The influence of maternal dietary exposure to dioxins and PCBs during pregnancy on ADHD symptoms and cognitive functions in Norwegian preschool children

BackgroundPolychlorinated dibenzo-p-dioxins/dibenzofurans (dioxins) and polychlorinated biphenyls (PCBs) are persistent organic pollutants (POPs) with potentially adverse impact on child neurodevelopment. Whether the potential detrimental effects of dioxins and PCBs on neurodevelopment are of specific or unspecific character is not clear.ObjectivesThe purpose of the current study was to examine the influence of maternal dietary exposure to dioxins and PCBs on ADHD symptoms and cognitive functioning in preschoolers. We aimed to investigate a range of functions, in particular IQ, expressive language, and executive functions.Material and methodsThis study includes n = 1024 children enrolled in a longitudinal prospective study of ADHD (the ADHD Study), with participants recruited from The Norwegian Mother and Child Cohort Study (MoBa). Boys and girls aged 3.5 years participated in extensive clinical assessments using well-validated tools; The Preschool Age Psychiatric Assessment interview (PAPA), Stanford-Binet 5th revision (SB-5), Child Development Inventory (CDI), and Behavior Rating Inventory of Executive Function, Preschool version (BRIEF-P). Maternal dietary exposure to dioxins and PCBs was estimated based on a validated food frequency questionnaire (FFQ) answered mid-pregnancy and a database of dioxin and PCB concentrations in Norwegian foods. Exposure to dioxins and dioxin-like PCBs (dl-compounds) was expressed in total toxic equivalents (TEQ), and PCB-153 was used as marker for non-dioxin-like PCBs (ndl-PCBs). Generalized linear and additive models adjusted for confounders were used to examine exposure-outcome associations.ResultsExposure to PCB-153 or dl-compound was not significantly associated with any of the outcome measures when analyses were performed for boys and girls together. After stratifying by sex, adjusted analyses indicated a small inverse association with language in girls. An increase in the exposure variables of 1 SD was associated with a reduction in language score of − 0.2 [CI − 0.4, − 0.1] for PCB-153 and − 0.2 [CI − 0.5, − 0.1] for dl-compounds in girls. For boys, exposure to PCB-153 or dl-compounds was not associated with language skills. The difference between sex-specific associations was not statistically significant (p-value = 0.13). No sex-specific effects were observed for ADHD-symptoms, IQ scores, or executive functions.ConclusionsWe found no indications that variation in current low-level exposure to PCB-153 or dl-compounds in Norway is associated with variation ADHD-symptoms, verbal/non-verbal IQ, or executive functions including working memory in preschoolers. However, our findings indicated that maternal dietary exposure to PCB-153 or dl-compounds during pregnancy was significantly associated with poorer expressive language skills in preschool girls, although the sex-specific associations were not significantly different.     

Exposure to organochlorines and mercury through fish and marine mammal consumption: Associations with growth and duration of gestation among Inuit newborns

BackgroundSeveral studies have reported negative associations of polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB) and mercury (Hg) with duration of gestation and fetal growth in fish eating populations. Docosahexaenoic acid (DHA) from fish, seafood and marine mammal intake has been reported to be positively related with pregnancy duration and fetal growth. So far, it remains unclear, however, if the associations of environmental contaminants (ECs) with growth are direct or mediated through their relation with the duration of gestation and the degree to which DHA intake during pregnancy attenuates the negative association of ECs with fetal growth.ObjectivesTo investigate direct and indirect associations of in utero exposure to ECs with fetal growth and pregnancy duration while taking into account the possible positive effects of DHA.MethodsPregnant Inuit women (N = 248) from Arctic Quebec were recruited and cord blood samples were analyzed for PCBs, HCB, Hg and DHA. Anthropometric measurements were assessed at birth. Path models were used to evaluate direct and indirect associations.ResultsCord concentrations of PCB 153, HCB and Hg were significantly associated with shorter duration of pregnancy (β varying from − 0.17 to − 0.20, p < 0.05). Path models indicated that the associations of PCBs, HCB and Hg with reduced fetal growth (β varying from − 0.09 to − 0.13, p < 0.05) were mediated through their relations with shorter gestation duration. Cord DHA was indirectly related to greater growth parameters (β varying from 0.17 to 0.20, p < 0.05) through its positive association with gestation duration.ConclusionPrenatal exposure to ECs was associated with reduced gestation duration, which is a recognized determinant of fetal growth. DHA intake during pregnancy appeared to have independent positive association with fetal growth by prolonging gestation. Whether these associations are causal remains to be elucidated.     

Dietary exposure to dioxins and PCBs in a large cohort of pregnant women: Results from the Norwegian Mother and Child Cohort Study (MoBa)

Exposure to dioxins and polychlorinated biphenyls (PCBs) during pregnancy and breastfeeding may result in adverse health effects in children. Prenatal exposure is determined by the concentrations of dioxins and PCBs in maternal blood, which reflect the body burden obtained by long term dietary exposure. The aims of this study were (1) to describe dietary exposure and important dietary sources to dioxins and PCBs in a large group of pregnant women and (2) to identify maternal characteristics associated with high dietary exposure to dioxins and PCBs. Dietary exposure to dioxins (sum of toxic equivalents (TEQs) from dioxin-like (dl) compounds) and PCB-153 in 83,524 pregnant women (gestational weeks 17–22) who participated in the Norwegian Mother and Child Cohort Study (MoBa) during the years 2002–2009 was calculated based on a food frequency questionnaire (FFQ) and a database of dioxin and PCB concentrations in Norwegian food. The median (interquartile range, IQR) intake of PCB-153 (marker of ndl-PCBs) was 0.81 (0.77) ng/kg bw/day. For dioxins and dioxin-like PCBs, the median (IQR) intake was 0.56 (0.37) pg TEQ/kg bw/day. Moreover, 2.3% of the participants had intakes exceeding the tolerable weekly intake (TWI) of 14 pg TEQ/kg bw/week. Multiple regression analysis showed that dietary exposure was positively associated with maternal age, maternal education, weight gain during pregnancy, being a student, and alcohol consumption during pregnancy and negatively associated with pre-pregnancy BMI and smoking. A high dietary exposure to PCB-153 or dl-compounds (TEQ) was mainly explained by the consumption of seagull eggs and/or pate with fish liver and roe. Women who according to Norwegian recommendations avoid these food items generally do not have dietary exposure above the tolerable intake of dioxins and dl-PCBs.     

Dietary benzo(a)pyrene intake during pregnancy and birth weight: Associations modified by vitamin C intakes in the Norwegian Mother and Child Cohort Study (MoBa)

BackgroundMaternal exposure to polycyclic aromatic hydrocarbons (PAH) during pregnancy has been associated with reduced fetal growth. However, the role of diet, the main source of PAH exposure among non-smokers, remains uncertain.ObjectiveTo assess associations between maternal exposure to dietary intake of the genotoxic PAH benzo(a)pyrene [B(a)P] during pregnancy and birth weight, exploring potential effect modification by dietary intakes of vitamins C, E and A, hypothesized to influence PAH metabolism.MethodsThis study included 50,651 women in the Norwegian Mother and Child Cohort Study (MoBa). Dietary B(a)P and nutrient intakes were estimated based on total consumption obtained from a food frequency questionnaire (FFQ) and estimated based on food composition data. Data on infant birth weight were obtained from the Medical Birth Registry of Norway (MBRN). Multivariate regression was used to assess associations between dietary B(a)P and birth weight, evaluating potential interactions with candidate nutrients.ResultsThe multivariate-adjusted coefficient (95%CI) for birth weight associated with maternal energy-adjusted B(a)P intake was − 20.5 g (− 31.1, − 10.0) in women in the third compared with the first tertile of B(a)P intake. Results were similar after excluding smokers. Significant interactions were found between elevated intakes of vitamin C (> 85 mg/day) and dietary B(a)P during pregnancy for birth weight (P < 0.05), but no interactions were found with other vitamins. The multivariate-adjusted coefficients (95%CI) for birth weight in women in the third compared with the first tertile of B(a)P intake were − 44.4 g (− 76.5, − 12.3) in the group with low vitamin C intakes vs. − 17.6 g (− 29.0, − 6.1) in the high vitamin C intake group.ConclusionThe results suggest that higher prenatal exposure to dietary B(a)P may reduce birth weight. Lowering maternal intake of B(a)P and increasing dietary vitamin C intake during pregnancy may help to reduce any adverse effects of B(a)P on birth weight.     

Persistent organic pollutants exposure during pregnancy,maternal gestational weight gain,and birth outcomes in the mother–child cohort in Crete,Greece (RHEA study)

BackgroundPersistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs) and pesticides bioaccumulate through the food chain and cross the placenta. POPs are developmental toxicants in animals but the epidemiological evidence on pregnancy outcomes is inconsistent. Maternal gestational weight gain has been recently suggested as a key factor explaining the association between PCBs with lower birth weight.AimsWe examined whether in utero exposure to current low levels of different POPs is associated with fetal growth and gestational age in a mother–child cohort in Crete, Greece (Rhea study), and evaluated specifically whether maternal gestational weight gain may affect this association.MethodsWe included 1117 mothers and their newborns from the Rhea study. Mothers were interviewed and blood samples collected during the first trimester of pregnancy. Information on birth outcomes was retrieved from medical records. Concentrations of several PCBs, other organochlorine compounds (dichlorodiphenyl dichloroethene [DDE], dichlorodiphenyl trichloroethane [DDT] and hexachlorobenzene [HCB]) and one polybrominated diphenyl ether congener (tetra-bromodiphenyl ether [BDE-47]), were determined in maternal serum by triple quadrupole mass spectrometry. Multiple linear regression models were used to investigate the associations of birth weight, gestational age, and head circumference with each compound individually on the log₁₀ scale, and with combined exposures through the development of an exposure score.ResultsIn multivariate models, birth weight was negatively associated with increasing levels of HCB (β = − 161.1 g; 95% CI: − 296.6, − 25.7) and PCBs (β = − 174.1 g; 95% CI: − 332.4, − 15.9); after further adjustment for gestational weight gain these estimates were slightly reduced (β = − 154.3 g; 95% CI: − 300.8, − 7.9 for HCB and β = − 135.7 g; 95% CI: − 315.4, 43.9 for PCBs). Furthermore, in stratified analysis, the association between POPs and birth weight was only observed in women with inadequate or excessive gestational weight gain. Small, negative associations were observed with head circumference while no association was observed with gestational age.ConclusionsThe findings suggest that prenatal exposure to PCBs and HCB impairs fetal growth and adds to the growing literature that demonstrates an association between low-level environmental pollutant exposure and fetal growth. Furthermore our results suggest that the association of POPs, maternal gestational weight gain and birth weight is probably more complex than that previously hypothesized.     

Development and validation of prediction models for blood concentrations of dioxins and PCBs using dietary intakes

BackgroundDioxins and PCBs accumulate in the food chain and might exert toxic effects in animals and humans. In large epidemiologic studies, exposure estimates of these compounds based on analyses of biological material might not be available or affordable.ObjectivesTo develop and then validate models for predicting concentrations of dioxins and PCBs in blood using a comprehensive food frequency questionnaire and blood concentrations.MethodsPrediction models were built on data from one study (n = 195), and validated in an independent study group (n = 66). We used linear regression to develop predictive models for dioxins and PCBs, both sums of congeners and 33 single congeners (7 and 10 polychlorinated dibenzo-p-dioxins and furans (PCDDs/PCDFs), 12 dioxin-like polychlorinated biphenyls (PCBs: 4 non-ortho and 8 mono-ortho), sum of all the 29 dioxin-like compounds (total TEQ) and sum of 4 non dioxin-like PCBs (∑ CB-101, 138, 153, 183 = PCB₄). We used the blood concentration and dietary intake of each of the above as dependent and independent variables, while sex, parity, age, place of living, smoking status, energy intake and education were covariates. We validated the models in a new study population comparing the predicted blood concentrations with the measured blood concentrations using correlation coefficients and Weighted Kappa (К_W) as measures of agreement, considering К_W > 0.40 as successful prediction.ResultsThe models explained 78% (sum dioxin-like compounds), 76% (PCDDs), 76% (PCDFs), 74% (no-PCBs), 69% (mo-PCBs), 68% (PCB₄) and 63% (CB-153) of the variance. In addition to dietary intake, age and sex were the most important covariates.The predicted blood concentrations were highly correlated with the measured values, with r = 0.75 for dl-compounds 0.70 for PCB₄, (p < 0.001) and 0.66 (p < 0.001) for CB-153. К_W was 0.68 for sum dl-compounds 0.65 for both PCB₄ and CB-153. Out of 33 congeners 16 (13 dl-compounds and 3 ndl PCBs) had К_W > 0.40.ConclusionsThe models developed had high power to predict blood levels of dioxins and PCBs and to correctly rank subjects according to high or low exposure based on dietary intake and demographic information. These models underline the value of dietary intake data for use in investigations of associations between dioxin and PCB exposure and health outcomes in large epidemiological studies with limited biomaterial for chemical analysis.     

Perinatal exposure to dioxins and dioxin-like compounds and infant growth and body mass index at seven years: A pooled analysis of three European birth cohorts

BackgroundDioxins and dioxin-like compounds are endocrine disrupting chemicals (EDCs). Experimental studies suggest perinatal exposure to EDCs results in later obesity. However, the few epidemiological investigations on dioxins are inconclusive. We investigated perinatal exposure to dioxins and dioxin-like compounds, infant growth and body mass index (BMI) in childhood.MethodsWe pooled data from 3 European birth cohorts (Belgian, Norwegian, Slovak) with exposure assessment in cord blood or breast milk. Two cohorts had dioxin-like toxicity assessed using dioxin-responsive chemical-activated luciferase expression (DR-CALUX) bioassay and one cohort had measured concentrations of dioxins, furans and dioxin-like polychlorinated biphenols with CALUX relative potency values applied. Growth was cohort- and sex-specific change in weight-for-age z-score between birth and 24 months (N = 367). BMI was calculated at around 7 years (median 7.17, interquartile range [IQR] 7.00–7.37 years, N = 251), and overweight defined according to international standards for children equivalent to adult BMI > 25 kg/m² (Cole and Lobstein, 2012). We fitted multivariate models using generalized estimating equations, and tested effect modification by sex, breastfeeding and cohort. Results per 10 pg CALUX TEQ/g lipid increase in exposure.ResultsDioxin exposure was highest in the Belgian and lowest in the Norwegian cohort; median (IQR) of the pooled sample 13 (12.0) pg CALUX TEQ/g lipid. Perinatal exposure to dioxins and dioxin-like compounds appeared associated with increased growth between 0 and 24 months (adjusted estimate for change in z-score: β = 0.07, 95% CI: − 0.01, 0.14). At 7 years, dioxins exposure was associated with a statistically significant increase in BMI in girls (adjusted estimate for BMI units β = 0.49, 95% CI: 0.07, 0.91) but not in boys (β = − 0.03, 95% CI: − 0.55, 0.49) (p-interaction = 0.044). Furthermore, girls had a 54% (− 6%, 151%) increased risk of overweight at 7 years (p-interaction = 0.023).ConclusionPerinatal exposure to dioxin and dioxin-like compounds was associated with increased early infant growth, and increased BMI in school age girls. Studies in larger sample sizes are required to confirm these sex-specific effects.     

Contaminant levels in Norwegian farmed Atlantic salmon (Salmo salar) in the 13-year period from 1999 to 2011

BackgroundEnvironmental pollutants such as dioxins and PCBs, heavy metals, and organochlorine pesticides are a global threat to food safety. In particular, the aquatic biota can bioaccumulate many of these contaminants potentially making seafood of concern for chronic exposure to humans.ObjectivesThe main objective was to evaluate trends of contaminant levels in Norwegian farmed Atlantic salmon in light of the derived tolerable intakes.MethodsThrough an EU-instigated surveillance programme, the Norwegian Food Safety Authority (NFSA) has between 1999 and 2011 collected more than 2300 samples of Norwegian farmed Atlantic salmon (Salmo salar) for contaminant analyses. The fillets of these fish were homogenised and analysed for dioxins, PCBs, heavy metals and organochlorine pesticides.ResultsThe levels of the contaminants mercury, arsenic, dioxins, dioxin-like PCBs and DDT in Norwegian farmed salmon fillet have decreased during our period of analyses. The levels of cadmium, lead and several organochlorine pesticides were too close to the limit of quantification to calculate time trends. For PCB₆ and quantifiable amounts of pesticides, except DDT, stable levels were observed.ConclusionThe contaminant levels in Norwegian farmed salmon have generally decreased between 1999 and 2011. Excluding other dietary sources, the levels of dioxins and dioxin-like PCBs in 2011 allowed consumption of up to 1.3 kg salmon per week to reach the tolerable weekly intake. The group of contaminants which was the limiting factor for safe consumption of Norwegian farmed salmon, based on currently established TWI values, is the sum of dioxins and dioxin-like PCBs.     

Dietary benzo(a)pyrene and fetal growth: Effect modification by vitamin C intake and glutathione S-transferase P1 polymorphism

BackgroundPrevious studies have reported maternal exposure to airborne polycyclic aromatic hydrocarbons (PAH), as well as DNA adducts reflecting total PAH exposure, to be associated with reduced fetal growth. The role of diet, the main source of PAH exposure among non-smokers, remains uncertain.ObjectiveTo assess associations between birth weight, length and small size for gestational age (SGA) with maternal intakes of the genotoxic PAH benzo(a)pyrene [B(a)P] during pregnancy, exploring potential effect modification by dietary intakes of vitamin C, vitamin E, alpha- and beta-carotene, as well as glutathione S-transferase P1 (GSTP1) polymorphisms, hypothesized to influence PAH metabolism.Methods657 women in the INMA (Environment and Childhood) Project from Sabadell (Barcelona) were recruited during the first trimester of pregnancy. Dietary B(a)P and nutrient intakes were estimated from food consumption data. Genotyping was conducted for the Ile105Val variant of GSTP1. Multivariable models were used to assess associations between size at birth and dietary B(a)P, evaluating potential interactions with candidate nutrients and GSTP1 variants.ResultsThere were significant interactions between elevated intakes of vitamin C (above the mean of 189.41 mg/day) and dietary B(a)P during the first trimester of pregnancy in models for birth weight and length (P < 0.05), but no interactions were found with other nutrients. B(a)P intakes were associated with significant reductions in birth weight and length (coefficient ± SE for a 1-SD increase in B(a)P: − 101.63 ± 34.62 g and − 0.38 ± 0.16 cm, respectively) among women with low, but not high, vitamin C intakes. Elevated dietary B(a)P was also associated with increased risk of SGA births among women with low dietary vitamin C. Among these women, associations were strongest in those carrying the GSTP1 Val allele, associated with lower contaminant detoxification activity.ConclusionResults suggest that dietary B(a)P exposure may impair fetal growth, particularly in genetically susceptible populations, and that increasing maternal intakes of vitamin C may help to reduce any adverse effects.     

Associations between maternal exposure to air pollution and traffic noise and newborn's size at birth: A cohort study

BackgroundMaternal exposure to air pollution and traffic noise has been suggested to impair fetal growth, but studies have reported inconsistent findings.ObjectiveTo investigate associations between residential air pollution and traffic noise during pregnancy and newborn's size at birth.MethodsFrom a national birth cohort we identified 75,166 live-born singletons born at term with information on the children's size at birth. Residential address history from conception until birth was collected and air pollution (NO₂ and NO_x) and road traffic noise was modeled at all addresses. Associations between exposures and indicators of newborn's size at birth: birth weight, placental weight and head and abdominal circumference were analyzed by linear and logistic regression, and adjusted for potential confounders.ResultsIn mutually adjusted models we found a 10 μg/m³ higher time-weighted mean exposure to NO₂ during pregnancy to be associated with a 0.35 mm smaller head circumference (95% confidence interval (CI): 95% CI: − 0.57; − 0.12); a 0.50 mm smaller abdominal circumference (95% CI: − 0.80; − 0.20) and a 5.02 g higher placental weight (95% CI: 2.93; 7.11). No associations were found between air pollution and birth weight. Exposure to residential road traffic noise was weakly associated with reduced head circumference, whereas none of the other newborn's size indicators were associated with noise, neither before nor after adjustment for air pollution.ConclusionsThis study indicates that air pollution may result in a small reduction in offspring's birth head and abdominal circumference, but not birth weight, whereas traffic noise seems not to affect newborn's size at birth.     

Prenatal methylmercury exposure and language delay at three years of age in the Norwegian Mother and Child Cohort Study

Prenatal methylmercury (MeHg) exposure and its possible neurodevelopmental effects in susceptible children are of concern. Studies of MeHg exposure and negative health outcomes have shown conflicting results and it has been suggested that co-exposure to other contaminants and/or nutrients in fish may confound the effect of MeHg. Our objective was to examine the association between prenatal exposure to MeHg and language and communication development at three years, adjusting for intake of fish, n − 3 long chain polyunsaturated fatty acids (n − 3 LCPUFAs) and co-exposure to dioxins and dioxin like polychlorinated biphenyls (dl-PCBs).We used data from the Norwegian Mother and Child Cohort Study (MoBa) collected between 2002 and 2008. The study sample consisted of 46,750 mother-child pairs. MeHg exposure was calculated from reported fish intake during pregnancy by a FFQ in mid-pregnancy. Children's language and communication skills were measured by maternal report on the Dale and Bishop grammar rating and the Ages and Stages communication scale (ASQ). We estimated odds ratios (OR) and 95% confidence intervals (CI) using logistic regressions.Median MeHg exposure was 1.3 μg/day, corresponding to 0.14 μg/kg bw/week. An exposure level above the 90th percentile (> 2.6 μg/day, > 0.29 μg/kg bw/week) was defined as the high MeHg exposure. Results indicated an association between high MeHg exposure and unintelligible speech with an adjusted OR 2.22 (1.31, 3.72). High MeHg exposure was also associated with weaker communication skills adjusted OR 1.33 (1.03, 1.70). Additional adjustment for fish intake strengthened the associations, while adjusting for PCBs and n − 3 LCPUFA from diet or from supplements had minor impact. In conclusion, significant associations were found between prenatal MeHg exposure above the 90th percentile and delayed language and communication skills in a generally low exposed population.     

Associations between blood persistent organic pollutants and 25-hydroxyvitamin D3 in pregnancy

Persistent organic pollutants (POPs) are suggested to contribute to lower vitamin D levels; however, studies in humans are scarce and have never focused on pregnancy, a susceptibility period for vitamin D deficiency. We investigated whether serum levels of POPs were associated with circulating 25-hydroxyvitamin D3 [25(OH)D3] concentration in pregnancy. Cross-sectional associations of serum concentrations of eight POPs with plasma 25(OH)D3 concentration were analyzed in 2031 pregnant women participating in the Spanish population-based cohort INfancia y Medio Ambiente (INMA) Project. Serum concentrations of POPs were measured by gas chromatography and plasma 25(OH)D3 concentration was measured by high-performance liquid chromatography in pregnancy (mean 13.3 ± 1.5 weeks of gestation). Multivariable regression models were performed to assess the relationship between blood concentrations of POPs and 25(OH)D3. An inverse linear relationship was found between serum concentration of PCB180 and circulating 25(OH)D3. Multivariate linear regression models showed higher PCB180 levels to be associated with lower 25(OH)D3 concentration: quartile Q4 vs. quartile Q1, coefficient = − 1.59, 95% CI − 3.27, 0.08, p trend = 0.060. A non-monotonic inverse relationship was found between the sum of predominant PCB congeners (PCB 180, 153 and 138) and 25(OH)D3 concentration: coefficient (95% CI) for quartile Q2 vs. Q1 [− 0.50 (− 1.94, 0.94)], quartile Q3 vs. Q1 [− 1.56 (− 3.11, − 0.02)] and quartile Q4 vs. Q1 [− 1.21 (− 2.80, 0.38)], p trend = 0.081. No significant associations were found between circulating 25(OH)D3 and serum levels of p,p′-DDE, p,p′-DDT, HCB, and ß-HCH. Our results suggest that the background exposure to PCBs may result in lower 25(OH)D3 concentration in pregnant women.     

Reduced birth weight in relation to pesticide mixtures detected in cord blood of full-term infants

Previous research has shown that prenatal exposure to pesticides may be associated with decreased fetal growth. The specific pesticides investigated and results reported across studies have been inconsistent, and there is a mounting need for the consideration of mixtures rather than individual agents in studies of health outcomes in relation to environmental exposures. There are also many individual pesticides that have not been investigated in human health studies to date. We conducted a pilot study in rural Zhejiang province, China, measuring 20 non-persistent pesticides (10 insecticides, 6 herbicides, 3 fungicides, and 1 repellant) in umbilical cord blood of 112 full term (> 37 weeks) infants. The pesticides detected with the greatest frequency were diethyltoluamide (DEET) (73%), a repellant, and vinclozolin (49%), a fungicide. The samples had detectable concentrations for a mean of 4.6 pesticides (SD = 1.9) with a maximum of 10. Adjusting for potential confounders, newborn birth weight was inversely associated with the number of pesticides detected in cord blood (p = 0.04); birth weight decreased by a mean of 37.1 g (95% CI, − 72.5 to − 1.8) for each detected pesticide. When assessing relationships by pesticide type, detection of fungicides was also associated with decreased birth weight (adjusted β = − 116 g [95% CI, − 212 to − 19.2]). For individual pesticides analyzed as dichotomous (detect vs. non-detect) variables, only vinclozolin (adjusted β = − 174 g [95% CI, − 312 to − 36.3]) and acetochlor (adjusted β = − 165 g [95% CI, − 325 to − 5.7]) were significantly associated with reduced birth weight. No significant associations were seen between birth weight and individual pesticides assessed as continuous or 3-level ordinal variables. Our findings from this pilot investigation suggest that exposure to fungicides may adversely impact fetal growth. Exposure to mixtures of multiple pesticides is also of concern and should be explored in addition to individual pesticides. Additional research is needed to establish causality and to understand the function and impact of fungicides and pesticide mixtures on fetal development.     

Prenatal exposure to PCB-153, p,p′-DDE and birth outcomes in 9000 mother–child pairs: Exposure–response relationship and effect modifiers

Low-level exposure to polychlorinated biphenyl-153 (PCB-153) and dichlorodiphenyldichloroethylene (p-p′-DDE) can impair fetal growth; however, the exposure–response relationship and effect modifiers of such association are not well established. This study is an extension of an earlier European meta-analysis. Our aim was to explore exposure–response relationship between PCB-153 and p-p′-DDE and birth outcomes; to evaluate whether any no exposure–effect level and susceptible subgroups exist; and to assess the role of maternal gestational weight gain (GWG). We used a pooled dataset of 9377 mother–child pairs enrolled in 14 study populations from 11 European birth cohorts. General additive models were used to evaluate the shape of the relationships between organochlorine compounds and birth outcomes. We observed an inverse linear exposure–response relationship between prenatal exposure to PCB-153 and birth weight [decline of 194 g (95% CI − 314, − 74) per 1 μg/L increase in PCB-153]. We showed effects on birth weight over the entire exposure range, including at low levels. This reduction seems to be stronger among children of mothers who were non-Caucasian or had smoked during pregnancy. The most susceptible subgroup was girls whose mothers smoked during pregnancy. After adjusting for absolute GWG or estimated fat mass, a reduction in birth weight was still observed. This study suggests that the association between low-level exposure to PCB-153 and birth weight exists and follows an inverse linear exposure–response relationship with effects even at low levels, and that maternal smoking and ethnicity modify this association.     

Human dietary intake of organohalogen contaminants at e-waste recycling sites in Eastern China

This study reports concentrations and human dietary intake of hexabromocyclododecanes (HBCDs), polychlorinated biphenyls (PCBs) as well as selected “novel” brominated flame retardants (NBFRs) and organochlorine pesticides, in ten staple food categories. Samples were sourced from areas in Taizhou City, eastern China, where rudimentary recycling and disposal of e-waste is commonplace, as well as from nearby non-e-waste impacted control areas. In most instances, concentrations in foods from e-waste recycling areas exceeded those from control locations. Concentrations of 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) and bis-(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (BEH-TBP) in samples from e-waste sites were 3.09–62.2 ng/g and 0.81–16.3 ng/g lipid weight (lw), respectively; exceeding consistently those in foods acquired from control sites by an order of magnitude in many cases. In contrast, while concentrations of HBCD in some foods from e-waste impacted areas exceed those from control locations; concentrations in pork, shrimp, and duck liver are higher in control samples. This highlights the potential significance of non-e-waste sources of HBCD (e.g. building insulation foam) in our study areas. While concentrations of DDT in all foods examined except pork were higher in e-waste impacted samples than controls; our exposure estimates were well below the provisional tolerable daily intake of 0.01 mg/kg bw/day derived by the Joint FAO/WHO Meeting on Pesticide Residues. Concentrations of ΣPCBs resulted in exposures (650 and 2340 ng/kg bw/day for adults and children respectively) that exceed substantially the Minimal Risk Levels (MRLs) for ΣPCBs of 20 ng/kg bw/day derived by the Agency for Toxic Substances & Disease Registry. Moreover, when expressed in terms of dioxin-like toxicity equivalency based on the four dioxin-like PCBs monitored in this study (DL-PCBs) (PCB-105, 118, 156, and 167); concentrations in e-waste impacted foods exceed limits set by the European Union in 6 of the 8 food groups studied and result in dietary exposures for children (10.2 pg TEQ/kg bw/day) that exceed the WHO tolerable daily intake of 1–4 pg TEQ/kg bw/day.     

Organophosphate pesticide exposure and perinatal outcomes in Shanghai,China

Although pesticide use is widespread in China, little is known about levels of exposure to organophosphate pesticides in the population and its potential adverse health effects. We investigated levels of organophosphate exposure in pregnant women and the association between organophosphate exposure and perinatal outcomes in Shanghai, China, by enrolling 187 healthy pregnant women between September 2006 and January 2007. Pesticide exposure was assessed by a questionnaire administered to the mothers in the hospital after delivery as well as by analyses of maternal urinary nonspecific metabolites of organophosphate pesticides (dimethyl and diethyl phosphates). Information on birth weight and length was collected from medical records. Geometric means of metabolites were 25.75 μg/L for dimethylphosphate (DMP); 11.99 μg/L for dimethylthiophosphate (DMTP); 9.03 μg/L for diethylphosphate (DEP); and 9.45 μg/L for diethyldithiophosphate (DETP). We found that a log unit increase in urinary DEP was associated with a decrease in gestational duration in girls by 1.79 weeks. [ß_adjusted = − 1.79 weeks per log₁₀ unit increase; 95% confidence interval (CI), −2.82 to − 0.76; p = 0.001]. These data suggest that high pesticide level might adversely affect duration of gestation although this association was not present among boys. No associations for any of the organophosphate exposure measures were present for birth weight and length, suggesting that organophosphate pesticides may have no effects on fetal growth. Given that maternal urine pesticide levels in Shanghai were much higher than those reported in developed countries, more studies on the effects of in utero organophosphate exposure on fetal growth and child neurodevelopment are warranted.     

Exposure to fine particle matter,nitrogen dioxide and benzene during pregnancy and cognitive and psychomotor developments in children at 15 months of age

BackgroundPrenatal exposure to air pollutants has recently been identified as a potential risk factor for neuropsychological impairment.ObjectivesTo assess whether prenatal exposure to fine particulate matter (PM_2.5), nitrogen dioxide (NO₂) and benzene were associated with impaired development in infants during their second year of life.MethodsRegression analyses, based on 438 mother–child pairs, were performed to estimate the association between mother exposure to air pollutants during pregnancy and neurodevelopment of the child. The average exposure to PM_2.5, NO₂ and benzene over the whole pregnancy was calculated for each woman. During the second year of life, infant neuropsychological development was assessed using the Bayley Scales of Infant Development. Regression analyses were performed to estimate the association between exposure and outcomes, accounting for potential confounders.ResultsWe estimated that a 1 μg/m³ increase during pregnancy in the average levels of PM_2.5 was associated with a − 1.14 point decrease in motor score (90% CI: − 1.75; − 0.53) and that a 1 μg/m³ increase of NO₂ exposure was associated with a − 0.29 point decrease in mental score (90% CI: − 0.47; − 0.11). Benzene did not show any significant association with development. Considering women living closer (≤ 100 m) to metal processing activities, we found that motor scores decreased by − 3.20 (90% CI: − 5.18; − 1.21) for PM_2.5 and − 0.51 (− 0.89; − 0.13) for NO₂, while mental score decreased by − 2.71 (90% CI: − 4.69; − 0.74) for PM_2.5, and − 0.41 (9% CI: − 0.76; − 0.06) for NO₂.ConclusionsOur findings suggest that prenatal residential exposure to PM_2.5 and NO₂ adversely affects infant motor and cognitive developments. This negative effect could be higher in the proximity of metal processing plants.     

Environmental exposure to lithium during pregnancy and fetal size: A longitudinal study in the Argentinean Andes

BackgroundLithium, used for treating bipolar disease, crosses freely the placenta and is classified as teratogenic. It is unclear to what extent environmental lithium exposure may affect fetal growth and development.ObjectivesTo elucidate potential effects of lithium exposure through drinking water during pregnancy on fetal size.MethodsWe developed a prospective population-based mother–child cohort (N = 194) in an area with highly varying drinking water lithium concentrations (5-1600 μg/L) in northern Argentinean Andes. Blood and urinary lithium concentrations (sampled repeatedly during pregnancy) were measured using inductively coupled plasma mass spectrometry. We measured fetal size by ultrasound in second and third trimesters, and weight, length and head circumference at birth. Multivariable models were used to examine associations between lithium exposure (continuous and in tertiles) and fetal size measures.ResultsLithium in maternal blood (median 25; range 1.9–145 μg/L) and urine (1645; 105–4600 μg/L) was inversely associated (apparently linearly) with all fetal measures (body, head and femur) in the second trimester, and with birth length (β − 0.53 cm per 25 μg/L increase in blood lithium, 95%CI − 1.0; − 0.052). An increase of 100 μg/L in blood was associated with 2 cm shorter newborns (about one standard deviation).ConclusionsLithium exposure through drinking water was associated with impaired fetal size and this seemed to be initiated in early gestation. Further studies are warranted to confirm causality and to understand the mechanisms. If confirmed, these findings have public health relevance and emphasize the need for more data on lithium concentrations in drinking water, including bottled water.     

Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in breast milk from Zhejiang,China

Breast milk samples (n = 74) from the general maternal population of Zhejiang province were analyzed for polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs). Samples were divided into urban and rural groups. Mean ∑PCDD/F, ∑PCB and ∑PBDE concentrations were 71.4 ± 40.8, 42774 ± 27841 and 2679 ± 944 pg g^− 1 lipid in the urban group and 38.6 ± 38.1, 26546 ± 11375 and 2731 ± 1093 pg g^− 1 lipid in the rural group, respectively. WHO-TEQ concentrations for dioxin-like PCBs and PCDD/Fs were 2.66 ± 1.43 and 3.90 ± 2.60 pg g^− 1 lipid in the urban group and 1.83 ± 0.93 and 2.27 ± 1.55 pg g^− 1 lipid in the rural group, respectively. Congener profiles for these pollutants were compared between human samples (adipose tissue and breast milk) and foodstuffs (seafood, hen eggs, and freshwater fish). Similar PCB and PCDD/F congener patterns were observed, suggesting that dietary intake is a significant source for human exposure to PCBs and PCDD/Fs. However, much lower PBDE congener levels were detected in breast milk than in foodstuffs, which implies that pathways other than dietary intake may also account for human exposure to PBDEs.     

Dietary exposure to polychlorinated biphenyls and risk of myocardial infarction in men — A population-based prospective cohort study

BackgroundMajor food contaminants such as polychlorinated biphenyls (PCBs) are proposed to play a role in the etiology of cardiovascular disease (CVD), but to date the impact of PCBs on cardiovascular health need to be explored.Methods and resultsWe assessed the association between validated food frequency questionnaire-based estimates of dietary PCB exposure and risk of myocardial infarction, ascertained through register-linkage, among 36,759 men from the population-based Swedish Cohort of Men, free of cardiovascular disease, diabetes and cancer at baseline (1997). Relative risks were adjusted for known cardiovascular risk factors, long-chain omega-3 fatty acids (eicosapentaenoic and docosahexaenoic acids) and methyl mercury exposure. During 12 years of follow-up (433,243 person-years), we ascertained 3005 incident cases of myocardial infarction (654 fatal). Compared with the lowest quintile of dietary PCB exposure (median 113 ng/day), men in the highest quintile (median 436 ng/day) had multivariable-adjusted relative risks of 1.74 (95% confidence interval [CI], 1.30–2.33; p-trend < 0.001) for total and 1.97 (95% CI 1.42–2.75; p-trend < 0.001) for non-fatal myocardial infarction. In mutually adjusted models, dietary PCB exposure was associated with an increased risk of myocardial infarction, while the intake of long-chain omega-3 fish fatty acids was associated with a decreased risk. We also observed an effect modification by adiposity on the association between of dietary PCB exposure and myocardial infarction, with higher risk among lean men (p value for interaction = 0.03).ConclusionsExposure to PCBs via diet was associated with increased risk of myocardial infarction in men.