By Dr. John Happs
Dichloro-diphenyl-trichloro-ethane (DDT) is an organo-chlorine insecticide first synthesised in 1874 by the Austrian chemist Othmar Zeidler. Its insect-killing capacity was later realised by the Swiss chemist Paul Muller in 1939.
Although it is readily absorbed through the exo-skeletons of insects, it is poorly absorbed through the skin of mammals. It kills insects by disrupting the transmission of electrical impulses between their nerve cells, causing them to fire spontaneously. Fortunately, DDT does not have the same impact on higher-order animals.
DDT was widely used by the military during World War 11 to control malaria, typhus and body lice and in 1944 Winston Churchill acknowledged the huge benefits that DDT offered to so many countries, saying:
“We have discovered many preventives against tropical diseases, and often against the onslaught of insects of all kinds, from lice to mosquitoes and back again. The excellent DDT powder which had been fully experimented with and found to yield astonishing results will henceforth be used on a great scale by the British forces in Burma and by the American and Australian forces in the Pacific and India in all theatres.”
Like so many other young and naïve people, I initially believed and was disturbed about the widespread use of DDT after reading Rachel Carson’s book Silent Spring (Houghton Mifflin, 1962). Her book was directed at synthetic pesticides, notably DDT, and the supposed dangers such pesticides posed for humans and wildlife.
Environmentalists seized on the dire warnings from Carson and protested against the use of DDT, believing without question what she had written about the dangers from this particular compound that can save so many lives and protect so many food crops.
Marjorie Mazel Hecht has described the demonization of DDT as “The Mother of environmental hoaxes” pointing out that it was banned in 1972 by the US Environmental Protection Agency for what the EPA’s administrator William Ruckelhaus confessed was on political grounds.
Paul Driessen reflected:
“Radical environmentalism rose to ascendancy on opposition to pesticides, specifically DDT. “If the environmentalists win on DDT,” Environmental Defense Fund scientist Charles Wurster told the Seattle Times in 1969, “they will achieve a level of authority they have never had before.” Using Rachel Carson’s often inaccurate book Silent Spring to drive a nasty campaign, they succeeded in getting the Environmental Protection Agency to ban US production and use of DDT in 1972, leading to a de facto global ban even to combat malaria.”
The ban was put in place despite 9,000 pages of testimony and a ruling by Edmund Sweeney that
“DDT is not carcinogenic, mutagenic, or teratogenic to man [and] these uses of DDT do not have a deleterious effect on fish, birds, wildlife, or estuarine organisms.”
Green groups have constantly promoted falsehoods about any level of DDT being carcinogenic in human beings and that it contributes to bird eggshell thinning and bird die-offs, despite there being no scientific evidence to support such claims.
Entomologist Dr. Gordon Edwards commented on Carson’s book:
“As I neared the middle of the book, the feeling grew in my mind that Rachel Carson was really playing loose with the facts and was also deliberately wording many sentences in such a way as to make them imply certain things without actually saying them. She was carefully omitting everything that failed to support her thesis that pesticides were bad, that industry was bad, and that any scientists who did not support her views were bad.”
To make his point, Edwards regularly consumed 1 tablespoon of DDT to demonstrate its safety. He was a keen mountaineer who died at the age of 84 during his climb of Divide Mountain in the Glacier National Park. His prescient warnings about the consequences of banning DDT have been so tragically borne out.
In 1990, an article in the medical journal The Lancet reported:
“The early toxicological information on DDT was reassuring; it seemed that acute risks to health were small. If the huge amounts of DDT used are taken into account, the safety record for human beings is extremely good. In the 1940s many people were deliberately exposed to high concentrations of DDT thorough dusting programmes or impregnation of clothes, without any apparent ill effect… In summary, DDT can cause toxicological effects but the effects on human beings at likely exposure are very slight.”
See: Roberts et al. (2010). The Excellent Powder: DDT’s Political and Scientific History. Dog Ear Publishing, Indianapolis.
Despite a study supporting the use of DDT by the U.S. Fish and Wildlife Service and a supportive 1970 report by the Pesticides Monitoring Journal, the EPA banned the use of DDT as did a number of nations that feared European countries would refuse to buy their agricultural exports if they continued their use of DDT.
Green zealots not only campaigned against the use of DDT, leading to the widespread increase in insect-borne disease, they were assisted in their crusade by the Intergovernmental Panel on Climate Change (IPCC) that blamed (imaginary) global warming for the increase in insect-borne disease. This the IPCC did without consulting publications by Dr. Paul Reiter, the world’s foremost expert in this area.
Reiter works at the Pasteur Institute in Paris and is chief of its Insects and Infectious Disease Unit. He is a specialist in the natural history and biology of mosquitoes, the epidemiology of the diseases they transmit, and strategies for their control.
Reiter was also chairman of the American Committee of Medical Entomology of the American Society for Tropical Medicine and Hygiene, and several committees of other professional societies. He has worked for the World Health Organization (WHO), the Pan American Health Organization and other agencies in investigations of outbreaks of mosquito-borne diseases, as well as AIDS, Ebola haemorrhagic fever and onchocerciasis. He was also an author for the IPCC’s Third Assessment Report (TAR) when he realized that his input was being ignored.
In 2001, the U.S. State Department nominated Reiter to be a Lead Author of the IPCC’s next health chapter. The IPCC was incorrectly arguing that (imaginary) global warming was increasing the habitats for mosquitoes, putting millions of people in the tropics at risk of contracting malaria and dengue with the prospect that these diseases would spread around a warming world.
Reiter protested, saying:
“I know of no major scientist with any long record in this field who agrees with the pronouncements of the alarmists at the IPCC.”
“On the contrary, all of us who work in the field are repeatedly stunned by the IPCC pronouncements. We protest, but are rarely quoted, and if so, usually as a codicil to the scary stuff.”
Reiter reported that, in its 1995 Second Assessment Report (SAR) chapter on Human Population Health, the IPCC displayed “glaring ignorance” about mosquitoes, their survival temperatures and the altitudes where mosquitoes can be found.
The IPCC scientists’ “glaring ignorance” struck a raw nerve with Reiter and his colleagues. Without any evidence, they were claiming that malarial mosquitoes do not ordinarily survive temperatures below 16oC to 18oC, not realizing that many species do and that many temperate species survive temperatures of minus 25oC. Neither did IPCC scientists know at what altitudes mosquitoes are to be found.
In testimony to the UK House of Lords, Reiter said:
“The paucity of information was hardly surprising: Not one of the lead authors had ever written a research paper on the subject. Moreover, two of the authors, both physicians, had spent their entire career as environmental activists.”
Reiter, like so many other scientists, resigned from the IPCC, saying:
“The IPCC has done a disservice to society by relying on “experts” who have little or no knowledge of the subject and allowing them to make authoritative pronouncements that are not based on sound science. In truth, the principal determinants of transmission of malaria and many other mosquito-borne diseases are politics, economics and human activities.”
Malaria continues to kill about 1.5 million people per annum, including around 800,000 children under 5 years of age. Malaria is treatable and preventable with current technology yet the majority of cases are found in the sub-Sahara where poverty is the biggest obstacle in dealing with this epidemic.
Gething et al. (May 2010) in the journal Nature optimistically stated:
“It has long been known that the range of malaria has contracted through a century of economic development and disease control.”
“Widespread claims that rising mean temperatures have already led to increases in worldwide malaria morbidity and mortality are largely at odds with observed decreasing global trends in both its endemicity and geographic extent.”
(Gething, P.W. et al. (2010). Climate Change and the Global Malaria Recession. Nature, 465 (7296): 34-345.)
In fact malaria has actually receded, contrary to what some global warming alarmists have been predicting although the Director-General of the World Health Organization (WHO), Margaret Chan, observed that the mosquito-borne Zika virus is spreading throughout the Americas and estimates that 3 to 5 million will eventually be infected by the virus.
Martha Mercer reported the real problems on her visit to Padre Paraiso in Brazil. She observed that houses have no screens on the windows and mosquito nets are unpopular, since they make hot nights even more uncomfortable. Additionally, garbage is collected from open metal baskets where water collects, forming:
“The perfect breeding ground for Aedes aegypti, the mosquito that spreads Zika, chikungunya, yellow fever, and dengue, which is also an epidemic in Brazil.”
There is no doubt that DDT is an effective killer of mosquitoes. South Africa adopted its use in 1946 and malaria cases declined to 10% of their earlier levels. Unfortunately, green zealots lobbied for the banning of DDT after reading Rachel Carson’s 1962 pseudo-scientific bestseller Silent Spring and the consequences were dire.
Dr. Roger Meiners is Professor of Economics and Law at the University of Texas at Arlington and a senior fellow at the Property and Environmental Research Center in Bozeman, Montana. He writes in “Silent Spring at 50: The False Crises of Rachel Carson” (Reassessing environmentalism’s fateful turn from science to advocacy):
“Carson made little effort to provide a balanced perspective and consistently ignored key evidence that would have contradicted her work. Thus, while the book provided a range of notable ideas, a number of Carson’s major arguments rested on what can only be described as deliberate ignorance.”
Sam Zaramba, from the Ugandan Health Ministry, reported that 370 children die from insect-borne disease every day in his country and between 500 and 800 million people currently suffer from malaria worldwide, mostly in poor countries.
Zaramba asks the question:
“Who anointed the free-earth, save the earth, global warming crowd, anti – DDT crowd, that the blacks and the other third world people suffer with malaria and mosquitos?”
In South Africa, DDT was banned in 1996 and malaria cases subsequently increased from 12,500 to 50,000 in 4 years. Fortunately, cases were reduced by 80% in Natal, once they started using DDT again. The introduction of DDT in Guyana was immediately apparent, leading Alexander King, co-founder of the Club of Rome to spitefully remark:
“When DDT was introduced for civilian use, within 2 years Guyana had almost eliminated malaria. But at the same time the birth rate had doubled. So my chief quarrel with DDT in hindsight is that it has greatly added to the population problem.”
So here we have another anti-human zealot who would rather see large numbers of people dying – presumably to save the planet for other life-forms. Perhaps King should share his views with these African women who see DDT as a Weapon of Mass Survival:
There is no doubt that DDT is the most inexpensive and effective way of preventing the transmission of insect-borne disease. It can be safely sprayed inside homes, thus avoiding any concerns about dangers to crops or wildlife. Millions of people are still dying annually from insect-borne diseases and the benefits of DDT should be obvious to all.
Fortunately the World Health Organization (WHO) eventually removed the ban on DDT. They reported that:
“DDT is one of the best tools we have against malaria and presents no health risk.”
Hopefully, the use of DDT will become more widespread and continue to save many lives from insect-borne disease although none of the green zealots who were responsible for its ban will take the blame for the tens of millions of deaths that have already occurred as a result of their ignorance, intransigence and anti-human stance.
Dr. John Happs M.Sc.1st Class; D.Phil. John has an academic background in the geosciences with special interests in climate, and paleoclimate. He has been a science educator at several universities in Australia and overseas and was President of the Western Australian Skeptics for 25 years.