This compilation of articles will be updated periodically and it is by no means comprehensive. The articles are arranged by category and in chronological order with the newest studies first. 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.
- Infants and breastfeeding (5 articles)
- Reproductive Impact (6 articles)
- Neurological Impacts (4 articles)
- Serum levels and other health impacts (13 articles)
- Environmental Impacts (4 articles)
Infants and breastfeeding
1) Bouwman H, Sereda B, and Meinhardt H.M. Simultaneous presence of DDT and pyrethroid residues in human breast milk from a malaria endemicarea in South Africa Environmental Pollution 2006 114: 902-917
PANNA Summary: Human breast milk is a known to be the best source ofnutrition for infants. In developing countries, especially in the ruralareas it is the primary source of food to infants sometimes until theage of 2, which is a particularly long period and can lead to asignificant transfer of pollutants. In Africa, malaria kills millionseach year even today. The use of pesticides for vector controlcontinues to rely on insecticide treated bed nets and residualspraying. While the Stockholm convention and Rollback malaria campaigncontinues to work towards reducing the reliance on malaria, it wasforced to reintroduce DDT in South Africa. Also, malaria is not theonly potential source of human exposure to pesticides. Pyrethroids,organophosphates and carbamates, etc., are now readily used in cropprotection and veterinary chemicals. The aim pf this study is toinvestigate and deliberate on the presence of DDT and other pyrethroidsin breast milk of three semi-urban populations. Results indicate thatDDT levels were lower than found in previous studies but the presenceof pyrethroids has added to another level of complexity. It shows thatmore work is required in this aspect. The author does stress that thereis no reason to implicate breastfeeding as a primary source ofnutrition in infants.
Abstract: DDT and pyrethroids were determined in 152 breast-milksamples from three towns in KwaZulu-Natal, South Africa, one of whichhad no need for DDT for malaria control. All compounds were foundpresent in breast milk. Primiparae from one town had the highest meanSDDT whole milk levels (238.23 mg/l), and multiparae from the same townhad the highest means for permethrin (14.51 mg/l), cyfluthrin (41.74mg/l), cypermethrin (4.24 mg/l), deltamethrin (8.39 mg/l), andpyrethroid (31.5 mg/l), most likely derived from agriculture. The ADIfor DDTwas only exceeded by infants from one town, but the ADI forpyrethroids was not exceeded. Since the ADI for DDT was recentlyreduced from 20 to 10 mg/kg/bw, we suggest that this aspect be treatedwith concern. We therefore raise a concern based on toxicantinteractions, due to the presence of four different pyrethroids andDDT. Breastfeeding however, remains safe under prevailing conditions.
2) Chen A, and Rogan W.J. Nonmalarial Infant Deaths and DDT Use forMalaria Control Emerging Infectious Diseases 2003 9(8): 960-964.
PANNA Summary: The authors examine the relationship between DDTspraying for malaria control and preterm births and shorter durationsof lactation in sub-Saharan Africa. They estimated the increase ininfant deaths that may have resulted from DDT spraying and make theclaim that the same amount of children may be dying from DDT as beingsaved by it for malaria control.
Abstract: Although dichlorodiphenyl trichloroethane (DDT) is beingbanned worldwide, countries in sub-Saharan Africa have soughtexemptions for malaria control. Few studies show illness in childrenfrom the use of DDT, and the possibility of risks to them from DDT usehas been minimized. However, plausible if inconclusive studiesassociate DDT with more preterm births and shorter duration oflactation, which raise the possibility that DDT does indeed have suchtoxicity. Assuming that these associations are causal, we estimated theincrease in infant deaths that might result from DDT spraying. Theestimated increases are of the same order of magnitude as the decreasesfrom effective malaria control. Unintended consequences of DDT use needto be part of the discussion of modern vector control policy.
3) Gladen, B. C. and Rogan, W. J. DDE and shortened duration oflactation in a northern Mexican town. American Journal of PublicHealth. 1995; 85(4):504-508.
PANNA summary: The authors found that DDE (a metabolite of DDT) levelsin the breast milk of mothers in an agricultural town in northernMexico is strongly linked to the length of time that they breastfeedtheir infants. Mothers with the highest levels of DDE breastfed foronly 3 months on average, while mothers with the lowest DDE levelsbreastfed for an average of 7.5 months. The authors conclude that DDTexposure may be contributing to the trend toward decreasing lengths oflactation world wide.
Abstract: OBJECTIVES: Worldwide declines in the duration of lactationare cause for public health concern. Higher levels of dichlorodiphenyldichloroethene (DDE) have been associated with shorter durations oflactation in the United States. This study examined whether thisrelationship would hold in an agricultural town in northern Mexico.
METHODS: Two hundred twenty-nine women were followed every 2 monthsfrom childbirth until weaning or until the child reached 18 months ofage. DDE was measured in breast milk samples taken at birth, and womenwere followed to see how long they lactated.
RESULTS: Median duration was 7.5 months in the lowest DDE group and 3months in the highest. The effect was confined to those who hadlactated previously, and it persisted after statistical adjustment forother factors. These results are not due to overtly sick children beingweaned earlier. Previous lactation lowers DDE levels, which produces anartifactual association, but simulations using best estimate s showthat an effect as large as that found here would arise throughthis mechanism only 6% of the time.
CONCLUSIONS: DDE may affect women'sability to lactate. This exposure may be contributing to lactationfailure throughout the world. (Statistics and Biomathematics Branch,National Institute of Environmental Health Sciences, Mail Drop A3-03POB 12233, Research Triangle Park, NC 27709, USA.)
4) 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 itsmetabolites in the blood of infants and the breast milk of theirmothers 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 asecondary source.
Abstract: The transfer of p,p'-DDT(1,1,1-tricholoro-2,2-bis(4-chlorophenyl)ethane) and its metabolites toinfants via breast-feeding was studied in an area of KwaZulu, SouthAfrica, where DDT is used to interrupt malaria transmission. Samples ofwhole blood were collected from 23 infants, together with samples ofbreast milk from their respective mothers. The mean sigma DDT (totalDDT) in the whole blood was 127.03 micrograms.l-1 and that in thebreast 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 (Pless than 0.05). A multiplicative regression analysis indicated thatsigma DDT increased significantly (P less than 0.01) in infant wholeblood with infant age. Multiple regression showed that 70.0% of thevariation in sigma DDT was due to the variation in parity of themother, age of the infant, and the sigma DDT in breast milk. Thesevariables accounted also for 76.3% of the variation in p,p'-DDE butonly for 38.2% of that in p,p'-DDT. Organochlorines were thereforelargely transferred to the infant from the mother, with DDT in theenvironment playing a secondary role. (Department of Zoology,University for Christian Higher Education, Potchefstroom, South Africa.)
5) Rogan, W. J.; Gladen, B. C.; McKinney, J. D.; Carreras, N.; Hardy,P.; Thullen, J.; Tingelstad, J., and Tully, M. Polychlorinatedbiphenyls (PCBs) and dichlorodiphenyl dichloroethene (DDE) in humanmilk: Effects on growth, morbidity, and duration of lactation. AmericanJournal of Public Health. 1987; 77(10):1294-1297.
PANNA summary: This study determined the effects of PCBs and DDE (DDTmetabolite) in breast milk on infant growth and health. Its mostsignificant finding was that higher levels of DDE are associated withmarkedly shorter duration of breast feeding, indicating that DDE issomehow interfering with mothers’ ability to breastfeed their children.
Abstract: We followed 858 children from birth to one year of age todetermine whether the presence of polychlorinated biphenyls (PCBs) anddichlorodiphenyl dichloroethene (DDE) in breast milk affected theirgrowth or health. Neither chemical showed an adverse effect on weightor frequency of physician visits for various illnesses, althoughdifferences were seen between breast-fed and bottle-fed children, withbottle-fed children being heavier and having more frequentgastroenteritis and otitis media. Children of mothers with higherlevels of DDE were breast-fed for markedly shorter times, butadjustments for possible confounders and biases did not change thefindings. In absence of any apparent effect on the health of thechildren, we speculate that DDE may be interfering with the mother'sability to lactate, possibly because of its estrogenic properties.
Reproductive Impacts
1) Aneck-Hahn, NH, Schulenburg, GW, Bornman, MS, Farias P, and De JagerC Impaired Semen Quality Associated With Environmental DDT Exposure inYoung Men Living in a Malaria Area in the Limpopo Province, SouthAfrica Journal of Andrology 2007 28(3).
PANNA Summary: This study found associations of DDT and DDE, abreakdown of DDT, associated with abnormal sperm, impaired spermmovement, and low ejaculate volume in semen from healthy men aged 18-40who live in an area in South Africa where DDT is sprayed every year.The results imply that non-occupational exposure to DDT is associatedwith impaired semen in men. The high exposure levels of DDT and DDE areof concern, as these levels may have far reaching implications forreproductive and general health.
Abstract: The pesticide DDT[1,1,1-trichloro-2,2-bis(chlorodiphenyl)ethane] is one of the 12persistent organic pollutants (POPs) that were under negotiation at theStockholm Convention, to restrict or ban their production and usebecause of to their toxicity, resistance to breakdown, bioaccumulationand potential for being transported over long distances. DDT hasestrogenic potential and the main metabolite p,p'-DDE is a potentanti-androgen. In response to mounting evidence on the endocrinedisrupting influence of environmental chemicals on human health, thisepidemiological study was initiated to test the hypothesis thatnon-occupational exposure to DDT affects male reproductive parameters.In a cross sectional study healthy male subjects (n=311) aged between18 and 40 years (23±5) were recruited from three communities in anendemic malaria area where DDT is sprayed annually. A semen analysisaccording to the World Health Organization (WHO)(1999) standards wasperformed. The Hamilton Thorne Computer Assisted Sperm Analysis (CASA)system was simultaneously used to determine additional sperm motilityparameters. Blood plasma samples were assayed for p,p'-DDT andmetabolites as a measure of exposure. The exposure levels wereexpressed as lipid adjusted p,p'-DDT and p,p'-DDE values. The meanp,p’-DDT and p,p'-DDE concentrations were 90.23 µg/g (±102.4) and215.47 µg/g (±210.6), respectively. The multivariate linear regressionanalyses indicated that: the mean CASA motility was lower with a higherp,p'-DDE concentration (beta = -0.02; p=0.001) and the CASA parameter,beat cross frequency (BCF)was higher with a higher p,p'-DDTconcentration (beta= 0.01; p =0.000). There was also a statisticallysignificantly positive association between the percentage sperm withcytoplasmic droplets and p,p’-DDT concentration(beta =0.0014; p=0.014). The ejaculate volume (mean:1.9±1.33mL) was lower than thenormal range ( 2.0mL)for the WHO, and a significant decrease withincreasing p,p'-DDE values was seen for both square rooted volume(beta=-0.0003; p= 0.024) and count (beta =-0.003; p= 0.04). Although therewere no associations between either p,p'-DDT or p,p'-DDE concentrationsand the rest of the seminal parameters, the incidence ofteratozoospermia (% Normal sperm <15%) (99%) was high. Twenty-eightpercent of the study group presented with oligozoospermia (< 20million sperm/mL) which had a significantly positive association withp,p'-DDE (OR:1.001; p = 0.03). There was a significantly positiveassociation between participants with asthenozoospermia (32%) andp,p'-DDT (OR:1.003, p = 0.006) and p,p'-DDE (OR:1.001, p = 0.02). Theresults imply that non-occupational exposure to DDT is associated withimpaired seminal parameters in men. The high exposure levels ofp,p'-DDT and p,p'-DDE are of concern, as these levels may have farreaching implications for reproductive and general health.
Full text: http://www.andrologyjournal.org/cgi/rapidpdf/jandrol.106.001701v1
2) Kilian E, Delport R, Bornman1 MS, & de Jager C Simultaneousexposure to low concentrations of dichlorodiphenyltrichloroethane,deltamethrin, nonylphenol and phytoestrogens has negative effects onthe reproductive parameters in male Spraque-Dawley rats Andrologia 200739: 128-135.
PANNA Summary: This study examines male reproductive development offour groups of rats, a control group and three groups givenpesticide-laced serums, including DDT. The rats were exposed in uteroand then given the serum for 10 weeks after birth. The rats exposed topesticides did not develop as well as the control group and thefindings that exposure to endocrine disrupting compounds may contributeto the deterioration of male reproductive health.
Abstract: Many reports suggest that male reproductive health hasdeteriorated over the last decades, possibly due to environmentalcontaminants that act as endocrine disruptors. This hypothesis wastested in Sprague-Dawley rats using a modified Organization forEconomic Cooperation and Development 415 one-generation test. Group Areceived cottonseed oil as control, and Groups B, C and D receiveddeltamethrin (DM); DM and dichlorodiphenyltrichloroethane (DDT); andDM, DDT, phytoestrogens and p-nonylphenol, respectively. Rats wereexposed in utero and then received the substances for 10 weeks. Theseminal vesicle mass (Group B; P = 0.046) and sperm count [Groups C (P= 0.013) and D (P = 0.003)] were lower and the anogenital distance[Group B (P = 0.047) C (P = 0.045) and D (P = 0.002)] shorter comparedwith the control group. The seminiferous tubule diameter [Groups B (P =<0.001), C (P = <0.001) and D (P = <0.001)] and epitheliumthickness [Groups B (P = 0.030), C (P = <0.001) and D (P =<0.001)] were smaller compared with the control. The histology ofthe testes showed signs of apical sloughing and vacuolisation. Liverweights [Groups C (P = 0.013) and D (P = 0.005)] and liver enzymes[Group D (P = 0.013)] were also affected. These findings may indicatethat simultaneous exposure to endocrine disrupting compoundscontributes to the deterioration observed in male reproductive health.
3) Fenster L, Eskenazi B, Anderson M, Bradman A, Harley K, Hernandez H,Hubbard A, Barr DB. Association of in utero organochlorine pesticideexposure and fetal growth and length of gestation in an agriculturalpopulation. Environ Health Perspectives 2006 114(4):597-602.
PANNA Summary: This detailed study examines the exposure of 11organochlorine pesticides as assessed by measurements in maternal serumis associated with shortened length of gestation and poorer fetalgrowth in a birth cohort from an agricultural community in the Salinasvalley, California. An association between increasing maternal HCBserum levels and decreased length of gestation was observed whereas anHCB associated decrease in crown-heel length as reported in a Spanishstudy by Ribas-Fito et al. 2000 was not found. Hence, even though therewas no positive finding of an adverse association of in uteroorganochlorine pesticide exposure with birth weight or crown – heellength using maternal serum, the study did find that exposure to HCBwas significantly related to a decrease in length of gestation .Theseresults are not conclusive because of multiple comparisons. HCB is notmanufactured anymore but is still produced as a byproduct due to whichit may still enter the environment and its potential reproductivetoxicity continues to remain as a concern for human populations.
Abstract: From 1940 through the 1970s, organochlorine compounds werewidely used as insecticides in the United States. Thereafter, their usewas severely restricted after recognition of their persistence in theenvironment, their toxicity in animals, and their potential forendocrine disruption. Although substantial evidence exists for thefetal toxicity of organochlorines in animals, information on humanreproductive effects is conflicting. We investigated whether infants'length of gestation, birth weight, and crown-heel length wereassociated with maternal serum levels of 11 different organochlorinepesticides: p,p -dichlorodiphenyltrichloroethane (p,p -DDT), p,p-dichlorodiphenyldichloroethylene (p,p -DDE), o,p-dichlorodiphenyltrichloroethane (o,p -DDT), hexachlorobenzene (HCB),gamma-hexachlorocyclohexane (gamma-HCCH), gamma-hexachlorocyclohexane(gamma-HCCH), dieldrin, heptachlor epoxide, oxychlordane,trans-nonachlor, and mirex. Our subjects were a birth cohort of 385low-income Latinas living in the Salinas Valley, an agriculturalcommunity in California. We observed no adverse associations betweenmaternal serum organochlorine levels and birth weight or crown-heellength. We found decreased length of gestation with increasing levelsof lipid-adjusted HCB (adjusted gamma = -0.47 weeks; p = 0.05). We didnot find reductions in gestational duration associated with any of theother organochlorine pesticides. Our finding of decreased length ofgestation related to HCB does not seem to have had clinicalimplications for this population, given its relatively low rate ofpreterm delivery (6.5%). (Division of Environmental and OccupationalDisease Control, California Department of Health Services, Richmond, CA94804, USA. lfenster@dhs.ca.gov)
4) Tiido T, Rignell-Hydbom A, Jönsson B, Lundberg Giwercman Y, Rylander L, Hagmar L and Giwercman A, Exposure to persistent organochlorine pollutantsassociates with human sperm Y:X chromosome ratio Human Reproduction2005 20(7):1903-1909
PANNA Summary: This study shows an association of DDE with increasedamounts of Y chromosome bearing sperm in Swedish fisherman. These dataadd to the growing body of evidence that exposure to persistent organicpollutants may alter the offspring sex ratio.
Abstract: During the last decades, there has been concern that exposureto endocrine disruptors, such as persistent organochlorine pollutants(POPs), may contribute to sex ratio changes in offspring of exposedpopulations. METHODS: To investigate whether exposure to2,2'4,4'5,5'-hexachlorobiphenyl (CB-153) and dichlorodiphenyldichloroethene (p,p'-DDE) affect Y:X chromosome proportion, semen of149 Swedish fishermen, aged 27–67 years, was investigated. The menprovided semen and blood for analysis of hormone, CB-153 and p,p'-DDElevels. The proportion of Y- and X-chromosome bearing sperm in semensamples was determined by two-colour fluorescence in situ hybridization(FISH) analysis. RESULTS: Log transformed CB-153 as well as logtransformed p,p'-DDE variables were both significantly positivelyassociated with Y chromosome fractions (P-values=0.05 and <0.001,respectively). Neither age, smoking, nor hormone levels showed anyassociation with Y-chromosome fractions. CONCLUSIONS: This is the firststudy to indicate that exposure to POPs may increase the proportion ofejaculated Y-bearing spermatozoa. These data add to the growing body ofevidence that exposure to POPs may alter the offspring sex ratio.
FullText: http://humrep.oxfordjournals.org/cgi/reprint/20/7/1903
5) Venners SA , Korrick S, Xu X, Chen C, Guang W, Huang A, Altshul L,Perry M, Fu L, and Wang X Preconception Serum DDT and Pregnancy Loss: AProspective Study Using a Biomarker of Pregnancy American Journal ofEpidemiology 2005 162(8): 709-716.
PANNA Summary: The authors measured levels of DDT in 388 women in Chinabetween 1996 and 1998. They measured DDT levels before conception andmonitored early pregnancy losses and spontaneous abortions in thepregnancies. There was a positive relationship between preconceptionDDT levels and the risk of subsequent early pregnancy loss.
Abstract: Previous studies of pregnancy losses and1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) were limitedbecause they did not include losses prior to clinical detection ofpregnancy and because exposures were measured after the pregnancies ofinterest. The authors examined the association of preconception serumtotal DDT (sum of DDT isomers and metabolites) concentration andsubsequent pregnancy losses in 388 newly married, nonsmoking, femaletextile workers in China between 1996 and 1998. Upon stoppingcontraception, subjects provided daily urine specimens and records ofvaginal bleeding for up to 1 year or until clinical pregnancy. Dailyurinary human chorionic gonadotropin was assayed to detect conceptionand early pregnancy losses, and pregnancies were followed to detectclinical spontaneous abortions. There were 128 (26%) early pregnancylosses in 500 conceptions and 36 (10%) spontaneous abortions in 372clinical pregnancies. Subjects were grouped in tertiles bypreconception 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 withgroup 1, group 2 had adjusted relative odds of early pregnancy lossesof 1.23 (95% confidence interval (CI): 0.72, 2.10), and group 3 hadadjusted odds of 2.12 (95% CI: 1.26, 3.57). The relative odds of earlypregnancy losses associated with a 10-ng/g increase in serum total DDTwere 1.17 (95% CI: 1.05, 1.29). The small number of spontaneousabortions following clinical detection of pregnancy were not associatedwith serum total DDT. In this population, there was a positive,monotonic, exposure-response association between preconception serumtotal DDT and the risk of subsequent early pregnancy losses.
6) Cohn, BA, PM Cirillo, MS Wolff, PJ Schwing, RD Cohen, RI Sholtz, AFerrara, RE Christianson, BJ van den Berg and PK Siiteri DDT and DDEexposure in mothers and time to pregnancy in daughters. The Lancet 2003361: 2205–06.
PANNA Summary: DDT and DDE were measured in serum samples from womenafter delivery between 1960 and 1963. Then 28-31 years later thewomen’s eldest daughters recorded their time until pregnancy. Thedaughter’s chances of pregnancy fell with the increase of DDT in themother’s serum.
Abstract: Reproductive-tract anomalies after administration of thepotent oestrogen, diethylstilboestrol, in pregnant women raisedconcerns about the reproductive effects of exposure to weaklyoestrogenic environmental contaminants such asbis[4-chlorophenyl]-1,1,1-trichloroethane (p, p′-DDT) or itsmetabolites, such as bis[4-chlorophenyl]-1,1-dichloroethene (p,p′-DDE). We measured p, p′-DDT and p, p′-DDE in preserved maternalserum samples drawn 1–3 days after delivery between 1960 and 1963. Werecorded time to pregnancy in 289 eldest daughters 28–31 years later.Daughters' probability of pregnancy fell by 32% per 10 μg/L p, p′-DDTin maternal serum (95% CI 11–48). By contrast, the probability ofpregnancy increased 16% per 10 μg/L p, p-DDE (6·27). The decreasedfecundability associated with prenatal p, p′-DDT remains unexplained.We speculate that the antiandrogenic activity of p, p -DDE may mitigateharmful androgen effects on the ovary during gestation or early life.Correspondence to: Dr Barbara A Cohn
Neurological Impacts
1) Eskenazi B, Marks AR, Bradman A, Fenster L, Johnson C, Barr DB,Jewell NP In Utero Exposure to Dichlorodiphenyltrichloroethane (DDT)and Dichlorodiphenyldichloroethylene (DDE) and Neurodevelopment amongYoung Mexican American Children Pediatrics 2006 118: 233-24.
PANNA Summary: This study examines the amounts of DDT and DDE inmother’s serum after delivery, and looks for associations between theselevels and the infants’ development using a standard development scale.The results show a relationship between lower psychomotor developmentscores and increased DDT in the mothers’ serum. The population studiedwas Mexican American farm-workers and their children in California.
Abstract: Objective: We investigated the relationship between prenatal exposure todichlorodiphenyltrichloroethane (DDT) anddichlorodiphenyldichloroethylene (DDE) and neurodevelopment of Mexicanfarm-workers’ children in California.
Methods: Participants from the Center for the Health Assessment of Mothers andChildren of Salinas study, a birth cohort study, included 360singletons with maternal serum measures of p,p_-DDT, o,p_-DDT, andp,p_-DDE. Psychomotor development and mental development were assessedwith the Bayley Scales of Infant Development at 6, 12, and 24 months.
Results:We found a _2-point decrease in Psychomotor Developmental Index scoreswith each 10-fold increase in p,p_-DDT levels at 6 and 12 months (butnot 24 months) and p,p_-DDE levels at 6 months only. We found noassociation with mental development at 6 months but a 2- to 3-pointdecrease in Mental Developmental Index scores for p,p-DDT and o,p-DDTat 12 and 24 months, corresponding to 7- to 10-point decreases acrossthe exposure range. Even when mothers had substantial exposure,breastfeeding was usually associated positively with Bayley scalescores.
Conclusions:Prenatal exposure to DDT, and to a lesser extent DDE, was associatedwith neurodevelopmental delays during early childhood, althoughbreastfeeding was found to be beneficial even among women with highlevels of exposure. Countries considering the use of DDT should weighits benefit in eradicating malaria against the negative associationsfound in this first report on DDT and human neurodevelopment.
2) Ribas-Fito N, Torrent M, Carrizo D, Munoz-Ortiz L, Julvez, J,Grimalt, JO, Sunyer, J In Utero Exposure to Background Concentrationsof DDT and Cognitive Functioning among Preschoolers. American Journalof Epidemiology 2006 164(10): 955-962
PANNA Summary: Exposure to DDT occurs both in utero and because of itslipophilicity, via breastfeeding. While animal studies have indicatedeffects on brain growth due to DDT exposure, neurodevelopment in humanis less documented. A study in 2005 reported higher concentrations ofDDE in newborns in Menorca, Spain, than in the Ribera d’Ebre cohort.This study is a follow up to the previous 2005 study to assess theassociation of cord serum levels of DDE and DDT with neurodevelopmentat age 4 years. The results indicated that prenatal exposure to lowlevel, concentrations of DDT and DDE at birth is associated with adecrease in verbal, memory, and quantitative and perceptual performanceskills among preschoolers. Hence, the author suggests that even thoughDDT is considered to be useful in malarial control, the evidence of itsadverse effects on health requires for appropriate research on itsbenefits versus its risks.
Abstract: p,p'-DDT (bis[p-chlorophenyl]-1,1,1-trichloroethane) is apersistent organochlorine compound that has been used worldwide as aninsecticide. The authors evaluated the association of cord serum levelsof DDT and its metabolite, 2, 2-bis (p-chlorophenyl)-1,1-dichloroethylene (DDE), with neurodevelopment at age 4 years. Twobirth cohorts in Ribera d'Ebre and Menorca (Spain) were recruitedbetween 1997 and 1999 (n=475). Infants were assessed at age 4 years byusing the McCarthy Scales of Children's Abilities. Organochlorinecompounds were measured in cord serum. Children's diet and parentalsociodemographic information was obtained through questionnaire.Results showed that DDT cord serum concentration at birth was inverselyassociated with verbal, memory, quantitative, andperceptual-performance skills at age 4 years. Children whose DDTconcentrations in cord serum were >0.20 ng/ml had mean decreases of7.86 (standard error, 3.21) points in the verbal scale and 10.86(standard error, 4.33) points in the memory scale when compared withchildren whose concentrations were <0.05 ng/ml. These associationswere stronger among girls. Prenatal exposure to background, low-levelconcentrations of DDT was associated with a decrease in preschoolers'cognitive skills. These results should be considered when evaluatingthe risk and benefits of spraying DDT during antimalaria and otherdisease-vector campaigns. (Dr. Nu´ ria Ribas-Fito´, Respiratory andEnvironmental Health Research Unit, IMIM, C. Doctor Aiguader 80, 08003Barcelona, Catalonia, Spain (e-mail: nribas@imim.es)
3) Sinha C, Seth K, Islam F, Chaturvedi RK, Shukla S, Mathur N,Srivastava N, Agrawal AK. Behavioral and neurochemical effects inducedby pyrethroid-based mosquito repellent exposure in rat offspringsduring prenatal and early postnatal period. Neurotoxicol Teratol. 20064: 472-81.
PANNA Summary: Studies have shown that newborn babies, pregnant andlactating mothers are more prone to toxics when exposed to pyrethroidsused as mosquito repellants since they stay for longer durations insidethe house. This pilot study found that prenatal, postnatal andperinatal exposure to pyrethroid-based Mosquito repellants could alterblood brain barrier permeability. Developing Central Nervous System hasbeen considered to be vulnerable to oxidative damagebrain region ascompared to other brain regions. The rat pups exposed to mosquitorepellants clearly indicated significant involvement of thehippocampus. Overall, the study claims to stress on the effect ofpyerethroid based repellants on the neurochemical and behavioraleffects and implies that pregnant women and infants may be greatlyoffset by the benefits of the protection of repellants if the result onrats are indicative of their effects.
Abstract: Synthetic pyrethroids, besides their use in agriculture,are prevalently used in our houses as mosquito repellent (MR) in theform of aerosol, mats, coils and liquid vaporizers. Inhalation of fumesof the MR/liquid vaporizers may get entry into the brain by breachingthe developing blood-brain barrier, hence deleterious to developingnervous system and can lead to long-term functional deficits. In thepresent study the consequence of MR exposure has further beeninvestigated at various stages of development, evaluating free radicalmediated effect pertinent to neurobehavioral and neurochemicalfunctioning. Rat pups were exposed to pyrethroid-based MR (allethrin3.6% w/v, 8 h/day through inhalation) during prenatal (GD1-20),postnatal (PND1-30) and perinatal (GD1-PND30) period of development andassessments were made on PND31. We observed significant oxidativestress, where an increase in lipid peroxidation and a decrease inantioxidants, glutathione, superoxide dismutase and catalase in variousbrain areas (cerebellum, corpus striatum, frontal cortex andhippocampus) were evident at all the exposure schedules. Thehippocampus was the most affected region and further exhibited alteredcholinergic functioning in the form of significant decrease incholinergic (muscarinic) receptor binding (prenatal 32%, postnatal 35%,perinatal 38%) and inhibition in acetylcholinesterase activity(prenatal 20%, postnatal 31% and perinatal 33%). The neurochemicalchanges were found to accompany decrease in learning and memoryperformance in exposed rats, the function governed by hippocampus. Theresult suggests that pyrethroid-based MR inhalation during earlydevelopmental period may have adverse effect on developing nervoussystem causing cholinergic dysfunction leading to learning and memorydeficit. (Developmental Toxicology Division, Industrial ToxicologyResearch Centre, Post Box-80, M.G. Marg Lucknow 226001, India. E-mailaddress: aka33@rediffmail.com (A.K. Agrawal)
4) van Wendel de Joode B, Wesseling C, Kromhout H, Monge P, GarciaM, Mergler D. Chronic nervous system effects of long-term occupationalexposure to DDT. Lancet 2001 Mar 31; 357(9261): 1014-16.
PANNA summary: This study found that retired malaria-control workerswho had worked spraying DDT did worse on tests of neurobehavioralfunctions than control groups, and that the longer they had worked withDDT, the poorer the test results. These results indicate that long-termexposure to DDT is measurably harmful.
Abstract: Dichlorodiphenyltrichloroethane (DDT) is a compound withmoderate toxicity that is judged to be safe for occupational use,although little is known about its long-term effects on the humannervous system. We investigated chronic nervous-system effects oflong-term occupational exposure to DDT by comparing the neurobehavioralperformance of retired malaria-control workers with a reference groupof retired guards and drivers. DDT-exposed workers did worse on testsassessing various neurobehavioral functions than controls; performancesignificantly deteriorated with increasing years of DDT application.Our results could not be explained by exposure tocholinesterase-inhibiting pesticides or other potential confoundingfactors.
Serum Levels and Other Health Impacts
1) McGlynn, KA, Quraishi, SM, Graubard, BI, Weber, JP, Rubertone MV, Erickson, RL. Persistent Organochlorine Pesticides and Risk of Testicular Germ Cell Tumors. Journal of the National Cancer institute May 2008 100: 603.
PANNA Summary: Exposure to DDT and other organochlorine pesticides has been suggested to cause a risk of testicular germ cell tumors. The authors tested serum and found that an increased exposure to DDE, a breakdown of DDT, may be associated with the risk of developing testicular germ cell tumors, especially during fetal life or from breastmilk.
Abstract: Background: Exposure to endocrine-disrupting chemicals, such as persistent organochlorine pesticides, has been suggested to increase the risk of testicular germ cell tumors (TGCTs).
Methods: To study the relationship of POP exposure to TGCT risk, prediagnostic serum samples from 754 case subjects and 928 control subjects enrolled in the Servicemen’s Testicular Tumor Environmental and Endocrine Determinants Study were analyzed for cis-nonachlor, trans-nonachlor, oxychlordane, total chlordanes, β-hexachlorocyclohexane, mirex, p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE), and p,p'-dichlorodiphenyltrichloroethane. Adjusted odds ratios (ORs) and their associated 95% confidence intervals (CIs) for the risk of TGCT overall and for the histological subgroups, seminoma and nonseminoma, were estimated using multivariable logistic regression. All statistical tests were two-sided.
Results: TGCT risk was statistically significantly associated with higher plasma levels of p,p'-DDE (for highest quartile [Q4] vs lowest quartile [Q1], OR = 1.71, 95% CI = 1.23 to 2.38, Ptrend = .0002) and of two chlordane components, cis-nonachlor (Q4 vs Q1, OR = 1.56, 95% CI = 1.11 to 2.18, Ptrend = .009) and trans-nonachlor (Q4 vs Q1, OR = 1.46, 95% CI = 1.07 to 2.00, Ptrend = .026). Seminoma risk was statistically significantly associated with p,p'-DDE (Q4 vs Q1, OR = 1.91, 95% CI = 1.22 to 2.99, Ptrend = .0008), cis-nonachlor (Q4 vs Q1, OR = 1.93, 95% CI = 1.27 to 2.93, Ptrend = .0045), trans-nonachlor (Q4 vs Q1, OR = 1.72, 95% CI = 1.11 to 2.67, Ptrend = .033), and a chlordane metabolite, oxychlordane (Q4 vs Q1, OR = 1.64, 95% CI = 1.04 to 2.60, Ptrend = .048), whereas nonseminoma risk showed a statistically significant association with p,p'-DDE only (Q4 vs Q1, OR = 1.63, 95% CI = 1.10 to 2.42, Ptrend = .0044).
Conclusions: Increased exposure to p,p'-DDE may be associated with the risk of both seminomatous and nonseminomatous TGCTs, whereas exposure to chlordane compounds and metabolites may be associated with the risk of seminoma. Because evidence suggests that TGCT is initiated in very early life, it is possible that exposure to these persistent organic pesticides during fetal life or via breast feeding may increase the risk of TGCT in young men.
2) Julia Green Brody, PhD , Kirsten B. Moysich, PhD, Olivier Humblet,MS, Kathleen R. Attfield, BS, Gregory P. Beehler, MA, Ruthann A. Rudel,MS Environmental pollutants and breast cancer Cancer 2007 109(S12):2667-2711
PANNA Summary: After analyzing the research already done onenvironmental pollutants and breast cancer, the authors conclude thatmore research measuring toxicity needs to be done. They also suggestthe development of better methods to measure exposure to toxicpollutants. Progress has been made in the last five years.
Abstract: Laboratory research has shown that numerous environmentalpollutants cause mammary gland tumors in animals; are hormonallyactive, specifically mimicking estrogen, which is a breast cancer riskfactor; or affect susceptibility of the mammary gland tocarcinogenesis. An assessment of epidemiologic research on thesepollutants identified in toxicologic studies can guide future researchand exposure reduction aimed at prevention. The PubMed database wassearched for relevant literature and systematic critical reviews wereentered in a database available at URL:www.silentspring.org/sciencereview and URL: www.komen.org/environment(accessed April 10, 2007). Based on a relatively small number ofstudies, the evidence to date generally supports an association betweenbreast cancer and polycyclic aromatic hydrocarbons (PAHs) andpolychlorinated biphenyls (PCBs) in conjunction with certain geneticpolymorphisms involved in carcinogen activation and steroid hormonemetabolism. Evidence regarding dioxins and organic solvents is sparseand methodologically limited but suggestive of an association.Methodologic problems include inadequate exposure assessment, a lack ofaccess to highly exposed and unexposed populations, and a lack ofpreclinical markers to identify associations that may be obscured bydisease latency. Among chemicals identified in toxicologic research asrelevant to breast cancer, many have not been investigated in humans.The development of better exposure assessment methods is needed to fillthis gap. In the interim, weaknesses in the epidemiologic literatureargue for greater reliance on toxicologic studies to develop nationalpolicies to reduce chemical exposures that may be associated withbreast cancer. Substantial research progress in the last 5 yearssuggests that the investigation of environmental pollutants will leadto strategies to reduce breast cancer risk. Cancer 2007. © 2007American Cancer Society. 1Silent Spring Institute, Newton,Massachusetts 2Department of Epidemiology, Roswell Park CancerInstitute, Buffalo, New York email: Julia Green Brodybrody@silentspring.org Correspondence to Julia Green Brody, SilentSpring Institute, 29 Crafts Street, Newton, MA 02458 Fax: (617) 332-4284
3) Cohn, BA, MS Wolff, PM Cirillo and RI Sholtz. DDT and breast cancerin young women: New data on the significance of age at exposureEnvironmental Health Perspectives 2007 115(10): 1406-1414.
PANNA Summary: The authors compared DDT in blood from women in Oakland,California taken between 1959-1967 and breast cancer in the same womenyears later. Women with high percentages of DDT in their blood werefive times more likely to have breast cancer.
Abstract: Background
Prior studies of DDT and breast cancer assessed exposure later in lifewhen the breast may not have been vulnerable, after most DDT had beeneliminated, and after DDT had been banned.
Objectives
Investigate whether DDT exposure in young women during peak DDT use predicts breast cancer.
Methods
We conducted a prospective, nested case-control study with a mediantime to diagnosis of 17 years using blood samples obtained from youngwomen from 1959-1967. Subjects were members of the Child Health andDevelopment Studies, Oakland, California, who provided blood samples 1to 3 days after giving birth (mean age 26 years). Cases (n=129)developed breast cancer before age 50 years. Controls (n=129) werematched to cases on birth year. Serum was assayed for p,p’-DDT, theactive ingredient of DDT, o,p’-DDT a low concentration contaminant, andp,p’-DDE, the most abundant p,p’-DDT metabolite.
Results
High levels of serum p,p’-DDT predicted a statistically significantfive-fold increased risk of breast cancer among women who were bornafter 1931. These women were under age 14 in 1945, when DDT came intowidespread use and mostly under age 20 as DDT use peaked. Women whowere not exposed to p,p’-DDT before age 14 showed no associationbetween p,p’-DDT and breast cancer (p=0.02 for difference by age).
Conclusions
Exposure to p,p’-DDT early in life may increase breast cancer risk.Many U.S. women heavily exposed to DDT in childhood have not yetreached age 50. The public health significance of DDT exposure in earlylife may be large.
Full text: http://www.ehponline.org/docs/2007/10260/abstract.html
4) McGlynn KA , Abnet CC , Zhang M, Sun XD, Fan JH, O’Brien TR, Wei WQ, Ortiz-Conde BA, Dawsey SM, Weber JP, Taylor PR, Katki H, Mark SD, Qiao YL SerumConcentrations of 1,1,1-Trichloro-2,2-bis (p-chlorophenyl)ethane (DDT)and 1,1-Dichloro-2,2-bis (p-chlorophenyl)ethylene (DDE) and Risk ofPrimary Liver Cancer. Journal of the National Cancer Institute 200698(14): 1005-1010.
PANNA Summary: Primary liver cancer is the sixth most common cancer inthe world. In China, DDT was banned for agricultural use in1983 butcontinues to produce for the manufacture of dicofol, a nonsystemicacaricide, for use in residential spraying in antimalarial campaigns.The dominant type of cancer in China too is hepatocellular carcinoma.This study thus studies the risk of liver cancer in Linxian, Chinawhich has a comparatively low incidence of cancer. The results of thisstudy indicated that there was a high risk of liver cancer inassociation with high levels of DDT. Animal studies have shown that DDThas a detrimental effect on the nervous system as well as the liver.Also, animal studies have found that undernourished animals have acloser association between liver cancer and DDT. Lixian population isalso poorly nourished. Hence it is possible that DDT is particularlycarcinogenic in humans who suffer from malnutrition. While the studydoes have several limitations, the findings do indicate that DDTexposure may be a risk factor for liver cancer in humans directlyexposed to DDT.
Abstract: Background
1,1,1-Trichloro-2,2-bis( p -chlorophenyl)ethane (DDT) exposure has beendemonstrated to cause liver tumors in laboratory rodents. DDT’spersistent metabolite and environmental degradation product,1,1-dichloro-2,2-bis( p -chlorophenyl)ethylene (DDE), has also beenassociated with liver tumors in laboratory animals. Whether DDT and DDEare associated with hepatocarcinogenesis in humans is not clear.
Methods
We carried out a nested case – control study among the participants ofthe Nutritional Intervention Trials in Linxian, China. The case groupincluded 168 individuals who developed liver cancer during the trials,and the control group included 385 individuals frequency-matched on ageand sex who were alive and well at the end of the study. Serumconcentrations of DDT and DDE were measured by gas chromatography –mass spectrometry. Odds ratios (ORs) and 95% confidence intervals (CIs)were calculated using multivariable analysis.
Results
In multivariable adjusted models, the risk of developing liver cancerincreased with increased serum DDT concentration (OR for quintile 1versus quintile 5 = 3.8, 95% CI = 1.7 to 8.6, P trend = .0024). Incontrast, there was no statistically signifi cant association betweenliver cancer and serum DDE concentration. The association between highserum DDT concentration and liver cancer was stronger among individualswith DDE concentrations below the median value (odds ratio for tertile3 versus tertile 1 = 3.55, 95% CI = 1.45 to 8.74) than those withconcentrations above the median (OR = 1.70, 95% CI = 0.97 to 2.98). Acalculation of crude liver cancer risk found that there would be 26liver cancers per 100 000 persons per year in the lowest quintile ofDDT exposure versus 46 liver cancers per 100 000 persons per year inthe highest quintile of DDT exposure.
Conclusions
DDT may be a risk factor for liver cancer, particularly among personswith lower DDE concentrations. Risk may be particularly increased amongpersons exposed directly to DDT resulting in a higher ratio of DDT toDDE) or, alternatively, risk may be associated with individual abilityto metabolize DDT to DDE.
5) Aimin, C. and W.J. Rogan. Health risks and benefits of bis(4-chlorophenyl)-1,1,1trichloroethane (DDT). US National Institute ofEnvironmental Health Sciences. Lancet 2005; 366: 763–73
PANNA summary: This article traces the health impacts and effectivenessor lack of effectiveness for countries continuing to use DDT formalaria control after its inclusion in the Stockholm Convention list ofchemicals targeted for a global ban in 2001. Due to a lack ofcontrolled testing and conflicting or inconclusive data it wasimpossible to determine the specific negative health effects of DDT.The authors call for more research to determine if the health risksoutweigh the health benefits.
Abstract: DDT (bis[4-chlorophenyl]-1,1,1-trichloroethane) is apersistent insecticide that was used worldwide from the mid-1940s untilits ban in the USA and other countries in the 1970s. When a global banon DDT was proposed in 2001, several countries in sub-Saharan Africaclaimed that DDT was still needed as a cheap and effective means forvector control. Although DDT is generally not toxic to human beings andwas banned mainly for ecological reasons, subsequent research has shownthat exposure to DDT at amounts that would be needed in malaria controlmight cause preterm birth and early weaning, abrogating the benefit ofreducing infant mortality from malaria. Historically, DDT has had mixedsuccess in Africa ; only the countries that are able to find and devotesubstantial resources towards malaria control have made major advances.DDT might be useful in controlling malaria, but the evidence of itsadverse effects on human health needs appropriate research on whetherit achieves a favourable balance of risk versus benefit. (EpidemiologyBranch, USNational Institute of Environmental Health Sciences, P O Box12233, Research Triangle Park, NC 27709, USA. rogan@niehs.nih.gov)
6) Toxicological Profile for DDT, DDE, and DDD. Prepared by SyracuseResearch Corporation for US Department of Health and Human Services,Public Health Service, Agency for Toxic Substances and DiseaseRegistry. September 2002. http://www.atsdr.cdc.gov/toxprofiles/tp35.html
PANNA summary: This report is concerned solely with DDT in the USA, sothere is very little attention paid to malaria or DDT’s use for vectorcontrol. The profile provides clear explanations of why DDT is still inthe U.S. environment when it was banned for use in this country in1972, how it persists in the soil and water, and how it moves from oneplace to another. The report cites many possible dangers of the toxinto public health. Health effects cited in this report include: nervoussystem effects, changes in liver enzymes, and “harmful effects” onreproduction and adrenal gland function. EPA has classified DDT and itsmetabolites as probable human carcinogens, though this report says thatthere is no evidence of increased cancer risk in humans.
(no abstract available)
7) Longnecker, M. P., M. A. Klebanoff, H. Zhou, J. W. Brock.Association between maternal serum concentration of the DDT metaboliteDDE and pre-term and small-for-gestational-age babies at birth. TheLancet 2001; 358: 110-114.
PANNA summary: This 2001 landmark study by the National Institute ofEnvironmental Health Sciences and three other organizations found astrong relationship between prematurely delivered and low birth weightbabies and mothers' blood levels of DDE, the metabolic breakdownproduct of DDT. The study took its data from children born between theyears 1959 and 1966, a time when DDT was still being used in the UnitedStates and so average blood levels of DDE were much higher than theyare in the U.S. today, but still lower than what they are in othercountries where DDT is still being used to control malaria. Theresearchers conclude that the ties between premature birth rates, amajor factor in infant mortality, and blood levels of DDE should leadto the reassessment of the costs and benefits of DDT-based malariacontrol strategies around the world.
Abstract: DDT (1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane) ishighly effective against most malaria-transmitting mosquitoes and isbeing widely used in malaria-endemic areas. The metabolite, DDE(1,1-dichloro-2,2-bis (p-chlorophenyl) ethylene), has been linked topre-term birth in small studies, but these findings are inconclusive.Our aim was to investigate the association between DDE exposure andpre-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 44,000eligible children born between 1959 and 1966 and measured the DDEconcentration in their mothers' serum samples stored during pregnancy.Complete data were available for 2,380 children, of whom 361 were bornpre-term and 221 were small-for-gestational age.
Findings The median maternal DDE concentration was 25 µg/L (range3-178)--several fold higher than current US concentrations. Theadjusted odds ratios (OR) of pre-term birth increased steadily withincreasing 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 alsoincreased, but less consistently (ORs=1, 1·9, 1·7, 1·6, 2·6; trendp=0·04). After excluding pre-term births, the association of DDE withsmall-for-gestational-age remained.
Interpretation The findings strongly suggest that DDT use increasespre-term births, which is a major contributor to infant mortality. Ifthis association is causal, it should be included in any assessment ofthe costs and benefits of vector control with DDT.
8) Longnecker, MP, MA Klebanoff, JW Brock, H Zhou, KA Gray, LLNeedham and AJ Wilcox. Maternal serum level of 1,1-Dichloro-2,2-bis(p-chlorophenyl) ethylene and risk of cryptorchidism, hypospadias, andpolythelia among male offspring. American Journal of Epidemiology Vol.155, No. 4 : 313-322.
PANNA summary: In light of recent findings that the metabolic byproductof DDT, DDE, blocks receptors for androgens (male hormones) in rats,scientists undertook this study to see if there is some similar effectin humans. They looked at data for mothers' blood levels of DDE (seearticle #1) and the frequency of birth defects in male babies from thesame set of children born between 1959 and 1966. They found thatelevated DDE levels in the mother's blood serum correlated withincreased incidence of undescended testicles, penis abnormalities, andextra nipples in male children.
Abstract: 1,1-Dichloro-2,2-bis (p-chlorophenyl) ethylene (p,p'-DDE) isa metabolite of the insecticide 2,2-bis (p-chlorophenyl)-1,1,1-trichloroethane (DDT) and is a ubiquitous environmentalcontaminant. Nearly everyone in the United States has a detectableserum level of DDE. DDE was recently found to inhibit binding ofandrogen to its receptor and to block androgen action in rodents.Normal development of male genitalia in mammals depends on androgenaction. The authors used stored serum samples to examine the relationbetween maternal DDE levels during pregnancy and adjusted odds ofcryptorchidism (n = 219), hypospadias (n = 199), and polythelia (extranipples) (n = 167) among male offspring, using a nested case-controldesign with one control group (n = 552). Subjects were selected fromthe Collaborative Perinatal Project, a US birth cohort study begun in1959-1966, when DDE levels were much higher than they are at present.Compared with boys whose mother's recovery-adjusted serum DDE level wasless than 21.4 microg/liter, boys with maternal levels greater than orequal 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 amodest-to-moderate association, but in no instance was the estimatevery precise. The results were inconclusive. (Epidemiology Branch,National Institute of Environmental Health Sciences, Research TrianglePark, NC 27709, USA. longnecker@niehs.nih.gov)
9) Bouwman, H., P. J. Becker, and C. H. J. Schutte. Malaria Controland Longitudinal Changes in Levels of DDT and Its Metabolites in HumanSerum from KwaZulu. Bulletin of the World Health Organization. 1994;72(6): 921-30.
PANNA Summary: Based on previous research, the authors propose thatuptake and elimination, two coexisting processes, control the changesin serum levels of DDT and its metabolites; and that these twoprocesses switch with age. To confirm this, the authors compared therates of change in addition to the change in levels. They found anincrease in DDT metabolites for the older group (=21 years) and adecrease in serum levels for the younger group (3 to 20 years) over a12-month period. Their data indicate that DDT levels increased fasterin the older group than in the younger group, and that there is a morerapid 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 inadults.
Abstract: Blood samples were obtained on four occasions over a 12-monthperiod from individuals living in KwaZulu , South Africa , who had beenexposed to DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) as aconsequence of its use in their homes to control transmission ofmalaria. The longitudinal changes in serum DDT and its majormetabolities, DDE and DDD, were determined. No additional risk wasconsidered to have been presented by the increases that occurredfollowing application of the pesticide. There were significantincreases in DDT, DDE and ?DDT (DDT + its metabolites) for the agegroup =21 years, but for the age group 3-20 years a reduction in serumlevels occurred over 12 months. Two concurrent processes probablygovern the increase and decrease in serum levels, and the relativecontributions of each interchange as the individual becomes older. Theresults suggest that children in KwaZulu experience conditions thatdiffer from those of their parents, as well as from those that affectchildren in developed countries. In consequence, it is desirable thatrisk assessments of vector control chemicals consider all sectors of apopulation. (Department of Zoology, Potchefstroom University forChristian Higher Education, South Africa.)
10) Bouwman, H., and C. H. J. Schutte. Effects of Sibship on DDT ResidueLevels 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 itsmetabolites of siblings in eight homesteads. The authors conclude thatthere is a strong correlation between siblings under malaria controlconditions and serum levels of DDT. They recommend that children alwaysbe included in environmental exposure studies and that separate riskassessments be done, since the young experience different environmentalcircumstances and are especially vulnerable during development.
(no abstract available)
11) Bouwman, H. DDT levels in serum, breast-milk and infants in variouspopulations in malaria and non-malaria controlled areas of KwaZulu.Medical Research Council. 1991:1-38.
Abstract: The World Health Organization (WHO) considers1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) safe to man and theenvironment when applied intra-domiciliary for malaria control.Research into the possible health effects under prevailing conditionsand taking social customs into account, have, however, been lacking.This study was undertaken to determine levels of DDT in serum andbreast-milk and possible risks posed by the insecticide to the healthof 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 theserum of members of families from a sprayed and a non-sprayed area, aswell as changes caused by indoor application of DDT; (2) To determinethe levels of DDT and its metabolites in the breast-milk of mothersfrom a sprayed and a non-sprayed area, as well as changes caused byindoor application of DDT; (3) To determine the uptake of DDT and itsmetabolites by the infant via breast-milk, and to develop a statisticalmodel that describes the dynamics; and (4) To determine the risk to thehealth of mother and infant posed by exposure to DDT and itsmetabolites.
12) Bouwman, H.; Cooppan, R. M.; Botha, M. J., and Becker, P. J.Serum levels of DDT and liver function of malaria control personnel. SAfr Med J. 1991; 79(6):326-329. ISSN: 0038-2469.
PANNA summary: This study found that blood levels of DDT and itsmetabolites are higher in people who work as DDT sprayers than for thegeneral population in KwaZulu, South Africa, where DDT is used formalaria control. Possible health risks to the sprayers from theseelevated levels, including evidence of reduced liver function, wereidentified.
Abstract: The levels of DDT and metabolites in serum of 23 applicatorsinvolved in malaria control operations in Natal were determined usinggas chromatography with electron capture detection. The mean levels(microgram/l, ppb) were 61.7 DDT, 129.3 DDE, 11.0 DDD and 202.0 sigmaDDT. Percentage DDT was 33.4%. These levels were higher than for an agematched sample of the general population in KwaZulu, who are protectedby DDT against malaria. Percentage DDT correlated negatively with age(P less than 0.05) for the applicators, suggesting a change inpharmacodynamics with age. Mean serum albumin, alkaline phosphatase,aspartate transferase and gamma-glutamyltransferase (GGT) levels didnot differ significantly from an age-matched control group, but themean GGT value for the applicators was higher than the maximum of thelaboratory normal range. Although not clinically significant, thealanine transferase was significantly higher in the applicators than inthe control group. These higher levels suggest a possible risk to thehealth of the sprayers, but uncertainties remain. (Research Institutefor Environmental Diseases of the South African Medical ResearchCouncil, Pretoria.)
13) Bouwman, H., R. M. Cooppan, P. J. Becker, et al. Malaria Controland Levels of DDT in Serum of Two Populations in KwaZulu. Journal ofToxicology and Environmental Health. 1991; 33(3): 141-55.
PANNA Summary: The authors established that the average level of DDTand its metabolites was higher in the population exposed to in-houseDDT application for malaria control than in the control group. Theresearchers also discovered that the levels of DDT and its metabolitesdecreased between the ages of three and twenty-nine years, yetfollowing age twenty-nine, the levels began to increase again. Based onthese results, the authors suggest that different processes govern DDTdynamics with relation to age. They also tested liver function andfound that, although DDT metabolite levels correlate with levels of theliver protein, alcohol consumption better predicted liver proteinlevels. Thus, the authors conclude that “DDT as used for malariacontrol does not adversely affect the liver function.”
Abstract: Concentrations of p,p'-DDT, p,p'-DDE, and p,p'-DDD weredetermined in serum of members of households of two different areas ofKwaZulu. Annual intradomiciliary application of DDT is used for theinterruption of malaria transmission in one area (the exposed group)while the other served as the control. Demographic differences betweenthe two groups resulted in significantly more females in the controlgroup. The two groups were comparable with respect to age. Serum fromhousehold members living in DDT-treated dwellings had significantlyhigher (p < .005) levels of ?DDT and metabolites (mean ?DDT 140.9µg/l) than those from the control area (mean ?DDT 6.04 µg/l).Percentage DDT was also significantly higher (p < .05) in theexposed group (28.9%) than the control group (8.3%). ?DDT for the 3-10yr age interval (168.6 µg/l) was significantly higher (p < .05) thanthe 20-29 (60.5 µg/l) and 30-39 (84.2 µg/l) yr age intervals. Thereseemed to be two groups with regard to accumulation and elimination.The age group 3-29 appeared to be eliminating DDT, most likelyaccumulated from contaminated breast milk, faster than they accumulatedit. From around 29 yr of age accumulation predominated as the levelsincreased with age. Regression analysis suggested pharmacokineticdifferences for DDE and DDT between the two groups. Liver functionparameters between the two groups only differed significantly forgamma-glutamyl transferase (g GT) (p < .005), but the influence ofdifference in alcohol consumption, which was significantly higher inthe exposed group (p < .0001), offered a better explanation. Thoseof 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 (20.2IU/l), but were not significantly different for DDT (p > .05). Thesafety of DDT used in malaria control for subjects aged 3 and older wasconfirmed by the levels of DDT in serum when compared with otherstudies, which showed lack of any negative effects associated withthese levels in adults, and an apparently normal liver function in theexposed and control groups. (Research Institute for EnvironmentalDiseases, Medical Research Council, Pretoria, Republic of South Africa.)
Environmental Impacts
1) Geisz, HN, Dickhut, RM, Cochran, MA, Fraser, WR, Ducklow HW. Melting Glaciers: A Probable Source of DDT to the Antarctic Marine Ecosystem, Environmental Science and Technology
PANNA Summary: Researchers found DDE and DDT in penguins confined to an island in the Antarctic. They continue to find DDT in the penguins over the last thirty years, which means there is continued exposure. The scientists believe the melting glaciers are releasing DDT and the penguins are continually exposed through the meltwater.
Abstract: Persistent organic pollutants reach polar regions by longrange tmospheric transport and biomagnify through the food
web accumulating in higher trophic level predators. We analyzedAde´lie penguin (Pygoscelis adeliae) samples collected
from 2004 to 2006 to evaluate current levels of ΣDDT (p,p′-DDT+p,p′-DDE) in these birds, which are confined to Antarctica.
Ratios of p,p′-DDT to p,p′-DDE in Ade´lie penguins have declined significantly since 1964 indicating current exposure
to old rather than new sources of ΣDDT. However, ΣDDT has not declined in Ade´lie penguins from the Western Antarctic
Peninsula for more than 30 years and the presence of p,p′- DDT in these birds indicates that there is a current source of DDT
to the Antarctic marine food web. DDT has been banned or severely restricted since peak use in the 1970s, implicating glacier
meltwater as a likely source for DDT contamination in coastal Antarctic seas. Our estimates indicate that 1-4
kg · y-1 ΣDDT are currently being released into coastal waters along the Western Antarctic Ice Sheet due to glacier ablation.
2) 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 inTorrance, California flushed more than 100 tons of DDT into the countysewer system, where it ran into the Pacific Ocean near the cliffs ofPalos Verdes. DDT remains on the ocean floor and is the nation'sdeepest and largest Superfund site. DDT levels in the bodies of fishcaught in this area and sold in Los Angeles are much higher thangovernment safety standards. EPA is filing suit against MontroseChemical to pay for the cost of cleaning up and restoring the watersoff Palos Verdes.
(no abstract available)
3) Douthwaite, R J, ed. DDT in the Tropics: The impact on wildlife inZimbabwe of ground-spraying for tsetse fly control. Canterbury, UK: R JDouthwaite 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 forInternational Development looking at the recovery of local wildlifeknown to have been affected after DDT spraying for tsetse fly controlin northwestern Zimbabwe 10 years earlier. The author argues that DDThas had relatively little impact on wildlife populations in the areacompared with the widespread woodland destruction by immigrant farmersand elephants. Deltamethrin, a synthetic pyrethroid that would perhapshave less impact on wildlife, has been used successfully for groundspraying instead of DDT, but it still costs too much to make it aviable solution. This report aims to inform use of DDT for tsetse flycontrol under the new POPs treaty that allows for limited use forvector control.
(no abstract available)
4) Wiktelius, S and CA Edwards. Organochlorine Insecticide Residues inAfrican Fauna: 1971-1995. Review of Environmental Contamination andToxicology 151: 1-37.
PANNA summary: Traces the use of organochlorine insecticides (includingDDT) in Africa and the levels of organochlorines subsequently found inthe tissues of terrestrial and aquatic animals. The authors found thatlevels, especially of DDT and diedrin, were "high enough to haveconsiderable potential for chronic toxicity, for causing behavioralchanges, or even for killing wild animals, particularly fish and birdsand possibly crocodiles." The author warns against possible long-termpopulation effects on the fauna of Africa if the use of organochlorinesis not restricted.
Abstract: Organochlorine insecticides (OCLs), which were introduced inthe decade following World War II, were used extensively in Europe, theU.S., and other developed countries into the 1970s. However, data beganto accumulate on their persistence in soils and aquatic sediments,their potential to be taken up into animal tissues and tobioconcentrate in birds and mammals in the higher tropic levels of foodchains and even in humans. As a result, registration authorities phasedout their use progressively, in Europe and the U.S., from 1973 onward.However, the production of OCLs in developed countries and their use indeveloping countries continued through the 1970s and 1980s into the1990s because they were no longer under patent agreement, wereinexpensive to manufacture, and were very effective in pest control. InAfrica, the use of OCLs continued well into the 1990s for the controlof mosquitoes, tsetse flies, and desert locusts as well as to combatvarious crop, animal, and human pests. Some of these uses involvedextensive spraying of large areas of nonagricultural land, therebyexposing many groups and species of wildlife to their residues.Although there is some evidence of a gradual decline in the use of OCLsin Africa, they are still being used in appreciable quantities. Duringthe past 25 years, there have been 50 published reports of OCL residuesin the various groups of invertebrate and vertebrate animalsconstituting the African fauna. These have been based on a diverserange of surveys, target animals, sampling methods, and analyticaltechniques. Moreover, they are extremely regionally-biased, the mostintense surveys being in Zimbabwe, Kenya, Egypt, and South Africa. DDTwas the most commonly used OCL, accounting for about half the totaluse, followed closely by dieldrin and HCH. Birds and fish have beensampled most intensively, with relatively few studies on other taxa. Wereviewed the OCL residue data on African fauna from these reports andsummarized the maximum and mean residues in the various groups ofterrestrial and aquatic invertebrates and vertebrates. Overall,residues in the fauna were the greatest for DDT, followed in turn bythose of dieldrin, HCH, endosulfan, and endrin, with small amounts ofaldrin and toxaphene being found in some animals. There were relativelyfew reports of OCL residues in terrestrial invertebrates and virtuallynone in aquatic invertebrates. Only a few reports demonstrated OCLresidues in terrestrial vertebrates, although high levels of DDT,dieldrin, and HCH were found in crocodile eggs and large residues ofdieldrin occurred in bats, squirrels, and monkeys. Considerable OCLresidues 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 toxicityor behavioral changes. The calculated maximum and mean OCL residues inthe various elements of the African fauna until 1995 were compared withthose calculated for corresponding faunal groups in Europe and the U.S.from their development and introduction up to 1973. The OCL residuesreported in African fauna between 1971 and 1975 tended to besignificantly higher overall than those published for Europe and theU.S. In particular, residues of DDT and dieldrin in African birds andtheir eggs were greater than those that had been incriminated ascausing significant eggshell thinning and reproductive failure inEuropean and U.S. aquatic and terrestrial birds up to 1973.Additionally, high DDT and dieldrin residues were reported from somespecies of African fish at levels that could potentially affect theirreproduction, have chronic toxic and behavioral effects, and evendrastically affect populations. Holistic case studies on the use ofOCLs to control tsetse flies and desert locusts were discussed. OCLlevels in trophic levels of fauna associated with Lake Kariba (betweenZambia and Zimbabwe) were summarized. (Swedish University ofAgricultural Sciences, Uppsala, Sweden)