Additional Concerns

We attach here some additional concerns about the spraying, which could not be included in the original op-ed because of word limitations:

•  The issue has been badly sensationalized by officials and the press. The CDC estimates that of those people who do contract the virus, 80% do not know they have it.  20% develop flu-like symptoms.  1 in 150 develop the more serious neuro-invasive form of the disease.  Sacramento County reported 49 cases of neuro-invasive WNv disease out of a population of 1.25 million, which yields 1 per 25,000.  One fatality was reported, for a ratio of less than 1 per million.  While any death is a tragedy, these low numbers hardly justify the anxiety officials and the media have fomented.  See “West Nile Risk Low” to help gain some perspective.

•  Indiscriminate spraying kills beneficial insects like bees, as well as predators like dragonflies.  Dragonfly experts tell us that since their reproductive cycle is much longer than that of mosquitoes, the spraying likely will make matters worse.

•  According to the label, “This product is highly toxic to fish.”  How can indiscriminate application from airplanes avoid poisoning numerous ponds and waterways throughout the area?

•  Officials insist that small doses are harmless.  Yet spraying with small doses is the ideal way to develop resistant strains of various insects, which puts us at risk for serious diseases in the future.  We believe that less-dangerous pesticides should be held in abeyance for use in serious epidemics and not in a matter such as this one.  Moreover, the dictum of “the dose makes the response” stems from the work of the 16th century physician and alchemist Paracelsus.  See “The ABC’s of Toxicology,” which notes that “In the standard pesticide dose- response relationship, responses increase as dose increases. However,  some chemicals have an inverted relationship and higher doses of the chemical ‘actually inhibit some responses that are stimulated by much lower doses’, ” and “By insisting that only an old and simplistic dose-response relationship can be relevant to pesticides, pesticide proponents are hiding from modern toxicology.”  Also see our discussion about how low doses of substances are not necessarily safe.

•  Some years back SYMVCD cultured its own Romanomermis culicivorax, a mosquito-parasitic nematode that has exhibited a 95% success rate at killing mosquitoes and has no human or environmental risks.  In some settings single inundative releases have yielded excellent results for a matter of years. Why has this practice been replaced with indiscriminate spraying from airplanes?  Culturing Romanomermis is a more labor-intensive process, but it is highly effective and keeps money in our community instead of paying a Mississippi firm to douse us with a pesticide manufactured by a Minnesota company.  See a more detailed discussion here.

•  Again, as to effectiveness, Ray Parsons, Ph.D., Medical entomologist & assistant director at Houston, Texas Mosquito Control Division states, “It is difficult to determine the effectiveness of pesticide spraying because there are currently no accurate means of measuring Culex mosquito populations. Therefore, scientists cannot accurately determine what percentage of the population has decreased after spraying.” See "The Truth About Mosquitoes and West Nile virus," a fact sheet from Beyond Pesticides.  As we noted in the op-ed, mosquito populations decline after the peak anyway.  Claims by officials that the spray was effective are based on unscientific analysis, and the conclusions have not been verified by independent analysis.

•  According to David Pimentel, Ph.D., an entomologist at Cornell University, close to 99.9 % of sprayed chemicals go off into the environment where they can have detrimental effects on public health and ecosystems, leaving 0.1% to actually hit the target pest.  See "The Truth About Mosquitoes and West Nile virus."

•  According to the New York State Department of Health, more people were reported to have gotten sick from pesticide spraying than from exposure to WNv in 2000.  See "The Truth About Mosquitoes and West Nile virus."

•  The SYMVCD manager has admitted that he is not following CDC protocols – in April of 2006 he reported to the Sacramento Environmental Commission that he had not put into place the staff necessary to handle another intense West Nile season using larval control, yet he has been predicting an intense year since October of 2005 (“Birds are first line of viral defense,” Brian Joseph, Sacramento Bee, October 2, 2005).  

•  We met with the district manager on July 5, and we agreed to canvas hot spots and distribute door hangers with volunteers.  We canvassed the hot spots immediately.  We were given maps of areas with several thousand homes, yet we were supplied with only 300 door hangers.  We had trouble getting more hangers, and only weeks later were eventually given 400 more.  However, the district manager criticized the volunteer effort as not being enough.  SYMVCD can afford approximately $700,000 to blanket Sacramento with poison in the summer of 2005, the last resort in the CDC protocol, yet it must depend on volunteers to educate people, a critical initial step in the CDC protocol.  Something is very wrong with this picture.

•  The district manager told us that he thought the biggest problem in terms of growing mosquitoes was in the back yards of town.  We thus recommended that SYMVCD hold a “backyard day,” with many types of publicity, including newspaper, television, City Council, sound trucks in neighborhoods, etc.  This has never materialized.  Instead, SYMVCD sprayed Davis after the precipitous drops in infected mosquitoes and total counts noted in the op-ed.

•  Pyrethrins decompose rather rapidly in the sunlight, but what about in the shade or in carpets in homes where children play?  The synergist, PBO, is not photo-sensitive at all, and we see estimates of half-life of 6 days to 6 months.  A recent study out of UC Berkeley concluded that PBO from the spraying in Sacramento last year got into the waterways and synergized toxic chemicals that were already there, making them twice as toxic.  So much for PBO rapidly deteriorating after spraying.  Furthermore, it is not clear what compounds PBO changes into, nor is the safety of those compounds clear.

•  We believe that people do not have the right to breed mosquitoes in their back yards and expose others to disease.  We also believe that SYMVCD does not have the right to expose all of us to toxic chemicals in an ineffective attempt to protect those who are most at risk to WNv.  We thus envision a two-pronged effort: 1) aggressive efforts to educate people and help them maintain their homes properly and eliminate backyard sources, and 2) aggressive efforts to protect those most at risk in the population via education, good screens, long-sleeve shirts, mosquito repellent, etc.  

•  Even if we assume that adulticiding is effective, no rigorous risk-benefit analyses have been done.

• A physician would have a difficult time recommending a vaccine for WNv, if one were to be developed, because the risk of adverse reaction to the standard pharmaceutically prepared vaccine is greater than the risk of exposure to serious disease from WNv.

•  The indicator of 5-infected-mosquitoes-per-1000-trapped has not been justified scientifically.  We know of nothing in the scientific literature to justify that figure, and we have been supplied no citations.  In any event, such a ratio is completely irrelevant as to the risk of the disease without an accurate estimate of the total Culex (the suspected vector) population.  We have seen none.

•  The typical pattern of WNv as it has come across the country has been a mild first year, a peak in the second year, and a tapering off in subsequent years.  Many scientists recommend that the disease should be allowed to run its course without attempted intervention with adulticides.  

•  Mosquito districts were set up to combat serious illnesses such as malaria and yellow fever.  We believe that the SYMVCD is violating the public trust by responding in this way to a much less dangerous disease.  Any resistance built up in insects from these applications will hamper efforts to deal with serious problems in the future.

We do indeed believe that there is a serious public-health problem in this area, but it is not WNv.