Here are some starting points for sources on the DDT controversy re the pathetic and dangerous misinformation and varying mendacities emaniating from the environmental movement over the last third of the 20th century.
Day of Reckoning for DDT Foes?
Op-Eds & Articles
by Steven J. Milloy
September 21, 2006
Last week’s announcement that the World Health Organization lifted its nearly 30-year ban on the insecticide DDT is perhaps the most promising development in global public health since… well, 1943 when DDT was first used to combat insect-borne diseases like typhus and malaria.
Overlooked in all the hoopla over the announcement, however, is the terrible toll in human lives (tens of millions dead — mostly pregnant women and children under the age of 5), illness (billions sickened) and poverty (more than $1 trillion dollars in lost GDP in sub-Saharan Africa alone) caused by the tragic, decades-long ban.
Much of this human catastrophe was preventable, so why did it happen? Who is responsible? Should the individuals and activist groups who caused the DDT ban be held accountable in some way?
Rachel Carson kicked-off DDT hysteria with her pseudo-scientific 1962 book, “Silent Spring.” Carson materially misrepresented DDT science in order to advance her anti-pesticide agenda. Today she is hailed as having launched the global environmental movement. A Pennsylvania state office building, Maryland elementary school, Pittsburgh bridge and a Maryland state park are named for her. The Smithsonian Institution commemorates her work against DDT. She was even honored with a 1981 U.S. postage stamp. Next year will be the 100th anniversary of her birth. Many celebrations are being planned.
It’s quite a tribute for someone who was so dead wrong. At the very least, her name should be removed from public property and there should be no government-sponsored honors of Carson.
The Audubon Society was a leader in the attack on DDT, including falsely accusing DDT defenders (who subsequently won a libel suit) of lying. Not wanting to jeopardize its non-profit tax status, the Audubon Society formed the Environmental Defense Fund (now simply known as Environmental Defense) in 1967 to spearhead its anti-DDT efforts. Today the National Audubon Society takes in more than $100 million per year and has assets worth more than $200 million. Environmental Defense takes in more than $65 million per year with a net worth exceeding $73 million.
In a February 25, 1971, media release, the president of the Sierra Club stated that his organization wanted “a ban, not just a curb” on DDT, “even in the tropical countries where DDT has kept malaria under control." Today the Sierra Club rakes in more than $90 million per year and has more than $50 million in assets.
Business are often held liable and forced to pay monetary damages for defective products and false statements. Why shouldn’t the National Audubon Society, Environmental Defense, Sierra Club and other anti-DDT activist groups be held liable for the harm caused by their recklessly defective activism?
It was, of course, then-Environmental Protection Agency administrator William Ruckelshaus who actually banned DDT after ignoring an EPA administrative law judge’s ruling that there was no evidence indicating that DDT posed any sort of threat to human health or the environment. Ruckleshaus never attended any of the agency’s hearings on DDT. He didn’t read the hearing transcripts and refused to explain his decision.
None of this is surprising given that, in a May 22, 1971, speech before the Wisconsin Audubon Society, Ruckleshaus said that EPA procedures had been streamlined so that DDT could be banned. Ruckleshaus was also a member of — and wrote fundraising letters for — the EDF.
The DDT ban solidified Ruckelshaus’ environmental credentials, which he has surfed to great success in business, including stints as CEO of Browning Ferris Industries and as a director of a number of other companies including Cummins Engine, Nordstrom, and Weyerhaeuser Company. Ruckelshaus currently is a principal in a Seattle, Wash., -based investment group called Madrona Venture Group.
Corporate wrongdoers — like WorldCom’s Bernie Ebbers and Tyco’s Dennis Kozlowski — were sentenced to prison for crimes against mere property. But what should the punishment be for government wrongdoers like Ruckleshaus who, apparently for the sake of his personal environmental interests, abused his power and affirmatively deprived billions of poor, helpless people of the only practical weapon against malaria?
Finally, there is the question of the World Health Organization itself. What’s the WHO been doing for all these years? There are no new facts on DDT — all the relevant science about DDT safety has been available since the 1960s. Moreover, the WHO’s strategy of mosquito bednets and malaria vaccine development has been a dismal failure. While the death toll in malarial regions has mounted, the WHO has been distracted by such dubious issues as whether cell phones and French fries cause cancer.
It’s a relief that the WHO has finally come to its senses, but on the other hand, the organization has done too little, too late. The ranks of the WHO’s leadership need to be purged of those who place the agenda of environmental elitists over the basic survival of the world’s needy.
In addition to the day of reckoning and societal rebuke that DDT-ban advocates should face, we should all learn from the DDT tragedy.
With the exception of Rachel Carson (who died in 1964), all of the groups and individuals above mentioned also promote global warming alarmism. If they and others could be so wrong about DDT, why should we trust them now? Should we really put the global economy and the welfare of billions at risk based on their track record?
How Environmentalism Kills the Poor – Malaria and the DDT Story
By Dr Roger Bate for Envirobio Conference, 14th November 2000 Paris.
The Author
Roger Bate (PhD Cambridge) is a fellow at the Institute of Economic Affairs in London and
a founder of the European Science and Environment Forum in Cambridge. He has published
numerous papers and edited four books for ESEF, with Butterworth Heinemann, What
Risk? Science, politics and public health, Environmental Health: Third World
Problems; First World Preoccupations (with Lorraine Mooney), Fearing Food: Risk,
health and environment (with Julian Morris), and most recently Life’s Adventure: Virtual
Risk in a Real World ( a collection of 65 of his newspaper articles). He can be
contacted on
rbate@iea.org.uk
Most of our pre-occupations arise from the modern paradox: while our longevity, health and
environment has never been better we spend more time than ever before worrying about all
three. Classic examples in Europe have been the various scares – nitrates, pesticides
residues, breast implants, passive smoking, nuclear power; more recently, mobile phones;
and GM foods. In some of these, the concern was completely invalid, in others the scare
was blown out of all proportion.
This paper is not aimed at exposing such scares, misinformation or exaggeration but to say,
even if some of the scares contain truth, it may be inappropriate for poor countries to be
worried too much about them. Indeed, it may be sensible for other countries to allow things
to happen which we would sensibly discourage or even prohibit.
You might think that the poorest less developed countries (LDCs) in the world would not
share our preoccupations, such as a cancer risk from overhead power-lines (when lack of
electricity for refrigeration of food and medicines, and lighting for education… is the real
problem). But often this isn’t the case. For example, it is instructive to see analysis of risk
issues in France and the francophone African State of Burkina Faso. The medical,
environmental, geographical and political realities of Burkina Faso are radically different
from France, yet a study of attitudes towards risk showed that Burkina Faso intellectuals
had approximately the same preoccupations as the French respondents and to the same
degree. In fact intellectual responses reflected media coverage in Burkina Faso, indicating
that reality plays a secondary role to the media’s representations of reality (Craven and
Johnson 1999).
Why this is the case is not properly established, but it appears that media coverage in LDCs
is likely to follow press coverage from powerful trading partners (such as USA), or former
colonial powers (such as France or Britain). It is also probable that poor country
intellectuals and political elites have been educated at Western universities, and share
western concerns. Furthermore, given that in LDCs tertiary educated people are rare, it is
likely that the educated are the ones writing the news.
But even where local media addresses local problems, the solutions proposed will often be
driven by western concerns, which may be inappropriate to local conditions. Sometimes
countries take an individual line, but in doing so they often go up against an unwritten
consensus, a tacit international agreement about the ‘correct’ way to deal with an issue, in
what is known in the jargon as a ‘status marker’ of opinion. Recent examples include: South
African President Thabo Mbeki’s stance on AIDS; Chinese official’s refusal to sanction a
UN Convention on tobacco; similarly OPEC states’ refusal to go along with the climate
change consensus. In all three examples they have felt the opprobrium of the Englishspeaking
media – conservative and socialist alike.
But on the whole poor country politicians do not go up against the international community
and problems often arise because of this. There are many examples of this from policy on
irrigation and agricultural development (where I have some knowledge) to education of
women and rights of the child (where I have none), but analysis is limited in the literature, not
because they are not plentiful but because research costs are high, not so much in
discovering anecdotal examples but in following them through into a detailed study.
I am lucky enough to have lived in South Africa on and off since 1994, and became aware
of one key example. And I want to track through this example to detail the unintended
consequences of policy. We hear that phrase, ‘unintended consequences’ often but we
don’t always appreciate the extent or depth (in terms of human lives) of the consequences.
Therefore, this paper concentrates on one main example to show the problem. But also to
show how necessary it is to dig to get the details, because the type of problem I discuss are
almost certainly increasing in number and severity, especially as our rich societies becomes
more risk averse, but poor countries still have problems we long said good bye to.
First, three short examples:
1.Concerns about trihalomethanes (compounds created in water chlorination, which are
carcinogenic in rats) in drinking water contributed to the Peruvian Government’s decision to
reduce the chlorination of drinking water. This decision was made simpler by the fact that
they simply didn’t have the money to fully implement the chlorination programme and this
gave them the perfect excuse: ‘the richest country in the world (the US EPA) thinks chlorine
poses a health problem so we are justified in not imposing this risk on our people’) This led
to the first outbreak of cholera in Peru in 1991, killing thousands. It then spread across
South America with nearly a million cases. As far as known trihalomethane compounds have
never killed anyone – but they are nasty for rats when drowned in the stuff (see Ghersi
1999).
2. A ban on trade in certain secondary metals (cadmium, zinc, nickel) has seriously harmed
the market and hence jobs for very poor traders in Asia. Metals pollution is an
environmental problem, but batteries we in the west throw away are scavenged by many
Asian traders for reuse and recycling. For them the risk of a bit of metal pollution is easily
outweighed by the benefit of jobs and income (albeit those benefiting from the jobs may not
be harmed by pollution even though occupational exposure says they’re first in line for any
risk). But the point is that such traders had no voice in a ban established by western interests
for western interests (See Evans 1996)
3. Another contentious example is from the development of nuclear power in LDCs. In
many poor African states there are no electricity grid systems (or they are very limited
highly-dispersed, sparse populations make the infrastructure unfeasibly expensive, plus the
equipment is often dismantled and used to build houses or burnt for firewood). Some large
industrial plants in remote locations use significant amounts of energy (an aluminium smelter
in Mozambique for example). Two technologies with potential here are nuclear and solar.
South African efforts to bring on line a new technology, the Pebble Bed Modular Reactor,
which could be used at the aluminium smelter, are being hampered by international rejection
of older nuclear technologies. Furthermore, although the Reactor would benefit Southern
Africa it is a home-grown technology, which arouses suspicion and mistrust from the
countries of the North – we forget that South Africa has many capable nuclear physicists
(see Kemm 1999).
There are, of course, other examples of this phenomenon, but now I will concentrate on the
main example, which is of the disease malaria and the use of the pesticide
dichlorodiphenyltrichloroethane, commonly know as DDT.
Malaria
Most people consider malaria to be a tropical disease, and indeed today it is. But this has
not always been the case. In the period called the Little Ice Age (over 300 years ago)
Malaria was common in England. At the time it was called the ague.
William Harvey (who discovered the circulation of blood) wrote: "When insects do swarm
extraordinarily and when… agues (especially quartans) appear early as about midsummer,
then autumn proves very sickly."
The diarist Samuel Pepys – suffered from chronic ague. Oliver Cromwell died of the Ague in
a cool September 1658.
William Shakespeare wrote about it in eight of his plays. Most notably in The Tempest (Act
II, Scene II), the slave Caliban curses his master Prospero and hopes that he will be struck
down by the disease: "All the infections that the sun sucks up/ From bogs, fens, flats, on my
master fall and make him/ By inch-meal a disease!"
The disease is caused by a parasitic single-cell protozoa – plasmodium (such as vivax and
falciparum) carried by the female Anopheles mosquito (such as atroparvus or funestus).
Depending on the type of plasmodia it either causes periodic fevers or in some people
death.
The cure, quinine powder, was used for the first time in 1660 (this is why we know Ague
was malaria, since the symptoms were the same, as was the cure). It became known as
Jesuit’s Powder, and helped cure French King Louis XIV’s son. Interestingly Protestants
didn’t like to use the powder as it was seen as a Catholic cure (See Reiter 2000 for a fuller
discussion).
Even though the cure was known, and the disease declined due to better drainage (removal
of mosquito habitat, often through planting eucalyptus trees) there were still major epidemics
in all of Europe up to the early part of the 1920s. There were even Russian epidemics as far
north as Archangel on the Arctic Circle, and also in Holland and Britain, as well as many US
States. Malaria was endemic to Southern US States and in Italy andGreece.
These countries completely eradicated malaria after the second world war when widespread
vector control (insecticidal spraying to kill the mosquito (which is the disease carrier or
vector) was undertaken – especially with DDT.
History of DDT
DDT was first synthesised in the 1880s by mistake and its insecticidal properties were not
rediscovered until the Swiss chemist Paul Müller was looking for a new agricultural
pesticide. Müller won the Nobel Prize in 1948 for this discovery. DDT was introduced to
control malaria, typhus and other insect-carried diseases by the US Military by 1944. After
the end of the Second World War DDT was in widespread use around the world for vector
control and in agriculture. The use of the pesticide led to enormous optimism and the belief
that malaria could be eradicated from the entire globe. The reasons for this optimism were
not hard to see. DDT was, and still is, highly effective in killing the malaria vector and so
interrupting the transfer of the malaria parasite. It is also safe, cheap and easy to use which
put it within reach of even the poorest countries’ health budgets. Shortly after the end of the
Second World War there was also a conviction that vector control, and in particular
pesticide spraying, was the only way in which the disease could be tackled.
The early successes of DDT were nothing short of spectacular. Scientists ‘thought that the
whole literature of agricultural and medical entomology would have to be re-written…
because of the use of DDT’ (Mellanby 1992:37). Mellanby even withdrew a book he had
written on medical entomology because he believed it would be overtaken by events. In
Europe and North America, DDT was widely used and within a few years, the disease had
been eradicated from both continents. It is thought that in one year alone, the transmission of
malaria in Greece came to a halt (Harrison, p. 231). One historian (Mack-Smith, 1959:494)
even suggested that malaria eradication ‘was the most important single fact in the whole of
modern Italian history’.
In South Africa, the malaria control programme adopted DDT in 1946 and shortly
afterwards, the number of cases in the then Transvaal declined to about one tenth of the
number of cases reported in 1942/3. In some areas of South Africa, DDT spraying stopped
altogether because of the success it had achieved and was only reintroduced after periods of
heavy rains, when malaria cases tended to rise.
Perhaps the most remarkable success story however was to be found in Sri Lanka (then
Ceylon). DDT spraying began in 1946 and, as with South Africa, was an instant success
with the island’s death rate from malaria falling dramatically. Within ten years, DDT use had
cut the incidence of malaria down from around three million cases to 7,300 and had
eliminated all malaria deaths (Harrison 1978: 230) By 1964, the number of malaria cases
had been reduced to just 29 and at the time it was assumed that the war against malaria in
Sri Lanka had been won.
India also used the pesticide to great effect. India at the time had a particularly bad malaria
problem, where every year around 75 million people contracted the disease and about
800,000 died. Almost the entire country was malarial, except for the mountainous areas and
there were, and still are, six Anopheline mosquito vectors. By using DDT, India managed to
bring the number of cases down from the estimated 75 million in 1951 to around 50,000 in
1961 (Harrison:1978: 247) The achievement of reducing the number of infections to this
degree cannot be overstated, however the success in India as in many other countries was
to be short-lived.
Success but no eradication
Complete eradication of malaria was achieved in only ten countries, four of which were in
Europe, and the other six in the Americas and the Caribbean. The international strategy of
eliminating malaria from the globe was led by WHO and largely funded by The United
States Agency for International Development (USAID). USAID contributed $1.2 billion to
the programme between 1950 and 1972. The WHO contributed far less, with $20.3 million
between 1956 and 1963, of which $17.5 million was contributed by the United States. All
other countries combined contributed only $2.8 million. (Baird 1999:14)
These efforts did not stretch to much of Africa, where the vast majority of cases occurred
and indeed still occur. It had been hoped that the swift and decisive use of DDT through
well planned and funded malaria control programmes throughout the world would achieve
success. For some countries, particularly those in Europe and the Americas it did. For
others the plans were not appropriate. While vector control using DDT certainly proved
effective, many countries (especially in Africa) did not have the infrastructure and capacity to
ensure that the spraying programmes were carried out systematically and effectively.
One of the reasons that the WHO pushed for rapid implementation of DDT spraying for an
intensive and limited time period was because of fears of resistance to the pesticide. The
problems of resistance to DDT first emerged in Greece in the early 1950s where it was
observed that the main Greek vector, Anopheles sacharovi showed physiological
resistance to the pesticide. Resistance to DDT was later observed in the Middle East, parts
of Indonesia and also in northern Nigeria in 1956.
Fears about the increase in resistance to DDT (and also another pesticide - Dieldrin) led the
WHO expert committee in 1956 to call once again for the swift and overwhelming vector
control programmes that would eliminate the pool of parasites before resistance could
develop. But for a variety of reasons, complacency, poor-training, poor DDT formulation1,
poor medical detection of cases, and lack of political will led to the demise by the mid
1960s of the Global Malaria Eradication Campaign which had been adopted by the World
Health Assembly in May 1955.
1 DDT is insoluble in water and hence has to be suspended in a solution with inert matter
(such as clay) to stop it sinking. Poor formulation is a key problem especially from DDT
sources in developing countries.
DDT was remarkably successful in almost all the countries in which it was used, however it
was never likely to work as a magic bullet. Malaria is a disease that is influenced by a
number of factors, such as climate and migration of people. Developing a malaria control
strategy that is solely reliant on vector control and in particular on the use of one pesticide
was optimistic at best and foolish at worst. The greater folly however was in the unilateral
way in which the policy was developed which failed to take into account the conditions
under which the policy would be implemented.
So to summarise in the early 1970s the WHO dropped DDT-based mosquito eradication
programme because of the following reasons:
1. DDT resistance;
2. Eradication of malaria from donor countries;
3. Lack of infrastructure in Sub-Saharan countries to support eradication programmes;
4. Environmental and health concerns about DDT (many of which have been later been
shown to be exaggerated).
Green backlash and its impact today
I will dwell on this last reason. While DDT was being used in malaria control campaigns and
also in agriculture, concerns were raised about the environmental impacts of the pesticide2.
Perhaps the most well known attack on DDT was Rachel Carson’s book Silent Spring,
which was published in 19623. The book popularised the scare associated with DDT and
claimed that it would have devastating impacts on birdlife, particularly those higher up the
food chain. The fears were based on the fact that DDT and its metabolites, DDE and DDD
accumulate in the body fat of animals. Despite the fact that many of the fears surrounding
DDT were unfounded and the studies upon which they were based were unscientific, DDT
was banned by the US Environmental Protection Agency in 1972
The EPA administrator, William Ruckelshaus overturned scientific reports and evidence
given by numerous expert witnesses, the conclusions of which were firmly against a ban of
DDT and argued in favour of its continued use. The US National Academy of Sciences
claimed that it had saved “500 million lives from malaria”. Whereas, Ruckelshaus argued
that the pesticide was “…a warning that man may be exposing himself to a substance that
may ultimately have a serious effect on his health”. Ruckelshaus’s preoccupations with
potentially negative environmental and health impacts (despite all the evidence to the
contrary) and refusal to accept the scientific advice offered most certainly condemned
millions to death in malarial countries by denying them access to this life saving pesticide4.
2 Before WWII it was generally argued that malaria control could only be afforded if it
contributed to agricultural development. For two decades from 1945 this link was dissolved
(Litsios 1997). But in recent decades a new parallel has emerged with the pre-war phase, in
that although much medical control of malaria is done for humanitarian reasons, the only
insecticides used in vector control are those that were developed for agriculture. DDT
remains the exception, that was developed for disease control, although the original research
was into agricultural pesticides.
3 Entomologists and other scientists in Britain and US were aware of the potential
environmental dangers of DDT in 1945. But at the time the acute toxicity problems from
other pesticides, including organophosphate pesticides dominated concerns of various
governmental scientific committees (Mellanby 1992:83).
4 Others had Neo-Malthusian objections. For example, the argument was made that it
would be unkind to keep people from “dying from malaria so that they could die more
slowly of starvation”, and even saw malaria as “a blessing in disguise, since a large
proportion of the malaria belt is not suited to agriculture, and the disease has helped to keep
DDT is banned
Most developed countries soon imposed outright bans on the chemical for all uses. Some
developing countries also imposed a complete ban of the pesticide – for agricultural use and
(and some for all uses). For example South Africa banned it for agricultural use in 1974. Sri
Lankan officials had stopped using DDT in 1964 believing the malaria problem was solved,
but by 1969 the number of cases had risen from the low of 17 (achieved when DDT was
used) to over half a million (Silva 1997). It is alleged that DDT was not widely re-introduced
because of mosquito resistance to it, and DDT use was finally abandoned in favour of
Malathion5 in 1977 (Spielman 1980). But pressure not to use DDT was applied by western
donors, and arguments of resistance were used as a political convenience. But recent
evidence shows that even where resistance to DDT has emerged the ‘excito-repellancy’ of
DDT causes mosquitoes not to enter buildings which have been sprayed (Roberts et al.
2000 ), in other words mosquitoes don’t like settling on areas sprayed with DDT. Hence it
is unlikely that malaria rates would have increased (significantly) even if resistance was
found.
Malaria Recovery
The failure to eradicate malaria led to calls for stabilisation, but without the use of DDT in
many countries (banned because of environmental concerns), malaria rates have bounced
back. The countries discussed before Sri Lanka, South Africa, India have all seen cases and
deaths rise significantly by many fold.
N.B. Some have claimed that the resurgence in the disease in the past 20 years has been
because of changes in climate due to man’s activities. But according to world expert Dr Paul
Reiter, head of Vector Control at CDC in US:
“Increase has been attributed to population increase, forest clearance, irrigation and other
agricultural activities, ecologic change, movement of people, urbanization, deterioration of
public health services, resistance to insecticides and antimalarial drugs, deterioration of
vector control operations, and disruptions from war, civil strife, and natural disasters. Claims
that malaria resurgence is due to climate change ignore these realities and disregard history”
(Reiter 2000).
Economic Costs
Other than obvious humanitarian reasons, controlling malaria is vital because the economic
costs are significant. Professor Jeffrey Sachs at the Harvard University Center for
International Development has analyzed the effects of malaria on 27 African economies from
1965 to 1990. The study found that the disease cut 1 percentage point a year from the
annual growth rates of those economies. If malaria had been eliminated in 1965, Africa's
annual gross domestic product would be $400 billion now, rather than $300 billion, the
man from destroying it – and from wasting his substance upon it” (Vogt 1949:13;28). The
modern day green version of this is stated by Gell-Man: “Some day anti-malarial vaccines
will probably be developed, which may even wipe out the various forms of the disease
entirely, but then another difficulty will arise: important wild areas that had been protected by
the dangers of malaria will be exposed to unwise development (1994:353).
5 The introduction of alternative pesticides had disastrous results for those doing the
spraying, with many deaths caused by poisoning from replacements. It should be recognised
that there are many examples of individuals eating DDT everyday for decades with no harm.
The DDT expert Kenneth Mellanby used to eat a pinch of DDT at every lecture he gave on
DDT over a period of 40 years (Mellanby 1992:75).
study estimated. The models did more than just assess the costs of treatment and losses
associated with death. They also estimated the losses to tourism and foreign investment from
malaria-prone countries; the damage done by large numbers of sick children missing school;
and the increase in population and impoverishment that ensues when parents decide to have
extra children because they know some will die (Gallup and Sachs 1998). Sachs’ study
confirms research done by Richard Tren of the NGO Africa Fighting Malaria which shows
that the cost to Southern Africa is several billion dollars a year, and this figure was far higher
in the past (see
www.iea.org.uk for Tren paper).
What is important for our discussion is that some countries have defied international opinion
and continued to use DDT. These countries have benefited from a lower death rate due to
malaria and hence a better economy.
Indeed, DDT has quietly been used in developing countries, such as South Africa,
Botswana, Equador, Indonesia and India for the past three decades, almost without
comment. In 1995, however, the United Nations Environment Programme (UNEP) decided
to promote a legal instrument that would ban or heavily restrict the use of 12 persistent
organic pollutants (POPs), including DDT (see
http://irtpc.unep.ch/pops).
Rise of Conventions – the international community has its way
Legal conventions set the ground rules and tone of whole treaty process. It usually
establishes conditions that are easy to agree among the parties. In the POPs treaty process
(as in all UNEP treaties), the developed world, mainly European and American interests, are
promoting the agenda and draft text. Since these countries neither produce nor use any of
the 12 chemicals to be targeted, it is simple for them to promote a total ban. Western
industry is not fighting to retain any of the chemicals, and the green pressure groups want a
total ban. The only reason the language is not completely prohibitionist is because of three
factors:
1. Western industry concern about what might be next. Once the initial 12 chemicals are
banned, the green pressure groups and the treaty secretariat will probably target other
chemicals which are produced and used in the west;
2. Official protests from developing countries that do produce and or use some of the 12
chemicals listed;
3. Pressure from two or three anti-malaria groups who are concerned about the fate of
malaria vector control without DDT.
The Status of the POPs instrument
A negotiating text for the treaty document is established, but certain textual changes can and
will be made prior to December when the final negotiating meeting will take place in South
Africa. Complete agreement on the treaty is held up on two issues: will DDT be reprieved?
And how will the rich countries pay for the developing countries to abandon the 12 POPs
(possibly including DDT).
It is possible, given pressure from the pro-DDT groups (including AFM, Malaria
Foundation International and the Malaria Project, as well as some University medic staff),
that DDT will be reprieved for use in malaria control. However, this is far from certain as
several important country delegates (from Scandinavia, some other European countries,
Argentina, Canada and possibly USA) still want a ban. And behind the scenes the pressure
groups are working on delegates for this forthcoming meeting. A special concern is financial
transfers to Francophone malarial African countries from green groups, and possibly
international agencies, to vote in favour of a DDT ban (but there is no data on this, just
speculation from various off the record sources)6.
However, at least a reprieve is possible. Prior to INC 3, it looked most unlikely. At the first
two meetings a straw poll showed that about 80% did not know that DDT was still used in
malaria control. At that time the Malaria Project put forward a letter signed by 400 malaria
experts including 3 Nobel Laureates to demand the right to use DDT. I watched in Geneva
as the letter was presented to the UN conference, and was astonished to see the WHO not
support the initiative – the representative looked embarrassed but obviously had his
instructions.
Indeed, medical leaders seem to want to pursue only two modes of attack: drugs and
bednets. Now there is nothing wrong with these two approaches, but to combat malaria
every weapon in the arsenal is required, which includes insecticides (and DDT). The people
on the ground know it, but it either hadn’t filtered through to the people in Geneva, or more
likely they overruled pesticide use, the head of the WHO is after all green apostle, Gro
Harlem Brundtland.
Furthermore, far from learning from past errors, such as ignoring local concerns and
adopting a one-weapon approach, the WHO and donor agencies, including USAID
continue to promote policies on political grounds.
However, after the letter presented at Geneva, and good media coverage (such as in the
NYT, Guardian, Economist) the WHO has now finally come out in favour of DDT. Even the
WWF has backtracked from calling for a ban, just yet. But aid agencies (including USAID7,
NORAD, SIDA.…), as well as EU country delegates still want a ban.
One way they may achieve this is by switching pressure from proposing an outright ban
(INC1-INC3) to proposing restricted trade (INC4). This is strategically sensible on their
part. Most people who bother to listen are convinced that DDT should still be used to
control malaria (today a child dies every 15 seconds from the disease), but they can also be
persuaded that we do not need international trade in the product (anti-globalisation
arguments about local production for local use, with concern about transporting toxic
chemicals, is the usual rhetoric). If they can persuade the delegates to ban trade in DDT then
this would be close to banning its use. Only China and India (and probably Russia) produce
DDT, and the quality is not the best (potentially leading to resistance in mosquitoes,
increased spray time – hence higher cost) (see Baird 1999). The impact of having
production in only a few countries is already problematic. For example, Botswana claims it
cannot get enough DDT for its malaria control programme, and is having to buy less of the
more expensive alternatives. Compliance with import restrictions, delays and uncertainties
have already forced Tanzania to reduce its DDT intake, because of bureaucratic cost.
Related Problems
Western chemical companies have become concerned by the possibility of a reprieve for
DDT. While overtly supportive of DDT, some may be funding the work of the green
6 What is certain is that the Francophone countries are angry at English-speaking African
nations. The English speaking nations dominated the Africa working group session at INC3
– because there was no French-English translator. The French speakers did not feel that
they were able to put there arguments across, and while UNEP were to blame, they
unfortunately decided to attack one bit of policy that was discussed at the meeting – support
for DDT use. Consequently the francophone countries are taken an anti-DDT stand on
political grounds (see Bate 2000).
7 A worrying example of USAID pressure is in Belize where officials, having imported seven
tonnes of DDT, decided not to use it all under pressure from USAID. Two tonnes was
found close to a water course in a poorly maintained state.
pressure groups to argue against DDT. The reason is financial – vector control is roughly
25% of the market for replacement pesticides for DDT. Re-introduction or expansion of
DDT-use in developing countries would cost certain companies tens of millions of dollars.
Furthermore, green pressure groups have moved from discussing the carcinogenic effects of
DDT to alarm over its possible endocrine disruption effects. Once again the evidence is
flimsy at best and there is no choice for the people exposed to malaria. But nevertheless, it is
once again gaining coverage in European press, and encouraging the prohibitionists within
the EU to push for an outright ban in December.
Related Advantages
While unfortunate for those contracting the disease, it is to our advantage that the final POPs
meeting is in South Africa, because SA has 500% more malaria cases this year than in
1997, and 30 times the cases in 1994 (incidentally, DDT use was dropped in 1996). INC
1-4 occurred in non-malarial countries (Vancouver, Geneva (twice), Bonn), where local
politicians knew and cared little about malaria issues. SA politicians are aware and have to
be seen to care about the issue. Furthermore in SA the media are interested in development
issues and especially the DDT/malaria issue, since they perceive correctly that western
attitudes are dictating policies for the poor.
Western media are beginning to wake up to the problems of mosquito-borne diseases such
as the West-Nile virus in New York State. There are also problems with mosquito control
in Florida. Here we have another example of unintended consequences. Regulations
designed by EPA to make Floridians and other Americans safe from pesticides are making it
prohibitively expensive (even in America) to develop new, or even re-test old products.
Every year there are fewer products (with notably different molecular structures) reaching
the market – which means faster mosquito resistance transferral. In a weird twist of fate,
mosquito abatement societies are trying to get the EPA to re-introduce pesticides that its
own regulations have made non-viable.
It remains to be seen what the outcome will be in December at the most important meeting
on DDT’s fate since the EPA hearings 30 years ago. But the real medical concerns of Africa
are seriously threatened by relatively trivial concerns from rich countries. The unintended
consequences of our policies are not just measured in billions of dollars, but in thousands,
maybe millions of lives.
References
Baird, J.K (1999) “Resurgent Malaria at the Millennium: Control Strategies in Crisis,
Parasitic Diseases Program,” Working Paper, US Naval Medical Research Unit, No. 2
Bate, R (2000) “A New Kind of Health Club”, Wall Street Journal Europe 15th May
Coetzee, M, & Hunt, R, (1993), “African Anopheline Mosquito Taxonomy and the Control
of Malaria, Published in, Entomologist Extraordinary, Botha de Meillon, edited by Maureen
Coetzee, Department of Medical Entomology, South African Institute for Medical
Research, Johannesburg
Coetzee, M, (Prof.), (2000), Head, Department of Medical Entomology, South African
Institute for Medical Research, Personal communication, 18 May 2000
Creamer, T. (1998), “Anti-malaria plan opens way for jobs in Lubombo,” Engineering
News, 13/11/1998
DeGregori, T 2000. Let Us Spray: Malaria and DDT in Mozambique. drkoop.com online
and ACSH.com online.
Dyson, J (2000) Why we must think again about DDT Readers Digest November
Gallup, J.L. and Sachs, J.D. (1998), “The Economic Burden of Malaria,” Centre for
International Development at Harvard, October 1998
Goklany, I.M. (2000), “Applying the Precautionary Principle to DDT, Global Warming, and
Genetically Modified Crops” in Rethinking Risk and the Precautionary Principle ed,
Julian Morris (Oxford Butterworth Heinemann)
Gell-Mann, M. (1994)”The Quark and the Jaguar” London: Little, Brown and Company.
Harrison, G (1978) “Mosquitoes, Malaria and Man: A History of the Hostilities Since
1880,” John Murray, London
Mack-Smith, d. (1959) “Italy: A Modern History” Chicago: University of Chicago Press.
Mellanby, K. (1992) “The DDT Story” The British Crop Protection Council, Surrey, UK
Reiter, P. (2000) “From Shakespeare to Defoe: Malaria in England in the Little Ice Age”
Emerging Infectious Diseases 6,:1. Centers for Disease Control and Prevention.
Spielman, A. (1980) “Environmental Health Impact of the Mahaweli Development Program
of Sri Lanka: Vector Borne Disease. A Report Submitted to the Government of Sri Lanka.
Verdoorn, G. H. Dr. (2000) Director, Poisons Working Group, Endangered Wildlife Trust,
Personal communication, 26 June 2000
Vogt, W. (1949) “The Road to Survival” London: Victor Gollancz Ltd.
World Health Organisation (1955) “Malaria Eradication. Proposal by the Director General
to the Eighth World Assembly, may 3. A8/P&B/10.
World Wildlife Fund, “Toxic Chemicals Initiative – Persistent Organic Pollutants,” WWF
web publication, <http://www.panda.org/toxics/areas_pops.cfm>
World Wildlife Fund, (2000), “UNEP Global POPs Treaty – INC4/Bonn. Eliminating
DDT and Protecting Public Health”, March 2000, WWF web publication
100 things you should know about DDT
by J. Gordon Edwards and Steven Milloy
I. Historical Background
II. Advocacy against DDT
III. EPA hearings
IV. Human exposure
V. Cancer
VI. Egg shell thinning
VII. Bald eagles
VIII. Peregrine falcons
IX. Brown pelicans
X. Bird populations increase during DDT years
XI.Erroneous detection
I. Historical Background
Discovered by accident, DDT became one of the greatest public health tools of the 20th century.
Overuse harmed its efficacy -- and made it politically unpopular.
1.
Dichloro-diphenyl-trichloroethane (DDT) was first synthesized, for no purpose, in 1874 by German chemist Othmar Zeidler. In 1939, Dr. Paul Müller independently produced DDT. Müller found that DDT quickly killed flies, aphids, mosquitoes, walking sticks and Colorado potato beetles. Müller and the Geigy corporation patented DDT in Switzerland (1940), England (1942) and U.S. (1943).
2.
The first large-scale use of DDT occurred in 1943 when 500 gallons of DDT were produced by Merck & Company and delivered to Italy to help squelch a rapidly spreading epidemic of louse-borne typhus. Later in 1943, the U.S. Army issued small tin boxes of 10 percent DDT dust to its soldiers around the world who used it to kill body lice, head lice and crab lice.
3.
Müller won the Nobel Prize in 1948 for his work on DDT.
4.
Peak usage occurred in 1962, when 80 million kilograms of DDT were used and 82 million kilograms produced.
5.
"In May 1955 the Eighth World Health Assembly adopted a Global Malaria Eradication Campaign based on the widespread use of DDT against mosquitos and of antimalarial drugs to treat malaria and to eliminate the parasite in humans. As a result of the Campaign, malaria was eradicated by 1967 from all developed countries where the disease was endemic and large areas of tropical Asia and Latin America were freed from the risk of infection. The Malaria Eradication Campaign was only launched in three countries of tropical Africa since it was not considered feasible in the others. Despite these achievements, improvements in the malaria situation could not be maintained indefinitely by time-limited, highly prescriptive and centralized programmes."
[Bull World Health Organ 1998;76(1):11-6]
6.
"To only a few chemicals does man owe as great a debt as to DDT... In little more than two decades, DDT has prevented 500 million human deaths, due to malaria, that otherwise would have been inevitable."
[National Academy of Sciences, Committee on Research in the Life Sciences of the Committee on Science and Public Policy. 1970. The Life Sciences; Recent Progress and Application to Human Affairs; The World of Biological Research; Requirements for the Future.]
7.
It is believed that [malaria] afflicts between 300 and 500 million every year, causing up to 2.7 million deaths, mainly among children under five years.
[Africa News, January 27, 1999]
8.
Some mosquitoes became "resistant" to DDT. "There is persuasive evidence that antimalarial operations did not produce mosquito resistance to DDT. That crime, and in a very real sense it was a crime, can be laid to the intemperate and inappropriate use of DDT by farmers, espeially cotton growers. They used the insecticide at levels that would accelerate, if not actually induce, the selection of a resistant population of mosquitoes."
[Desowitz, Relief Society. 1992. Malaria Capers, W.W. Norton & Company]
9.
"Resistance" may be a misleading term when discussing DDT and mosquitoes. While some mosquitoes develop biochemical/physiological mechanisms of resistance to the chemical, DDT also can provoke strong avoidance behavior in some mosquitoes so they spend less time in areas where DDT has been applied -- this still reduces mosquito-human contact. "This avoidance behavior, exhibited when malaria vectors avoid insecticides by not entering or by rapidly exiting sprayed houses, should raise serious questions about the overall value of current physiological and biochemical resistance tests. The continued efficacy of DDT in Africa, India, Brazil, and Mexico, where 69% of all reported cases of malaria occur and where vectors are physiologically resistant to DDT (excluding Brazil), serves as one indicator that repellency is very important in preventing indoor transmission of malaria."
[See, e.g., J Am Mosq Control Assoc 1998 Dec;14(4):410-20; and Am J Trop Med Hyg 1994;50(6 Suppl):21-34]
II. Advocacy against DDT
DDT was demagogued out of use.
10.
Rachel Carson sounded the initial alarm against DDT, but represented the science of DDT erroneously in her 1962 book Silent Spring. Carson wrote "Dr. DeWitt's now classic experiments [on quail and pheasants] have now established the fact that exposure to DDT, even when doing no observable harm to the birds, may seriously affect reproduction. Quail into whose diet DDT was introduced throughout the breeding season survived and even produced normal numbers of fertile eggs. But few of the eggs hatched." DeWitt's 1956 article (in Journal of Agriculture and Food Chemistry) actually yielded a very different conclusion. Quail were fed 200 parts per million of DDT in all of their food throughout the breeding season. DeWitt reports that 80% of their eggs hatched, compared with the "control"" birds which hatched 83.9% of their eggs. Carson also omitted mention of DeWitt's report that "control" pheasants hatched only 57 percent of their eggs, while those that were fed high levels of DDT in all of their food for an entire year hatched more than 80% of their eggs.
11.
Population control advocates blamed DDT for increasing third world population. In the 1960s, World Health Organization authorities believed there was no alternative to the overpopulation problem but to assure than up to 40 percent of the children in poor nations would die of malaria. As an official of the Agency for International Development stated, "Rather dead than alive and riotously reproducing."
[Desowitz, Relief Society. 1992. Malaria Capers, W.W. Norton & Company]
12.
The environmental movement used DDT as a means to increase their power. Charles Wurster, chief scientist for the Environmental Defense Fund, commented, "If the environmentalists win on DDT, they will achieve a level of authority they have never had before.. In a sense, much more is at stake than DDT."
[Seattle Times, October 5, 1969]
13.
Science journals were biased against DDT. Philip Abelson, editor of Science informed Dr. Thomas Jukes that Science would never publish any article on DDT that was not antagonistic.
14.
William Ruckelshaus, the administrator of the U.S. Environmental Protection Agency who made the ultimate decision to ban DDT in 1972, was a member of the Environmental Defense Fund. Ruckelshaus solicited donations for EDF on his personal stationery that read "EDF's scientists blew the whistle on DDT by showing it to be a cancer hazard, and three years later, when the dust had cleared, EDF had won."
15.
But as an assistant attorney general, William Ruckelshaus stated on August 31, 1970 in a U.S. Court of Appeals that "DDT has an amazing an exemplary record of safe use, does not cause a toxic response in man or other animals, and is not harmful. Carcinogenic claims regarding DDT are unproven speculation." But in a May 2, 1971 address to the Audubon Society, Ruckelshaus stated, "As a member of the Society, myself, I was highly suspicious of this compound, to put it mildly. But I was compelled by the facts to temper my emotions ... because the best scientific evidence available did not warrant such a precipitate action. However, we in the EPA have streamlined our administrative procedures so we can now suspend registration of DDT and the other persistent pesticides at any time during the period of review." Ruckelshaus later explained his ambivalence by stating that as assistant attorney general he was an advocate for the government, but as head of the EPA he was "a maker of policy."
[Barrons, 10 November 1975]
16.
Environmental activists planned to defame scientists who defended DDT. In an uncontradicted deposition in a federal lawsuit, Victor Yannacone, a founder of the Environmental Defense Fund, testified that he attended a meeting in which Roland Clement of the Audubon Society and officials of the Environmental Defense Fund decided that University of California-Berkeley professor and DDT-supporter Thomas H. Jukes was to be muzzled by attacking his credibility.
[21st Century, Spring 1992]
III. EPA hearings
DDT was banned by an EPA administrator who ignored the decision of his own administrative law judge.
17.
Extensive hearings on DDT before an EPA administrative law judge occurred during 1971-1972. The EPA hearing examiner, Judge Edmund Sweeney, concluded that "DDT is not a carcinogenic hazard to man... DDT is not a mutagenic or teratogenic hazard to man... The use of DDT under the regulations involved here do not have a deleterious effect on freshwater fish, estuarine organisms, wild birds or other wildlife."
[Sweeney, EM. 1972. EPA Hearing Examiner's recommendations and findings concerning DDT hearings, April 25, 1972 (40 CFR 164.32, 113 pages). Summarized in Barrons (May 1, 1972) and Oregonian (April 26, 1972)]
18.
Overruling the EPA hearing examiner, EPA administrator Ruckelshaus banned DDT in 1972. Ruckelshaus never attended a single hour of the seven months of EPA hearings on DDT. Ruckelshaus' aides reported he did not even read the transcript of the EPA hearings on DDT.
[Santa Ana Register, April 25, 1972]
19.
After reversing the EPA hearing examiner's decision, Ruckelshaus refused to release materials upon which his ban was based. Ruckelshaus rebuffed USDA efforts to obtain those materials through the Freedom of Information Act, claiming that they were just "internal memos." Scientists were therefore prevented from refuting the false allegations in the Ruckelshaus' "Opinion and Order on DDT."
IV. Human exposure
Actual human exposures have always been far lower than the "acceptable" level.
20.
Human ingestion of DDT was estimated to average about 0.0026 milligrams per kilogram of body weight per day (mg/kg/day) about 0.18 milligrams per day.
[Hayes, W. 1956. J Amer Medical Assn, Oct. 1956]
21.
In 1967, the daily average intake of DDT by 20 men with high occupational exposure was estimated to be 17.5 to 18 mg/man per day, as compared with an average of 0.04 mg/man per day for the general population.
[IARC V.5, 1974].
22.
Dr. Alice Ottoboni, toxicologist for the state of California, estimated that the average American ingests between 0.0006 mg/kg/day and 0.0001 mg/kg/day of DDT.
[Ottoboni, A. et al. California's Health, August 1969 & May 1972]
23.
"In the United States, the average amount of DDT and DDE eaten daily in food in 1981 was 2.24 micrograms per day (ug/day) (0.000032 mg/kg/day), with root and leafy vegetables containing the highest amount. Meat, fish, and poultry also contain very low levels of these compounds."
[Agency for Toxic Substances and Disease Registry. 1989.Public Health Statement: DDT, DDE, and DDD]
24.
The World Health Organization set an acceptable daily intake of DDT for humans at 0.01 mg/kg/day.
25.
"Air samples in the United States have shown levels of DDT ranging from 0.00001 to 1.56 micrograms per cubic meter of air (ug/m3), depending on the location and year of sampling. Most reported samples were collected in the mid 1970s, and present levels are expected to be much lower. DDT and DDE have been reported in surface waters at levels of 0.001 micrograms per liter (ug/L), while DDD generally is not found in surface water. National soil testing programs in the early 1970s have reported levels in soil ranging from 0.18 to 5.86 parts per million (ppm)."
[Agency for Toxic Substances and Disease Registry. 1989.Public Health Statement: DDT, DDE, and DDD]
V. Cancer
DDT was alleged to be a liver carcinogen in Silent Spring and a breast carcinogen in Our Stolen Future.
26.
Feeding primates more than 33,000 times the average daily human exposure to DDT (as estimated in 1969 and 1972) was "inconclusive with respect to a carcinogenic effect of DDT in nonhuman primates."
[J Cancer Res Clin Oncol 1999;125(3-4):219-25]
27.
A nested case-control study was conducted to examine the association between serum concentrations of DDE and PCBs and the development of breast cancer up to 20 years later. Cases (n = 346) and controls (n = 346) were selected from cohorts of women who donated blood in 1974, 1989, or both, and were matched on age, race, menopausal status, and month and year of blood donation. "Even after 20 years of follow-up, exposure to relatively high concentrations of DDE or PCBs showed no evidence of contributing to an increased risk of breast cancer."
[Cancer Epidemiol Biomarkers Prev 1999 Jun;8(6):525-32]
28.
To prospectively evaluate relationships of organochlorine pesticides and PCBs with breast cancer, a case-control study nested in a cohort using the Columbia, Missouri Breast Cancer Serum Bank. Women donated blood in 1977- 87, and during up to 9.5 years follow-up, 105 donors who met the inclusion criteria for the current study were diagnosed with breast cancer. For each case, two controls matched on age and date of blood collection were selected. Five DDT analogs, 13 other organochlorine pesticides, and 27 PCBs were measured in serum. Results of this study do not support a role for organochlorine pesticides and PCBs in breast cancer etiology.
[Cancer Causes Control 1999 Feb;10(1):1-11]
29.
A pooled analysis examined whether exposure to DDT was associated with the risk of non-Hodgkin's lymphoma among male farmers. Data from three case-control studies from four midwestern states in the United States (Nebraska, Iowa, Minnesota, Kansas) were pooled to carry out analyses of 993 cases and 2918 controls. No strong consistent evidence was found for an association between exposure to DDT and risk of non-Hodgkin's lymphoma.
[Occup Environ Med 1998 Aug;55(8):522-7]
30.
"We measured plasma levels of DDE and PCBs prospectively among 240 women who gave a blood sample in 1989 or 1990 and who were subsequently given a diagnosis of breast cancer before June 1, 1992. We compared these levels with those measured in matched control women in whom breast cancer did not develop. Data on DDE were available for 236 pairs, and data on PCBs were available for 230 pairs. Our data do not support the hypothesis that exposure to [DDT] and PCBs increases the risk of breast cancer."
[N Engl J Med 1997;337:1253-8]
31.
"... weakly estrogenic organochlorine compounds such as PCBs, DDT, and DDE are not a cause of breast cancer."
[http://www.nejm.org/content/1997/0337/0018/1303.asp]
32.
To examine any possible links between exposure to DDE, the persistent metabolite of the pesticide dicophane (DDT), and breast cancer, 265 postmenopausal women with breast cancer and 341 controls matched for age and center were studied. Women with breast cancer had adipose DDE concentrations 9.2% lower than control women. No increased risk of breast cancer was found at higher concentrations. The odds ratio of breast cancer, adjusted for age and center, for the highest versus the lowest fourth of DDE distribution was 0.73 (95% confidence interval 0.44 to 1.21) and decreased to 0.48 (0.25 to 0.95; P for trend = 0.02) after adjustment for body mass index, age at first birth, and current alcohol drinking. Adjustment for other risk factors did not materially affect these estimates. This study does not support the hypothesis that DDE increases risk of breast cancer in postmenopausal women in Europe.
[BMJ 1997 Jul 12;315(7100):81-5]
33.
No correlation at the population level can be demonstrated between exposures to DDT and the incidence of cancer at any site. It is concluded that DDT has had no significant impact on human cancer patterns and is unlikely to be an important carcinogen for man at previous exposure levels, within the statistical limitations of the data.
[IARC Sci Publ 1985;(65):107-17]
34.
Syrian golden hamsters were fed for their lifespan a diet containing 0, 125, 250 and 500 parts per million (ppm) of DDT. The incidence of tumor bearing animals was 13% among control females and ranged between 11-20% in treated females. In control males 8% had tumors. The incidence of tumor bearing animals among treated males ranged between 17-28%.
[Tumori 1982 Feb 28;68(1):5-10]
35.
None of 35 workers heavily exposed to DDT (600 times the average U.S. exposure for 9 to 19 years) developed cancer.
[Laws, ER. 1967. Arch Env Health 15:766-775]
36.
Men who voluntarily ingested 35 mgs of DDT daily for nearly two years were carefully examined for years and "developed no adverse effects."
[Hayes, W. 1956. JAMA 162:890-897]
37.
DDT was found to reduce tumors in animals.
[Laws, ER. 1971. Arch. Env Health, 23:181-184; McLean, AEM & EK McLean. 1967. Proc Nutr Soc 26;Okey, AB. 1972. Life Sciences 11:833-843;Sillinskas, KC & AB Okey. 1975. J Natl Cancer Inst 55:653- 657, 1975]
38.
Rodent tests for a carcinogenic effect of DDT, DDE and TDE produced equivocal results despite extremely high doses (642 ppm of DDT, 3,295 ppm of TDE and 839 ppm of DDE).
[National Toxicology Program, TR-131 Bioassays of DDT, TDE, and p,p'-DDE for Possible Carcinogenicity (CAS No. 50-29-3, CAS No. 72-54-8, CAS No. 72-55-9)]
VI. Egg-shell thinning
DDT was alleged to have thinned bird egg shells.
39.
Many experiments on caged-birds demonstrate that DDT and its metabolites (DDD and DDE) do not cause serious egg shell thinning, even at levels many hundreds of times greater than wild birds would ever accumulate.
[Cecil, HC et al. 1971. Poultry Science 50: 656-659 (No effects of DDT or DDE, if adequate calcium is in diet); Chang, ES & ELR Stokstad. 1975. Poultry Science 54: 3-10 1975. (No effects of DDT on shells); Edwards, Jersey Girl. 1971. Chem Eng News p. 6 & 59 (August 16, 1971) (Summary of egg shell- thinning and refutations presented revealing all data); Hazeltine, WE. 1974. Statement and affidavit, EPA Hearings on Tussock Moth Control, Portland Oregon, p. 9 (January 14, 1974); Jeffries, DJ. 1969. J Wildlife Management 32: 441-456 (Shells 7 percent thicker after two years on DDT diet); Robson, Washington et al. 1976. Poultry Science 55:2222- 2227; Scott, ML et al. 1975. Poultry Science 54: 350-368 (Egg production, hatchability and shell quality depend on calcium, and are not effected by DDT and its metabolites); Spears, G & P. Waibel. 1972. Minn. Science 28(3):4-5; Tucker, RK & HA Haegele. 1970. Bull Environ Contam. Toxicol 5:191-194 (Neither egg weight nor shell thickness affected by 300 parts per million DDT in daily diet);Edwards, Jersey Girl. 1973. Statement and affidavit, U.S. Senate Committee on Agriculture, 24 pages, October 24, 1973; Poult Sci 1979 Nov;58(6):1432-49 ("There was no correlation between concentrations of pesticides and egg shell thinning] .") ]
40.
Experiments associating DDT with egg shell thinning involve doses much higher than would ever be encountered in the wild.
[J Toxicol Environ Health 1977 Nov;3(4):699-704 (50 ppm for 6 months); Arch Environ Contam Toxicol 1978;7(3):359-67 ("acute" doses); Acta Pharmacol Toxicol (Copenh) 1982 Feb;50(2):121-9 (40 mg/kg/day for 45 days); Fed Proc 1977 May;36(6):1888-93 ("In well-controlled experiments using white leghorn chickens and Japanese quail, dietary PCBs, DDT and related compounds produced no detrimental effects on eggshell quality. ... no detrimental effects on eggshell quality, egg production or hatchability were found with ... DDT up to 100 ppm)]
41.
Laboratory egg shell thinning required massive doses of DDE far in excess of anything expected in nature, and massive laboratory doses produce much less thinning than is seen in many of the thin-shelled eggs collected in the wild.
[Hazeltine, WE. 1974. Statement and affidavit, EPA Hearings on Tussock Moth Control, Portland Oregon, p. 9 (January 14, 1974)]
42.
Years of carefully controlled feeding experiments involving levels of DDT as high as present in most wild birds resulted in no tremors, mortality, thinning of egg shells nor reproductive interference.
[Scott, ML et al. 1975. Poultry Science 54: 350-368 (Egg production, hatch ability and shell quality depend on calcium, and are not effected by DDT and its metabolites)]
43.
Egg shell thinning is not correlated with pesticide residues.
[Krantz WC. 1970 (No correlation between shell-thinning and pesticide residues in eggs) Pesticide Monitoring J 4(3): 136-141; Postupalsky, S. 1971. Canadian Wildlife Service manuscript, April 8, 1971 (No correlation between shell-thinning and DDE in eggs of bald eagles and cormorants); Anon. 1970. Oregon State University Health Sciences Conference, Annual report, p. 94. (Lowest DDT residues associated with thinnest shells in Cooper's hawk, sharp-shinned hawk and goshawk); Claus G and K Bolander. 1977. Ecological Sanity, David McKay Co., N.Y., p. 461. (Feeding thyreprotein causes hens to lay lighter eggs, with heavier, thicker shells)]
44.
Among brown pelican egg shells examined there was no correlation between DDT residue and shell thickness.
[Switzer, B. 1972. Consolidated EPA hearings, Transcript pp. 8212-8336; and Hazeltine, WE. 1972. Why pelican eggshells are thin. Nature 239: 410-412]
45.
Egg shells of red-tailed hawks were reported to be six percent thicker during years of heavy DDT usage than just b