lyme disease cases between the two groups.
Beyond Pesticides believes that it is wrong to put Maryland families at risk of pesticide exposure, especially since the study proved ineffective in its first year. Beyond Pesticides has spoken directly with state health officials in an effort to relate concerns about this study. “It’s improper to be conducting a human experiment like this,” said Jay Feldman, executive director of Beyond Pesticides.
Bifenthrin is identified as an endocrine disruptor by the European Union in May 2010, and is considered a possible carcinogen by the U.S Environmental Protection Agency (EPA). It is a pyrethroid class pesticide, a group of known neurotoxic chemicals. A recent study in the journal Environmental Health Perspectives (2007) of infants born to women with agricultural exposure shows a possible impact of bifenthrin on the occurrence of autism spectrum disorders. EPA studies with rodents test subjects have led the organization to classify bifenthrin as a possible carcinogen due to the increase of bladder, kidney, and lung tumors in mice exposed to the substance. Further, EPA studies have associated bifenthrin with developmental/reproductive effects, and an increased risk of ovulatory dysfunction in females. See Beyond Pesticides’ action alert on EPA’s proposal to expand the use of these pesticides.
The CDC website and informed consent form do not elucidate the hazards posed by this pesticide.
It reads, “If a person (including a young child or a pregnant woman) or animal were to swallow breathe or touch the chemical, the individual or animal is not likely to become ill. If the chemical comes into contact with the skin or eyes before it has dried, some individuals may have short term irritation that will likely disappear within 12 hours. There are no studies that indicate bifenthrin exposure risks in humans are increased for children or women who are pregnant. At the beginning of the study, you will receive a bifenthrin product information sheet about how to clean skin, flush eyes, and if you should seek medical attention for yourself or pets in case this occurs.”
Beyond Pesticides has stated that it is misleading for the CDC to claim that there are no studies that indicate exposure risks for humans are increased for children or pregnant women. In fact, it would be highly unethical to conduct such a study. Instead, EPA extrapolates the impact on people based upon data from rodent/animal studies. Volunteers for the study may interpret the CDC’s statements to indicate that the pesticide is safe for people, when in reality it is a potential carcinogen.
Lyme disease is the most prevalent tick-borne disease in the U.S. It is caused by the bacterium Borrelia Burgdorferi that is harbored by several species of ticks, but most significantly the blacklegged tick that is ubiquitous in the northeastern and north central United States. According to Bryan Schwartz, M.D. of John Hopkins University, ticks start their life feeding on smaller hosts, such as small birds and reptiles, but prefer to feed on white-footed mice (Peromyscus leucopus), a notorious transmitter and reservoir of the bacterium. After molting, adult ticks prefer to feed on larger mammals, such as deer and humans, at which time they may have already picked-up the bacterium. An infected tick transmits the disease by biting and attaching itself to its host. Research suggests that a tick must feed for 24-48 hours before B. Burgdorferi is transmitted to the host. This makes proper education and awareness about Lyme disease prevention incredibly important.
Although Beyond Pesticides commends the state for attempting to address this serious disease, we advocate for the least-toxic method of tick control possible. For more information on non-toxic tick control, see our fact sheet.
Take Action: Contact Maryland’s Department of Health and Mental Hygiene and let them know pesticides controls are not the answer to Lyme Disease!
E-mail: healthmd@dhmh.state.md.us
Toll Free Phone: 1-877-4MD-DHMH (1-877-463-3464)
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
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