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Pesticide Use in the City of St. Louis
by Daniel McKeel, MD,
Washington University School of Medicine
[The following is from a public forum on pesticide spraying for West Nile Virus held by the Gateway Green Alliance of St. Louis, Missouri on February 5, 2003]
The important formula is risk versus benefit of pesticide spraying to control West Nile Virus diseases. After studying this issue, I believe the risk of pesticide “fogging” (aerial spraying from trucks) far outweighs the benefit to control mosquito populations that transmit the virus to people. First, I want to review the latest medical data on the prevalence and incidence of West Nile Virus illnesses. Next I want to tell you about new data concerning pesticides and emerging evidence that one pesticide, rotenone (which is not using in the St. Louis spraying program), causes Parkinson’s disease.
The West Nile Virus story
West Nile Virus (WNV), a flavivirus, is not strictly a St. Louis problem; it is global. At the time WNV was sweeping across America starting in 1999, it was also spreading in Romania, Russia and Israel from its endemic sites in Africa, Asia, Europe and Australia. In the US, WNV spread from New York City starting in 1999 across the country from East to the West Coast.
Most persons who get infected with WNV are asymptomatic. A large majority of symptomatic people develop a self-limited febrile illness (viremia) with non-specific flu-like symptoms. A third group, 0.1–1% of the total, develop more serious brain inflammation (meningitis, encephalitis) with neurologic impairment as primary symptoms.
The risk we need to be concerned about is that of many toxic chemicals combined….
The Centers for Disease Control and Prevention website (www.cdc.gov) provides a summary of state by state total WNV infections and deaths to date that have been reported to them. Thus far, the CDC has recorded 4007 total cases and 263 deaths due to WNV. This a fatality rate of 6.6%. This number of WNV deaths should be compared to more than 200,000 US deaths due to influenza virus during 2002. For the year, Illinois had 836 cases and 56, Missouri had 169 cases and 5 deaths, and Kentucky had 75 cases and 5 deaths. The high Illinois to Missouri case/death rate was also observed during the St. Louis viral encephalitis epidemic that first hit the City 50 years ago. St. Louis viral encephalitis is still with us (endemic), but the peak incidence of yearly new cases has sharply declined from the earlier epidemic.
Problems with pesticide spraying
We learned when meeting with the City that 96% of the sprayed agent (ANVIL 2+2 brand of the pyrethrin compound sumithrin) is an oil-based, supposedly inert component that is dispersed into the air as micro-fine particulates. However, oil is very sticky for many toxic chemicals that get carried into the lungs along with sumithrin and piperonyl butoxide (itself a toxic carcinogen added as a “synergist”) to cause illness and chronic diseases.
Richard Stevson’s letter to Don Fitz also reneged on Mark Ritter and Larry Kettelhut’s promise made to us when we met with the City. They promised to provide us with the chemical composition of the inert agents in Anvil 2+2. The letter said “...For adulticiding effectiveness and information on the inert ingredients in Anvil 2+2 you can call...” Again, to me, this is a totally irresponsible and inappropriate response to tell a citizen to the do the Health Department’s job after being told in a meeting the Health Department would and could supply this information. I am certain the department could use the leverage of a big order (sales contract) to demand that Clark Mosquito, Inc. disclose all of the constituents in their product, including the so-called “inert” ingredients.
Because of our City Health Department’s cavalier and unresponsive attitude described above, I was neither surprised nor upset to see that Cuyahoga County and the City of Cleveland are being sued by Ohio activists seeking a legal injunction against widespread pesticide spraying. They cite lack of efficacy and adverse public health effects for synthetic pyrethrins (sumithrin used in the City of St. Louis is among this class of pesticides) in their claim. I plan to write the City of St. Louis Health Department and urge them to carry out their primary responsibility to protect the public health and welfare. Our group plans to continue working with Larry Kettelhut, Richard Stevson and Mark Ritter to exchange information and possibly persuade them that pesticide fogging is actually detrimental to the public health, the reverse of it’s intended function. Ultimately the goal will be to make fogging contingent on demonstrated efficacy and solid surveillance data that CDC insists is also necessary.
Finally, I want to tell you about some new data and a new study from CDC that is the first real step at defining the adverse health effects of multiple toxins on humans. The best scientists in my field [McKeel directs the Neuropathology Core Laboratory of the Washington University Alzheimer’s Disease Research Center], now have convincing evidence that a widely used pesticide, rotenone, directly causes Parkinson’s disease in humans and when given to laboratory rats. Rotenone damages mitochondria, the cell’s energy factory, and releases toxic molecules such as cytochrome C that activate apoptotic (one of the main ways cells die) caspase enzymes that target and kill the key dopamine-producing cells in specific brain regions that mediate Parkinson’s disease. Thus, rotenone causes the specific pathology that we use to diagnose Parkinson’s disease.
The CDC (http://www.cdc.gov/) in January 31, 2003 released (available as a PDF file at: http://www.cdc.gov/exposurereport/) a $6.5 million two year research study where 116 toxic chemicals and heavy metals (including lead) were studied in blood and urine samples from 2,500 people. The study is entitled “Second National Report on Human Exposure to Environmental Chemicals.” The results showed that while smoking, related by-products, and lead levels were decreasing in the US, children’s levels and lead and smoking constituents were still two-fold higher than adults. A number of classes of pesticides, herbicides and insect repellents were analyzed.
With respect to pesticide spraying in St. Louis, the bad news was that people already have in their bodies a large number of related chemicals–and certainly don’t need any more! The effects are cumulative and largely unknown for even two combined toxic chemicals, the report admits. Thus, it is scientifically misleading to say that ANVIL (sumithrin), for example, is within EPA permissible (not the same as safe) limits as though exposure were to one chemical alone. The risk we need to be concerned about is that of many toxic chemicals combined, which is much higher.
Good medical science advocated by expert professionals should be the guide here, not the self-serving whims of local politicians.
In summary, I am now convinced that the demonstrated risks of pesticide spraying, as documented in the scientific literature, in the absence of evidence from the city that their spraying program reduces the West Nile vector mosquito populations (the benefit of spraying), outweigh the benefits to human health and safety. Thus, I will continue to work with the City Health Department and concerned citizens groups in order to convince the City to: (1) present and justify their vector control program to public scrutiny, and (2) to abolish the indiscriminate “convenience” spraying which is mainly cosmetic, dangerous to our health, and unnecessary except in extreme conditions with defined scientific trigger points. Good medical science advocated by expert professionals should be the guide here, not the self-serving whims of local politicians.
[21 apr 03]