Serum DDT and DDE Levels in Pregnant Women of Chiapas,Mexico

The authors measured the main ingredients of technical DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl [p,p[icaron]-DDT]) and its principal metabolite, 1,1-dichloro-2,2-bis (p-chlorophenyl)ethylene [p,p[icaron]-DDE]) in serum collected from 52 pregnant women in Tapachula, Chiapas, Mexico in 1998. The median lipid-adjusted serum levels for the women were 676 ng/g p,p[icaron]-DDT (range: 56–23,169 ng/g) and 4,843 ng/g p,p[icaron]-DDE (range: 113–41, 964 ng/g). In regression analysis, serum DDT and DDE increased with age (test for trend, p = .022) but decreased with total lactation (test for trend, p < .001). Residence in a house that had ever been sprayed for malaria control was also related to serum DDT and DDE. This study provides evidence of high-level exposure to DDT and DDE among pregnant women living in Chiapas, Mexico, despite countrywide restrictions on its use at the time.     

Breast cancer, lactation history, and serum organochlorines

The authors analyzed the relation between lactation history, organochlorine serum levels-in particular, 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE)-and the risk of breast cancer within a subsampe from a larger breast cancer case-control study conducted among women living in Mexico City, Mexico, between 1990 and 1995. From the original study, they selected a random sample of 260 subjects (1:1 case/control ratio). Analysis was restricted to 120 cases and 126 controls who had given birth to at least one child and had complete information on all key variables. Serum DDE levels were higher among cases (mean = 3.84 microg/g lipids, standard deviation = 5.98) than among controls (mean = 2.51 microg/g lipids, standard deviation = 1.97). After adjustment for age, age at menarche, duration of lactation, Quetelet index, and serum DDT levels, serum DDE levels were positively related to the risk of breast cancer (adjusted odds ratio (OR)Q1-Q2 = 1.24, 95% confidence interval (CI): 0.50, 3.06; ORQ1-Q3 = 2.31, 95% CI: 0.92, 5.86; ORQ1-Q4 = 3.81, 95% CI: 1.14, 12.80; test of trend, p = 0.02). The increased risk associated with higher serum DDE levels was more apparent among postmenopausal women (ORQ1-Q4 = 5.26, 95% CI: 0.80, 34.30; test of trend p = 0.03). A longer period of lactation was associated with a slightly decreased risk of breast cancer independently of serum DDE levels (OR = 0.91, 95% CI: 0.85, 0.99 change in risk per 10 months of lactation). Serum DDT level was not related to the risk of breast cancer. The data suggest that high levels of exposure to DDE may increase women's risk of breast cancer, particularly among postmenopausal women.     

Organochlorine Pesticide Levels in Breast Milk in Guerrero,Mexico

In Mexico, organochlorine pesticides were used in public health and agriculture programs, causing chronic exposure to the population. Human breast milk samples were collected from 171 mothers who were residents from Guerrero, Mexico. Analysis was carried out by gas chromatography. Median concentrations (mg/kg on fat basis) for the following pesticides were: HCB, 0.009; β-HCH, 0.004; pp’DDE, 0.760; op’DDT, 0.016; pp’DDT, 0.045; and Σ-DDT, 0.833. These values are lower than in other States in Mexico, and in some countries where the use of these pesticides was banned more than 30 years ago. Differences were found in HCB, pp’DDE and pp’DDT concentrations in groups divided according to age (p < 0.05). The older age groups had higher concentrations, except for the comparison between groups 21–23/24–28 years, which were 0.913 and 0.530 mg/kg of pp’DDE, respectively. Given the restrictions on use, a greater decrease in organochlorine pesticide levels in human milk is expected in a few years.     

Organochlorine chemical residues in white pelicans and western grebes from the klamath basin,california

Samples were analyzed for 12 organochlorine chemicals. Concentrations of DDT + DDD and dieldrin in American white pelican(Pelecanus erythrorhynchos) eggs collected at the Klamath Basin National Wildlife Refuges decreased from 1969 to 1981; DDE and polychlorobiphenyl (PCB) residues did not significantly change. Differences between PCB residues in eggs collected from Lower Klamath and Clear Lake colonies in 1969 suggest different migration routes or wintering areas between populations nesting at these two locations. White pelican and western grebe(Aechmophorus occidentalis) PCB/DDE ratios were 0.13 and 1.58, respectively, suggesting different exposure patterns. White pelican eggshell thickness increased between 1969 and 1981, but remained significantly less than pre-1947 values. Western grebe shell thickness was not significantly different from pre-1947 values. Endrin caused some of the pelican mortalities in the Klamath Basin from 1975 to 1981. Pelicans may have acquired endrin in California, but possibly from areas outside of the Klamath Basin.     

Predictors of Plasma DDT and DDE Concentrations among Women Exposed to Indoor Residual Spraying for Malaria Control in the South African Study of Women and Babies (SOWB)

Background: Few studies have examined predictors of DDT (dichlorodiphenyltrichloroethane) and DDE (dichlorodiphenyldichloroethylene) levels among residents in homes sprayed with DDT for malaria control with the aim of identifying exposure-reduction strategies.Methods: The present analysis included 381 women enrolled in the Study of Women and Babies (SOWB) during 2010–2011, from eight South African villages in the Limpopo Province, South Africa. Indoor residual spraying (IRS) occurred in half of the villages. Questionnaires regarding various demographic and medical factors were administered and blood samples were obtained. We classified the women into three exposure groups by type of residence: unsprayed village (n = 175), IRS village in household with a low likelihood of DDT use (non-DDT IRS household, n = 106), IRS village in household with a high likelihood of DDT use (DDT IRS household, n = 100). We used multivariable models of natural log-transformed DDT plasma levels (in micrograms per liter) and DDE (in micrograms per liter) to identify predictors for each group.Results: Median levels of DDT and DDE among women in unsprayed villages were 0.3 [interquartile range (IQR): 0.1–0.9] and 1.7 (IQR: 0.7–5.5), respectively. Median levels of DDT and DDE among women in DDT IRS households were 2.6 (IQR: 1.1–6.6) and 8.5 (IQR: 4.7–18.0), respectively. In unsprayed villages, women with water piped to the yard, rather than a public tap, had 73% lower DDT (95% CI: –83, –57%) and 61% lower DDE (95% CI: –74, –40%) levels. In DDT IRS households, women who reported taking more than six actions to prepare their home before IRS (e.g., covering water and food) had 40% lower DDT levels (95% CI: –63, –0.3%) than women who took fewer than four actions.Conclusion: The predictors of DDT and DDE plasma levels identified in the present study may inform interventions aimed at decreasing exposure. Among households where DDT is likely to be used for IRS, education regarding home preparations may provide an interventional target.Citation: Whitworth KW, Bornman RM, Archer JI, Kudumu MO, Travlos GS, Wilson RE, Longnecker MP. 2014. Predictors of plasma DDT and DDE concentrations among women exposed to indoor residual spraying for malaria control in the South African Study of Women and Babies (SOWB). Environ Health Perspect 122:545–552; http://dx.doi.org/10.1289/ehp.1307025     

Effect of soy‐derived isoflavonoids on the induced growth of MCF‐7 cells by estrogenic environmental chemicals

Isoflavonoids are natural plant compounds and possess antitumorigenic properties. Many environmental chemicals have been found to be estrogenic and can enhance tumor growth in estrogen receptor‐positive cells. In the present study, the effects of genistein, daidzein, biochanin A, formononetin, and equol on the proliferation of estrogen receptor‐positive MCF‐7 cells induced by synthetic chemicals 1‐(o‐chlorophenyl)‐1‐(p‐chlorophenyl)‐2,2,2‐trichloroethane (o,p'‐DDT), 4‐nonylphenol (4‐NP), and 5‐octylphenol (5‐OP) found in the environment were investigated. Genistein, biochanin A, equol, and to some extent daidzein, but not formononetin, at <10 μM can enhance the growth of MCF‐7 cells in the absence of environmental chemicals. Formononetin was toxic to MCF‐7 cells at the tested concentrations. The environmental chemicals 4‐NP, 5‐OP, and o,p'‐DDT and the natural estrogen 17β‐estradiol at 5, 5, and 10 μM and 5 nM, respectively, induced proliferation of MCF‐7 cells. In the presence of isoflavonoids (>25 μM), the environmental chemical‐induced cell proliferation was inhibited. Individually, genistein (IC50 = 25–33 μM) was the most potent inhibitor against the induced proliferation of MCF‐7 cells of the isoflavonoids needed for a 50% suppression of growth induced by 4‐NP, 5‐OP, and o,p'‐DDT. A mixture of isoflavonoids was the most potent inhibitor against the induced proliferation. Estrogen receptor‐dependent and ‐independent pathways could be involved in the inhibitory actions of isoflavonoids. Because it is impossible to have a chemical‐free environment, the in vitro data presented here are of practical importance to develop evolving dietary strategies and tactics against the adverse health effects of environmental chemicals.     

Milk feeding and dietary patterns predict weight and fat gains in infancy

Current guidelines recommend that infants are exclusively breast fed for the first 6 months of life, with particular solid foods being gradually introduced from 6 months. Our objective was to compare the growth of infants whose feeding most closely followed current guidelines with the growth of infants with other feeding practices. Participants were 1740 infants in a prospective cohort study in Southampton, UK. At 6 and 12 months, infants’ milk feeding was recorded, diets assessed using food frequency questionnaires (FFQ), and anthropometry performed. Principal components analysis was used to identify patterns of foods in the diet using the food intakes assessed by the FFQs. Two patterns (‘infant guidelines’ and ‘adult foods’) explained most variance in infant diet at 6 and 12 months of age. The main outcomes were conditional growth in weight, length and skinfold thickness from 0–6 and 6–12 months. Infants who were breast fed from 0–6 months gained weight, length and adiposity more slowly than formula‐fed infants, independent of age at introduction of solids and maternal factors: compared with infants who were breast fed from 0–6 months, formula‐fed infants gained 0.21 standard deviation scores (SDS) in weight [95% confidence interval (CI) 0.00, 0.42]. Infants whose dietary pattern was most similar to current feeding guidelines, with high frequencies of fresh fruit and vegetables, home‐prepared foods and breast milk, gained weight and skinfold thickness more rapidly from 6 to 12 months than other infants, independent of milk feeding, age at introduction of solids and maternal factors. Compared with infants in the lowest quarter, infants in the highest ‘infant guidelines’ score quarter gained 0.24 SDS [95% CI 0.06, 0.43] in weight and 0.26 SDS [95% CI 0.07, 0.45] in skinfold thickness. Conversely, infants whose diets had the highest frequencies of breads and processed foods gained weight less rapidly from 6 to 12 months than other infants. The extent to which the patterns of diet and growth we have described will influence the current or later health of infants is unknown. We are following up the infants in this study to assess the impact of these patterns beyond the first year of life. These associations should also be examined in other settings and populations.     

Global surveillance of DDT and DDE levels in human tissues

The organochlorine insecticide dichlorodiphenyltrichloroethane (DDT) was initially introduced for control of vector-borne discases It was banned in the United States by the Environmental Protection Agency in 1972 because of potential harmful effects on humans, wildlife and the environment. Since it is a potential human carcinogen, the United Nations Environmental Program (UNEP) has recently restricted the use of DDT in developing countries until alternative methods of vector control are sought. DDT and its metabolite, dichlorodiphenyltrichloroethylene (DDE) are lipid soluble, and bioaccumulate more in human adipose tissue, than breast milk and serum. This article is a review of DDT and DDE levels in human tissues from different countries in the world. Data on p,p'-DDT and p,p'-DDE levels in human adipose tissue, breast milk and serum were selected from more recent literature. It was discovered that countries in Africa, Asia, and Latin America with more recent exposure to DDT and DDE have higher levels in human tissue than in Europe and the United States. The global concern for DDT and DDE is the environmental spread and persistence in the food chain. Hypothetically, there is a potential risk of harmful effects of DDT and DDE to human health. UNEP has cautiously taken action to protect human health, the environment and the earth from further destruction by persistent organic pollutants. Further exposure to DDT should be prevented to achieve this goal.     

The Pine River Statement: Human Health Consequences of DDT Use

Objectives

Dichlorodiphenyltrichloroethane (DDT) was used worldwide until the 1970s, when concerns about its toxic effects, its environmental persistence, and its concentration in the food supply led to use restrictions and prohibitions. In 2001, more than 100 countries signed the Stockholm Convention on Persistent Organic Pollutants (POPs), committing to eliminate the use of 12 POPs of greatest concern. However, DDT use was allowed for disease vector control. In 2006, the World Health Organization and the U.S. Agency for International Development endorsed indoor DDT spraying to control malaria. To better inform current policy, we reviewed epidemiologic studies published from 2003 to 2008 that investigated the human health consequences of DDT and/or DDE (dichlorodiphenyldichloroethylene) exposure.

Data sources and extraction

We conducted a PubMed search in October 2008 and retrieved 494 studies.

Data synthesis

Use restrictions have been successful in lowering human exposure to DDT, but blood concentrations of DDT and DDE are high in countries where DDT is currently being used or was more recently restricted. The recent literature shows a growing body of evidence that exposure to DDT and its breakdown product DDE may be associated with adverse health outcomes such as breast cancer, diabetes, decreased semen quality, spontaneous abortion, and impaired neurodevelopment in children.

Conclusions

Although we provide evidence to suggest that DDT and DDE may pose a risk to human health, we also highlight the lack of knowledge about human exposure and health effects in communities where DDT is currently being sprayed for malaria control. We recommend research to address this gap and to develop safe and effective alternatives to DDT.     

PCBs, DDE, and child development at 18 and 24 months.

To determine whether perinatal exposure to "background" levels of polychlorinated biphenyls (PCBs) or dichlorodiphenyldichloroethene (DDE) affected child development, we followed a cohort of children through the age of 2 years; 676 were tested at 18 months and 670 at 24 months with the Bayley Scales. Transplacental and cumulative exposures from breast milk to both chemicals were estimated for each child from analyses of breast milk and other samples. Bayley testing was done without knowing the chemical levels. At 18 and 24 months, adjusted scores on the psychomotor scales were 4 to 9 points lower among children in the top fifth percentile of transplacental PCB exposure, significantly so at 24 months. There were no consistent effects apparent from exposure to PCBs through breast milk, nor from DDE exposure. We conclude that there is a small delay in motor maturation attributable to transplacental exposure to PCBs that is still detectable at 24 months. There is no evidence of an effect from the larger but later exposure through breast milk, although effects may emerge as the children age.     

In utero p,p'-DDE exposure and infant neurodevelopment: a perinatal cohort in Mexico

BACKGROUND: Evidence suggests that p,p'-dichlorodiphenyldichloroethene (DDE) affects neurodevelopment in infants, although a critical exposure window has not yet been identified. OBJECTIVES: Our goal was to assess the prenatal DDE exposure window and its effect on the psychomotor development index (PDI) and mental development index (MDI) during the first year of life. METHODS: We recruited 244 children whose pregnancies and deliveries were uncomplicated, and whose mothers were monitored throughout the pregnancy. Participating mothers were not occupationally exposed to DDT (dichlorodiphenyltrichloroethane) but were residents of a zone in Mexico with endemic malaria. We measured serum levels of DDE before pregnancy and during each trimester of the pregnancy. We evaluated PDI and MDI of the Bayley Scales for Infant Development (BSID-II), at 1, 3, 6, and 12 months of age. We adjusted for quality of the home environment and maternal intellectual coefficient (IQ). We used generalized mixed-effects models for statistical analysis. RESULTS: Third-trimester DDE level (7.8 +/- 2.8 ppb) was significantly higher than the level at baseline, first, and second trimesters, but the differences never exceeded 20%. Only DDE levels during the first trimester of pregnancy were associated with a significant reduction in PDI (every doubled increase of DDE level reduced the PDI 0.5 points). DDE was not associated with MDI. CONCLUSIONS: A critical window of exposure to DDE in utero may be the first trimester of the pregnancy, and psychomotor development is a target of this compound. Residues of DDT metabolites may present a risk of developmental delay for years after termination of DDT use.     

In utero and childhood DDT,DDE, PBDE and PCBs exposure and sex hormones in adolescent boys: The CHAMACOS study

Dichlorodiphenyltrichloroethane (DDT), polybrominated diphenyl ether (PBDE) flame retardants, and polychlorinated biphenyls (PCBs) are believed to be endocrine-disrupting chemicals (EDCs) in humans and animals. The purpose of this study is to examine the relationship of in utero and childhood exposure to these purported EDCs and reproductive hormones in adolescent boys who participated in CHAMACOS, an ongoing birth cohort in California's Salinas Valley. We measured o,p′- and p,p′-DDT, p,p′-DDE, PBDEs and PCBs in serum collected from mothers during pregnancy or at delivery and from their sons at 9 years. We measured concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and total testosterone (T) from 234 of their sons at 12 years. In adjusted models, we found that a 10-fold increase in maternal prenatal serum concentrations of BDE-153 was associated with a 22.2% increase (95% CI: 1.0, 47.9) in FSH, a 96.6% increase (95% CI: 35.7, 184.7) in LH, and a 92.4% increase (95% CI: 20.9, 206.2) increase in T. Similarly, BDE-100 concentrations were associated with increases in boys’ LH levels. A 10-fold increase in total prenatal ΣPCBs was associated with a 64.5% increase (95% CI: 8.6, 149.0) in FSH, primarily driven by non- dioxin-like congeners. Boys' hormone levels were only marginally associated with prenatal DDT or DDE in primary models, but when boys' Tanner stage at age 12 was added to models, prenatal maternal DDT levels were associated with decreases in LH (adjusted percent change per 10-fold increase = ?18.5%, 95% CI: ?29.8, ?5.4) and T (percent change = ?18.2%, 95% CI: ?30.2, ?4.2) and DDE with LH (percent change = ?18.3%, 95% CI: ?32.9, ?0.6). Exposures measured in the children's serum at 9 years also showed associations between BDE-153 and ΣPCBs. However, there is evidence that these associations appear to be mediated by child BMI. This study suggests associations on male hormones of 12 year old boys related to exposure to certain EDC exposure prenatally. The implications on future reproductive function in puberty and adulthood should be determined.     

Prenatal concentrations of polychlorinated biphenyls, DDE, and DDT and overweight in children: a prospective birth cohort study

Background: Recent experimental evidence suggests that prenatal exposure to endocrine-disrupting chemicals (EDCs) may increase postnatal obesity risk and that these effects may be sex or diet dependent.Objectives: We explored whether prenatal organochlorine compound (OC) concentrations [polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), and dichlorodiphenyltrichloroethane (DDT)] were associated with overweight at 6.5 years of age and whether child sex or fat intakes modified these associations.Methods: We studied 344 children from a Spanish birth cohort established in 1997–1998. Overweight at 6.5 years was defined as a body mass index (BMI) z-score ≥ 85th percentile of the World Health Organization reference. Cord blood OC concentrations were measured and treated as categorical variables (tertiles). Children’s diet was assessed by food frequency questionnaire. Relative risks (RRs) were estimated using generalized linear models.Results: After multivariable adjustment, we found an increased RR of overweight in the third tertile of PCB exposure [RR = 1.70; 95% confidence interval (CI): 1.09, 2.64] and the second tertile of DDE exposure (RR = 1.67; 95% CI: 1.10, 2.55), but no association with DDT exposure in the population overall. Associations between overweight and PCB and DDE concentrations were strongest in girls (p-interaction between 0.01 and 0.28); DDT was associated with overweight only in boys. For DDT we observed stronger associations in children with fat intakes at or above compared with below the median, but this interaction was not significant (p-interaction > 0.05).Conclusions: This study suggests that prenatal OC exposures may be associated with overweight in children and that sex and high-fat intake may influence susceptibility.     

In vitro studies of DDT,DDE, and ATPase as related to avian eggshell thinning

Interspecific and inter-tissue differences were found in thein vitro sensitivity of oligomycin sensitive Mg²⁺ATPase (O.S.-ATPase) from avian mitochondrial homogenates to DDE. The enzyme from the target tissue, the shell gland of kestrels, which lay thin-shelled eggs on exposure to DDE, showed significantly greater sensitivity to DDE than O.S.-ATPase in muscle and brain preparations. The O.S.-ATPase from chicken shell gland was about nine times less sensitive than that from the kestrel. DDT, in contrast to DDE, was highly effective on O.S.-ATPase in all tissues tested from the three species of birds. In contrast to the high sensitivity of O.S.-ATPase, O.Ins.-ATPase and Na⁺-K⁺ATPase were not significantly affected by DDE or DDT. In addition, Ca²⁺-ATPases from mitochondrial and microsomal preparations from shell gland of kestrels were only minimally affected by DDT and DDE at concentrations over 20 times greater than those which inhibited O.S.-ATPase. The selectivity of DDE action in the eggshell thinning of kestrel is correlated with its action on shell gland O.S.-ATPases. However, because DDT effectively inhibits O.S.-ATPase from all tissues studied a combined effect is possible. Both would cause a reduction in ATP synthesis affecting energy-linked calcium transport. The need forin vivo studies including mitochondrial calcium transport is emphasized.Paper No. 11877, Scientific Journal Series, Minnesota Agricultural Experiment Station, University of Minnesota, St. Paul, MN 55108     

Exposure to Dichlorodiphenyltrichloroethane and the Risk of Breast Cancer: A Systematic Review and Meta-analysis

Objectives

This study extended and updated a meta-analysis of the association between exposure to dichlorodiphenyltrichloroethane (DDT) and the risk of breast cancer.

Methods

We reviewed the published literature on exposure to DDE and breast cancer risk to update a meta-analysis from 2004. The total of 35 studies included 16 hospital-based case–control studies, 11 population-based case–control studies, and 10 nested case–control studies identified through keyword searches in the PubMed and EMBASE databases.

Results

The summary odds ratio (OR) for the identified studies was 1.03 (95% confidence interval 0.95–1.12) and the overall heterogeneity in the OR was observed (I² = 40.9; p = 0.006). Subgroup meta-analyses indicated no significant association between exposure to DDE and breast cancer risk by the type of design, study years, biological specimen, and geographical region of the study, except from population-based case–control studies with estimated DDE levels in serum published in 1990s.

Conclusion

Existing studies do not support the view that DDE increases the risk of breast cancer in humans. However, further studies incorporating more detailed information on DDT exposure and other potential risk factors for breast cancer are needed.     

Organochlorine chemical residues in herring gulls,ring-billed gulls,and common terns of western lake superior

Residues of polychlorinated biphenyls (PCBs), DDE, DDT, and hexachlorobenzene (HCB) were analyzed for three age classes (e.g., pre-fledge muscle and blood, and post-fledge muscle) of the herring gull, ring-billed gull, and common tern for samples collected in the western end of Lake Superior in 1977. Concentrations of PCBs were highest and HCB concentrations were lowest of the chemicals analyzed in all four sample types and for all three species. Without exception, concentrations of all residues increased from the pre-fledge to the post-fledge stage despite this being a period of dilution. Residue concentrations of PCBs, DDE, and DDT in the eggs were higher (P < .01) for the herring gull than for the ring-billed gull and common tern, but concentrations in the latter two species were similar. All residue concentrations in the pre-fledge samples of the common tern and herring gull were similar (P > 0.05); both species had higher concentrations of PCBs and DDT than the ring-billed gull. The herring gull had higher residue concentrations of HCB and DDE than the ring-billed gull, but the common tern did not differ from the ring-billed gull for HCB or DDE. Residue concentrations among the three species were similar in the post-fledge samples, however, there was an increasing pattern of residue concentrations in the common tern relative to the gull species. Principal component analysis revealed that residue concentrations of PCBs, DDE, and DDT were highly correlated (r > .76) in all three sample types and the first principal component could express a high proportion of the variation (>65%) in residue concentrations. In contrast, HCB residues were more independent and correlated (r > .53) with the second principal component. There was little correspondence between blood residue samples and the pre-fledge muscle samples. Residue concentration differences among the species are probably related to different life histories. The concentrations are below those that affect reproduction in the gull species, but potential impairment cannot be excluded for the common tern.     

Prenatal organochlorine compound exposure, rapid weight gain, and overweight in infancy

Background

Although it has been hypothesized that fetal exposure to endocrine-disrupting chemicals may increase obesity risk, empirical data are limited, and it is uncertain how early in life any effects may begin.

Objectives

We explored whether prenatal exposure to several organochlorine compounds (OCs) is associated with rapid growth in the first 6 months of life and body mass index (BMI) later in infancy.

Methods

Data come from the INMA (Infancia y Medio-Ambiente) Child and Environment birth cohort in Spain, which recruited 657 women in early pregnancy. Rapid growth during the first 6 months was defined as a change in weight-for-age z-scores > 0.67, and elevated BMI at 14 months, as a z-score ≥ the 85th percentile. Generalized linear models were used to estimate the risk of rapid growth or elevated BMI associated with 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene (DDE), hexachlorobenzene, β-hexachlorohexane, and polychlorinated biphenyls in first-trimester maternal serum.

Results

After multivariable adjustment including other OCs, DDE exposure above the first quartile was associated with doubling of the risk of rapid growth among children of normal-weight (BMI < 25 kg/m²), but not overweight, mothers. DDE was also associated with elevated BMI at 14 months (relative risk per unit increase in log DDE = 1.50; 95% confidence interval, 1.11–2.03). Other OCs were not associated with rapid growth or elevated BMI after adjustment.

Conclusions

In this study we found prenatal DDE exposure to be associated with rapid weight gain in the first 6 months and elevated BMI later in infancy, among infants of normal-weight mothers. More research exploring the potential role of chemical exposures in early-onset obesity is needed.     

Addition of Supplementary Foods and Infant Growth (2 to 24 Months)

Objective: To determine the effect of adding supplementary foods on infant growth 2 to 8 and 12 to 24 months.

Methods: Length (cm/month) and weight (kg/month) of white infants (n = 94) were measured five to nine times from 2 to 24 months of age. Mothers reported birth weights, infants’ ages at first introduction of supplementary food, illnesses and information sources about infant feeding. Simple linear regression equations were used to compute slopes for each child (unit changes in length and in weight by age). Stepwise linear regression was used to determine the effect on weight and length slopes by the introduction of supplementary foods (e.g., an infant’s age when cereal, fruit, juice, vegetables and a meat cluster were first added) to the diet. Breast feeding (months duration or ever fed), illness scores and gender were covariates in the regression models.

Results: A significant model (F = 10.09, p = .002) for weight gain (2 to 8 months) showed that gender explained 10% of the variance; for length slope, the model was non-significant and gender explained 3% of the variance. Females had a slower weight gain compared to that of males. None of the covariates or supplementary foods were retained in the models. Weight prior to 12 months was the best predictor (p = .0001, 54% of the variance) of weight gain 12 to 24 months.

Conclusions: Unit changes in weight or length for an infant’s age were not statistically associated with the timing of when supplementary foods were first added to the diet 2 to 8 or 12 to 24 months. Weight prior to 12 months was a significant predictor of weight gain 12 to 24 months.     

Serum DDT and DDE levels in pregnant women of Chiapas, Mexico

The authors measured the main ingredients of technical DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl [p,p'-DDT]) and its principal metabolite, 1,1-dichloro-2,2-bis (p-chlorophenyl)ethylene [p,p'-DDE]) in serum collected from 52 pregnant women in Tapachula, Chiapas, Mexico in 1998. The median lipid-adjusted serum levels for the women were 676 ng/g p,p'-DDT (range: 56-23,169 ng/g) and 4,843 ng/g p,p'-DDE (range: 113-41,964 ng/g). In regression analysis, serum DDT and DDE increased with age (test for trend, p = .022) but decreased with total lactation (test for trend, p < .001). Residence in a house that had ever been sprayed for malaria control was also related to serum DDT and DDE. This study provides evidence of high-level exposure to DDT and DDE among pregnant women living in Chiapas, Mexico, despite countrywide restrictions on its use at the time.