APPENDIX II-BA:  Letter from Malinowski, Boulder County Department of Public Health, 6-27-07.

 

This was sent as an attachment to an e-mail sent 7-16-07.

 

Mr. Malinowski states that the half-life of permethrin is less than 12 hours.  He is inaccurate by 5,900 %.  Please see the Permethrin Fact Sheet from the National Pesticide Hotline in Appendix II-BB of my website.  The half-life of Permethrin in the sunlight is 30 days.

 

 

Public Health

June 27, 2007

To Whom It May Concern:

Thank you for contacting Boulder County with your concerns regarding mosquito control and the chemical applications that are sometimes used. There are two different mosquito control programs in Boulder County. The first is a program that is conducted within the Mosquito Con-trol District. The purpose of this program is to control nuisance level populations of mosquitoes in the district. The second program in Boulder County monitors the population and infection rate of Culex species mosquitoes, to protect citizens from contracting West Nile Virus. If the popula-tion of infected mosquitoes reaches a high level, the county may recommend emergency spray-ing. The decision to recommend emergency spraying for adult mosquitoes is not made lightly and is only made after thoughtful consideration.

The focus of mosquito control efforts within both unincorporated Boulder County and our indi-vidual municipalities is on Integrated Pest Management (IPM). IPM has three components: wa-ter and habitat control to reduce breeding areas, the use of a biological agent to kill larva before they reach the adult stage, and the use of chemical applications to reduce adult populations when necessary. Larvaciding and habitat control make up more than ninety percent of the IPM effort in Boulder County.

If the preferred methods of mosquito control fail to maintain low mosquito populations, chemical applications may be used. This includes any emergency spraying for Culex mosquitoes, which transmit West Nile Virus. West Nile Virus is a serious human health threat. While the disease most often manifests as a self-resolving fever, for many people the impact of the disease lasts for months; and for still others, the impacts can be debilitating and lifelong. In fact, a study of the 2003 Colorado WNV epidemic demonstrated that the infection caused considerable, long-lasting, severe illness. In 2003, Boulder County had 420 cases of WNV; 54 of those individuals con-tracted encephalitis and/or meningitis, and 7 of the cases resulted in death. In 2006, WNV con-tinued to impact residents of Boulder County by infecting 74 individuals, which included one death.

Mosquito trap data is one of the main considerations Boulder County Public Health (BCPH) uses when making the recommendation to spray. There is an extensive network of mosquito traps located throughout Boulder County. These traps are set weekly and are used to sample the type and number of mosquitoes present. Female Culex mosquitoes are the ones responsible for Administration/Environmental Health 􀁹 3450 Broadway 􀁹 Boulder, CO 80304 􀁹 303-441-1100 Boulder (Sundquist) 􀁹 3482 Broadway 􀁹 Boulder, CO 80304 􀁹 303-413-7500 (mailing address: 3450 Broadway Addiction Recovery Center (ARC) 􀁹 3470 Broadway 􀁹 Boulder, CO 80304 􀁹 303-441-1275 (mailing address: 3450 Broway) Longmont 􀁹 529 Coffman, Suite 200 􀁹 Longmont, CO 80501 􀁹 303-678-6166 Lafayette 􀁹 1345 Plaza Ct. N., Suite 3A 􀁹 Lafayette, CO 80026 􀁹 303-666-0515 www.BoulderCountyHealth.org


 

Page Two

June 27, 2007

transmitting WNV, and they are counted and sent to the State of Colorado lab for WNV testing. When large numbers of WNV-infected female Culex mosquitoes exist and a significant number of those mosquitoes test positive for WNV, there is an even greater threat of human infection of the disease.

When we at BCPH compare the risk of increasing WNV infection in humans with the risk of re-ducing the population of infected mosquitoes using Permethrin (the spray that is applied by a registered applicator strictly following guidelines for use), it is clear which option to choose. The Agency for Toxic Substances and Disease Registry (ATSDR) confirms that Permethrin has been used for many years, with no indication of significant adverse effects on humans when used as recommended.

A walk down any hardware store aisle or a visit to your local greenhouse will reveal a number of insecticides available to the public that are much more toxic than Permethrin. Consumers legally buy and use these other products on their properties at will – independently and without obliga-tion to surrounding residents. An organized, community-based mosquito program, such as the one in Boulder County Mosquito Control District, is much safer than the possible overuse of a broad array of much more toxic chemicals that can be used by individuals.

When used as recommended, Permethrin spray breaks down relatively rapidly in the environ-ment. Sunlight is the major means for breaking down pyrethroids, such as Permethrin. Once exposed to sunlight, the half-life for pyrethroids is less than twelve hours. Pyrethroids are gener-ally considered immobile in soils, and therefore are unlikely to leach into our groundwater. To minimize the impact to open waters, spraying only occurs when wind speed is less than 10 miles per hour.

Residents who do not want their properties to be sprayed have the option of placing their names on the notification or “no spray” list. Individuals on that list are contacted prior to any mosquito-spraying event occurring near their homes. In addition, the community is notified of any spray event in notices that are published in the Boulder Daily Camera and Longmont Times-Call prior to a spray event.

For more information about WNV and its prevention or detection, or for more detail on mosquito control efforts in Boulder County, please visit our website at www.BoulderCountyMosquito.net or call Boulder County Public Health at 303-441-1564.

Sincerely,

Joe Malinowski Administration/Environmental Health 􀁹 3450 Broadway 􀁹 Boulder, CO 80304 􀁹 303-441-1100 Boulder (Sundquist) 􀁹 3482 Broadway 􀁹 Boulder, CO 80304 􀁹 303-413-7500 (mailing address: 3450 Broadway) Addiction Recovery Center (ARC) 􀁹 3470 Broadway 􀁹 Boulder, CO 80304 􀁹 303-441-1275 (mailing address: 3450 Broadway) Longmont 􀁹 529 Coffman, Suite 200 􀁹 Longmont, CO 80501 􀁹 303-678-6166 Lafayette 􀁹 1345 Plaza Ct. N., Suite 3A 􀁹 Lafayette, CO 80026 􀁹 303-666-0515 www.BoulderCountyHealth.org

Consumer Protection Program Coordinator