Hindsight check: LL2-11 (Ch 11 DDT: fifty years since Silent Spring)#

Source section: EEA, Late lessons from early warnings: science, precaution, innovation (EEA Report No 1/2013), Ch 11, by Henk Bouwman, Riana Bornman, Henk van den Berg and Henrik Kylin (report pp. 240–260; PDF pp. 242–262). There are no panels. Check window: publication (2013) to late September 2026. Checked: 25 September 2026.

Method note. - General web search was unavailable for this pass because the session’s search budget was exhausted. I retrieved sources by fetching primary repositories directly: - the Stockholm Convention website (the DDT Register, the pages on the DDT expert group and the intersessional consultations, and the COP-10, COP-11 and COP-12 decisions and meeting documents); - WHO (the prequalified vector-control product list and the World Malaria Report 2025 page); - the IARC Monographs (Volume 113, DDT chapter, full text); - ATSDR’s 2022 Toxicological Profile for DDT, DDE, and DDD (chapter 1, full text); - Europe PMC, for peer-reviewed abstracts and, where open access, full text; - the IUCN press release archive, the US EPA historical archive and the Federal Register. - Where a point rests on an abstract only, I say so. - Annex 3 does not apply. DDT was not a case in the 2001 volume, so there is no Annex 3 update. - I read only the section digest, the section’s source extract and web sources. Page numbers are report pages of the 2013 volume. - Conflicts of role. Two of the chapter’s authors are also the authors of much of the later evidence. - Henk van den Berg is a Secretariat-selected member of the Stockholm Convention’s DDT expert group for 2023–2027 [S1, Annex III]. He is first author of the 2017 trend analysis [S9] and of the 2025 Lancet Planetary Health Personal View [S10]. Much of what follows on production and use therefore comes from a chapter author acting in an official capacity. The underlying numbers, however, are Parties’ own questionnaire returns. The conclusions were adopted by the Conference of the Parties (COP) [S2, S4, S5], and WHO’s note to COP-12 was written independently [S3]. - Riana Bornman is a co-author of the VHEMBE birth-cohort papers [S23–S29]. These include null results for DDT on outcomes the chapter highlighted, which counts in the authors’ favour.

Overview#

1. The central forecast was right on direction but wrong on pace. The chapter expected DDT’s “final demise” to be “some way off” and saw no clear decline since the Stockholm Convention (pp. 244, 252). - What happened: - Global use fell from over 5,000 t a year (the chapter’s figure) to 370 t in 2023 [S1]. - India’s use fell from 3,092 t in 2014 to 196 t in 2023, and India said it would stop using DDT for vector control from April 2025 [S1]. - Only India, South Africa and Zimbabwe reported use in 2023 [S1, S10]. - Production (all at HIL (India) Limited) was 309 t in 2023, about 7% of the 2005 level [S1]. - Eight Parties have withdrawn from the DDT Register [S6]. - What drove the fall: the causes were operational, not the governance route the chapter described. The main ones were: - resistance to DDT itself, for example only 34% mortality in India’s main malaria vector in 2022–23 [S1]; - new insecticides for indoor spraying, and a shift towards bed nets; - falling malaria in India; - national policy [S1]. The UNEP “road map” the chapter pointed to stayed almost unfunded [S1]. - What the chapter got right: - There is still no timetable. COP-12 (May 2025) again found a “continued need”, now “justified only in a few specific settings”, and set no end date [S2]. - The last users cite the cost of alternatives [S1]. - Obsolete stocks (at least 4,727 t worldwide) and legacy contamination persist [S1, S47, S48].

2. The health evidence moved, but not in the way the chapter framed it. - Cancer classification. IARC reclassified DDT from “possibly” to “probably carcinogenic to humans” (Group 2A) in 2015. The human evidence was for liver cancer, testicular cancer and non-Hodgkin lymphoma. For breast cancer IARC found “no association overall” [S15, S16]. - The chapter’s breast-cancer lead. The chapter’s lead example, early-life exposure and breast cancer, has been extended by the same research group. Their later studies covered in-utero exposure and breast cancer up to age 54 [S18, S19], and effects in a third generation [S22]. The US ATSDR (2022) nonetheless judges the evidence on breast cancer in women to be consistently null [S17]. - Birth defects. The +33% rate of urogenital birth defects the chapter cites (Bornman 2010) was not replicated. In the chapter authors’ own South African birth cohort (VHEMBE), maternal DDT and DDE were not associated with hypospadias, but pyrethroid metabolites were [S23]. ATSDR describes the evidence as consistently showing “no associations with male reproductive system birth defects” [S17]. - Where the evidence did firm up. Associations have become more consistent for type 2 diabetes [S17, S30, S31] and for wheeze in children [S17, S27]. - So is the evidence “mounting”? It has broadened, and the hazard classification has risen. But several of the chapter’s headline examples have not held.

3. The governance stance the chapter argued for has largely been adopted. - WHO. WHO moved from “still needed” (2011) to calling DDT “a last resort, not a first choice” (2023 guidelines). It has prequalified no DDT product [S1, S3]. - The Conference of the Parties. It narrowed the justification for continued use [S2, S4, S5]. - Exposure monitoring. The COP encouraged monitoring of exposure in spray workers and households [S4]. - Research on sprayed homes. The research gap on indoor residual spraying (IRS) that the chapter identified has been partly filled by a large birth cohort [S23–S29, S34].

4. Mechanisms the chapter emphasised were confirmed, some strongly: - Insecticide resistance erodes each single tool (p. 251). This was confirmed strongly. - Resistance to pyrethroids is reported in 87% of reporting countries, and to organochlorines in 82% [S1]. - There are early signs of resistance to newer insecticide classes [S1] and to the pyrethroid India now uses against sandflies [S43]. - Substitutes carry their own uncertainties (p. 250). This was also confirmed. In VHEMBE, the pyrethroids used in place of DDT were linked to: - hypospadias [S23]; - poorer neurodevelopment [S24]; - childhood infections [S28]. - Restrictions leak where regulation is weak (p. 244). This was confirmed. - A 2021 global survey found widespread shortcomings in how countries manage vector-control insecticides [S13]. - DDT is still misused on khat crops in Ethiopia [S45, S46].

5. The South African story needs qualifying. The chapter attributes the fall in cases after 2000 to reintroducing DDT. The published record, which already existed in 2005, attributes it to several changes together: - DDT reintroduced; - a switch to artemisinin combination treatment (artemether-lumefantrine) in 2001; - cross-border spraying in southern Mozambique under the Lubombo Spatial Development Initiative (LSDI) [S38–S40].

The pyrethroid-resistant An. funestus reinvasion itself is well established. Its “threshold of proof” effect is consistent with South Africa’s slow switch, but cost is now the stated barrier [S1, S41].

6. The commemorative claims on birds are mixed. - Holding up: - Raptor recovery after the bans continued; US bald eagle numbers roughly quadrupled between about 2007 and 2018 [S54]. - More than 10% of bird species are threatened: 11.5% in October 2025 [S50]. - Not holding up: - The “bird chorus” of common farmland birds has declined sharply since 1970 [S52, S53]. - European analyses identify agricultural intensification, “in particular pesticides and fertiliser use”, as the main pressure [S53]. - A historical error. The chapter says Kennedy led to a “complete ban”. In fact the 1972 US EPA cancellation exempted public-health and export uses [S55].

Implication for weight. - Give strong weight to the chapter’s mechanistic lessons. Each is confirmed by evidence largely independent of the authors: - adaptive resistance wears down single-mode fixes; - cheap incumbents persist where alternatives cost more; - restrictions leak where regulation is weak; - persistent products leave costs that outlive their use; - substitutes bring their own uncertainties. - Give moderate or low weight to: - the specific health claims, several of which did not replicate; - the single-cause South African narrative; - the chapter’s pessimistic timeline. - A lesson the chapter could not have drawn in 2013: the eventual exit came mainly because the incumbent failed on its own terms (vectors became resistant) and substitutes matured. Health-based precaution played a smaller part. Periodic review with a public register and structured consultation then helped convert this into withdrawals [S1, S6].

Claim-by-claim#

Claim 1: Global DDT use exceeds 5,000 t a year and “has not declined substantially since the Stockholm Convention was enacted”; India uses 82%; African users rose from 4 (2000) to 9 (2008), and whether the 2009 African decline is “part of a new trend” “remains to be seen” (p. 244)#

Original claim (p. 244). - Global use for disease-vector control is “estimated at more than 5 000 tonnes of active ingredient”. It “has fluctuated during the past decade but has not declined substantially since the Stockholm Convention was enacted” (citing van den Berg et al. 2012). - India uses 82%. - The number of African countries using DDT rose from four in 2000 to nine in 2008. Ethiopia, Mozambique and Uganda had reportedly stopped. - “It remains to be seen whether the decline in DDT use in Africa in 2009 is part of a new trend.”

Subsequent developments - A re-analysis by a chapter author revised the baseline trend. Van den Berg et al. (2017) evaluated 2001–2014 for the Convention’s first effectiveness evaluation [S9]: - Average use fell 30%, from 5,388 t a year (2001–2007) to 3,772 t a year (2008–2014). Production fell 32%, from 5,144 t to 3,491 t. - India accounted for 84% of use over 2001–2014. - The decline “was to a large extent attributable to India”. - In sub-Saharan Africa, use “increased from 2001 until 2009, but declined thereafter”. This happened as Ethiopia, Eritrea and Zambia switched away, “due to the development of DDT resistance”. - The authors’ own summary was a “modest decline”. The chapter’s figure of over 5,000 t matched the 2001–2007 average. By 2008–2014 the average had already fallen to about 3,800 t. - Collapse after 2014. - DDT expert group report to COP-12, February 2025 [S1]: - Global use was 849 t in 2021, 570 t in 2022 and 369.6 t in 2023. Average use in 2021–2023 was 60% below 2018–2020. - India’s use was 670 t, 387 t and 196 t over the same three years, down from 3,092 t in 2014. - India “has indicated it will no longer use DDT for disease vector control from April 2025”. The expert group lists the factors behind India’s decline as “national policy support for the phase-out of DDT, DDT resistance in vector populations, an increased use of ITNs, a shift … to alternative insecticides for IRS, and progress in the control of malaria”. - Declining need is visible in other indicators too. India’s reported incidence of kala-azar (visceral leishmaniasis, the second disease DDT was sprayed against) reached the elimination threshold in 2023 [S42]. - The Lancet Planetary Health Personal View (July 2025) says “Only three countries, India, South Africa, and Zimbabwe, were still using DDT in 2023” (abstract) [S10]. - If India’s exit holds, the remaining reported use in 2023 terms would be about 173 t a year, almost all in Zimbabwe. This is my arithmetic from the table in [S1]. - The African trend. It did continue. - Reported users in 2021–2023 were South Africa (10–20 t a year) and Zimbabwe (a flat 162.8 t reported for each year, which looks like an estimate) [S1]. - Namibia and Zambia reported zero use and “no plans” to reintroduce it. Eswatini has not sprayed DDT since 2014/15. Mozambique stopped in 2015 [S1]. - There is one counter-current. Zimbabwe newly notified the register in 2018 and its use rose 7% between reporting periods [S1, S6]. - Verification gap. I found no independent confirmation that India actually stopped domestic use in April 2025. The Stockholm questionnaire for 2024–2025 was due on 30 June 2026 [S2], and no report on it is yet public. The fourth intersessional meeting (5–7 May 2026) has posted only its agenda [S8].

Verdict: weakened. - The claim that use “has not declined substantially” was already an overstatement by 2008–2014, on the co-author’s own later data. - Since then, use has fallen by more than 90%. - The open question about Africa (“remains to be seen”) has been answered: it was a new trend. Zimbabwe is the exception.

Implications for weight. The chapter’s snapshot was reasonable for about 2009 but should not be read as evidence of durable lock-in. The better-supported lesson concerns what moved use: - resistance in the target organism; - the arrival of substitutes; - declining need.

Trend statements in the chapter rest on one research group’s datasets. Later data from the same group reversed the picture, which is a reminder to date-stamp such claims.

Claim 2: India is the sole producer; China has recently stopped; South Africa formulates Indian technical DDT for export to other African countries (pp. 243–244, 253)#

Original claim (pp. 243–244; Table 11.1, p. 253). “Currently, DDT is produced only in India”. “China has recently stopped production”. “South Africa formulates DDT using technical product from India, and exports the formulated product to several other African countries.”

Subsequent developments - India. - “Since 2008, India has been the only country producing DDT.” The sole producer is HIL (India) Limited, a government enterprise with one plant at Rasayani, Maharashtra. It produced 309 t in 2023 [S1]. - India says its current production is “for export purposes only”. It has asked for “guidance on when it should cease the production of DDT for export to the few remaining DDT-using Parties in southern Africa” [S1]. - With support from the Global Environment Facility (GEF), HIL “has shifted from DDT production towards” alternatives, including insecticide-treated nets (ITNs) and the biological larvicide Bti [S1]. - China discontinued production in 2008 and exports in 2010 [S9]. It withdrew from the DDT Register on 28 February 2014 [S6]. - DPR Korea reported production, mainly for agriculture and forestry, but data run only to 2006 [S9]. The chapter’s “only India” slightly overstates what was known. - South Africa’s role as formulator. - In 2017 South Africa was described as having a facility at which imported technical DDT “has been formulated and re-packaged for national use and for distribution” [S9]. - By 2021–2023, India exported DDT to South Africa, Zambia and Zimbabwe, “All … as 75% WP formulation” [S1]. (WP means wettable powder, the ready-to-spray form.) South Africa reported imports only in 2021. - I found no evidence that South Africa still formulates DDT or re-exports it. Its role as a regional hub appears to have ended, but no source says so explicitly. - Reporting quality. India’s export figures and the importers’ figures “do not tally”. For example, India reported exporting to Zambia in 2021, while Zambia reported zero imports [S1].

Verdict: held up. India remained the sole producer and China the recent exit. The South African formulation role appears to have lapsed since, and the DPR Korea caveat applies.

Implications for weight. Reliable as a factual snapshot. Supply concentrated in one state-owned producer also created a clear lever for exit: once India decided to stop domestic use, only export demand kept the plant running.

Claim 3: There is “a roadmap for the exit of DDT” but “no timetable”; given R&D budgets and political agendas “the final demise of DDT still seems some way off”; DDT will remain in inert environmental media “for decades” (p. 252)#

Original claim (p. 252). “Although there is a roadmap, there is no timetable … Given the current climate regarding research and development budgets and interfacing political agendas, the final demise of DDT still seems some way off.” DDT “will probably remain in inert environmental media for decades to come.”

Subsequent developments - Still no timetable. - COP-10 (2022) noted that because DDT-using countries target malaria elimination by 2030, “it is assumed that DDT use may not be needed after that date”. This is an assumption, not a binding date [S4]. The same decision started consultations with registered Parties on a possible phase-out plan [S4]. - COP-11 (2023) and COP-12 (May 2025) each concluded there is a continued need. COP-12 said it was “justified only in a few specific settings, which take into account the affordability of vector control, insecticide resistance management and the need for outbreak response”. The next evaluation is at COP-13 [S5, S2]. - The DDT expert group (in 2020) judged it “appropriate for COP to take additional steps towards a focused phasing out of DDT” [S7]. - The road map was under-resourced, as the chapter feared. - UNEP prepared the road map in 2015. - In 2023 UNEP reported “the financial basis for the operations of the DDT Road map remained extremely weak, and no new financial contributions were made available”. It said the sustainability of the Global Alliance on alternatives to DDT “is threatened by the lack of resources” [S1]. - National road maps were piloted only in Namibia and Uganda, with foundation funding [S1]. - But the demise came faster than the chapter implied (Claim 1). - The expert group calls the recent reductions “milestones along the path towards a global phase-out” [S1]. - The Lancet Planetary Health Personal View calls phase-out “within reach” [S10]. - The remaining barriers are the same ones the chapter named. The direct costs of alternatives are “usually higher than those for DDT”, and “global progress in malaria control and elimination has stalled” [S1]. - Procurement cost for new IRS products is “roughly 2–3 times higher” than for DDT, but indirect costs for DDT, such as safeguards, disposal and transport, are higher [S1]. - Without external finance, “it is possible or likely that some of these countries will continue using DDT as long as vectors remain susceptible” [S1]. - Malaria rose to an estimated 282 million cases and 610,000 deaths in 2024 [S12]. - Environmental persistence is confirmed. - Obsolete stocks are estimated at at least 4,727 t worldwide (inventories from 2014 and 2017), including in countries that recently stopped [S1]. COP-12 asked Parties to add stockpile plans to their national implementation plans [S2]. - Off Southern California, sediment contamination “continues to mirror the spatial legacy of dumping”. This is “despite more than half a century since the cessation of industrial dumping”, and fish contamination tracks sediment levels [S47]. - Deep-basin sediments show “sluggish transformation” and an ongoing secondary source of DDE [S48]. - In KwaZulu-Natal, eggs of fish-eating birds show eggshell thinning associated with DDE and DDD [S49].

Verdict: partly held up. - “No timetable” and persistence in the environment: held up, and strengthened for persistence. - “Some way off”: this held only in the literal sense, since DDT is still produced and used in 2026. The scale of use collapsed much sooner than the chapter implied, and not because the road map was funded.

Implications for weight. The lesson that an open-ended exemption does not by itself produce an exit holds. What moved things were non-governance factors (resistance, new products, falling need), plus a light procedural push from registers and consultations. The legacy lesson, that persistent products leave long-lived costs, is among the best supported in the chapter.

Claim 4: After South Africa stopped DDT (1996), pyrethroid-resistant An. funestus reinvaded and caused serious outbreaks; cases fell after DDT was reintroduced (2000); this “probably increased the threshold of expectation of proof” for alternatives (pp. 243, 250)#

Original claim (pp. 243, 250). - An. funestus “was able to reinvade the country because it had developed resistance to the pyrethroids”. The authors describe this as “unique to South Africa”. - Serious outbreaks forced the government “to revert to DDT, after which the number of malaria cases declined”. “DDT had to be re-introduced to return to pre-1996 levels of morbidity and mortality.” - The pyrethroid failure “has probably increased the threshold of expectation of proof of sustainability” for alternatives.

Subsequent developments (and pre-2013 literature the chapter did not cite) - Concurrent causes. The recovery was not attributable to DDT alone. - Barnes et al. (2005): KwaZulu-Natal’s 1995–2000 surge was “fuelled by pyrethroid and sulfadoxine-pyrimethamine resistance”. In response “vector control was strengthened and artemether-lumefantrine (AL) was deployed”. - Barnes et al. continued: in the following year, malaria admissions and deaths at sentinel facilities fell 89%. By 2003 malaria outpatient cases and admissions had fallen 99%. They concluded that AL “together with concurrent strengthening of vector control measures … contributed” [S38]. - Craig et al. (2004): across 30 years of case data, overall malaria levels tracked drug resistance and, possibly, HIV prevalence, while climate drove variation from year to year [S39]. - The LSDI malaria programme, a cross-border spraying effort across South Africa, Swaziland and Mozambique that began in 2000, was associated with a 99% fall in cases in South Africa against the 2000 baseline [S40]. - These papers predate the chapter. The chapter cites Maharaj et al. (2005) but not this literature. - Did the “threshold of proof” effect persist? - South Africa still used 10–20 t a year in 2021–2023 “because of the high cost and availability of the alternative insecticides”. It says a full switch needs “inter-ministerial coordination and further political support” [S1]. - A 2024 field trial in KwaZulu-Natal found three newer IRS products “suitable replacements for DDT”. Each needed just one spray round per season, and one outperformed DDT on mud walls [S41]. - The expert group lists “evidence base: local evaluation of pre-qualified IRS products” among the barriers to be addressed [S1]. - A reactive, targeted IRS strategy proved non-inferior and cheaper than blanket spraying in a 2021 cluster-randomised trial in South Africa [S37]. - Resistance status in South Africa. Vectors there have “remained mostly susceptible” to DDT, but “there have been signs that DDT resistance is emerging across the subregion” [S1].

Verdict: partly held up. - The reinvasion is well established. - The claim that cases fell because of DDT oversimplifies. Treatment policy and regional vector control changed at the same time. - The “threshold of proof” hypothesis is plausible and consistent with South Africa’s slow switch. Later evidence points more to cost and institutions than to demands for proof.

Implications for weight. The case remains a genuine warning: removing an incumbent before its substitute is proven against the actual target can backfire. But it should be cited as a package failure followed by a package recovery. Its evidential weight for “the incumbent was indispensable” is lower than the chapter implies. The authors themselves called the case “unique” (p. 243).

Claim 5: Resistance to DDT and other insecticides is “now widespread in sub-Saharan Africa and India”; improved formulations of existing insecticides “will be available soon”, new molecules will take “considerably longer”; resistance will continue against any new mode of action unless selection pressure is reduced (pp. 243, 251)#

Original claim (pp. 243, 251). Resistance “to DDT, and to other available insecticides, is now widespread in sub-Saharan Africa and India”. “Improved formulations of existing insecticide molecules will be available soon although new insecticide molecules will take considerably longer”. “Evolutionary selection for resistance will continue against any new modes of action unless the selection pressure on vector populations is substantially reduced.”

Subsequent developments - Resistance. - Pyrethroid resistance is detected in at least one malaria vector in at least one location in 87% of reporting countries. For organochlorines the figure is 82%, for carbamates 69% and for organophosphates 60% [S1]. - India reported an average of 34% mortality to DDT in An. culicifacies (33 tests, 2022–23) [S1]. - Resistance to DDT drove exits in Ethiopia, Eritrea and Zambia after 2009 [S9], and in India [S1]. - Timeline of new products. It matched the prediction. WHO prequalification dates, from the current list [S11]: - Actellic 300CS, an improved capsule formulation of the existing insecticide pirimiphos-methyl, is listed with a prequalification date of 29 January 2018. Like other early dates on the list, this appears to reflect the transfer from WHO’s earlier evaluation scheme rather than first availability. - Clothianidin, a neonicotinoid new to indoor spraying: SumiShield 50WG, 25 October 2017. - Clothianidin plus deltamethrin: Fludora Fusion, 13 December 2018. - Broflanilide, in a new insecticide group with a unique mode of action: VECTRON T500, 11 March 2023. - Chlorfenapyr for spraying: Sylando 240 SC, 5 December 2024. - Isocycloseram: SOVRENTA 15WP, 11 April 2025. - Nets combining chlorfenapyr with a pyrethroid are now recommended by WHO where vectors resist pyrethroids [S1]. - WHO told COP-12 that “The arsenal of insecticides for indoor residual spraying has never been greater” [S3]. - Every insecticide class available for IRS is also used in agriculture, including clothianidin and broflanilide [S1]. This matters for resistance, because selection pressure comes from both sectors. - Resistance to new modes of action. - “resistance to neonicotinoids (which include clothianidin) exists in malaria vectors in Africa”. Of 37 bioassay results in 2020–2021, four showed confirmed and five suspected resistance [S1]. - Vector populations “are adapting to the use of the PBO synergist” used in some nets [S1]. - India’s sandfly vector now shows early signs of resistance to alpha-cypermethrin, the insecticide that replaced DDT for kala-azar [S43]. - A 2021 global survey found that “IRS programs have been slow to react to detection of pyrethroid resistance”, with “proactive resistance management … generally weak”. It also raised product-stewardship concerns about the “intensive use of recently introduced insecticide products” [S14]. - Because these insecticide classes are also used in agriculture, the expert group says resistance management “should be developed together with the agricultural sector” [S1].

Verdict: strengthened. Each part of the claim has been borne out: resistance spread, formulations came before new molecules, and resistance is already emerging against the new modes of action.

Implications for weight. This is one of the chapter’s most robust lessons. An adaptive target erodes any single-mode fix unless the underlying selection pressure is reduced. Supplying new tools one after another does not escape that dynamic. The management problem is chronic, not a one-off substitution.

Claim 6: Evidence of adverse human-health effects is “mounting”; examples include a fivefold breast-cancer risk after pre-pubertal exposure (Cohn 2007) and +33% urogenital birth defects in sprayed villages (Bornman 2010), plus neurodevelopmental, miscarriage, preterm and diabetes associations; IARC classifies DDT as “possibly carcinogenic” (pp. 245–248)#

Original claim (pp. 245–248). - The chapter quotes the authors’ 2011 paper: “The evidence of adverse human health effects due to DDT is mounting” (p. 248). - It highlights: - Cohn et al. (2007): highest vs lowest tertile of DDT, five times the breast-cancer risk in women exposed at or before age 14; - Bornman et al. (2010): a 33% greater chance of a urogenital birth defect in DDT-sprayed villages; - associations with semen quality, miscarriage, preterm delivery, neurodevelopment (including ADHD-type behaviour) and diabetes. - IARC’s classification is given as “possibly carcinogenic to humans” (p. 245).

Subsequent developments - IARC (June 2015 meeting; Monograph 113). - DDT is now “probably carcinogenic to humans (Group 2A)”. - The rationale was “limited evidence in humans”, with positive associations for “cancers of the liver and testis, and non-Hodgkin lymphoma”. IARC also found “sufficient evidence” in experimental animals and “strong mechanistic evidence” (receptor-mediated effects, immunosuppression, oxidative stress) [S15, S16]. - On breast cancer, the working group found “No association overall … Several meta-analyses [concluded] that DDE is not associated with an increased risk”. The influence of age at exposure “remains of interest” [S15]. - ATSDR (April 2022). Its full profile says most outcomes show “inconsistent evidence”. It lists these exceptions [S17]: - “consistent evidence” for maternal exposure and wheeze in children; - “no associations with male reproductive system birth defects”; - associations with type 2 diabetes; - associations with liver cancer; - “no associations with breast cancer in women, pancreatic cancer, or endometrial cancer”. ATSDR notes that the studies are observational and often fail to control for co-occurring organochlorines such as PCBs. - Breast cancer and exposure windows. - Cohn and colleagues, same cohort. - In utero exposure to o,p′-DDT predicted daughters’ breast cancer by age 52 (OR 3.7, 95% CI 1.5–9.0; 118 cases) [S18]. - Extending follow-up to diagnoses at ages 50–54, p,p′-DDT was associated with risk “for all women” (OR 1.99 per doubling). The association was concentrated in women first exposed after infancy. For earlier diagnoses, risk was tied to exposure from infancy through puberty [S19]. - Grandmothers’ DDT was associated with obesity and early menarche in their granddaughters [S22]. - Independent meta-analyses. These go both ways: - no association overall (Ingber et al. 2013; summary OR 1.05 for DDE, 1.02 for DDT; 46 studies) [S20]; - a positive association in prospective studies with more than 10 years of follow-up (summary OR 1.41 for p,p′-DDT; Ugalde-Resano et al. 2024) [S21]. - The early-life-window hypothesis has strengthened. The adult-exposure association has not. - Urogenital birth defects. - The VHEMBE birth cohort (Limpopo, 2012–13; co-authored by Bornman) examined 359 boys. Only 68 could be fully assessed because of phimosis. “No associations were found between p,p′-DDT, p,p′-DDE … and hypospadias”. Pyrethroid metabolites were associated (relative risk about 1.6 per tenfold increase) [S23]. The sample is small, but the result does not replicate the 2010 finding for DDT. - ATSDR’s summary on male reproductive birth defects is consistent with this [S17]. - Neurodevelopment and behaviour. - VHEMBE: “DDT and DDE were not associated with significantly lower scores for any BSID-III scale” at ages 1–2. Pyrethroids were associated with poorer social-emotional and language scores [S24]. - At age 2, maternal DDT and DDE were associated with more withdrawn behaviour (RR 1.12 per tenfold increase in DDT) and oppositional behaviour (RR 1.30 for DDT, 1.39 for DDE) [S26]. - A Finnish national cohort found maternal DDE in the top quartile was associated with autism (OR 1.32), and with autism with intellectual disability (OR 2.21) [S32]. - ATSDR judges the neurological evidence in humans inconsistent [S17]. - Other VHEMBE outcomes. These are mixed: - DDT was associated with larger birth size in girls [S25]; - DDT was associated with wheeze (OR 1.5) [S27]; - “limited evidence” linked DDT to infections, while pyrethroids were associated [S28]; - there was no association with weight trajectories [S29]. - Diabetes. - A meta-analysis of prospective studies found a pooled OR of 1.44 (95% CI 1.00–2.07) for p,p′-DDE and type 2 diabetes, and none for p,p′-DDT [S30]. - Broader meta-analyses report ORs of 1.13 [S31] and 1.61–1.67 [S44]. - New endpoints. One study reported sperm-epigenome differences associated with DDE in South African and Greenlandic men, with confounding acknowledged [S33]. - Contrary advocacy. The chapter cites, but does not summarise, critics who defend DDT’s safety (Tren and Roberts 2011). A 2017 essay argued that portraying DDT as “a safe, life-saving compound” rests on misuse of toxicological data by groups “committed to repealing environmental regulations” (Yang, Ward and Kahr; abstract only; the abstract names no specific authors). As DDT use has collapsed, this policy argument has largely gone quiet.

Verdict: partly held up. - Held up: - The hazard classification rose, which vindicates concern. - Associations for diabetes, wheeze and early-life breast cancer have firmed up. - Evidence has broadened to new endpoints. - Not held up: - The birth-defect finding the chapter highlighted did not replicate. - The main breast-cancer evidence remains null for adult exposure. - The strongest new human evidence for cancer is at sites the chapter barely discussed (liver, testis, lymphoma). - The chapter’s own “centrist” framing, that DDT cannot be declared safe, has held. “Mounting” was true in breadth but overstated for several specifics.

Implications for weight. - The general lesson holds: latency and critical exposure windows delay detection, and single studies should not anchor policy. - Individual headline associations in the chapter should not be cited without these later checks. The chapter relies heavily on its authors’ own studies, and the fivefold figure comes from one small nested study. - The VHEMBE pyrethroid findings strengthen the chapter’s separate point (p. 250) that substitutes carry their own, less-studied hazards.

Claim 7: WHO’s EHC 241 (2011) found IRS household exposures “generally … below potential levels of concern” but higher in some areas, flagging women of childbearing age and transfer to foetus and infant; WHO’s 2011 position is that DDT is “still needed” because no alternative has “equivalent efficacy and operational feasibility” (p. 252)#

Original claim (p. 252, Box 11.3). The chapter reports these WHO positions accurately as of 2011.

Subsequent developments - The EHC 241 risk judgement is unchanged and still the reference. The 2025 expert group repeats its conclusion. It adds that in some areas exposures exceeded levels of concern “particularly for the unborn child and for infants via lactation”. It also notes that serum levels in spray workers were associated “with carcinogenic and male reproductive effects” [S1]. I found no WHO re-evaluation replacing EHC 241. - WHO’s policy position has shifted. - The 2023 WHO Guidelines for malaria, as quoted to COP-12, say the expanded range of IRS products “has provided additional options”. - They also say “WHO considers DDT to be a last resort, not a first choice”. - Countries using DDT should reassess the continued need at least every two years [S1]. - No prequalified product. WHO “has not prequalified any DDT product”. WHO recommends that only prequalified products be used for IRS [S1]. - WHO’s own note to COP-12 (February 2025). The 2011 statement technically still stands, but “many of the conditions that were present in 2011 have changed substantially”. In 2011 there were 12 IRS insecticides in 4 classes. In early 2025 there were 29 prequalified products in 6 classes [S3]. - The COP followed the same path. - COP-12 (2025) found a continued need “only in a few specific settings” [S2]. - COP-10 had encouraged monitoring of exposure among spray workers and households [S4]. This follows the chapter’s call to reduce and study exposure (p. 249).

Verdict: partly held up. The chapter’s record of EHC 241 held up and remains the operative risk assessment. The 2011 “still needed” rationale, which the chapter reports without endorsing, has been overtaken: WHO now treats DDT as a last resort.

Implications for weight. The case shows an authoritative “no equivalent alternative” judgement losing force within about a decade as substitutes matured. The WHO statement was never formally withdrawn, only surrounded by newer guidance. Positions of this kind should be treated as dated and conditional.

Claim 8: IRS residents are arguably “the largest non-occupationally exposed community in the world”; exposure comes mainly via home-produced food, soil and indoor air; there is no breast-milk residue limit, and the cow’s-milk limit is exceeded; IRS procedures have been “static since … the early 1940s”; very little has been published on domestic exposure (pp. 247–249)#

Original claim (pp. 247–249). - The “millions of people living in dwellings treated by DDT … could be the largest non-occupationally exposed community in the world”. - Uptake is “mainly through DDT entering the food chain in the immediate environs”. The main sources are chickens and outdoor soil, with indoor air as an important route. - There is no maximum residue level for breast milk, and infant intake exceeds the cow’s-milk limit. - IRS procedures “have remained static since their introduction in the early 1940s”. - “Despite the decades of DDT used as IRS, very little has been published on this subject.”

Subsequent developments - The exposed population has shrunk sharply. - The share of the at-risk population protected by IRS (with any insecticide) fell from 5.3% in 2010 to 1.6% in 2023. In India, 3 million fewer people were covered in 2023 than in 2022 [S1]. - With India’s exit and most of Africa’s, the DDT-exposed IRS population is now mainly in Zimbabwe and parts of South Africa [S1]. - A 2015 VHEMBE paper estimated that about 123 million people may be highly exposed to insecticides through IRS, counting all insecticides (abstract) [S34]. - The “largest community” claim was plausible in 2013, mainly because of India, but it no longer describes the present. - The exposure pathways the chapter described were confirmed. - Chicken eggs from a DDT-sprayed village contained a median of 11,000 ng/g wet mass of total DDT. The authors propose egg consumption as a target for reducing exposure, “probably best achieved by reducing the DDT concentrations in soils” [S35]. - Undisturbed house dust correlated with women’s serum DDT (Spearman’s rho 0.68). The home environment “may be an important determinant/source” of exposure [S34]. - The research gap has been partly filled. The VHEMBE birth cohort (752 mother–child pairs, 2012–13, in a sprayed area) produced a series of studies on DDT and pyrethroid exposure and child outcomes [S23–S29]. This is the IRS-specific research the chapter asked for (p. 247). - Breast milk. - WHO/UNEP global surveys (2000–2010) found the highest total-DDT levels in less industrialised countries. National pooled samples were “below or around those considered safe”, and the benefits of breastfeeding “far outweigh the possible disadvantages” [S36]. - Pooled national samples do not capture IRS hotspots, so they neither confirm nor refute the chapter’s household-level concern. - I did not verify whether any breast-milk residue limit has since been set; I found none. - IRS practice. - Not static in general. Examples include: - reactive, targeted IRS, which proved non-inferior and cheaper in a South African trial and cuts the number of houses sprayed [S37]; - WHO’s recommendation to consider reactive IRS near elimination [S1]; - long-lasting new formulations needing one round a year [S1, S41]; - a revised WHO IRS manual [S1]. - For DDT specifically, I found no evidence of changed application practice. The “Total Homestead Environment” approach has generated studies but, as far as I could find, no programme-level exposure-reduction protocol.

Verdict: partly held up. - The pathway findings were confirmed. - The research gap was real and has been partly closed. - The scale claim was plausible for 2013 but has lapsed. - “Static” procedures are no longer accurate for IRS in general.

Implications for weight. The underlying lesson is well supported. Evidence is thinnest where exposure is highest, and people who are both protected and exposed have had the trade-off made for them. This is shown by how much new, relevant evidence a single cohort produced once it was funded. As a description of current exposure, the chapter is now out of date.

Claim 9: A global survey found “critical deficiencies in the capacity for regulatory control and management of pesticides” in DDT-using countries; DDT is illegally diverted to agriculture and termite control; DPR Korea possibly uses it widely in agriculture (p. 244)#

Original claim (p. 244). Citing Matthews et al. (2011) and van den Berg et al. (2011), the survey revealed “critical deficiencies”. “There are clear indications that DDT has been illegally traded on local markets for use in agriculture and termite control”. There is information suggesting DDT “is, or has been, widely used in agriculture” in DPR Korea.

Subsequent developments - Capacity. - A WHO-led global survey (94 countries responding) found that in 50–75% of countries, vector-control insecticides were procured by agencies over which central authorities “lacked control”. Large fractions (29–78%) showed “shortcomings in worker safety, pesticide storage practices and pesticide waste disposal”. The authors concluded that “Critical shortcomings … are common” [S13]. - In the DDT questionnaire, 85% of responding Parties said their DDT laws are “fully enforced”. This is self-reported [S1]. - Import and export records do not tally [S1]. - South Africa and Zambia reported no quality control of imported DDT [S1]. - Reporting remains poor. In the first effectiveness evaluation, 42% of Parties did not respond to any national-reporting cycle [S9]. Three of the 13 registered Parties did not return the 2021–2023 questionnaire [S1]. - Diversion. - Khat grown in Ethiopia carries DDT residues. A 2017 market study found DDT in 80% of samples, some above FAO limits, with a pattern indicating mostly historical use [S45]. - A 2024 scoping review states “farmers are misusing DDT and applying it to Khat”. It reports very high concentrations at some sites that “may indicate increasing recent unmonitored application” [S46]. These are secondary syntheses of field studies. - DPR Korea. The latest data in the convention record run to 2006 (91–97% of use in agriculture and forestry) [S9]. I found nothing more recent. The status is unknown. - Stockpiles. Obsolete DDT is present “in countries across all regions” [S1]. It remains a potential source of leakage.

Verdict: held up. Weak pesticide governance and leakage to unapproved uses were confirmed by later independent surveys and field data.

Implications for weight. Robust. A restriction to an “acceptable purpose” depends on enforcement capacity in exactly the places least able to supply it. The data needed to check compliance are themselves incomplete and self-reported.

Claim 10: Silent Spring “triggered” environmental chemistry; the Swedish DDT laboratory (1964) led to the identification of PCBs (1966); bans “resulted in the return of the bird chorus”; more than 10% of bird species are threatened (pp. 241–242, 253); partly unreferenced#

Original claim (pp. 241–242, 253). - “Arguably” Silent Spring triggered environmental chemistry as a discipline. The Swedish government funded a DDT-analysis laboratory at Stockholm University from 1964, which led to the identification of PCBs as environmental contaminants in 1966 (p. 242). - Kennedy’s response led “to its complete ban in the United States” (p. 241). - “The ban on DDT and other chemicals resulted in the return of the bird chorus to affected areas” (p. 241, unreferenced). - “More than 10 % of bird species worldwide [are] now threatened”, which the authors take as evidence that “we missed the obvious early signposts” (p. 253).

Subsequent developments - History. - The 1966 identification of PCBs by Sören Jensen’s Swedish work is not contested. Later retrospectives treat Jensen’s work as formative for the field [Martin 2021, Ambio, abstract only]. “Triggered” is an interpretive claim the chapter itself hedges with “arguably”. No later development bears on it. - The “complete ban” is inaccurate. The US EPA’s 1972 cancellation order “cancelling nearly all remaining Federal registrations” excepted “Public health, quarantine, and a few minor crop uses … as well as export”. It was issued by EPA Administrator Ruckelshaus, not the Kennedy administration [S55]. This is a correction to the chapter rather than a post-2013 development. - The “bird chorus”. - Raptors recovered, as expected once DDT was removed. The US Fish and Wildlife Service estimates that bald eagle populations in the lower 48 states “have quadrupled” between 2007 and the 2018 surveys [S54]. South African bird eggs still show DDT-linked eggshell effects where spraying continues [S49]. - Common birds, the literal chorus, have declined: - North America has had “a net loss approaching 3 billion birds, or 29% of 1970 abundance” [S52]. - In Europe (170 species, 28 countries, 37 years), “agricultural intensification, in particular pesticides and fertiliser use, is the main pressure for most bird population declines” [S53]. - These declines are driven mainly by pesticides other than DDT and by habitat change. So the “return of the chorus” is true only for species harmed by DDT specifically. - Threat status. - BirdLife (2022): “more than one in eight” species at risk of extinction; “nearly half” declining [S51]. - IUCN Red List (10 October 2025): 1,256 of 11,185 bird species (11.5%) are threatened, and 61% have declining populations, up from 44% in 2016. The main driver is “habitat loss and degradation, driven especially by agricultural expansion and intensification and logging” [S50].

Verdict: partly held up. “More than 10% threatened” held, and the raptor recovery is well documented. The “return of the bird chorus” is overstated: common farmland birds have declined steeply since the bans, largely from other agricultural pressures. The “complete ban” was never complete.

Implications for weight. The chapter’s closing rhetoric (p. 253) is best read as commemoration, not evidence. - Two defensible points survive: - removing one hazardous product brought back the species it harmed most visibly; - the broader pressure from agrochemicals simply moved to other substances and pathways. - This supports a lesson about substitution. Banning one product addresses that product’s harms, not the wider practice that created them.

Sources#

All retrieved 25 September 2026 unless noted. “Abstract only” means I read the Europe PMC abstract, not the full text.

Stockholm Convention, UNEP and WHO - [S1] Secretariat of the Stockholm Convention. Report of the DDT expert group on the production and use of DDT for disease vector control and on the intersessional process of consultations with Parties in the DDT Register. UNEP/POPS/COP.12/INF/8, 10 February 2025 (full text; Annex I report, Annex III membership). https://www.pops.int/Portals/0/download.aspx?d=UNEP-POPS-COP.12-INF-8.English.pdf - [S2] Conference of the Parties to the Stockholm Convention. Decision SC-12/2: DDT. COP-12, Geneva, 28 April–9 May 2025. https://www.pops.int/Portals/0/download.aspx?d=UNEP-POPS-COP.12-SC-12-2.English.pdf - [S3] World Health Organization. Note from the World Health Organization on the continued need for DDT for disease vector control. UNEP/POPS/COP.12/INF/69, 25 February 2025. https://www.pops.int/Portals/0/download.aspx?d=UNEP-POPS-COP.12-INF-69.English.pdf - [S4] Conference of the Parties. Decision SC-10/6: DDT. COP-10, 2022. https://www.pops.int/Portals/0/download.aspx?d=UNEP-POPS-COP.10-SC-10-6.English.pdf - [S5] Conference of the Parties. Decision SC-11/2: DDT. COP-11, May 2023. https://www.pops.int/Portals/0/download.aspx?d=UNEP-POPS-COP.11-SC-11-2.English.pdf - [S6] Stockholm Convention. Acceptable Purposes: DDT (DDT Register and withdrawals: China 28/02/2014; Morocco 2015; Madagascar, Marshall Islands, Yemen 2023; Venezuela, Mozambique 2024; Zimbabwe notified 12/01/2018; Micronesia notified 12/11/2020). https://chm.pops.int/Implementation/Exemptions/AcceptablePurposes/AcceptablePurposesDDT/tabid/456/Default.aspx - [S7] Stockholm Convention. DDT Overview (includes the DDT expert group’s 2020 conclusion on a “focused phasing out”). https://www.pops.int/Implementation/PesticidePOPs/DDT/Overview/tabid/378/Default.aspx - [S8] Stockholm Convention. Intersessional process of consultations with Parties in the DDT register, and the page for the 4th meeting (IPoC4), Geneva, 5–7 May 2026 (agenda only posted). https://www.pops.int/Implementation/PesticidePOPs/DDT/Intersessionalprocessofconsultations/tabid/9857/Default.aspx ; https://www.pops.int/Implementation/PesticidePOPs/DDT/Intersessionalprocessofconsultations/Meetings/DDTIPoC4/tabid/10504/Default.aspx - [S9] van den Berg, H., Manuweera, G., Konradsen, F. Global trends in the production and use of DDT for control of malaria and other vector-borne diseases. Malaria Journal 2017;16:401 (published 5 October 2017; full text via Europe PMC, PMC5629760). https://doi.org/10.1186/s12936-017-2050-2 - [S10] van den Berg, H., Amwele, H. R., Brooke, B. D., Fortelius, L. E., Jain, T., Karunaratne, S. H. P. P., Munyinda, N. S., Rubio-Palis, Y., Yadav, R. S., Kleinschmidt, I. DDT: last mile in the global phase-out of its use for disease vector control? Lancet Planetary Health 2025;9(8):101283 (published 17 July 2025; abstract only). https://doi.org/10.1016/j.lanplh.2025.06.007 - [S11] WHO Prequalification. Prequalified vector control product list (IRS and ITN products with prequalification dates; no DDT product listed). https://extranet.who.int/prequal/vector-control-products/prequalified-product-list - [S12] WHO Global Malaria Programme. World malaria report 2025 (4 December 2025): 282 million cases and 610,000 deaths in 2024. https://www.who.int/teams/global-malaria-programme/reports/world-malaria-report-2025 - [S13] van den Berg, H., et al. Management of insecticides for use in disease vector control: a global survey. BMC Infectious Diseases 2021;21:468 (22 May 2021; abstract only). https://doi.org/10.1186/s12879-021-06155-y - [S14] van den Berg, H., et al. Recent trends in global insecticide use for disease vector control and potential implications for resistance management. Scientific Reports 2021;11:23867 (13 December 2021; abstract only). https://doi.org/10.1038/s41598-021-03367-9

Hazard assessments - [S15] IARC. IARC Monographs Volume 113: DDT, Lindane, and 2,4-D (meeting June 2015; DDT chapter version of 1 March 2019): sections 5.2 and 6 (full text). https://publications.iarc.who.int/550 ; chapter PDF: https://publications.iarc.who.int/download/Vol113-007-DDT-01032019.pdf - [S16] Loomis, D., et al. (IARC Monograph Working Group). Carcinogenicity of lindane, DDT, and 2,4-dichlorophenoxyacetic acid. Lancet Oncology 2015;16(8) (published online June 2015; metadata only). https://doi.org/10.1016/S1470-2045(15)00081-9 - [S17] Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological Profile for DDT, DDE, and DDD. April 2022, chapter 1 (full text). https://www.atsdr.cdc.gov/toxprofiles/tp35.pdf

Health studies (abstracts via Europe PMC) - [S18] Cohn, B. A., et al. DDT exposure in utero and breast cancer. Journal of Clinical Endocrinology & Metabolism 2015;100(8):2865–2872 (16 June 2015). https://doi.org/10.1210/jc.2015-1841 - [S19] Cohn, B. A., Cirillo, P. M., Terry, M. B. DDT and breast cancer: prospective study of induction time and susceptibility windows. JNCI 2019;111(8):803–810. https://doi.org/10.1093/jnci/djy198 - [S20] Ingber, S. Z., et al. DDT/DDE and breast cancer: a meta-analysis. Regulatory Toxicology and Pharmacology 2013;67(3):421–433 (8 September 2013). https://doi.org/10.1016/j.yrtph.2013.08.021 - [S21] Ugalde-Resano, R., et al. Biological concentrations of DDT metabolites and breast cancer risk: an updated systematic review and meta-analysis. Reviews on Environmental Health 2025;40(1):225–236 (online 9 December 2024). https://doi.org/10.1515/reveh-2024-0021 - [S22] Cirillo, P. M., La Merrill, M. A., Krigbaum, N. Y., Cohn, B. A. Grandmaternal perinatal serum DDT in relation to granddaughter early menarche and adult obesity. Cancer Epidemiology, Biomarkers & Prevention 2021;30(8):1480–1488. https://doi.org/10.1158/1055-9965.EPI-20-1456 - [S23] Bornman, R., et al. Maternal exposure to DDT, DDE, and pyrethroid insecticides for malaria vector control and hypospadias in the VHEMBE birth cohort study, Limpopo, South Africa. Science of the Total Environment 2022;845:157084 (5 July 2022). https://doi.org/10.1016/j.scitotenv.2022.157084 - [S24] Eskenazi, B., et al. Prenatal exposure to DDT and pyrethroids for malaria control and child neurodevelopment: the VHEMBE cohort, South Africa. Environmental Health Perspectives 2018;126(4):047004. https://doi.org/10.1289/EHP2129 - [S25] Chevrier, J., et al. Associations of maternal exposure to DDT and pyrethroids with birth outcomes among participants in VHEMBE. American Journal of Epidemiology 2019;188(1):130–140. https://doi.org/10.1093/aje/kwy143 - [S26] An, S., et al. In-utero exposure to DDT and pyrethroids and child behavioral and emotional problems at 2 years of age in the VHEMBE cohort. Chemosphere 2022;306:135569. https://doi.org/10.1016/j.chemosphere.2022.135569 - [S27] Huq, F., et al. Associations between prenatal exposure to DDT and DDE and allergy symptoms and diagnoses in VHEMBE. Environmental Research 2020;185:109366. https://doi.org/10.1016/j.envres.2020.109366 - [S28] Davis, B., et al. Association between prenatal exposure to indoor residual spraying insecticides and infection rates among South African children (VHEMBE). Science of the Total Environment 2024;918:170483. https://doi.org/10.1016/j.scitotenv.2024.170483 - [S29] Kim, J., et al. Prenatal exposure to insecticides and weight trajectories among South African children in the VHEMBE birth cohort. Epidemiology 2022;33(4):505–513. https://doi.org/10.1097/EDE.0000000000001487 - [S30] Hernández-Mariano, J. Á., et al. Exposure to the pesticide DDT and risk of diabetes and hypertension: systematic review and meta-analysis of prospective studies. International Journal of Hygiene and Environmental Health 2022;239:113865. https://doi.org/10.1016/j.ijheh.2021.113865 - [S31] Tian, W., et al. Association between DDT or its byproducts and T2DM: a systematic review and meta-analysis. Frontiers in Endocrinology 2025;16:1634292 (6 October 2025). https://doi.org/10.3389/fendo.2025.1634292 - [S32] Brown, A. S., et al. Association of maternal insecticide levels with autism in offspring from a national birth cohort. American Journal of Psychiatry 2018;175(11):1094–1101. https://doi.org/10.1176/appi.ajp.2018.17101129 - [S33] Lismer, A., et al. The association between long-term DDT or DDE exposures and an altered sperm epigenome: a cross-sectional study of Greenlandic Inuit and South African VhaVenda men. Environmental Health Perspectives 2024;132(1):17008. https://doi.org/10.1289/EHP12013

Exposure and IRS practice - [S34] Gaspar, F. W., et al. Undisturbed dust as a metric of long-term indoor insecticide exposure: residential DDT contamination from indoor residual spraying and its association with serum levels in the VHEMBE cohort. Environment International 2015;85:163–167. https://doi.org/10.1016/j.envint.2015.09.014 - [S35] Bouwman, H., Bornman, R., van Dyk, C., Barnhoorn, I. First report of the concentrations and implications of DDT residues in chicken eggs from a malaria-controlled area. Chemosphere 2015;137:174–177. https://doi.org/10.1016/j.chemosphere.2015.06.097 - [S36] van den Berg, M., et al. WHO/UNEP global surveys of PCDDs, PCDFs, PCBs and DDTs in human milk and benefit–risk evaluation of breastfeeding. Archives of Toxicology 2017;91(1):83–96 (online 20 July 2016). https://doi.org/10.1007/s00204-016-1802-z - [S37] Bath, D., et al. Effectiveness and cost-effectiveness of reactive, targeted indoor residual spraying for malaria control in low-transmission settings: a cluster-randomised, non-inferiority trial in South Africa. Lancet 2021;397:816–827. https://doi.org/10.1016/S0140-6736(21)00251-8

South Africa, 1996–2000 and after - [S38] Barnes, K. I., et al. Effect of artemether-lumefantrine policy and improved vector control on malaria burden in KwaZulu-Natal, South Africa. PLoS Medicine 2005;2(11):e330. https://doi.org/10.1371/journal.pmed.0020330 - [S39] Craig, M. H., Kleinschmidt, I., Le Sueur, D., Sharp, B. L. Exploring 30 years of malaria case data in KwaZulu-Natal, South Africa: part II. The impact of non-climatic factors. Tropical Medicine & International Health 2004;9(12):1258–1266. https://doi.org/10.1111/j.1365-3156.2004.01341.x - [S40] Maharaj, R., Moonasar, D., Baltazar, C., Kunene, S., Morris, N. Sustaining control: lessons from the Lubombo spatial development initiative in southern Africa. Malaria Journal 2016;15:409. https://doi.org/10.1186/s12936-016-1453-9 - [S41] Maharaj, R., et al. Field evaluation of the residual efficacy of new generation insecticides for potential use in indoor residual spray programmes in South Africa. Malaria Journal 2024;23:127. https://doi.org/10.1186/s12936-024-04963-6

India: resistance and declining need - [S42] Pandey, D. K., et al. Kala-azar elimination in India: reflections on success and sustainability. International Health 2025;17(4):416–422 (abstract only). https://doi.org/10.1093/inthealth/ihaf013 - [S43] Shukla, A., et al. Presence of localized elevated metabolic enzymes and kdr mutations in the voltage-gated sodium channel gene indicate early evidence of resistance of Phlebotomus argentipes to alpha-cypermethrin in Bihar, India. Parasites & Vectors 2026;19:206 (31 March 2026). https://doi.org/10.1186/s13071-026-07339-8

Diabetes meta-analysis (additional) - [S44] Yipei, Y., et al. Assessing the risk of diabetes in participants with DDT DDE exposure: a systematic review and meta-analysis. Environmental Research 2022;210:113018 (abstract only). https://doi.org/10.1016/j.envres.2022.113018

Misuse - [S45] Mekonen, S., Ambelu, A., Negassa, B., Spanoghe, P. Exposure to DDT and its metabolites from khat (Catha edulis) chewing: consumers risk assessment from southwestern Ethiopia. Regulatory Toxicology and Pharmacology 2017;87:64–70. https://doi.org/10.1016/j.yrtph.2017.05.008 - [S46] Ali, S. A., Destaye, A. G. Apparent khat chewers exposure to DDT in Ethiopia and its potential toxic effects: a scoping review. Regulatory Toxicology and Pharmacology 2024;147:105555 (online 22 December 2023). https://doi.org/10.1016/j.yrtph.2023.105555

Legacy contamination - [S47] McGill, L., et al. The persistent DDT footprint of ocean disposal, and ecological controls on bioaccumulation in fishes. PNAS 2024;121(45):e2401500121 (28 October 2024). https://doi.org/10.1073/pnas.2401500121 - [S48] Schmidt, J. T., et al. Disentangling the history of deep ocean disposal for DDT and other industrial waste off Southern California. Environmental Science & Technology 2024;58(9):4346–4356. https://doi.org/10.1021/acs.est.3c08575 - [S49] Bouwman, H., et al. Evidence of impacts from DDT in pelican, cormorant, stork, and egret eggs from KwaZulu-Natal, South Africa. Chemosphere 2019;225:647–658. https://doi.org/10.1016/j.chemosphere.2019.03.043

Birds and history - [S50] IUCN. Arctic seals threatened by climate change, birds decline globally – IUCN Red List. Press release, Abu Dhabi, 10 October 2025. https://iucn.org/press-release/202510/arctic-seals-threatened-climate-change-birds-decline-globally-iucn-red-list - [S51] BirdLife International. State of the World’s Birds 2022 (27 September 2022; landing page). https://www.birdlife.org/papers-reports/state-of-the-worlds-birds-2022/ - [S52] Rosenberg, K. V., et al. Decline of the North American avifauna. Science 2019;366(6461):120–124. https://doi.org/10.1126/science.aaw1313 - [S53] Rigal, S., et al. Farmland practices are driving bird population decline across Europe. PNAS 2023;120(21):e2216573120. https://doi.org/10.1073/pnas.2216573120 - [S54] US Fish and Wildlife Service. Permits for Incidental Take of Eagles and Eagle Nests, final rule, 89 FR 9920, 12 February 2024 (citing USFWS 2021, Bald Eagle Population Size: 2020 Update). https://www.federalregister.gov/documents/2024/02/12/2024-02182/permits-for-incidental-take-of-eagles-and-eagle-nests - [S55] US EPA. DDT Ban Takes Effect. Press release, 31 December 1972 (EPA archive). https://www.epa.gov/archive/epa/aboutepa/ddt-ban-takes-effect.html

Cited in text without a number (abstract only) - Yang, J., Ward, M. D., Kahr, B. Abuse of Rachel Carson and misuse of DDT science in the service of environmental deregulation. Angewandte Chemie International Edition 2017;56(34):10026–10032. https://doi.org/10.1002/anie.201704077 - Martin, J. W. Revisiting old lessons from classic literature on persistent global pollutants. Ambio 2021;50(3):534–538. https://doi.org/10.1007/s13280-020-01413-w