U.S. takes new view on DDT in Africa

Possibly the best news I've heard in a few decades.

Silent Spring and the "research" behind it was such a load of crap but had a life of its own with the baby boom...

finally!

After 100 million or more deaths, this travesty finally
gets ended.

Great achievement by the ecology lobby. . . (sarc/off)

Silent Spring and the "research" behind it was such a load of crap but had a life of its own with the baby boom...

Now can someone re-examine the Global Warming resesrch too? How about the so-called dangers of nuclear energy? We baby boomers were had.

"Please ping others to this great news" PING!

We think DDT is safe when used correctly and are not aware of any human health risks.

I didn't there were any health risks for humans with DDT-I thought it caused thin shells on bird egss.

Yes, finally! But after years of letting people die unnecessarily.

One of my early years chores was "painting" the screens with DDT for my grandmother.

Not uncommon then.

Great news. Long overdue. This could save millions of people from a horrible fate. But I'm sure the usual Watermellons will distort the hell out of this and continue their junk science lies.

Sub-Saharan Africa – A Region At Risk: The vast majority of global polio cases are now found in Nigeria – 544 out of 717 cases as of 22 Sept 2004. In 2003, Nigeria and Niger were the only two countries in the region to have endemic polio transmission

from just one site: http://www.reliefweb.int/rw/rwb.nsf/AllDocsByUNID/20f57d9b94eb08bd85256f1c0066509c

Might want to look at the research on the links between DDT and polio -

My litmus test is to look at the research on both sides. If the negatives have plausibility - I'd prefer to err on the side of safety.

Monsanto and the other big chem companies have been pushing to get DDT back on line for decades. They have the big money and the big lobby's...

U.S. government officials are enthusiastically endorsing and funding the use of DDT in sub-Saharan Africa

WTF? Funding? I need to consult my pocket version of the Constitution more often I guess. And somehow I don't believe ANY of the "funding" will be coming from the "officials".

I don't think these people will be happy with the announcement (and its timing) :

Environmentalists Urge Elimination of DDT for Malaria Control
By Lisa Schlein
Geneva
02 May 2006

Environmentalists are calling for the elimination of the toxic chemical, DDT, which is still used in large parts of Africa to combat malaria. The continued use of DDT is on the agenda of a week-long conference in Geneva aimed at strengthening measures to rid the world of some of its most dangerous chemicals.

More than 500 delegates from 130 countries and many non-governmental organizations are attending the annual conference of the Stockholm Convention on Persistent Organic Pollutants. POPs, as they are called, include 12 hazardous pesticides and industrial chemicals.

The full story is at http://www.voanews.com/english/2006-05-02-voa53.cfm

In the interests of honesty, they should call themselves the Friends of the Anopheles Mosquito.

-Eric

I guess they decided Rachel has murdered enough Africans.

"Environmentalists liked things as they were previously, when USAID's malaria-prevention efforts focused primarily on handing out drug treatments and insecticide-treated bed netting to people living in areas at risk for heavy mosquito infestation."

I bet they liked that better because it causes more people to die, which is exactly what the latter day eugenicists in the environmental movement want.

I thought it caused thin shells on bird egss.

Turns out that it didn't, and Rachal Carson didn't know what she was talking about.

What in the world could possibly be the connection between polio and DDT?

Amen to that! DDT is the best way to defeat many mosquito born illnesses. I would hope that DDT would be used responablely anywhere in the world that mosquito born illnesses plague mankind.

DDT info. History DDT was first synthesized in 1874 by Othmar Ziedler, but its insecticidal properties were not discovered until 1939, by the Swiss scientist Paul Hermann Müller, who was awarded the 1948 Nobel Prize in Physiology and Medicine for his efforts. DDT is the best-known of a number of chlorine-containing pesticides used in the 1940s and 1950s. It was used extensively during World War II by Allied troops and certain civilian populations to control insect typhus and malaria vectors (nearly eliminating typhus as a result). Civilian suppression used a spray on interior walls, which kills mosquitoes that rest on the wall after feeding to digest their meal; resistant strains are repelled from the area. Entire cities in Italy were dusted to control the typhus carried by lice. DDT also sharply reduced the incidence of biting midges in Great Britain, and was used extensively as an agricultural insecticide after 1945. DDT was responsible for eradicating malaria from Europe and North America. Though today malaria is considered a tropical disease, it was more widespread prior to an extensive malaria eradication program carried out in the 1950s. Though this program was initially highly successful worldwide (reducing mortality rates from 192 per 100,000 to a low of 7 per 100,000), resistance emerged in many insect populations over time. DDT was less effective in tropical regions due to the continuous life cycle of mosquitoes and poor infrastructure. It was not pursued aggressively in sub-Saharan Africa due to these perceived difficulties, with the result that mortality rates in the area were never reduced to the same dramatic extent, and now constitute the bulk of malarial deaths worldwide, especially following the resurgence of the disease as a result of microbe resistance to drug treatments and the spread of the deadly malarial variant caused by Plasmodium falciparum. In the 1970s and 1980s, agricultural use of DDT was banned in most developed countries, and DDT was replaced in most antimalarial uses by less persistent, but more expensive, alternative insecticides. DDT was first banned from use in Norway and Sweden in 1970, but was not banned in the United Kingdom until 1984. As of 2006, DDT continues to be used in other (primarily tropical) countries where mosquito-borne malaria and typhus are serious health problems. Use of DDT in public health to control mosquitoes is primarily done inside buildings and through inclusion in household products and selective spraying; this greatly reduces environmental impact compared to the earlier widespread use of DDT in agriculture. It also reduces the risk of resistance to DDT.[2] This use only requires a small fraction of that previously used in agriculture; for the whole country of Guyana, covering an area of 215,000 km², the required amount is roughly equal to the amount of DDT that might previously have be used to spray 4 km² of cotton during a single growing season.[3] The Stockholm Convention, ratified in 2001 and effective as of 17 May 2004, calls for the elimination of DDT and other persistent organic pollutants, barring health crises. The Convention was signed by 98 countries and is endorsed by most environmental groups. However, a total elimination of DDT use in many malaria-prone countries is currently unfeasible because there are few affordable or effective alternatives for controlling malaria, so public health use of DDT is exempt from the ban until such alternatives are developed. Malaria Foundation International states: The outcome of the treaty is arguably better than the status quo going into the negotiations over two years ago. For the first time, there is now an insecticide which is restricted to vector control only, meaning that the selection of resistant mosquitoes will be slower than before.[4] [edit] Environmental impact Overall, DDT concentrates in biological systems (particularly in body fat), it is a toxin across a certain range of phyla, and it bioaccumulates up the food chain, reaching its greatest concentrations in higher animals such as humans. DDT is a persistent organic pollutant and is highly persistent in the environment. It has a reported half life of between 2-15 years and is immobile in most soils. Its half life is 56 days in lake water and approximately 28 days in river water. Routes of loss and degradation include runoff, volatilization, photolysis and biodegradation (aerobic and anaerobic). These processes generally occur slowly. Breakdown products in the soil environment are DDE (1,1-dichloro-2,2-bis(p-dichlorodiphenyl)ethylene) and DDD (1,1-dichloro-2,2-bis(p-chlorophenyl)ethane), which are also highly persistent and have similar chemical and physical properties. In the United States, human blood and fat tissue samples collected in the early 1970s showed detectable levels in all samples. A later study of blood samples collected in the later half of the 1970s showed that blood levels were declining further, but DDT or metabolites were still seen in a very high proportion of the samples. DDT is an organochlorine. Some organochlorines have been shown to have weak estrogenic activity; that is, they are chemically similar enough to estrogen to trigger hormonal responses in contaminated animals. This hormonal-mimicking activity has been observed when DDT is used in laboratory studies involving mice and rats as test subjects, but available epidemiological evidence does not indicate that these effects have occurred in humans as a result of DDT exposure. DDT and its metabolic products accumulate through the food chain, with apex predators such as raptors having a higher concentration of the chemicals than other animals sharing the same environment. In particular, DDT has been cited as a major reason for the decline of the bald eagle in the 1950s and 1960s. In general, however, DDT in small quantities has very little effect on birds; its primary metabolite, DDE, has a much greater impact. DDT and DDE have little impact on some non-predatory birds, such as the chicken. DDT is highly toxic to aquatic life, including crayfish, daphnids, sea shrimp and many species of fish. DDT may be moderately toxic to some amphibian species, especially in the larval stages. In addition to acute toxic effects, DDT may bioaccumulate significantly in fish and other aquatic species, leading to long-term exposure. By the 1950s, in some cases, doses of DDT and other insecticides had to be doubled or tripled as resistant insect strains developed. In addition, the evidence began to grow that the chemical had a tendency to become more concentrated at higher levels in the food chain. [edit] Impact on human health There are no substantial scientific studies so far which prove that DDT is particularly toxic to humans or other primates, compared to other widely-used pesticides. DDT can be applied directly to clothes and used in soap, with no demonstrated ill effects.[5] Indeed, DDT has on rare occasions been administered orally as a treatment for barbiturate poisoning.[6] Most of the precise toxicological data on DDT and its metabolites comes from animal experiments; epidemiological and toxicological studies on humans are less precise, because they come from populations who are either exposed to the compounds in manufacturing or spraying, or are third world populations; in either case, they are exposed to multiple pesticides and many other risk factors. Taking these limitations into account, the EPA estimates with "medium" confidence (due to "shorter duration than desired" of the studies) based mainly on liver toxicity in rats, that no non-carcenogenic effect will be seen at an oral exposure of less than 5 x10-4 mg/kg-day as a conservative limit including a 10-fold safety factor for generalizing from rats to humans, and another 10-fold factor to account for human subpopulations which may be exceptionally sensitive.[7] Similarly, the EPA classifies DDT as class B2, a probable human carcinogen, based on observed carcinogenicity in animals, i.e. tumors (generally of the liver) in seven studies in various mouse strains and three studies in rats, and on structural similarity to other carcinogens such as DDE, DDD, dicofol, and chlorobenzilate.[8] The risk factor for oral ingestion is estimated at 3.4x10-1 per mg/kg-day or 9.7x10-6 per ug/L for drinking water, which translates into a cancer risk of 1 in 10,000 for 10 ug/L, 1 in 100,000 for 1 ug/L, or 1 in 1,000,000 for 0.1 ug/L; the risk factor for inhalation is estimated at 9.7x10-5 per ug/m3, which translates into a cancer risk of 1 in 10,000 for 1 ug/m3, 1 in 100,000 for 0.1 ug/m3, or 1 in 1,000,000 for 0.01 ug/m3.[9] A review article[10] in The Lancet concludes Although DDT is generally not toxic to human beings and was banned mainly for ecological reasons, subsequent research has shown that exposure to DDT at amounts that would be needed in malaria control might cause preterm birth and early weaning, abrogating the benefit of reducing infant mortality from malaria. ... DDT might be useful in controlling malaria, but the evidence of its adverse effects on human health needs appropriate research on whether it achieves a favourable balance of risk versus benefit. Future perspectives Although acute toxic effects are scarce, toxicological evidence shows endocrine-disrupting properties; human data also indicate possible disruption in semen quality, menstruation, gestational length, and duration of lactation. The research focus on human reproduction and development seems to be appropriate. DDT could be an effective public-health intervention that is cheap, longlasting, and effective. However, various toxic-effects that would be difficult to detect without specific study might exist and could result in substantial morbidity or mortality. Responsible use of DDT should include research programmes that would detect the most plausible forms of toxic effects as well as the documentation of benefits attributable specifically to DDT. Although this viewpoint amounts to a platitude if applied to malaria research in Africa, the research question here could be sufficiently focused and compelling, so that governments and funding agencies recognise the need to include research on all infant mortality when DDT is to be used. [edit] Conflicting Studies Direct studies have not found a link between DDT and breast cancer in humans.[11] [12] Some evidence suggests a link between DDT and breast cancer in humans. For example, diminishing rates of breast cancer in Israel have paralleled a precipitous decline in environmental contamination with DDT and benzene hexachloride. [1] [2] (See also [13], [14], [15]) Dr. Mary Wolf published a 1993 article in the Journal of the National Cancer Institute indicating a statistically significant correlation between DDT metabolites in the blood and the risks of developing breast cancer in the general population. Others have disputed this research. In one study, primates were fed 33,000 times more DDT than the estimated exposure of adult humans in 1969. No conclusive link with cancer was detected.[16] A study of 692 women, half of them control subjects, over a period of twenty years established no correlation between serum DDE and breast cancer. DDE is a matabolite of DDT, and correlates with DDT exposure.[17] A study examined 35 workers exposed to 600 times the average DDT exposure levels over a period of 9 to 19 years. No elevated cancer risk was observed.[18] In another study, humans voluntarily ingested 35 mg of DDT daily for about two years, and were then tracked for several years afterward. No elevated risk was observed.[19] The review discussed above summarizes the available evidence, in slightly more detail: In people, DDT use is generally safe; large populations have been exposed to the compound for 60 years with little acute toxicity apart from a few reports of poisoning. Doses as high as 285 mg/kg taken accidentally did not cause death, but such large doses did lead to prompt vomiting. One dose of 10 mg/kg can result in illness in some people. Subclinical and subtle functional changes have not been meticulously sought until the past few decades. Occupational exposure to DDT was associated with reduced verbal attention, visuomotor speed, sequencing, and with increased neuropsychological and psychiatric symptoms in a dose-response pattern (ie, per year of DDT application) in retired workers aged 55–70 years in Costa Rica. Although DDT or DDE concentrations were not determined in this study, they probably were very high. Although extensively studied, there is no convincing evidence that DDT or its metabolite DDE increase human cancer risk. Mainly on the basis of animal data, DDT is classified as a possible carcinogen (class 2B) by the International Agency for Research on Cancer (IARC) and as a reasonably anticipated human carcinogen by the US National Toxicology Program. Breast cancer has been examined most closely for an association with p,p'-DDE. In a study in 1993, 37 breast cancer patients had higher serum DDE concentrations (11·8 μg/L) than controls (7·7 μg/L), and results from several subsequent studies supported such an association. However, large epidemiological studies and subsequent pooled and meta-analyses failed to confirm the association. With detailed work history of chemical manufacturing workers to estimate DDT exposure, a nested case-control study reported occupational DDT exposure associated with increased pancreatic cancer risk. A weak association of self-reported DDT use with pancreatic cancer was reported in another case-control study. A report indicated a higher standardised mortality ratio for pancreatic cancer in outdoor workers with a history of DDT exposure of less than 3 years, but the standardised mortality ratio of DDT workers with exposure of 3 years or more was not significantly raised.[20]