The question seemed simple.
“In human medicine, most people would agree that a person gets a cold or flu when their immune system is suppressed. Has anyone considered what is suppressing the immune system of people and chickens?” in Vietnam, making them more susceptible to the deadly effects of H5N1? Has anyone investigated what suppresses the immune systems of migratory birds?” The question was put to Dr. Alex Thiermann, President of the OIE, the World Organization for Animal Health, at the First Summit on Avian Influenza held in Washington, DC, on February 27-28, 2006. His response: “No one is looking at this.” In fact, no one has thought about it,” he echoed to journalists and scientists during the coffee break that followed.
An investigation into the immunosuppressive effects of environmental chemicals, with a particular focus on dioxin, may shed light on the seemingly scattered and unconnected outbreaks of bird flu around the world. The association between dioxin and influenza may even explain the increased number of deaths in China, Vietnam and, in particular, Indonesia.
Dioxin: the most toxic chemical on earth
Dioxin is a general term that describes a complex family of more than 400 chemicals. An unintentional waste product, dioxin is formed during industrial processes that combine chlorine with an organic substance, such as wood, pulp, or paper, in the presence of heat. Production facilities that manufacture pesticides melted down copper foil and bleach, all of which release dioxins as by-products. Additionally, dioxin can enter the environment through the incineration of plastics, particularly those that burn medical and municipal waste.
A very persistent chemical, dioxin can take more than 15 years to break down to half its original concentration. If released into local water supplies, eg ponds and rivers, it can accumulate in fish. If aquatic life does not immediately absorb it, the remaining dioxin quickly settles in the sediment. It will stay there, virtually forever, unless it moves up the food chain through grasses and frogs, becoming particularly toxic to humans and waterfowl.
Dioxin has been shown to disrupt the immune system at exposures as low as 1.0 ppt. This is the equivalent of a single drop of liquid placed in the center car of a ten-kilometer (6.2-mile) long freight train.(1) Because the chemicals are usually a mix of toxic compounds and not toxic, a score is assigned to each chemical. developed called Toxic Equivalence (TEQ). The TEQ of any chemical is established by comparing it to TCDD, the most toxic form of dioxin in the world.
Dioxin Combined With Influenza Viruses: Serious Consequences
There is a definite link between dioxin exposure and the effect of influenza viruses on the immune system, a connection that has been studied in laboratory mice.
Research has clearly shown that two types of white blood cells, natural killer (NK) cells and CD8+ cells, are exquisitely sensitive to extremely small concentrations of TCDD. Studies have shown that if mice are subjected to 100-1000 ppt TCDD before being challenged with common influenza A viruses, the number of mice that die is significantly higher than the number of unexposed control mice previously to this dioxin. (2) In another study, when mice were given as little as 10 ppt TCDD one week before being challenged with influenza A viruses, the Mortality rate among duplicate mice. The researchers noted that this was the “smallest toxic dose of dioxin ever shown” to suppress the immune system’s ability to ward off influenza.(3)
In a third study, fluid extracted directly from the lungs of dead mice showed that the increased mortality observed in mice exposed to TCDD was due to the intense inflammatory action of dioxin. Death was not due to viral infection alone.(4) In other words, the combination of influenza viruses and dioxin caused so much inflammation in the lungs, due to a massive storm of cytokines, that normal lung tissue destroyed and caused death. of most mice.
Dioxin in Vietnam
The volume of herbicides sprayed during the American conflict in Vietnam between 1961 and 1971 has been estimated at more than 19 million liters. The highest concentrations were deposited over the Mekong Delta in what is now southern Vietnam. The containers with dioxin were known as Agent Orange, identified by barrels with orange stripes. More than 30 years later, this persistent chemical remains in the soil and food of local residents and continues to cause serious health problems.
In the absence of continuous aerial spraying, the main route of dioxin entry into the body is through food grown in toxic soils. Canadian researchers found dioxin levels in soil samples in different regions of southern Vietnam as high as 898 ppt. The most extreme levels of contamination – in the area of Lake Bien Hung – were measured in greater than 1.1 million ppt.(5)
In 2002, dioxin levels were measured in 16 different food samples that were collected from local markets around Lake Bien Hung in southern Vietnam. The preliminary results began. Three of the samples contained levels of dioxin that were so extraordinarily high that they were sent to a second independent laboratory for further analysis. The second lab confirmed the disturbing results. In the final report, chemical contaminants and high dioxin concentrations, up to 536 ppt, were detected in all 16 food samples. To put these elevated levels into perspective, the typical level of dioxin found in food is less than 0.1 ppt.(6)
Dioxin, influenza and humans: a connection?
In May 2006, Indonesia reported a cluster of human avian influenza cases involving eight family members, seven of whom died. All but one person in the family appeared to have contracted the virus from another family member. This became the first reported incidence of H5N1 spreading from one person to another, and then to another. Alarmed officials feared that the bird flu virus had acquired characteristics that would soon allow it to pass easily from human to human.
The members of the deceased family lived in a small village in the Karo district located in the Indonesian province of North Sumatra. The Karo Highlands border Lake Toba, the world’s largest volcanic lake. Southeast Asia’s largest lake, Toba, has been deteriorating since 1998, helpless against Indorayon, a paper, pulp and rayon manufacturer owned by multinational companies and financed by the World Bank. Until it was closed, Indorayon was the biggest polluter of Lake Toba in the last decade, dumping tons of chlorine and dioxin into the waters.
Interestingly, hundreds, perhaps thousands, of people with H5N1 influenza have not been sick enough to require medical attention, as WHO spokesman Dick Thompson confirmed in March 2005.(7) However, between 2003 and 11 As of April 2007, there have been 291 cases and 171 deaths, with 61% of deaths in Vietnam and Indonesia. An investigation, perhaps including a fat biopsy, should be done to determine if the people who died had significantly higher concentrations of dioxin in their bodies than the people who were exposed to H5N1 and remained well or fully recovered.
What can be done?
A global pandemic is brewing, but not because a virus can “jump between species” and rapidly circumnavigate the globe, annihilating everyone in its path. It appears that only those most at risk will be affected. But critically important information is missing: What is each person’s individual risk level? Beyond spending billions on global bureaucratic preparation, true prevention is in order through the development of tests and detoxification methods for humans.
Instead of funding the development of a vaccine that, as a marginal chance of being effective, would be better off spending billions of dollars funding international environmental cleanup programs. Legislative initiatives that enforce international treaties already on the books may be the best way to avert disaster.
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(1) Quynh, Hoang Trong, MD, et al. “Long-Term Consequences of the Vietnam War”, Nordic News Network, Report of the Environmental Conference on Cambodia, Laos and Vietnam.
(2) Burleson, GR, et al. “Effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on host resistance of influenza virus in mice”, Toxicological Sciences, 29 (1996): 40-47
(3) Burleson, GR, et al. “Effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on host resistance of influenza virus in mice”, Toxicological Sciences, 29 (1996): 40-47.
(4) Luebke, RW, et al. “Mortality in mice exposed to dioxin and infected with influenza: mitochondrial toxicity (Reye-like syndrome) versus increased inflammation as a mode of action”, Toxicological Sciences 69 (2002): 109-116.
(5) Schecter, A., Quynh, HT, Pavuk, M., Papke, O., Malisch, R., Constable, JD “Food as a source of dioxin exposure in residents of Bien Hoa City, Vietnam “, Journal of Occupational and Environmental Medicine 45 (2003): 781-788. PMID: 12915779.
(6) Schecter A., et al. “Food as a source of dioxin exposure in residents of Bien Hoa City, Vietnam,” Journal of Occupational and Environmental Medicine 45 (2003): 781-788. PMID: 12915779.
(7) 23 Roos, Roberto. “Relatives of avian flu patients have asymptomatic cases”, Noticias CIDRAP, March 9, 2005.