Daily News Archive
From August 16, 2006                                                                                                        

Cities Renew Inefficient Spray Campaigns
(Beyond Pesticides, August 16, 2006) Three more US cities have restarted their spraying campaigns against West Nile virus in the wake of several human cases. In Lincoln, Nebraska, a third human case was confirmed this week and officials say that this, combined with the high levels of positive tests in birds around the area, has caused them to begin spraying Anvil 2+2 throughout the community. New Iberia, Louisiana, has similarly decided to renew aerial spraying after two ponds in a near-by county were found to contain WNv-positive mosquitoes. Even a county in California, a state renowned for its progressive stance towards toxins, has sprayed their town twice this week after 10 confirmed or suspected cases of WNv, and “epidemic conditions,” began to frighten residents. To date, the CDC reports a total of 192 cases of WNv in the United States in 2006, including 6 deaths.

Communities are choosing what they perceive as a “safer” class of pesticide, pyrethroids, to blanket their homes and streets. However, synthetic pyrethroids or pyrethrins, including such brand names as Anvil 2+2 bring yet another set of human health and environmental impacts to the national stage. These chemicals, derived originally from chrysanthemums, have been engineered to become more toxic in order to be more deadly to the pests they are fighting. Unfortunately for those believing their claim of safety, this means that they are toxic for humans as well.

Additionally, they accumulate in the environment, causing serious damage to ecosystems around the treated area. A study of pesticides in bodies of water in the agriculture-dominated Central Valley in California found high levels of synthetic pyrethroid insecticides in stream sediments levels toxic to freshwater bottom dwellers in almost 50 percent of the sampled locations. A follow-up study found high levels of pyrethroids in stream sediments in urban areas in California, resulting from residential use of pyrethroids. In the residential study, pyrethroids are found in every sediment sample, and in half of the samples they cause total or near-total mortality to Hyalella azteca, a small bottom-dwelling crustacean that is generally regarded as a sensitive “warning” species.

Often aerial spraying is used to treat the area for adult mosquitoes, despite the inefficiency of adulticiding campaigns and their prohibitive costs. The efficacy of ground or aerially spraying in densely vegetated or urban areas is highly questionable. According to one of the nation's foremost experts on pesticide spraying, David Pimentel, Ph.D entomologist at Cornell University, the effectiveness of ultra low volume aerial spraying ranges from 42% to 93 %, however only 10%-25 5 of the insecticide actually reaches the target area. Up to 90 % drifts from the area being targeted. Dr. Pimentel states that “in order to prove whether pesticides are effectively killing mosquitos, you need five days of monitoring mosquito populations before and after the spraying.” Even then, there may be a population explosion due to the killing of natural predators or resistance among mosquitos that were not killed. “Without proper monitoring protocols, we may, in a sense, be giving the public a false sense of security that spraying is reducing the risk of contracting WNv or EEE,” says Eileen Gunn, Project Director at Beyond Pesticides.

Beyond Pesticides advocates for full disclosure of both the risk of contracting diseases and the risks of pesticides exposures (see below). We advise communities to adopt a preventive, health-based mosquito management plan and has several resource publications on the issue, including the Public Health Mosquito Management Strategy: For Decision Makers and Communities. Additonal materials such as safer repellents, mosquito control pesticides, public service announcements to distribute to your local radio stations, and community policies throughout the nation can be found online at http://www.beyondpesticides.org/mosquito or by contacting Beyond Pesticides.

Take Action: Contact your local radio station programming director and ask how to send a public service announcement. Send on of the three recorded MP3 versions of our public service announcement (PSA) which address the public's role in removing breeding grounds for mosquitos in their own backyards. The text and MP3s, along with a cover letter are available at public service announcements. If you are part of an organization, please feel free to ad your name to the PSA.