 |
DDT and Malaria Resource Center 
The following is a compilation of selected articles related to the use of the pesticide DDT to control malaria. For each article, we provide a full citation, our own brief summary, the original abstract, and a direct link to the original source when available. The articles cover a range of issues and perspectives, and are grouped in the following categories:
This compilation will be updated periodically and it is by no means comprehensive. We hope it will prove to be a useful tool in the ongoing discussion among policymakers, advocacy groups and the media regarding the use of DDT and the need to improve efforts to effectively control malaria. For detailed information on the toxicity, health effects and regulatory status of DDT, visit PANNA's on-line Pesticide Database. For a list of additional web resources, click here. This resource was last updated January 26, 2006. BASIC FACTS ABOUT DDTDDT is a pesticide that was used heavily worldwide in the 1950s and 1960s both in agricultural production and for malaria control. Concerns about impacts on wildlife populations - particularly predatory birds - led to the phase out of DDT in many countries in the 1970s. Use of the pesticide for malaria control has continued in some regions, though most countries now rely on combinations of other control methods. DDT has been in the news in recent years as an international treaty, the Stockholm Convention, raised the possibility of global elimination of DDT and its "loss" as a tool for malaria control. At the same time, much more is now known about the human health effects of exposure to DDT and its breakdown products. To learn more basic information about DDT, including where it continues to be used and produced, see " DDT and Malaria: Answers to Common Questions." To learn more about DDT and the Stockholm Convention, see the debate section below as well as World Wildlife Fund's series of reports on DDT. A) DDT’S IMPACT ON HUMAN HEALTH AND THE ENVIRONMENT
B) THE DEBATE OVER DDT
C) MALARIA CONTROL: ASIA
D) MALARIA CONTROL: AFRICA
E) MALARIA CONTROL: THE AMERICAS
F) MALARIA CONTROL: GENERAL AND MULTI-REGIONAL
A) DDT’S EFFECTS ON HEALTH AND THE ENVIRONMENT1) Longnecker, M. P., M. A. Klebanoff, H. Zhou, J. W. Brock. Association between maternal serum concentration of the DDT metabolite DDE and pre-term and small-for-gestational-age babies at birth. The Lancet 2001; 358: 110-114. PANNA summary: This 2001 landmark study by the National Institute of Environmental Health Sciences and three other organizations found a strong relationship between prematurely delivered and low birth weight babies and mothers' blood levels of DDE, the metabolic breakdown product of DDT. The study took its data from children born between the years 1959 and 1966, a time when DDT was still being used in the United States and so average blood levels of DDE were much higher than they are in the U.S. today, but still lower than what they are in other countries where DDT is still being used to control malaria. The researchers conclude that the ties between premature birth rates, a major factor in infant mortality, and blood levels of DDE should lead to the reassessment of the costs and benefits of DDT-based malaria control strategies around the world. Abstract: Background DDT (1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane) is highly effective against most malaria-transmitting mosquitoes and is being widely used in malaria-endemic areas. The metabolite, DDE (1,1-dichloro-2,2-bis (p-chlorophenyl) ethylene), has been linked to pre-term birth in small studies, but these findings are inconclusive. Our aim was to investigate the association between DDE exposure and pre-term birth. Methods Our study was based on the U.S. Collaborative Perinatal Project (CPP). From this study we selected a subset of more than 44,000 eligible children born between 1959 and 1966 and measured the DDE concentration in their mothers' serum samples stored during pregnancy. Complete data were available for 2,380 children, of whom 361 were born pre-term and 221 were small-for-gestational age. Findings The median maternal DDE concentration was 25 µg/L (range 3-178)--several fold higher than current US concentrations. The adjusted odds ratios (OR) of pre-term birth increased steadily with increasing concentrations of serum DDE (ORs=1, 1·5, 1·6, 2·5, 3·1; trend p<0·0001). Adjusted odds of small-for-gestational-age also increased, but less consistently (ORs=1, 1·9, 1·7, 1·6, 2·6; trend p=0·04). After excluding pre-term births, the association of DDE with small-for-gestational-age remained. Interpretation The findings strongly suggest that DDT use increases pre-term births, which is a major contributor to infant mortality. If this association is causal, it should be included in any assessment of the costs and benefits of vector control with DDT. 2) van Wendel de Joode B, Wesseling C, Kromhout H, Monge P, Garcia M, Mergler D. Chronic nervous system effects of long-term occupational exposure to DDT. Lancet 2001 Mar 31; 357(9261): 1014-16. PANNA summary: This study found that retired malaria-control workers who had worked spraying DDT did worse on tests of neurobehavioral functions than control groups, and that the longer they had worked with DDT, the poorer the test results. These results indicate that long-term exposure to DDT is measurably harmful. Abstract: Dichlorodiphenyltrichloroethane (DDT) is a compound with moderate toxicity that is judged to be safe for occupational use, although little is known about its long-term effects on the human nervous system. We investigated chronic nervous-system effects of long-term occupational exposure to DDT by comparing the neurobehavioral performance of retired malaria-control workers with a reference group of retired guards and drivers. DDT-exposed workers did worse on tests assessing various neurobehavioral functions than controls; performance significantly deteriorated with increasing years of DDT application. Our results could not be explained by exposure to cholinesterase-inhibiting pesticides or other potential confounding factors. 3) Longnecker, MP, MA Klebanoff, JW Brock, H Zhou, KA Gray, LL Needham and AJ Wilcox. Maternal serum level of 1,1-Dichloro-2,2-bis (p-chlorophenyl) ethylene and risk of cryptorchidism, hypospadias, and polythelia among male offspring. American Journal of Epidemiology Vol. 155, No. 4 : 313-322. PANNA summary: In light of recent findings that the metabolic byproduct of DDT, DDE, blocks receptors for androgens (male hormones) in rats, scientists undertook this study to see if there is some similar effect in humans. They looked at data for mothers' blood levels of DDE (see article #1) and the frequency of birth defects in male babies from the same set of children born between 1959 and 1966. They found that elevated DDE levels in the mother's blood serum correlated with increased incidence of undescended testicles, penis abnormalities, and extra nipples in male children. Abstract: 1,1-Dichloro-2,2-bis (p-chlorophenyl) ethylene (p,p'-DDE) is a metabolite of the insecticide 2,2-bis (p-chlorophenyl) -1,1,1-trichloroethane (DDT) and is a ubiquitous environmental contaminant. Nearly everyone in the United States has a detectable serum level of DDE. DDE was recently found to inhibit binding of androgen to its receptor and to block androgen action in rodents. Normal development of male genitalia in mammals depends on androgen action. The authors used stored serum samples to examine the relation between maternal DDE levels during pregnancy and adjusted odds of cryptorchidism (n = 219), hypospadias (n = 199), and polythelia (extra nipples) (n = 167) among male offspring, using a nested case-control design with one control group (n = 552). Subjects were selected from the Collaborative Perinatal Project, a US birth cohort study begun in 1959-1966, when DDE levels were much higher than they are at present. Compared with boys whose mother's recovery-adjusted serum DDE level was less than 21.4 microg/liter, boys with maternal levels greater than or equal to 85.6 microg/liter had adjusted odds ratios of 1.3 (95% confidence interval (CI): 0.7, 2.4) for crypt-orchidism, 1.2 (95% CI: 0.6, 2.4) for hypospadias, and 1.9 (95% CI: 0.9, 4.0) for polythelia. For cryptorchidism and polythelia, the results were consistent with a modest-to-moderate association, but in no instance was the estimate very precise. The results were inconclusive. (Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA. longnecker@niehs.nih.gov) 4) Bouwman, H. DDT levels in serum, breast-milk and infants in various populations in malaria and non-malaria controlled areas of KwaZulu. Medical Research Council. 1991:1-38. Abstract: The World Health Organization (WHO) considers 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) safe to man and the environment when applied intra-domiciliary for malaria control. Research into the possible health effects under prevailing conditions and taking social customs into account, have, however, been lacking. This study was undertaken to determine levels of DDT in serum and breast-milk and possible risks posed by the insecticide to the health of lactating mothers and their infants. The aims of the study were: (1) To determine the levels of DDT and its metabolites, DDD and DDE, in the serum of members of families from a sprayed and a non-sprayed area, as well as changes caused by indoor application of DDT; (2) To determine the levels of DDT and its metabolites in the breast-milk of mothers from a sprayed and a non-sprayed area, as well as changes caused by indoor application of DDT; (3) To determine the uptake of DDT and its metabolites by the infant via breast-milk, and to develop a statistical model that describes the dynamics; and (4) To determine the risk to the health of mother and infant posed by exposure to DDT and its metabolites. 5) Bouwman, H.; Becker, P. J.; Cooppan, R. M., and Reinecke, A. J. Transfer of DDT used in malaria control to infants via breast milk. Bulletin of the World Healt Organization. 1992; 70(2):241-50. ISSN: 0042-9686. PANNA summary: This is a study of the levels of DDT and its metabolites in the blood of infants and the breast milk of their mothers in KwaZulu, South Africa where DDT is used to control malaria. It was found that breastfeeding is the primary source of DDT in babies' blood, and that it accumulates with age. DDT in the environment is a secondary source. Abstract: The transfer of p,p'-DDT (1,1,1-tricholoro-2,2-bis(4-chlorophenyl)ethane) and its metabolites to infants via breast-feeding was studied in an area of KwaZulu, South Africa, where DDT is used to interrupt malaria transmission. Samples of whole blood were collected from 23 infants, together with samples of breast milk from their respective mothers. The mean sigma DDT (total DDT) in the whole blood was 127.03 micrograms.l-1 and that in the breast milk, 15.06 mg.kg-1 (milk fat). The % DDT (% DDT of sigma DDT) was significantly higher in the infant blood than in the breast milk (P less than 0.05). A multiplicative regression analysis indicated that sigma DDT increased significantly (P less than 0.01) in infant whole blood with infant age. Multiple regression showed that 70.0% of the variation in sigma DDT was due to the variation in parity of the mother, age of the infant, and the sigma DDT in breast milk. These variables accounted also for 76.3% of the variation in p,p'-DDE but only for 38.2% of that in p,p'-DDT. Organochlorines were therefore largely transferred to the infant from the mother, with DDT in the environment playing a secondary role. (Department of Zoology, University for Christian Higher Education, Potchefstroom, South Africa.) 6) Bouwman, H.; Cooppan, R. M.; Botha, M. J., and Becker, P. J. Serum levels of DDT and liver function of malaria control personnel. S Afr Med J. 1991; 79(6):326-329. ISSN: 0038-2469. PANNA summary: This study found that blood levels of DDT and its metabolites are higher in people who work as DDT sprayers than for the general population in KwaZulu, South Africa, where DDT is used for malaria control. Possible health risks to the sprayers from these elevated levels, including evidence of reduced liver function, were identified. Abstract: The levels of DDT and metabolites in serum of 23 applicators involved in malaria control operations in Natal were determined using gas chromatography with electron capture detection. The mean levels (microgram/l, ppb) were 61.7 DDT, 129.3 DDE, 11.0 DDD and 202.0 sigma DDT. Percentage DDT was 33.4%. These levels were higher than for an age matched sample of the general population in KwaZulu, who are protected by DDT against malaria. Percentage DDT correlated negatively with age (P less than 0.05) for the applicators, suggesting a change in pharmacodynamics with age. Mean serum albumin, alkaline phosphatase, aspartate transferase and gamma-glutamyltransferase (GGT) levels did not differ significantly from an age-matched control group, but the mean GGT value for the applicators was higher than the maximum of the laboratory normal range. Although not clinically significant, the alanine transferase was significantly higher in the applicators than in the control group. These higher levels suggest a possible risk to the health of the sprayers, but uncertainties remain. (Research Institute for Environmental Diseases of the South African Medical Research Council, Pretoria.) 7) Gladen, B. C. and Rogan, W. J. DDE and shortened duration of lactation in a northern Mexican town. American Journal of Public Health. 1995; 85(4):504-508. PANNA summary: The authors found that DDE (a metabolite of DDT) levels in the breast milk of mothers in an agricultural town in northern Mexico is strongly linked to the length of time that they breastfeed their infants. Mothers with the highest levels of DDE breastfed for only 3 months on average, while mothers with the lowest DDE levels breastfed for an average of 7.5 months. The authors conclude that DDT exposure may be contributing to the trend toward decreasing lengths of lactation world wide. Abstract: OBJECTIVES. Worldwide declines in the duration of lactation are cause for public health concern. Higher levels of dichlorodiphenyl dichloroethene (DDE) have been associated with shorter durations of lactation in the United States. This study examined whether this relationship would hold in an agricultural town in northern Mexico. METHODS. Two hundred twenty-nine women were followed every 2 months from childbirth until weaning or until the child reached 18 months of age. DDE was measured in breast milk samples taken at birth, and women were followed to see how long they lactated. RESULTS. Median duration was 7.5 months in the lowest DDE group and 3 months in the highest. The effect was confined to those who had lactated previously, and it persisted after statistical adjustment for other factors. These results are not due to overtly sick children being weaned earlier. Previous lactation lowers DDE levels, which produces an artifactual association, but simulations using best estimates show that an effect as large as that found here would arise through this mechanism only 6% of the time. CONCLUSIONS. DDE may affect women's ability to lactate. This exposure may be contributing to lactation failure throughout the world. (Statistics and Biomathematics Branch, National Institute of Environmental Health Sciences, Mail Drop A3-03 POB 12233, Research Triangle Park, NC 27709, USA.) 8) Rogan, W. J.; Gladen, B. C.; McKinney, J. D.; Carreras, N.; Hardy, P.; Thullen, J.; Tingelstad, J., and Tully, M. Polychlorinated biphenyls (PCBs) and dichlorodiphenyl dichloroethene (DDE) in human milk: Effects on growth, morbidity, and duration of lactation. American Journal of Public Health. 1987; 77(10):1294-1297. PANNA summary: This study determined the effects of PCBs and DDE (DDT metabolite) in breast milk on infant growth and health. Its most significant finding was that higher levels of DDE are associated with markedly shorter duration of breast feeding, indicating that DDE is somehow interfering with mothers’ ability to breastfeed their children. Abstract: We followed 858 children from birth to one year of age to determine whether the presence of polychlorinated biphenyls (PCBs) and dichlorodiphenyl dichloroethene (DDE) in breast milk affected their growth or health. Neither chemical showed an adverse effect on weight or frequency of physician visits for various illnesses, although differences were seen between breast-fed and bottle-fed children, with bottle-fed children being heavier and having more frequent gastroenteritis and otitis media. Children of mothers with higher levels of DDE were breast-fed for markedly shorter times, but adjustments for possible confounders and biases did not change the findings. In absence of any apparent effect on the health of the children, we speculate that DDE may be interfering with the mother's ability to lactate, possibly because of its estrogenic properties. 9) Douthwaite, R J, ed. DDT in the Tropics: The impact on wildlife in Zimbabwe of ground-spraying for tsetse fly control. Canterbury, UK: R J Douthwaite and Associates, Environmental Management Consultants, 1999. (see the International Centre for Pesticide Safety's Review at: http://www.icps.it/english/bollettino/psn97/970307.htm) PANNA summary: A report on studies funded by the UK's Department for International Development looking at the recovery of local wildlife known to have been affected after DDT spraying for tsetse fly control in northwestern Zimbabwe 10 years earlier. The author argues that DDT has had relatively little impact on wildlife populations in the area compared with the widespread woodland destruction by immigrant farmers and elephants. Deltamethrin, a synthetic pyrethroid that would perhaps have less impact on wildlife, has been used successfully for ground spraying instead of DDT, but it still costs too much to make it a viable solution. This report aims to inform use of DDT for tsetse fly control under the new POPs treaty that allows for limited use for vector control. (no abstract available) 10) Booth, William. EPA moves to cap risks of DDT on ocean floor. The Washington Post. September 5, 2000. A03. PANNA summary: Between 1947 and 1971, Montrose Chemical's plant in Torrance, California flushed more than 100 tons of DDT into the county sewer system, where it ran into the Pacific Ocean near the cliffs of Palos Verdes. DDT remains on the ocean floor and is the nation's deepest and largest Superfund site. DDT levels in the bodies of fish caught in this area and sold in Los Angeles are much higher than government safety standards. EPA is filing suit against Montrose Chemical to pay for the cost of cleaning up and restoring the waters off Palos Verdes. (no abstract available) 11) Wiktelius, S and CA Edwards. Organochlorine Insecticide Residues in African Fauna: 1971-1995. Review of Environmental Contamination and Toxicology 151: 1-37. PANNA summary: Traces the use of organochlorine insecticides (including DDT) in Africa and the levels of organochlorines subsequently found in the tissues of terrestrial and aquatic animals. The authors found that levels, especially of DDT and diedrin, were "high enough to have considerable potential for chronic toxicity, for causing behavioral changes, or even for killing wild animals, particularly fish and birds and possibly crocodiles." The author warns against possible long-term population effects on the fauna of Africa if the use of organochlorines is not restricted. Abstract: Organochlorine insecticides (OCLs), which were introduced in the decade following World War II, were used extensively in Europe, the U.S., and other developed countries into the 1970s. However, data began to accumulate on their persistence in soils and aquatic sediments, their potential to be taken up into animal tissues and to bioconcentrate in birds and mammals in the higher tropic levels of food chains and even in humans. As a result, registration authorities phased out their use progressively, in Europe and the U.S., from 1973 onward. However, the production of OCLs in developed countries and their use in developing countries continued through the 1970s and 1980s into the 1990s because they were no longer under patent agreement, were inexpensive to manufacture, and were very effective in pest control. In Africa, the use of OCLs continued well into the 1990s for the control of mosquitoes, tsetse flies, and desert locusts as well as to combat various crop, animal, and human pests. Some of these uses involved extensive spraying of large areas of nonagricultural land, thereby exposing many groups and species of wildlife to their residues. Although there is some evidence of a gradual decline in the use of OCLs in Africa, they are still being used in appreciable quantities. During the past 25 years, there have been 50 published reports of OCL residues in the various groups of invertebrate and vertebrate animals constituting the African fauna. These have been based on a diverse range of surveys, target animals, sampling methods, and analytical techniques. Moreover, they are extremely regionally-biased, the most intense surveys being in Zimbabwe, Kenya, Egypt, and South Africa. DDT was the most commonly used OCL, accounting for about half the total use, followed closely by dieldrin and HCH. Birds and fish have been sampled most intensively, with relatively few studies on other taxa. We reviewed the OCL residue data on African fauna from these reports and summarized the maximum and mean residues in the various groups of terrestrial and aquatic invertebrates and vertebrates. Overall, residues in the fauna were the greatest for DDT, followed in turn by those of dieldrin, HCH, endosulfan, and endrin, with small amounts of aldrin and toxaphene being found in some animals. There were relatively few reports of OCL residues in terrestrial invertebrates and virtually none in aquatic invertebrates. Only a few reports demonstrated OCL residues in terrestrial vertebrates, although high levels of DDT, dieldrin, and HCH were found in crocodile eggs and large residues of dieldrin occurred in bats, squirrels, and monkeys. Considerable OCL residues were reported in a few species of fish, especially Barbus, Clarias, Hydrocynus, Labeo, Sarotherodon, Epiplatys, and Synodontis. These residues were at levels that could have caused chronic toxicity or behavioral changes. The calculated maximum and mean OCL residues in the various elements of the African fauna until 1995 were compared with those calculated for corresponding faunal groups in Europe and the U.S. from their development and introduction up to 1973. The OCL residues reported in African fauna between 1971 and 1975 tended to be significantly higher overall than those published for Europe and the U.S. In particular, residues of DDT and dieldrin in African birds and their eggs were greater than those that had been incriminated as causing significant eggshell thinning and reproductive failure in European and U.S. aquatic and terrestrial birds up to 1973. Additionally, high DDT and dieldrin residues were reported from some species of African fish at levels that could potentially affect their reproduction, have chronic toxic and behavioral effects, and even drastically affect populations. Holistic case studies on the use of OCLs to control tsetse flies and desert locusts were discussed. OCL levels in trophic levels of fauna associated with Lake Kariba (between Zambia and Zimbabwe) were summarized. (Swedish University of Agricultural Sciences, Uppsala, Sweden) 12) Toxicological Profile for DDT, DDE, and DDD. Prepared by Syracuse Research Corporation for US Department of Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry. September 2002. http://www.atsdr.cdc.gov/toxprofiles/tp35.html PANNA summary: This report is concerned solely with DDT in the USA, so there is very little attention paid to malaria or DDT’s use for vector control. The profile provides clear explanations of why DDT is still in the U.S. environment when it was banned for use in this country in 1972, how it persists in the soil and water, and how it moves from one place to another. The report cites many possible dangers of the toxin to public health. Health effects cited in this report include: nervous system effects, changes in liver enzymes, and “harmful effects” on reproduction and adrenal gland function. EPA has classified DDT and its metabolites as probable human carcinogens, though this report says that there is no evidence of increased cancer risk in humans. (no abstract available) 13) Altshul, L., C. Chen, L. Fu, W.Guang, A. Huang , S. Korrick, M. Perry, S. A. Venners, X. Wang, and X. Xu. Preconception Serum DDT and Pregnancy Loss: A Prospective Study Using a Biomarker of Pregnancy. American Journal of Epidemiology Advance Access. August 2005. Vol. 162, No. 8. PANNA summary: The authors investigated the effect of DDT on pregnancy losses in a group of women in Anhui , China . The researchers found a positive exposure-response association between DDT traces found within the body and the risk of successive early pregnancy losses. Abstract: Previous studies of pregnancy losses and 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) were limited because they did not include losses prior to clinical detection of pregnancy and because exposures were measured after the pregnancies of interest. The authors examined the association of preconception serum total DDT (sum of DDT isomers and metabolites) concentration and subsequent pregnancy losses in 388 newly married, nonsmoking, female textile workers in China between 1996 and 1998. Upon stopping contraception, subjects provided daily urine specimens and records of vaginal bleeding for up to 1 year or until clinical pregnancy. Daily urinary human chorionic gonadotropin was assayed to detect conception and early pregnancy losses, and pregnancies were followed to detect clinical spontaneous abortions. There were 128 (26%) early pregnancy losses in 500 conceptions and 36 (10%) spontaneous abortions in 372 clinical pregnancies. Subjects were grouped in tertiles by preconception serum total DDT concentration (group 1: 5.5–22.9 ng/g; group 2: 23.0–36.5 ng/g; group 3: 36.6– 113.3 ng/g). Compared with group 1, group 2 had adjusted relative odds of early pregnancy losses of 1.23 (95% confidence interval (CI): 0.72, 2.10), and group 3 had adjusted odds of 2.12 (95% CI: 1.26, 3.57). The relative odds of early pregnancy losses associated with a 10-ng/g increase in serum total DDT were 1.17 (95% CI: 1.05, 1.29). The small number of spontaneous abortions following clinical detection of pregnancy were not associated with serum total DDT. In this population, there was a positive, monotonic, exposure-response association between preconception serum total DDT and the risk of subsequent early pregnancy losses. 14) Aimin, C. and W.J. Rogan. Health risks and benefits of bis (4-chlorophenyl)-1,1,1trichloroethane (DDT). US National Institute of Environmental Health Sciences. 2005 Lancet 2005; 366: 763–73 PANNA summary: This article traces the health impacts and effectiveness or lack of effectiveness for countries continuing to use DDT for malaria control after its inclusion in the Stockholm Convention list of chemicals targeted for a global ban in 2001. Due to a lack of controlled testing and conflicting or inconclusive data it was impossible to determine the specific negative health effects of DDT. The authors call for more research to determine if the health risks outweigh the health benefits. Abstract: DDT (bis[4-chlorophenyl]-1,1,1-trichloroethane) is a persistent insecticide that was used worldwide from the mid-1940s until its ban in the USA and other countries in the 1970s. When a global ban on DDT was proposed in 2001, several countries in sub-Saharan Africa claimed that DDT was still needed as a cheap and effective means for vector control. Although DDT is generally not toxic to human beings and was banned mainly for ecological reasons, subsequent research has shown that exposure to DDT at amounts that would be needed in malaria control might cause preterm birth and early weaning, abrogating the benefit of reducing infant mortality from malaria. Historically, DDT has had mixed success in Africa ; only the countries that are able to find and devote substantial resources towards malaria control have made major advances. DDT might be useful in controlling malaria, but the evidence of its adverse effects on human health needs appropriate research on whether it achieves a favourable balance of risk versus benefit. (Epidemiology Branch, USNational Institute of Environmental Health Sciences, P O Box 12233, Research Triangle Park, NC 27709, USA. rogan@niehs.nih.gov) 15) Bouwman, H., and C. H. J. Schutte. Effects of Sibship on DDT Residue Levels in Human Serum from a Malaria Endemic Area in Northern KwaZulu . Bulletin of Environmental Contaminants and Toxicology. 1993; 50: 300-7. PANNA Summary: This study analyzes serum levels of DDT and its metabolites of siblings in eight homesteads. The authors conclude that there is a strong correlation between siblings under malaria control conditions and serum levels of DDT. They recommend that children always be included in environmental exposure studies and that separate risk assessments be done, since the young experience different environmental circumstances and are especially vulnerable during development. (no abstract available) 16) Bouwman, H., R. M. Cooppan, P. J. Becker, et al. Malaria Control and Levels of DDT in Serum of Two Populations in KwaZulu. Journal of Toxicology and Environmental Health. 1991; 33(3): 141-55. PANNA Summary: The authors established that the average level of DDT and its metabolites was higher in the population exposed to in-house DDT application for malaria control than in the control group. The researchers also discovered that the levels of DDT and its metabolites decreased between the ages of three and twenty-nine years, yet following age twenty-nine, the levels began to increase again. Based on these results, the authors suggest that different processes govern DDT dynamics with relation to age. They also tested liver function and found that, although DDT metabolite levels correlate with levels of the liver protein, alcohol consumption better predicted liver protein levels. Thus, the authors conclude that “DDT as used for malaria control does not adversely affect the liver function.” Abstract: Concentrations of p,p'-DDT, p,p'-DDE, and p,p'-DDD were determined in serum of members of households of two different areas of KwaZulu. Annual intradomiciliary application of DDT is used for the interruption of malaria transmission in one area (the exposed group) while the other served as the control. Demographic differences between the two groups resulted in significantly more females in the control group. The two groups were comparable with respect to age. Serum from household members living in DDT-treated dwellings had significantly higher (p < .005) levels of ?DDT and metabolites (mean ?DDT 140.9 µg/l) than those from the control area (mean ?DDT 6.04 µg/l). Percentage DDT was also significantly higher (p < .05) in the exposed group (28.9%) than the control group (8.3%). ?DDT for the 3-10 yr age interval (168.6 µg/l) was significantly higher (p < .05) than the 20-29 (60.5 µg/l) and 30-39 (84.2 µg/l) yr age intervals. There seemed to be two groups with regard to accumulation and elimination. The age group 3-29 appeared to be eliminating DDT, most likely accumulated from contaminated breast milk, faster than they accumulated it. From around 29 yr of age accumulation predominated as the levels increased with age. Regression analysis suggested pharmacokinetic differences for DDE and DDT between the two groups. Liver function parameters between the two groups only differed significantly for gamma-glutamyl transferase ( g GT) (p < .005), but the influence of difference in alcohol consumption, which was significantly higher in the exposed group (p < .0001), offered a better explanation. Those of the exposed group that consumed alcohol had a significantly higher (p < .05) mean g GT level (41.5 IU/l) than those that did not (20.2 IU/l), but were not significantly different for ?DDT (p > .05). The safety of DDT used in malaria control for subjects aged 3 and older was confirmed by the levels of DDT in serum when compared with other studies, which showed lack of any negative effects associated with these levels in adults, and an apparently normal liver function in the exposed and control groups. ( Research Institute for Environmental Diseases, Medical Research Council, Pretoria , Republic of South Africa .) 17) Bouwman, H., P. J. Becker, and C. H. J. Schutte. Malaria Control and Longitudinal Changes in Levels of DDT and Its Metabolites in Human Serum from KwaZulu. Bulletin of the World Health Organization. 1994; 72(6): 921-30. (Regional: Africa ) PANNA Summary: Based on previous research, the authors propose that uptake and elimination, two coexisting processes, control the changes in serum levels of DDT and its metabolites; and that these two processes switch with age. To confirm this, the authors compared the rates of change in addition to the change in levels. They found an increase in DDT metabolites for the older group (=21 years) and a decrease in serum levels for the younger group (3 to 20 years) over a 12-month period. Their data indicate that DDT levels increased faster in the older group than in the younger group, and that there is a more rapid reduction in serum DDT in the younger group. The authors' findings and analyses support the proposition that the body's rate and, perhaps, process of eliminating DDT is different in children than in adults. Abstract: Blood samples were obtained on four occasions over a 12-month period from individuals living in KwaZulu , South Africa , who had been exposed to DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) as a consequence of its use in their homes to control transmission of malaria. The longitudinal changes in serum DDT and its major metabolities, DDE and DDD, were determined. No additional risk was considered to have been presented by the increases that occurred following application of the pesticide. There were significant increases in DDT, DDE and ?DDT (DDT + its metabolites) for the age group =21 years, but for the age group 3-20 years a reduction in serum levels occurred over 12 months. Two concurrent processes probably govern the increase and decrease in serum levels, and the relative contributions of each interchange as the individual becomes older. The results suggest that children in KwaZulu experience conditions that differ from those of their parents, as well as from those that affect children in developed countries. In consequence, it is desirable that risk assessments of vector control chemicals consider all sectors of a population. ( Department of Zoology, Potchefstroom University for Christian Higher Education, South Africa .) B) THE DEBATE OVER DDT1) Roberts, D. R. DDT is still needed for disease control. Pesticide Safety News. V. 5, No. 4, 1st trimester 2002. http://www.icps.it/english/bollettino/psn02/05020401.htm Liroff, R. DDT's future under the Stockholm Convention. Pesticide Safety News. V. 5, No. 4, 1st trimester 2002. http://www.icps.it/english/bollettino/psn02/05020402.htm PANNA summary: The closing remarks of two authors after an extended debate in this publication. Roberts argues that DDT use should not be eliminated under the Stockholm Convention, and its additional reduction should not be a goal. Agricultural use, the main source of DDT that has built up in the environment, has already been eliminated by most nations and is banned under the Stockholm Convention. DDT levels in the environment are already falling and will continue to fall once it is banned for agricultural use worldwide. So, the much less harmful public health uses of DDT should be allowed to continue uninhibited. Liroff summarizes findings on DDT's health and environmental impacts since Stockholm treaty negotiations began in 1998, and also indicates successes with alternatives to DDT in Latin American countries. He points out that access to DDT will not be denied outright, and that countries still using it for malaria control will be allowed to continue doing so. However, he argues that the over-arching goal should be a reduction of reliance on DDT and other pesticides for any and all uses, and so efforts should be made toward the development and implementation of less harmful and more integrated alternative approaches to malaria control. (no abstract available) 2) Article: Politically Incorrect U.N. July 12, 2001. Review & Outlook, The Wall Street Journal. available at: http://www.junkscience.com/july01/wsj-UN.htm Response: Liroff, Rich. Alternatives to DDT can control malaria. July 19, 2001. Letters to the Editor: The Wall Street Journal. Copyright (c) 2001, Dow Jones & Company, Inc., p. A23. PANNA summary: The Wall Street Journal applauds the U.N for its "politically incorrect" stance in the report Making New Technologies Work for Human Development, which supports the use of DDT for malaria control (and criticizes environmental and public health groups concerned about genetically modified foods). (no abstract available) Full text of response: Your July 12 editorial "Politically Incorrect U.N." congratulates the U.N. for supporting use of DDT for malaria control. In so doing, the Journal is perpetuating the myth that environmentalists want DDT banned regardless of its usefulness in combating malaria. The World Wildlife Fund supports reduced reliance on DDT for malaria control primarily because of the hazards it poses to human health when it is sprayed indoors and the demonstrated success of alternative approaches. DDT contaminates food and mothers' milk. Just this week, the British medical journal The Lancet reports that DDE -- a breakdown product of DDT -- is associated with pre-term deliveries and low birth weights. Mexico and Vietnam are among the countries that have successfully controlled malaria while eliminating DDT, showing the promise of alternative methods. The World Health Organization's Roll Back Malaria program emphasizes use of bed nets treated with other chemicals. The new Stockholm Convention on Persistent Organic Pollutants (POPs) -- negotiated under U.N. auspices -- provides for DDT's continued use for malaria control, increased investments in and periodic evaluations of alternatives, and the ultimate elimination of DDT when countries are satisfied the alternatives are workable. WWF and the many other environmental and public health organizations who were observers at the treaty negotiations endorse this prudent approach. (Richard A. Liroff, Ph.D, Director, Alternatives to DDT Project, World Wildlife Fund,Washington) 3) Roberts, D.R. DDT Risk Assessments Environmental Health Perspectives, Correspondence. Volume 109, Number 7, July 2001. p. A 302-3. Liroff, R. DDT Risk Assessments: Response. Environmental Health Perspectives, Correspondence. Volume 109, Number 7, July 2001. p. A 302-3. PANNA summary: Roberts contends that environmentalists bent on eliminating DDT and its subsequent ban in many countries have caused the resurgence of diseases previously controlled by DDT, as well as diverted research attention and funds from the development of insecticidal methods of disease control into research on the adverse effects of DDT. Roberts in essence blames environmentalists for “spiraling increases in disease rates” he says are preventable by DDT. Liroff points out that the language of the Stockholm treaty, while recognizing a total elimination of DDT as an end goal, provides for the slow phase-out of the insecticide for vector control. He counters Roberts’ claims by pointing to Roberts’ own history of staunch defense of DDT and downplay of the toxicological risks. Liroff concludes that while DDT is very effective, less risky alternatives should be sought out and used. Full text: DDT Risk Assessments Two recent articles in EHP (1,2) and the latest Agency for Toxic Substances and Disease Registry toxicologic profile for DDT (3) make repeated references to DDT risks. These statements of risk, like so many others, are one-sided and give no consideration to colossal increases in diseases previously controlled with DDT. Behind disease statistics are grievous human tragedies, as with the case of a little girl who died of an infection that could have been prevented if her house had been sprayed with DDT. She lived in a village in the Andes and was 8 years old in 1998 when she died of bartonellosis. Bartonellosis was previously controlled through malaria housespray programs, but without DDT, the disease returned. One-sided and narrowly focused risk assessments form the bedrock of anti-DDT advocacy (4,5), but advocacy for global elimination of DDT through United Nations Environment Programme (UNEP) treaty negotiations failed (6). Countries can continue using DDT for disease control, and DDT is not listed for global elimination. This outcome was possible only through efforts of hundreds of scientists on behalf of hundreds of millions of people at risk of illness and death from malaria (7). Environmental activists who still want DDT eliminated and who are surprised by the lack of cost-effective alternatives should understand that global vilification of DDT eliminated almost all research on public health insecticides. Lack of research support persists and contrasts sharply with the richness of funds for research on adverse health effects of DDT; 29 major projects are presently funded by the National Institutes of Health (National Institute of Environmental Health Sciences, National Cancer Institute, National Institute of General Medical Sciences, and the National Institute of Child Health and Human Development) (3). The evidence of DDT efficacy in controlling diseases is irrefutable. In just 3 years, house spraying in Guyana reduced maternal and infant mortalities by 56% and 39%, respectively, and reduced malaria cases by 99% (8). Similar evidence from other geographic areas persuaded delegates to UNEP treaty negotiations that DDT is still needed. Yet, and in spite of all contrary evidence, the UN program to phase out DDT is unabated (9,10). The current “phase-out” program by the World Health Organization’s Roll Back Malaria initiative and the Global Environment Facility (Washington, DC) includes no publicized disease control performance standards and does not include appropriate on-site studies or tests to determine, under varying epidemiologic and environmental conditions, that DDT alternatives will provide adequate and sustained protection of rural populations. After years of successful efforts, the modus operandi of DDT elimination remains the same: apply political and economic pressures, convince country politicians that DDT is not needed, pass laws banning its use, and let impoverished rural populations quietly suffer spiraling increases in disease rates (11,12). Even short-term commitments of funds for purchasing the more expensive and less effective DDT alternatives are a continuation of past practices: in the end, disease rates will increase. The Andean girl’s death is one of millions of preventable deaths that occurred as national and international regulations, trade barriers, international policies, and UN resolutions were applied to stop public health uses of DDT (13). With absolute certainty, the best measures of success in the anti-DDT campaign are increases in disease and death from malaria, leishmaniasis, bartonellosis, dengue fever, and dengue hemorrhagic fever. We can add to this list the renewed threat that urban yellow fever will once again ravage populations of the Americas. Even this emerging threat is linked to past failures to continue appropriate public health uses of DDT. The Andean girl’s unrecognized but precious stake in the DDT issue was her life, now lost. How many millions more must die because of hypothetical risks from minute quantities of DDT sprayed on internal house walls? (Donald R. Roberts, Uniformed Services University of the Health Sciences, Bethesda, Maryland, droberts@usuhs.mil) Full Text: DDT Risk Assessments: Response Donald Roberts contends that organizations such as the World Wildlife Fund (WWF) failed in efforts to eliminate DDT under the recently negotiated persistent organic pollutants (POPs) treaty. To the contrary, the WWF strongly supports the treaty’s language on DDT. Throughout the negotiations, the WWF recognized that DDT should not be banned immediately and that uncertainties about the cost and effectiveness of alternatives required flexibility in treaty language (1,2). Reflecting this, the new treaty proclaims ultimate elimination of DDT as a goal while establishing a mechanism for reducing reliance on DDT and promoting alternatives (3). As a result of the treaty, new funds are being provided by the Global Environment Facility to develop malaria control programs that reduce use of DDT. Roberts has been an outspoken defender of DDT. He has prolifically and passionately downplayed the toxicologic risks of DDT while emphasizing its effectiveness for malaria control (4–6). He frequently argues that external political pressures drive poorer nations to abandon DDT, thereby endangering millions of the world’s most impoverished people. Malaria-endemic countries have had ample scientific justification for seeking alternatives. For example, in the mid-1990s, Mexican public health researchers expressed concern about high human exposures to DDT as a result of malaria control operations (7,8). Mexico has since eliminated DDT while successfully combating malaria. South Africa also sought to reduce use of DDT in the mid-1990s because of concern about elevated levels in mothers’ milk (9). One species of mosquito was resistant to alternative sprays, so South Africa resumed using DDT. South Africa concluded that the hazards from malaria outweigh those associated with DDT exposure. South Africa’s experience underscores the importance of the flexibility provided by the POPs treaty. Brazil and India offer important lessons about limits to DDT’s effectiveness. During the late 1980s and early 1990s, malaria rates in Brazil went up even as spraying of houses with DDT increased, but dropped after Brazil shifted strategies (10). With assistance from the World Bank, India is reducing its reliance on DDT. The main rural malaria vector (responsible for 65% of India’s malaria) is resistant to DDT (11). Indian researchers found elevated levels of DDT in buffalo milk, soil, water, and human blood where DDT had been sprayed to control malaria (12,13). The ATSDR’s 2000 update of its toxicologic profile for DDT/DDE (14) reflects major concerns raised by the WWF and other environmental and public health groups during the POPs negotiations. In contrast to the previous profile published in the early 1990s, the update contains a large section, “Health Effects in Wildlife Potentially Relevant to Human Health,” reminding readers that animals are sentinels for health effects in humans. A new section captioned “Children’s Susceptibility” reiterates a central message from the U.S. National Academy of Sciences’ landmark 1993 report on pesticides in the diets of infants and children (15): children are not little adults, but may be uniquely susceptible and exposed to pesticides. The data in the toxicologic profile support the logic of the POPs treaty: DDT can be valuable for controlling malaria, but it is prudent to reduce human exposures. Recent studies on humans, too late to be included in the toxicologic profile, further support such caution. For example, Longnecker et al. (16) found that DDE concentrations in mothers are associated with increased risk of pre-term delivery and lowered birth weight. Roberts takes EHP’s contributors to task for their “one-sided” references to DDT’s risks and their failures to account for DDT’s benefits. Roberts’ encomium to DDT is itself one-sided. Why expose humans to hazards from DDT when less risky strategies might be employed? The POPs treaty encourages development of alternatives and provides a new funding mechanism to support malaria control. (Richard A. Liroff, Alternatives to DDT Project, World Wildlife Fund, Washington, D.C., Rich.Liroff@wwfus.org) 4) Attaran, A. and R. Maharaj. Doctoring malaria, badly: The global campaign to ban DDT. British Medical Journal. V 321, 2 December 2000. Liroff, Rich. Commentary: Reduction and elimination of DDT should proceed slowly. British Medical Journal. V 321, 2 December 2000. PANNA summary: Attaran and Maharaj argue that attempts to ban DDT are not only naïve, but unethical. DDT is the cheapest and the most effective method of vector control, and no other method has come close—integrated vector management is still being tested and has never been used successfully in a nation-wide program, and other insecticides are often more expensive, less effective, and run into problems of vector resistance. While DDT may be hazardous to human health, there have been no conclusive studies to that effect. The authors find the precautionary principle ridiculous in this instance—removing the best malaria-fighting chemical because it might be carcinogenic, and thereby allowing malaria to spread and take more lives hardly seems cautious. (Center for International Development, Harvard University: amir_attaran@harvard.edu, South Africa Department of Health, Communicable Disease Control) Liroff's response addresses the fears of a medical establishment that he feels is unreasonably frightened of the Stockholm Convention. The convention does not ban DDT outright, but provides for its continued use where necessary, and eventual phase out. Liroff cites the US National Academy of Sciences and Agency for Toxic Substances and Disease Registry reports to the effect that DDT has adverse effects on the immune, endocrine, and reproductive systems, and that exposure to DDT at certain crucial stages of fetal and/or child development could lead to consequences later in life. While the global burden of malaria is a serious problem, especially on the poorest nations, some countries such as Mexico have had a great deal of success in moving to alternatives, and so it is not unreasonable to expect that a move away from DDT could not only protect human and environmental health but also improve the effectiveness of malaria control. The POPs convention needs to ensure that DDT is still available and affordable to countries that need it, and that supplies are tightly monitored so they cannot be used illegally for agriculture. (World Wildlife Fund, Alternatives to Malaria Project) (no abstract available) 5) Attaran, Amir. DDT saves lives. The Globe, Canada. December 5, 2000. Watt-Cloutier, S.; R. Charlie, and J. Crump. We can all win. The Globe, Canada. December 11, 2000. Attaran, PANNA summary: Attaran targets the Canadian government's support of the Stockholm Convention on the eve of the Johannesburg meeting in December, 2000. The environmentalists, he says, are being naïve. DDT may kill birds, but it saves people. The amount of DDT used for malaria control has little or no environmental impact compared to the amounts that were being applied for agricultural uses in Rachel Carson's day, so why make it harder and more expensive for "world's poorest, most disease-ridden countries to obtain?" Attaran says calling on the precautionary principle in this instance is tantamount to "stepping into speeding traffic as a "precaution" against tripping on a crack in the sidewalk." He scolds the Chretien government for their strong support of global elimination of DDT. Watt-Cloutier et al, Full Text: Amir Attaran's portrayal of Canada's position on global management of chemicals (DDT Saves Lives – Dec. 5), currently being negotiated in Johannesburg, misrepresents what is going on. Indigenous peoples from Northern Canada here in Johannesburg are replying not only to defend Canada but also to set the record straight. We do so because Mr. Attaran's widely reported views sow mistrust between delegations from the developed and developing worlds, thus undermining the efforts of us all to achieve a global convention on 12 persistent organic pollutants (POPs), including DDT. Mr. Attaran says: "Not only is Environment Canada arguing in the Johannesburg treaty negotiations that DDT should be eliminated once and for all, it has also proposed that the treaty not include a financial aid mechanism to help poor countries finance the alternatives. Canada is alone among wealthy countries in advocating this parsimony. Such policies literally kill." The government of Canada has pressed for a global POPs convention as have Northern indigenous peoples who have attended all five international negotiating sessions over the last two years. Many POPs used in tropical and temperate countries end up in the Arctic, contaminating the food web and subsequently Inuit and other indigenous peoples who eat traditional food. When used to control malaria, DDT saves the lives of thousands of people every year. While phasing out the use of DDT is an objective of the international negotiations, nobody supports a ban that puts lives at risk. When this issue surfaced in negotiations in 1999, Canadian indigenous peoples said they would refuse to be party to an agreement that threatened the health of others, notwithstanding the threat of POPs to their own health. The view of Northern indigenous peoples is also the fundamental position of all countries participating in the negotiations and all non-governmental organizations observing the debate. Any phase-out of DDT will be conditional upon the availability of cost-effective alternatives. Mr. Attaran's contention that Canada refuses to help finance the convention including development of alternatives to DDT is demonstrably untrue. The Minister of Finance announced $20 million in his February budget for exactly this purpose. Canada was the first nation to provide such support and is effectively advocating additional financial and technical assistance to developing countries and "economies in transition" (the old Soviet bloc). A global POPs convention will not be finalized and ratified unless both developing and developed countries conclude that it helps them. There is no alternative to a "win-win" convention, notwithstanding Dr. Attaran's view from Harvard University. (Sheila Watt-Cloutier, President, Inuit Circumpolar Conference (Canada), Robert Charlie, Council for Yukon First Nations, and John Crump, Executive Director, Canadian Arctic Resources Committee) 6) Roberts, D.R.; S. Manguin, and J. Mouchet. DDT house spraying and re-emerging malaria. Lancet 2000; 356: 330-332. Smith, A. G. How toxic is DDT? Lancet, 22 July 2000. Commentary Volume 356, Number 9226. PANNA summary: Roberts et.al. highlight the many accomplishments of DDT in malaria control over the last 55 years. A worldwide ban on DDT that would require malaria-endemic nations to reduce house spraying programs, and in turn lead to an increased malaria burden in those countries. Especially now as malaria is on the rise again and re-invading areas where it had previously been eradicated, the authors recommend that “the global response to burgeoning malaria rates should allow for DDT residual house spraying where it is known to be effective and necessary.” In response to the Roberts, Manguin, and Mouchet article, Smith surveys studies of DDT’s effects on human health and notes that considering the great quantities of DDT that have been used and the depth that the chemical has been studied, relatively few incidences of adverse effects on humans have been found. However, “the perceived rather than the calculated risks from DDT use are an important consideration in maintaining public confidence.” For this reason, Smith advises that DDT use continue to be tightly controlled and effects closely monitored. (no abstract available) 7) Roberts, D.R. DDT and the global threat of reemerging malaria. Pesticide Safety News, vol. 3 no. 4, December 1999. http://www.icps.it/english/bollettino/psn99/990404.htm Liroff, R. Balancing risks of DDT and malaria in the global POPs treaty. Pesticide Safety News, vol 4, no 2, June 2000. http://www.icps.it/English/Bollettino/Index-boll.htm PANNA summary: Roberts argues that DDT has not been convincingly linked to public health problems, and that pressure not to use DDT for malaria control are unwarranted and irresponsible. He challenges the use of Mexico as a model for controlling malaria without DDT, saying that "only time will tell" whether the alternative approaches adopted by the country will be successful in the long run. He highlights data from several countries in South America showing a link between falling DDT use and rising incidence of malaria. Liroff responds to Roberts' arguments with information on the current status of the international negotiations on POPs and the case for phasing out DDT. He identifies ways to strengthen malaria control programs, and h argues that the implementation of an effective integrated strategy of malaria control combined with DDT rollbacks would be a "win-win" situation. (no abstract available) 8) McGinn, Anne Platt. Malaria, Mosquitoes, and DDT: A toxic war against a global disease. WorldWatch. May/June 2002, pp.16., http://www.worldwatch.org/mag/2002/15-03.html PANNA summary: A well-balanced article, interesting for its current statistics on the prevalence of malaria worldwide and comparisons with other diseases of global concern like AIDS. Briefly describes malaria—the history of the disease and its phases and symptoms. Includes comments on the Stockholm Convention and a list of the four guiding principles of WHO's Roll Back Malaria program. McGinn concludes that there is no place for DDT in modern malaria control efforts—it’s simply obsolete, and half a century of experience has shown that there is little justification for its continued use. (no abstract available) 9) Gladwell, Malcolm. The Mosquito Killer: Millions of people owe their lives to Fred Soper - Why isn’t he a hero? The New Yorker: Annals of Public Health. July 2, 2001. pp. 42-51. PANNA summary: A rich historical piece that brings a unique perspective to the present debates, this article traces the history of DDT’s use for malaria control, with special attention to Fred Soper. Soper worked for the Rockefeller Foundation in the days before the WHO and UN. “With DDT as his weapon, Soper almost saved the world from one of its most lethal afflictions. Had he succeeded, we would not today be writing DDT’s obituary. We would view it in the same heroic light as penicillin and the polio vaccine.” Gladwell traces the history of Soper’s and DDT’s successes and failures, from the discovery of DDT’s miraculous insecticidal capability in the early forties, through the rise and fall of the global malaria eradication campaign of the sixties, which Soper led, to the post-Silent Spring environmentalists’ movement to limit and ban use of DDT. (no abstract available) 10) Attaran, A. In praise of DDT. Pesticide Outlook. June 2001; p. 83. PANNA summary: The author "argues the case for the retention of DDT in the battle against malaria as the POPs Convention reaches the signing stage." He points to incidences in Africa and Asia where malaria was almost completely under control until the country started phasing out DDT, at which time there were huge rebounds in the numbers of malaria cases. It is, in his eyes, a case of pitting speculative though unproven health risks of DDT as a toxin against the definite health risks of malaria if DDT, the cheapest and still most effective solution, is not used. (no abstract available) 11) Attaran, A.; D.R. Roberts, C.F. Curtis, and W.L. Kilama. Balancing risks on the backs of the poor. Nature Medicine 2000 Jul; 6(7): 729-31. http://www.malaria.org/attarannaturemed.html PANNA summary: Attaran, Roberts, et al are quite forceful in presenting their case as to why the Stockholm Convention and "First World Environmentalists" should not continue with their campaign to "reduce and/or eliminate" the use of DDT for malaria control. They argue that studies of the harmful effects of DDT on humans and the environment either are inconclusive, haven't been replicated, or were due to large scale agricultural use of DDT in the past, while DDT's effectiveness as a tool for malaria control is undeniable and backed by decades of experience. Environmentalists in industrialized countries have the luxury of placing environmental concerns above poverty alleviation, while developing countries do not have the same luxury. Malaria is one of the major factors keeping underdeveloped nations in poverty, and environmentalists' attempts to take DDT, the most powerful and effective weapon in the arsenal, away from those nations for their own environmental concerns amounts to eco-imperialism. Abstract: Malaria kills over one million people, mainly children, in the tropics each year, and DDT remains one of the few affordable, effective tools against the mosquitoes that transmit the disease. Attaran et al. explain that the scientific literature on the need to withdraw DDT is unpersuasive, and the benefits of DDT in saving lives from malaria are well worth the risks. (Center for International Development, Kennedy School of Government, Harvard University, Cambridge, Massachussetts 02138, USA amir_attaran@harvard.edu) 12) Raloff, Janet. The case for DDT: What do you do when a dreaded an environmental pollutant saves lives? Science News, Vol. 158, No. 1, July 1, 2000, p. 12. http://www.sciencenews.org/20000701/bob8.asp PANNA summary: Raloff summarizes recent findings and arguments around the push to ban DDT, citing Roberts and Liroff, among others. She finds that arguments for continued use of DDT are very strong—although our eventual goal should be elimination, it would be disastrous to abandon DDT prematurely, and it should be brought back in areas where its decreased use has caused malaria infection rates to surge, especially in Latin America. It would, however, be unwise to rely on only one tool, and so many scientists advocate increased research into the development of new methods as well. (no abstract available) 13) Curtis, C.F. and J.D. Lines. Should DDT be banned by international treaty? Parasitology Today 2000 Mar; 16(3): 119-21. Abstract: The insecticide DDT has been an effective and affordable means of malaria control in many countries, but pressure for its use to be banned is mounting. Here, Chris Curtis and Jo Lines take a critical look at evidence that links house spraying by DDT with harm to the environment and human health, and stress the need for resources for alternatives to DDT to be made available to countries that would be affected by a DDT ban. (London School of Hygiene and Tropical Medicine, Keppel Street, London, UK WC1E 7HT. chris.curtis@lshtm.ac.uk) 14) Roberts, D., C. Curtis, R. Tren, et al. Malaria Control and Public Health . Emerging Infectious Diseases [letter]. 2004; 10(6): 1170-1. Response: Chen, A., and W. J. Rogan. Malaria Control and Public Health . Emerging Infectious Diseases. 2004; 10(6): 1172. Available Online at: http://www.cdc.gov/ncidod/EID/vol10no6/03-0787_03-1116.htm PANNA Summary: Roberts et al. refute the arguments Chen and Rogan made in their article “Nonmalarial infant death and DDT use for malaria control,” published in 2003. Roberts et al. claim that Chen and Rogan's conclusions require “substantial evidence of a causal relationship between DDT and adverse consequences of DDT [indoor residue spraying] for malaria control,” and that no adverse effects on maternal health or infant survival are attributable to DDT. They assert that DDT spraying is still the cheapest, most effective malaria control method. (Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, Bethesda , Maryland ; droberts@usuhs.mil.) In response, Chen and Rogan admit that causality has not been demonstrated between DDT and shortened lactation or preterm birth, but claim “the evidence is sufficiently strong that the possibility of causality cannot be dismissed.” They insist that we should proceed with caution regarding the use of DDT because its safety has not been “demonstrated absolutely.” (Epidemiology Branch, National Institute of Environmental Health Sciences ( niehs ), Research Triangle Park , North Carolina ; rogan@niehs.nih.gov .) (no abstracts available) C) MALARIA CONTROL: ASIA1) Henley, David. Malaria past and present: The case of North Sulawesi, Indonesia. Southeast Asian Journal of Tropical Medicine and Public Health. Sept 2001, vol. 32, no. 3, p. 595-607. PANNA summary: According to the author, the most likely source of the long-term decline of malaria in North Sulawesi is large-scale conversion of forest to permanent farmland. DDT was being sprayed until the last of the national stock was used up in 1993 after a ban that started in 1990, then other more expensive chemicals were used until about 1997. During that period, malaria rates went down steadily. But in 1997 with the economic downturn in Asia, the government of Indonesia cut back spending on malaria control significantly and since then, malaria has made a small though significant resurgence. The author concludes that it is unlikely for environmental management, bed nets, or anti-malaria medication to be as effective as insecticide spraying in controlling malaria in North Sulawesi. Abstract: The incidence and impact of malaria in North Sulawesi have declined both in the short term during the 1990s, and over a much longer timespan (though perhaps less continuously) since the end of the colonial period. The improvement already seems to have been well underway before deliberate vector control activities became extensive in the second half of the 1970s, and environmental changes affecting the Anopheles mosquito fauna, in particular the replacement of primary and secondary forest by permanent farmland, are probably the principal reasons for the long-term trend; other possible factors include the increasing use of antimalarial drugs. The well-documented decline in malaria incidence over the years 1991-1997, nevertheless, probably reflects the unprecedented scale of residual insecticide spraying in the province during that period, while the slight resurgence of the disease in the last three years corresponds to the subsequent cessation of house spraying as a result of the current economic crisis. Despite the evident importance of environmental change as a factor ameliorating the malaria situation in the long term, experience from the colonial era suggests that the prospects for deliberate environmental management (species sanitation) as an alternative malaria control strategy are poor. (Royal Institute for Linguistics and Anthropology (KITLV), Leiden, The Netherlands. henley@kitlv.nl) 2) Barcus, Mazie J., F. Laihad, M. Sururi, P. Sismadi, H. Marwoto, M. J. Bangs, and J. K. Baird. Epidemic malaria in the Menoreh Hills of central Java. American Journal of Tropical Medicine and Hygiene. 60(3). 2002 pp. 281-292. PANNA summary: DDT spraying and the introduction of chloroquine medication for malaria starting in the 1950s virtually eradicated endemic malaria from the island of Java. DDT spraying was abandoned by the Republic of Indonesia in the late 1980s and stocks were depleted by the early 1990s. Spraying of less effective and more expensive pesticides continued through the early 1990s. This study shows that the sharp decline in government spending on malaria control since the economic downturn of the late 1990s, especially the curtailment of indoor spraying, has lead to a real epidemic of malaria in the hills of central Java. The authors call for a revival of residual indoor spraying programs as the only proven effective solution to the outbreak. Abstract: After more than 50 years of effective management, resurgent malaria threatens residents in the Menoreh Hills and the foothills of the Dieng Plateau of Central Java, Indonesia. The Dieng Plateau dominates the highland center of Central Java. The steep Menoreh Hills, surrounded by rice paddy habitats, cover approximately 500 km2 with no peaks greater than 1,000 m. We studied epidemic malaria in Purworejo district, one of the three districts containing the Menoreh Hills. Between 1986 and 1995, the annual parasite incidence (API) in Purworejo ranged from 2 to 11 cases per 1,000 residents per year and was typically approximately 5 per 1,000. In 2000 the API was 44.5. This sharp increase was confined to subdistricts in and around the Menoreh Hills and Dieng Plateau foothills. The primary vectors of malaria, those favoring steep, forested hillsides on Java, were Anopheles maculatus and Anopheles balabacensis. Deterioration of vector control activity, followed by a severe economic downturn in 1997, may explain the epidemic. Malaria in the Menoreh Hills and lower Dieng Plateau threatens surrounding areas of rice paddy inhabited by Anopheles aconitus as well as a nearby coastal habitat where the even more efficient vector Anopheles sundaicus occurs in abundance. Most of the 130 million people living on Java never experienced the hyper- and holoendemic malaria that occurred throughout most of the island before the effective DDT spraying and chloroquine treatment campaigns of the 1950s. Reintroduced endemic malaria threatens the island of Java. (U.S. Naval Medical Research Unit # 2, Jakarta, Indonesia) 3) Sharma, V.P. Current scenario of malaria in India. Parassitologia 41: 349-53, 1999. PANNA summary: The author reviews statistics of malaria incidence and control in India. DDT is the insecticide most widely used for malaria control, followed by HCH, malathion, and synthetic pyrethroids, and they are all used for residual indoor spraying in rural areas and anti-larva operations in urban areas. The major vector species has become resistant to DDT and HCH in most of the country. At the same time, malaria rates are increasing in many parts of the country because of man-made environmental changes like irrigation projects and piped-in water supplies—anywhere rapid development is happening, malaria is invading. Indian national and state governments continue to pour resources and energy into the problem, with help from the World Bank. Abstract: The Indian National Malaria Eradication Programme (NMEP) is reporting 2.5 to 3 million malaria cases, and about 1,000 malaria deaths annually. Malaria in the northeastern states is stable and in the peninsular India unstable. There are six major and three minor malaria vectors, of which Anopheles culicifacies transmits malaria in rural areas and An. stephensi in the towns. Other vectors are of local importance. Plasmodium vivax is the dominant infection and accounts for 60-65% cases whereas P. falciparum contributes 30-35% cases. Field operations to control malaria are impeded by resistance and/or exophilic vector behavior, parasite resistance to antimalarial drugs, operational problems in spraying, failure to search breeding of mosquitoes at weekly intervals, staff shortages and financial constraints. Resurgent malaria invaded new ecotypes created by green revolution, industrial growth and urban development resulting in paradigm shift towards man-made malaria. NMEP has launched a world bank-assisted enhanced malaria control project with primary emphasis to protect 62.2 million high risk population in 7 states. (Malaria Research Centre, Delhi, India. vps@icmrmrc.ren.nic.in) 4) Agarwal, Ravi. No Future in DDT: A case study of India. Pesticide Safety News, May 2001. PANNA summary: India is an important case study to understand that DDT is becoming obsolete, not only owing to concerns over its toxicity, but also because it is losing its effectiveness in treating malaria. India has been manufacturing and using DDT for more than 50 years. Use for agriculture was banned in 1989, and use for malaria has been declining in favor of more multi-sector approaches to the problem, since unsafe levels of DDT are turning up in food supplies and the egg shells of large predatory birds, and its effectiveness is waning anyway. India currently spends 35% of its health budget on malaria control each year. The current strategy is based on prioritizing control in high-risk areas, reducing the use of chemical insecticides, and the prevention and control of epidemics through community participation, the use of bed nets, and early diagnosis and treatment. The use of DDT in urban areas has halted completely. (no abstract available) 5) Sharma, V.P. Environmental management in malaria control in India. In Malaria: waiting for the vaccine. Targett, GAT. Ed. England: John Wiley & Sons Ltd, 1991.
|