Never Banned: What Actually Happened to DDT in Malaria Control

1. Introduction: a debt this journal owed

In its article on Silent Spring, this journal wrote that there is a substantial literature arguing that restrictions on DDT cost lives in malaria control, that we had not assessed it, and that it deserved its own treatment rather than a paragraph. This is that treatment.

1.1 Both halves matter

The first half contradicts the popular claim. The second half concedes the grievance behind it. Sections 3 to 10 establish the first and §§18 to 20 take the second seriously.

2. What we are and are not assessing

Scope, stated before anything else, because this subject invites overreach.

We are not assessing the human health evidence on DDT. Whether the compound causes harm to people at exposure levels arising from indoor spraying is a toxicological question outside our competence, and this journal has declined comparable questions before.

We are not assessing the ecological evidence. Eggshell thinning, persistence and bioaccumulation are the subject of a large literature we have not read.

We are not taking a position on whether any country should use it. That is a policy judgement for the people who bear the malaria burden, and §9 records that many of them have made it.

2.1 What we are assessing

Two things. What the restrictions legally were, which is a matter of record. And what the entomology says about how well the compound worked and why, which is this journal's subject.

3. The claim in its popular form

Stating it fairly before examining it.

The account runs: a 1962 book generated public alarm; regulators banned DDT; malaria control programmes in endemic countries lost their most effective tool; and deaths followed that would not otherwise have occurred.

3.1 The chronology it rests on

A news account records that in 1955 a health agency endorsed DDT use for a global campaign that within 12 years freed developed countries, along with parts of Asia and Latin America, from risk of infection, and that environmental protest led the Environmental Protection Agency to ban the use of DDT in the U.S.⁹

3.2 The first part is not in dispute

The campaign's early results were real and large. What follows concerns the second part.

3.3 Why the claim is persuasive

Because each link in it is individually true or nearly so. The book existed and was influential. A regulator did act in 1972. Use did collapse. Malaria did not stay suppressed in much of the world.

What the chain omits is whether the regulatory action reached the use at issue, and §§4 to 8 are about that omission. Our view is that this is a case where a causal story survives because nobody checks its second link, which is a failure mode this journal has met before in trade claims about products.

3.4 And why it matters to get right

Not for the sake of a historical score. Because the same argument is made today about other compounds and other restrictions, and a template that skips the question of what was actually prohibited will produce the same error again.

4. What the scholarly source says

The direct contradiction.

A review chapter in an academic volume on malaria states that DDT for disease vector control was never banned but international pressure restricted its implementation in malarious countries.¹

4.1 Never banned

Not restricted to a shortlist of countries, not subject to special permission, not banned and later un-banned. The use category at issue was never prohibited.

5. The 1972 action

The event usually described as the ban.

A general reference source states that although the 1972 US action did not amount to a total prohibition, public health uses were allowed under strict conditions, it effectively ended widespread agricultural spraying.⁸

5.1 What it actually ended

Agricultural spraying in one country, which had never been the malaria application.⁸

5.2 And it spread

The same source records that other countries moved in similar directions throughout the 1970s and 1980s, with several European nations restricting or banning agricultural use in that period, and that by the early 1990s more than two dozen countries had enacted full prohibitions.⁸

Full prohibitions in more than two dozen countries is a real fact and it is the strongest evidence for the popular claim. We note that none of the sources we read identifies those countries as the malaria-endemic ones.

6. The Stockholm Convention

The international instrument, and the exemption inside it.

The review states that although the Stockholm Convention of 2001 targeted DDT as 1 of 12 persistent organic pollutants for phase-out and eventual elimination, it allowed a provision for its continued indoor use for disease vector control.¹

A regulator's summary puts it more bluntly: the convention bans all uses of DDT except for a limited exemption for the use of DDT to control mosquitoes that transmit the microbe that causes malaria, and it is up to individual countries to decide whether to use DDT.²

6.1 The language problem

A magazine article notes that the phase-out commitment is often loosely referred to as a ban.⁷

Which is where much of the confusion originates. A treaty that lists a substance for eventual elimination while exempting the use in question is reported as a ban by people on both sides of the argument.

7. The health agency's position

What the body usually cast as the villain actually said.

The review records that in 2006, the World Health Organization issued a position statement promoting the use of indoor residual spraying (IRS) with DDT for malaria vector control in epidemic and endemic areas, and that other international organizations concurred because of the great burden of malaria and the relative ineffectiveness of current treatment and control strategies.¹

7.1 Promoting, not permitting

The agency's stated position in 2006 was advocacy for the use, not reluctant tolerance.¹

7.2 And it remains one of twelve

A regulator records that DDT is one of 12 pesticides recommended by the World Health Organization for indoor residual spray programs, particularly for use in African countries where malaria remains a major human health problem.²

8. What countries are permitted to do

The permission, in the convention secretariat's own words.

A joint status paper states that the agency recommends DDT for use in indoor residual spraying only, and that DDT is still needed because there is no alternative of both equivalent efficacy and operational feasibility, especially for areas with perennial and long seasonal malaria transmission.³

It quotes the operative permission: countries can use DDT for as long as necessary, in the quantity needed, provided that the guidelines and recommendations of WHO and the Stockholm Convention are all met, and until locally appropriate and cost-effective alternatives are available for a sustainable transition from DDT.³

8.1 Read the permission

For as long as necessary, in the quantity needed.³ That is not a constrained allowance and it appears in a document produced by the treaty secretariat.

9. Who is asking for it

A fact that complicates the framing of the debate as environmentalists against the poor.

A journal commentary records that at the recent fifth meeting of the Conference of Parties to the Stockholm Convention, Namibia and the regional bloc announced their intention to produce DDT locally, and that the 35 heads of state and government who are members of the African Leaders Malaria Alliance recently endorsed use of DDT in indoor residual spraying.⁵

9.1 Why this is worth stating early

Because the argument is frequently framed as wealthy environmentalists denying a tool to poor countries, and that framing requires the poor countries to be asking for it and being refused.

The first half is documented.⁵ The second half is what §§4 to 8 contradict: the permission exists, has existed throughout, and is described by the treaty secretariat in unusually generous terms.³

9.2 The authors' reading of that

They argue that such organized actions by affected countries bespeak broad recognition of scientific issues and continuing need for DDT in malaria control programs and expose the misrepresentations of those who contend support for DDT is limited to a small number of extremists.⁵

That source is advocacy for continued use and we flag it as such. The factual content, that thirty-five African heads of state endorsed the use, is a strong point and we report it as theirs.

10. So what was restricted

Assembling the answer.

The review supplies the mechanism: because of the growing environmental concerns, the agricultural use of DDT diminished rapidly from the 1970s onward, affecting use of the insecticide for public health.¹

10.1 Affecting use for public health

Not prohibiting it. Affecting it, through supply, price, manufacturing capacity, donor preferences and the political cost of using a compound other countries had banned.¹

10.2 Which is the honest version of the grievance

Something real happened and it was not a ban on vector control. It was the collapse of a global production and distribution system built for agriculture, plus international pressure, and the malaria programmes were downstream of both.

That formulation is ours and we think it is what the sources support.

10.3 An indication that the restriction was effective

One general source notes that global totals are a fraction of what they were in the 1960s and that many countries that once relied on DDT have transitioned to other insecticides.⁸

11. The tonnage

The scale of what was actually being used, which reframes everything.

The review records that before the 1972 action DDT was registered for use in 334 agricultural products, that driven by the expansion of commercial agriculture, large areas in India and the Central American countries were intensively treated with DDT in the 1960s and 1970s where national eradication campaigns were also operational, and that between 1940 and 1973, estimates indicated that more than 2 million tons (4 billion pounds) of DDT were used in the United States, about 80% of them in agriculture.¹

11.1 The sentence inside that

Large areas were intensively treated for agriculture where national eradication campaigns were also operational.¹

The same mosquito populations the health campaigns were spraying were simultaneously being exposed, across whole landscapes, by farmers who were not part of any eradication programme.

11.2 Two million tons is difficult to picture

Four billion pounds, in one country, over thirty-three years.¹ Indoor residual spraying applies small amounts to the interior walls of houses, as one source describes it.⁸ The two activities are not comparable in scale, and only one of them was the malaria programme.

11.3 Which is the setup for §12

12. The resistance that followed

The consequence, stated in the same passage.

Over that period some level of resistance was reported in populations of 98 species of economically important insects.¹

12.1 Ninety-eight species

By the early 1970s, before any of the restrictions at issue took effect in malarious countries.¹

12.2 What that does to the counterfactual

The popular claim requires that the compound would have kept working had it not been restricted. Resistance in ninety-eight species, generated principally by agricultural use, is evidence against that premise.

It does not settle it, because resistance in economically important insects is not the same as resistance in the specific anopheline vectors in the specific places that mattered. We flag that limit and §24 repeats it.

13. Which is the earlier article's argument

The connection this journal did not expect to find.

Our Silent Spring article established that the book's case was not primarily that pesticides are poison. It was that indiscriminate broad-spectrum use destroys the tool through resistance and through the loss of natural control, and therefore defeats itself.

13.1 The two million tons

Eighty per cent of the United States tonnage went to agriculture across three decades.¹ Resistance appeared in ninety-eight species.¹

That is the argument, demonstrated on the compound whose restriction the book is blamed for.

13.2 Stating it carefully

We are not claiming this proves the book right or the critics wrong about the consequences of restriction. We are observing that the mechanism the book described is visible in the same historical record the critics cite, and that the agricultural use which generated the resistance is the use that was actually stopped.

That observation is ours.

14. The West African programme

Turning from the politics to the entomology, with the best documented field programme we located.

A retrospective paper describes a five-year indoor residual spraying programme beginning in 1953 in a pilot zone in what is now Burkina Faso, using DDT or dieldrin, with entomological and parasitological evaluation.⁴

Against the control zone, DDT produced a reduction of approximately 95% and 67% in the biting rate of the principal vector, indoors and outdoors respectively.⁴

14.1 Those are large effects

A ninety-five per cent reduction in indoor biting is a serious public health result and it is worth stating before the complication.

14.2 What indoor residual spraying assumes

The method applies a persistent insecticide to interior wall surfaces so that a mosquito which enters a house, feeds, and then rests on a wall to digest the blood meal acquires a lethal dose.⁸

Note the chain of assumptions. The vector must enter buildings, must feed indoors, must rest indoors afterwards, and must rest on a treated surface rather than an untreated one. Break any link and the method degrades.

14.3 Which is why the compound's persistence mattered

A residue that lasts months on a wall is what makes one spraying round cover a transmission season, and this journal's article on substrate effects and residual efficacy describes how much that depends on what the wall is made of. Mud, lime wash and painted plaster do not behave alike.

15. The irritancy paradox

The complication, and it is the most interesting finding in this article.

The same paper reports that because of its irritant action, DDT increased the exophagy coefficient of the vector five-fold.⁴

15.1 Exophagy is outdoor feeding

The mosquitoes shifted from biting indoors to biting outdoors, by a factor of five, because the treated surfaces irritated them.⁴

15.2 The mechanism working against itself

Indoor residual spraying assumes the vector enters a building, rests on a treated wall and acquires a dose. A compound that drives the vector out before it rests protects the occupant that night and moves the biting to where the wall cannot reach it.

The 67 per cent outdoor reduction shows the effect was not total.⁴ The five-fold shift shows the direction the population moved.

16. Why that matters beyond malaria

Because this journal has now found the same principle four times in different literatures.

Our article on boric acid quoted an industry association arguing that its toxicity is relatively low and that what compensates is lack of repellency, so that insects do not avoid it.

Our article on minimum risk pesticides found essential oil constituents that are strongly repellent and weakly lethal, and observed that driving bed bugs off a surface in an apartment building moves them next door.

Our articles on glucose aversion and on rodent neophobia found behavioural avoidance defeating otherwise adequate toxicants.

16.1 And the same tension appears in the formulation choice

Our bed bug articles described the trade's move away from repellent pyrethroid sprays toward non-repellent products and baits, for precisely this reason: a treatment the insect detects is a treatment it can route around.

The malaria programmes had the opposite requirement. A householder wants fewer mosquitoes in the room tonight, which irritancy delivers, and the epidemiologist wants fewer infective bites over a season, which it may not.

16.2 The general statement

Repellency and lethality are in tension. A compound that the target avoids delivers a smaller dose, and a control strategy that depends on the target contacting a treated surface is undermined by anything that discourages contact.

That is our formulation, and DDT's exophagy result is the largest-scale documented instance of it we have found.

17. The dieldrin arm

The other half of the same programme, which is a resistance story.

Dieldrin had no impact on the vector's biting rate either indoors or outdoors, owing to the species' resistance to that insecticide.⁴

17.1 In 1953

Resistance to the alternative compound was already defeating it at the start of the programme.⁴

This journal's article on resistance reversion found the cyclodiene resistance allele persisting in wild populations for years after that chemistry was withdrawn, and dieldrin is a cyclodiene. The allele in question has been reported in malaria mosquitoes, in fruit flies and in German cockroaches.

17.2 And it shaped what came next

A programme that finds its second insecticide already useless has no rotation available, which this journal's article on rotation evidence identifies as the basic requirement of resistance management. You cannot alternate between one chemistry and an ineffective one.

17.3 So the counterfactual has to account for this too

An argument that restrictions removed the only effective tool must contend with a documented case, two decades before any restriction, of the second tool already being useless in the same pilot zone.

18. The case for continued use, at its strongest

Stated as its proponents make it, because this journal's practice is to give a position its best form.

There is no equivalent replacement. The treaty secretariat's own status paper states that DDT is still needed because there is no alternative of both equivalent efficacy and operational feasibility, especially for areas with perennial and long seasonal malaria transmission.³

It is cheap. An advocacy source states that it remains the cheapest and most effective means for controlling mosquitoes.⁶ That source is a policy institute arguing a position and is flagged accordingly.

Affected countries want it. Thirty-five African heads of state endorsed its use in indoor residual spraying.⁵

The phase-out commitment creates pressure regardless of the exemption. The same advocacy source notes that the health agency, which had removed its ban on DDT use for public health, was however charged to reduce and ultimately eliminate DDT.⁶

And use has in fact collapsed. Global totals are a fraction of the 1960s figure.⁸

18.1 That is a serious argument

An exemption that exists on paper while the surrounding commitment is to elimination, in a market where production capacity has gone, is not the same thing as an unrestricted permission. We think this is the strongest form of the case and it does not depend on a ban having occurred.

19. The case against, at its strongest

And the other side, given the same treatment.

The legal claim is false. Vector control was exempted at every stage.¹²³

The health agency promoted the use. In a 2006 position statement.¹

The tool was substantially spent before restriction. Ninety-eight species with some level of resistance by the early 1970s.¹

Agriculture spent it. Eighty per cent of the tonnage, applied across landscapes where eradication campaigns were simultaneously operating.¹

And the compound had a structural limitation. Irritancy drove a five-fold increase in outdoor feeding in one documented programme, which no policy decision caused.⁴

19.1 The reputational point

A magazine article observes that by virtue of its massive misuse in the 1960s and 1970s, DDT gained a bad reputation that was hard to shake.⁷

Which locates the cause of the political difficulty in the agricultural overuse rather than in the book.

20. Where the two sides actually disagree

Narrowing it, which is the useful thing to do with a polarised argument.

They do not disagree that vector control was legally permitted throughout. They do not disagree that use collapsed anyway. They do not disagree that resistance was widespread.

20.1 The real disagreement

Whether the collapse in use was caused principally by international pressure and stigma, which could have been otherwise, or principally by resistance, cost, operational difficulty and the loss of agricultural-scale manufacturing, which could not.

That is an empirical question about attribution, it is hard, and none of the sources we read attempts to quantify it. Our view is that this is where the argument should be conducted and mostly is not.

20.2 Why the attribution question is hard

Because the causes are not independent. Agricultural overuse generated the resistance, the resistance reduced efficacy, the reduced efficacy made programmes expensive, the environmental record generated the stigma, and the stigma reduced donor willingness. Each factor made the others worse.

Disentangling that would require counterfactual modelling nobody appears to have attempted, and we are not in a position to attempt it either.

20.3 And a second disagreement

Whether the health harms of the compound are real at exposure levels arising from indoor spraying. A commentary describes the view that adverse health evidence is mounting as itself a minority view and the argument built on it as false, which is a strong claim from an advocacy source.⁵ Per §2 we are not adjudicating it.

21. The cost-effectiveness finding

One result that cuts against the no-alternative claim and deserves recording.

A magazine article reports that in 2007, the WHO concluded that long-lasting insecticide treated bed nets were more cost-effective than DDT spraying in high malaria transmission areas.⁷

21.1 Which is an entomologically sensible result

A treated net puts the insecticide between the vector and the sleeping person, so it does not depend on the vector resting on a wall, and it is not defeated by the shift to outdoor feeding to the same degree. That reasoning is ours.

21.2 And it addresses the exophagy problem only partly

A net protects a sleeping person and does nothing for somebody sitting outside in the evening, which is when a population shifted toward outdoor feeding would be biting. Our articles on the Winnipeg mosquito programme and on vector surveillance describe the same structural issue in a different disease system.

21.3 And it is contested

The treaty status paper's position that no alternative has equivalent efficacy and operational feasibility postdates or coexists with that conclusion.³⁷ We report both and do not resolve them.

22. What this changes about the earlier article

Revisiting our own work, which is the point of writing this.

Our Silent Spring article recorded the malaria argument as a serious one we had not assessed. We have now assessed the factual core of it and found the central legal claim incorrect.¹

22.1 What we would now add to that article

That the book is blamed for a prohibition that did not occur in the use category at issue, and that the mechanism it actually described, resistance generated by indiscriminate broad-spectrum use, is visible in the same record at ninety-eight species.¹

22.2 What we would not add

Any claim that restriction was costless. Section 18 is a serious argument and we have not refuted it, because the attribution question in §20.1 is genuinely open.

23. What a structural pest contractor takes from it

Three transferable things, since this journal is not about malaria.

Repellency is a cost, not only a benefit. The five-fold exophagy shift is the clearest documented case, and §16 lists the others this journal has found.⁴

Use outside your programme determines your resistance. The agricultural tonnage selected the populations the health campaigns then had to treat.¹ A contractor treating one unit in a building where everybody else is applying consumer products faces a smaller version of the same problem.

And a tool can be lost without anybody banning it. Resistance, cost, manufacturing and reputation each withdraw a product from practical use, and this journal's articles on rotation and on reversion describe how quietly that happens.

23.1 The last of those is the one contractors underrate

A product that remains registered, remains effective and remains purchasable can still become commercially unusable because clients will not accept it. Our articles on cosmetic pesticide policy and on consumer products both describe that dynamic operating in this province.

Which means a trade that wants to keep its tools has an interest in not squandering them, and the two million tons in §11 is what squandering looks like at scale.

23.2 And the surveillance point

The West African programme is notable partly because it measured. Biting rates indoors and outdoors, against a control zone, with parasitological evaluation alongside.⁴ The exophagy shift was detectable only because somebody was counting outdoor biting as well as indoor.

A programme that had measured only the thing it was trying to improve would have recorded a ninety-five per cent success. This journal's articles on detection and on what a zero means are about the same hazard in a smaller setting.

24. Limitations and open questions

This is a contested political subject and our sources are not neutral. Two are explicit advocacy for continued use, one is a magazine article sympathetic to the other side, and we have flagged each in the reference list.⁵⁶⁷

We did not read the primary documents. Not the convention text, not the 1972 decision, not the 2006 position statement. Every legal characterisation here reaches us through secondary description.¹²

The resistance figure is about the wrong insects. Ninety-eight species of economically important insects is not a statement about anopheline vectors, and §12.2 says so.¹

The West African paper was read in translation from an abstract. The percentages and the five-fold exophagy figure come from a French-language abstract and we have not seen the methods.⁴

One programme is not a generalisation. The irritancy result is from one pilot zone, one vector species and one period, and vectors differ in how much they rest indoors to begin with.⁴

We have not quantified anything. The attribution question in §20.1 is the substance of the dispute and we have not attempted to answer it, nor found a source that does.

And the health question is untouched. Per §2, deliberately.

Sections 1.1, 5.1, 10.2, 11.1, 12.2, 13, 15.2, 16, 17.2, 18.1, 20, 21.1, 22 and 23 are our reasoning. The reading of what was actually restricted, the connection between agricultural tonnage and campaign-area resistance, the repellency generalisation, the location of the real disagreement, the bed net reasoning and the transferable lessons are ours rather than sourced positions.

25. Conclusion

DDT for disease vector control was never banned. The 1972 United States action was not a total prohibition and allowed public health uses; the Stockholm Convention listed the compound for phase-out while exempting indoor vector control; a health agency position statement in 2006 promoted indoor residual spraying with it; the treaty secretariat records that countries may use it for as long as necessary, in the quantity needed; and thirty-five African heads of state have endorsed it.¹²³⁵

Something real nevertheless happened, and the honest description is in the same sentence as the correction: international pressure restricted its implementation in malarious countries.¹ Agricultural use collapsed, which took the manufacturing base and the price with it, and a phase-out commitment sat alongside the exemption. That is a serious grievance and it does not require a ban to have occurred.

The entomology is unkind to everybody. More than two million tons went into the United States alone between 1940 and 1973, about eighty per cent of it agricultural, applied across the same landscapes where eradication campaigns were operating, and resistance appeared in ninety-eight species before the restrictions took hold.¹ In a five-year programme beginning in 1953, the compound cut indoor biting by ninety-five per cent and, through the same irritancy that produced the protection, raised outdoor feeding five-fold.⁴ A tool that teaches its target to avoid the treated surface is a tool with a built-in limit, and no regulator wrote that limit into it.

References

1. Dichlorodiphenyltrichloroethane for indoor residual spraying in Africa: how can it be used for malaria control? Review chapter in an academic volume on malaria, hosted in a national library bookshelf. Used for the statement that in 2006 a global health agency issued a position statement promoting indoor residual spraying with the compound for malaria vector control in epidemic and endemic areas, with other international organisations concurring because of the burden of malaria and the relative ineffectiveness of current treatment and control strategies; for the statement that although the 2001 convention targeted the compound as one of twelve persistent organic pollutants for phase-out and eventual elimination, it allowed a provision for continued indoor use in disease vector control; for the statement that before the compound was officially banned in the United States in 1972 it was registered for use in 334 agricultural products; for the account that driven by the expansion of commercial agriculture, large areas in India and Central American countries were intensively treated in the 1960s and 1970s where national eradication campaigns were also operational; for the estimate that between 1940 and 1973 more than 2 million tons were used in the United States, about 80 per cent of them in agriculture, and that some level of resistance was reported in populations of 98 species of economically important insects; and for the statements that because of growing environmental concerns agricultural use diminished rapidly from the 1970s onward, affecting use of the insecticide for public health, and that the compound for disease vector control was never banned but international pressure restricted its implementation in malarious countries. https://www.ncbi.nlm.nih.gov/books/NBK1724/
2. DDT: a brief history and status. National environmental regulator summary page. Used for the account that countries negotiated a treaty to enact global bans or restrictions on persistent organic pollutants including this compound; that the convention bans all uses except for a limited exemption for use against mosquitoes transmitting the microbe that causes malaria; that the compound is one of twelve pesticides recommended by a global health agency for indoor residual spray programmes, particularly in African countries where malaria remains a major health problem; and that it is up to individual countries to decide whether to use it. https://www.epa.gov/ingredients-used-pesticide-products/ddt-brief-history-and-status
3. Global status of DDT and its alternatives for use in vector control. Status paper prepared for the convention secretariat in collaboration with a global health agency and an environment programme. Used for the statements that the agency recommends the compound for use in indoor residual spraying only; that it is still needed because there is no alternative of both equivalent efficacy and operational feasibility, especially for areas with perennial and long seasonal malaria transmission; for the quoted permission that countries can use it for as long as necessary, in the quantity needed, provided the guidelines and recommendations of the agency and the convention are met, and until locally appropriate and cost-effective alternatives are available for a sustainable transition; and for the record that a global strategic paper on elimination was drafted in 2005 and remained to be completed, with the conference of parties requesting further preparation in 2007. http://chm.pops.int/Portals/0/docs/from_old_website/documents/ddt/Global%20status%20of%20DDT%20SSC%2020Oct08.pdf
4. Lessons from the malaria vector control programme based on indoor residual spraying with DDT or dieldrin in a West African pilot zone: failure or success? Journal article in a tropical medicine bulletin, read as a French-language abstract. Used for the description of a five-year indoor residual spraying programme beginning in 1953 in a pilot zone, using either compound, with entomological and parasitological evaluation; for the result that against the control zone, the first compound induced reductions of approximately 95 and 67 per cent in the biting rate of the principal vector indoors and outdoors respectively; for the finding that because of its irritant action that compound increased the vector's outdoor feeding coefficient five-fold; and for the finding that the second compound had no impact on the vector's biting rate either indoors or outdoors, given the species' resistance to it. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9022765/
5. The DDT paradox. Commentary in an environmental health journal arguing for continued use of the compound in malaria control. Advocacy source, cited as attributed material. Used for the reports that at the fifth meeting of the conference of parties to the convention a named country and a regional bloc announced their intention to produce the compound locally, and that thirty-five heads of state and government who are members of an African malaria alliance endorsed its use in indoor residual spraying; for the authors' argument that such organised actions by affected countries bespeak broad recognition of scientific issues and continuing need, and expose the misrepresentations of those contending that support is limited to a small number of extremists; and for their position that the interpretation that evidence of adverse health effects is mounting is itself a minority view and that an argument built on it is false. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3230456/
6. Bring back DDT. Policy institute commentary. Advocacy source arguing a position, cited as attributed material. Used for the statements that in 2004 the persistent organic pollutants convention was signed by 170 countries restricting use of the compound to vector control and thus permitting its public health use; that the health agency, which had removed its ban on use for public health, was nevertheless charged to reduce and ultimately eliminate it; that one country continues to produce and use it for public health purposes and has opposed a proposed deadline for prohibition; that the same country no longer appears to be using it for house spraying as it did under named national programmes of 1953 and 1958; and for the author's claim that it remains the cheapest and most effective means for controlling mosquitoes. https://www.cato.org/commentary/bring-back-ddt
7. Rehabilitating Carson. General interest magazine article. Journalistic source sympathetic to one side of the dispute, cited as attributed material. Used for the observations that the convention prohibits use of the compound except for disease control and calls for all use to be phased out, with the phase-out commitment often loosely referred to as a ban; that by virtue of its massive misuse in the 1960s and 1970s the compound gained a bad reputation that was hard to shake; for the quoted concession from a prominent advocate of continued use that his position had mellowed; for the report that at meetings on implementation the health agency restated its position stressing commitment to eventual phase-out while noting that use would continue until adequate substitutes were found; and for the report that in 2007 the agency concluded that long-lasting insecticide treated bed nets were more cost-effective than spraying in high transmission areas. https://www.prospectmagazine.co.uk/world/environment-news/52371/rehabilitating-carson
8. Is DDT still being used? General reference website article. Non-specialist secondary source, cited as attributed material. Used for the statements that under the convention the compound is restricted but not fully banned worldwide, with countries facing high malaria burdens permitted to use it for indoor residual spraying, described as a targeted method applying small amounts to interior walls to kill mosquitoes that land there; that the exemption exists because in certain regions it remains effective, affordable and longer lasting than many alternatives; that a small number of countries in sub-Saharan Africa and South Asia have reported using it in recent years; that global totals are a fraction of 1960s levels and many countries that once relied on it have transitioned to other insecticides; that the 1972 United States action did not amount to a total prohibition since public health uses were allowed under strict conditions, though it effectively ended widespread agricultural spraying; and that other countries moved similarly through the 1970s and 1980s, with more than two dozen having enacted full prohibitions by the early 1990s. https://www.worldatlas.com/conservation/is-ddt-still-being-used.html
9. Health agency calls for spraying controversial compound to fight malaria. Archived university-hosted news article. Journalistic source, cited as attributed material. Used for the account that the compound was first used widely during the Second World War to control typhus and body lice on soldiers, that within a few years one country was free of malaria, that in 1955 the health agency endorsed its use for a global campaign which within twelve years freed developed countries along with parts of Asia and Latin America from risk of infection, that reports in the 1960s raised concerns about its effects on birds and the food chain, and that environmental protest led the national regulator to ban its use domestically. https://archive-yaleglobal.yale.edu/content/who-calls-spraying-controversial-ddt-fight-malaria