Lower birth weight and increased body fat at school age in children prenatally exposed to modern pesticides: a prospective study

Effect of perinatal exposure to glyphosate and its mixture with 2,4-D and dicamba on rat dam kidney and thyroid function and offspring's health

The increasing use of the herbicide mixture of glyphosate, dicamba and 2-4-D to deal with glyphosate-resistant weeds raises concerns regarding human health and environmental risks. This study aimed to evaluate the effects of developmental exposure to glyphosate and a herbicide mixture containing glyphosate, dicamba and 2-4-D on rat dams' kidney and thyroid function and offspring's health. Pregnant Wistar rats were exposed from day-6 of gestation till weaning to regulatory relevant doses of glyphosate corresponding to the European Union (EU) acceptable daily intake (ADI; 0.5 mg/kg bw/day), and the no-observed-adverse-effect level (NOAEL; 50 mg/kg bw/day), and to a mixture of glyphosate, dicamba and 2,4-D all at the EU ADI (0.5, 0.002 and 0.3 mg/kg bw/day) respectively. After weaning the dams were sacrificed and blood and organs were collected. The pups' health was assessed by measuring viability, gestational and anogenital indices. Perinatal exposure to GLY alone and the herbicide mixture resulted in anti-androgenic effects in male offspring. In dams, exposure to glyphosate resulted in kidney glomerular and tubular dysfunction as well as increased thyroid hormone levels in a dose-dependent manner. Furthermore, exposure to the herbicide mixture resulted in effects similar to those observed with glyphosate at the NOAEL, suggesting at least an additive effect of the herbicide mixture at doses individually considered safe for humans.

Fetal Organophosphate Pesticide Exposure and Child Adiposity Measures at 10 Years of Age in the General Dutch Population

BACKGROUND

Fetal exposure to organophosphate (OP) pesticides might lead to fetal metabolic adaptations, predisposing individuals to adverse metabolic profiles in later life.

OBJECTIVE

We examined the association of maternal urinary OP pesticide metabolite concentrations in pregnancy with offspring body mass index (BMI) and fat measures at 10 years of age.

METHODS

Between 2002 and 2006, we included 642 mother-child pairs from the Generation R Study, a population-based prospective cohort study in Rotterdam, the Netherlands. We measured maternal urinary concentrations of OP pesticide metabolites, namely, dialkyl phosphates, including three dimethyl and three diethyl phosphates in early-, mid- and late-pregnancy. At 10 years of age, child total and regional body fat and lean mass were measured through dual energy X-ray absorptiometry, and abdominal and organ fat through magnetic resonance imaging.

RESULTS

Higher maternal urinary pregnancy-average or trimester-specific dialkyl, dimethyl, or diethyl phosphate concentrations were not associated with childhood BMI and the risk of overweight. In addition, we did not observe any association of dialkyl, dimethyl, or diethyl phosphate concentrations with total and regional body fat, abdominal visceral fat, liver fat, or pericardial fat at child age of 10 y.

CONCLUSION

We observed no associations of maternal urinary dialkyl concentrations during pregnancy with childhood adiposity measures at 10 years of age. Whether these associations develop at older ages should be further studied. https://doi.org/10.1289/EHP12267.

Prenatal exposure to organophosphate and pyrethroid insecticides and the herbicide 2,4-dichlorophenoxyacetic acid and size at birth in urban pregnant women

BACKGROUND

Organophosphate insecticides and the herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D) are used to protect crops or control weeds. Pyrethroids are used to manage pests both in agriculture and in residences, and to reduce the transmission of insect-borne diseases. Several studies have reported inverse associations between exposure to organophosphates (as a larger class) and birth outcomes but these associations have not been conclusive for pyrethroids or 2,4-D, specifically. We aimed to investigate the association between birth outcomes and urinary biomarkers of pyrethroids, organophosphates and 2,4-D among healthy pregnant women living in New York City.

METHODS

We quantified urinary biomarkers of 2,4-D and of organophosphate and pyrethroid insecticides from 269 women from two cohorts: a) Thyroid Disruption And Infant Development (TDID) and b) Sibling/Hermanos cohort (S/H). We used weighted quantile sum regression and multivariable linear regression models to evaluate the associations between a mixture of urinary creatinine-adjusted biomarker concentrations and birth outcomes of length, birthweight and head circumference, controlling for covariates. We also used linear regression models and further classified biomarkers concentrations into three categories (i: non-detectable; ii: between the limit of detection and median; and iii: above the median) to investigate single pesticides' association with these birth outcomes. Covariates considered were delivery mode, ethnicity, marital status, education, income, employment status, gestational age, maternal age and pre-pregnancy BMI. Analyses were conducted separately for each cohort and stratified by child sex within each cohort.

RESULTS

In TDID cohort, we found a significant inverse association between weighted quantile sum of mixture of pesticides and head circumference among boys. We found that the urinary biomarkers of organophosphate chlorpyrifos, TCPy, and 2,4-D had the largest contribution to the overall mixture effect in the TDID cohort among boys (b = -0.57, 95%CI: -0.92, -0.22) (weights = 0.81 and 0.16 respectively) but not among girls. In the multivariable linear regression models, we found that among boys, for each log unit increase in 3,5,6-trichloro-2-pyridinol (TCPy, metabolite of organophosphate chlorpyrifos) in maternal urine, there was a -0.56 cm decrease in head circumference (95%CI: -0.92, -0.19). Among boys in the TDID cohort, 2,4-D was associated with smaller head circumference in the second (b = -1.57; 95%CI: -2.74, -0.39) and third (b = -1.74, 95%CI: -2.98, -0.49) concentration categories compared to the first. No associations between pyrethroid and organophosphate biomarkers and birth outcomes were observed in girls analyzed in WQS regression or individually in linear regression models in TDID cohort. In the S/H cohort, head circumference increased with higher concentrations of 3-phenoxybenzoic acid (3-PBA, a biomarker of several pyrethroids) (b = 0.53, 95%CI: 0.03, 1.04) among boys and head circumference was lower among girls in the high compared to low category of 2,4-D (b = -2.27, 95%CI: - 3.98, -0.56). Birth length was also positively associated with the highest concentration of 2,4-D compared to the lowest among boys (b = 4.01, 95%CI: 0.02,8.00).

CONCLUSIONS

Weighted quantile sum of pesticides was negatively associated with head circumference among boys in one cohort. Nonetheless, due to directional homogeneity assumption in WQS no positive associations were detected. In linear regression models with individual pesticides, concentrations of TCPy were inversely associated with head circumference in boys and higher concentrations of 2,4-D was inversely associated with head circumference among girls; 2,4-D concentrations were also associated with higher birth length among boys. Concentrations of 3-PBA was positively associated with head circumference among boys.

Residential proximity to pesticide applications in Argentine Patagonia: impact on pregnancy and newborn parameters

Among residents living close to agricultural fields who are potentially exposed to pesticides, pregnant women and their fetuses are of particular concern for their vulnerability to environmental chemicals. In this collaborative multicenter study, we covered a wide distribution of participants in the most important fruit production zone of north Patagonia (Argentina) to investigate whether maternal residential proximity to fruit croplands with intense pesticide applications (rural group -RG-) is associated with pregnancy complications and alterations in their newborn parameters compared to the urban population (urban group -UG-). A total of 776 pregnant women met the inclusion criteria. The percentage of threatened miscarriage was significantly higher in the RG than in the UG. The percentage of miscarriage, threat of premature labor, intrauterine fetal death, preterm premature rupture of membranes, and intrauterine growth retardation were similar in both groups. Newborn anthropometric parameters were corrected by sex and gestational age prior to statistical analysis. Length at birth and head circumference were lower in the RG than in the UG. Birth weight was similar in both groups. The percentage of head circumference less than the 5th percentile and the ponderal index were greater in the RG than in the UG. Our results suggest that proximity to pesticide applications may increase the risk of pregnancy complications and altered newborn parameters.

Perinatal effects of persistent organic pollutants on thyroid hormone concentration in placenta and breastmilk

Thyroid hormones (TH) are known to play a critical role in regulating many biological processes including growth and development, energy homeostasis, thermogenesis, lipolysis and metabolism of cholesterol. Severe TH deficiency especially during fetal development results in cretinism, but can also lead to an imbalance in metabolism with, among others, an alteration in body weight composition. Over the past two decades, increasing evidence has shown that certain persistent organic pollutants (POP) can interfere with the endocrine system. These POP referred to as "endocrine disrupting chemicals" are widely present in the environment and populations are exposed globally. Moreover, epidemiological studies have shown that a particularly sensitive period is the pre- and postnatal time. Indeed, perinatal exposure to such chemicals could lead to the onset diseases in later life. It is known, that, maternal thyroid hormones are transported by the placenta to the fetus from 6 weeks of gestation and it seems that during the first trimester, and part of the second, the fetus is entirely dependent on maternal TH supply for its development. Interferences in the TH-network as a consequence of the exposure to such pollutants could cause variations in TH concentration. Only small changes in maternal thyroid hormone levels in early stages of pregnancy can influence fetal neurological and cardiovascular development, as well as according to recent studies, have effect on childhood body composition. With this review, we will report the most recent and important studies concerning the association between thyroid hormone concentration and POP levels measured during the perinatal period. We will mostly focus on the data recently reported on placenta and breastmilk as main sources for understanding the potential consequences of exposure. The possible link between exposure to pollutants, TH dysregulation and possible adverse outcome will also be briefly discussed. From our literature search, several studies support the hypothesis that pre- and postnatal exposure to different pollutants might play a role in causing variation in thyroid hormone concentration. However, few research papers have so far studied the relationship linking exposure to pollutants, TH concentration and possible health consequences. Therefore, this review highlights the need for further research in this direction.

The LH/FSH ratio is not a sex-dimorphic marker after infancy: data from 6417 healthy individuals and 125 patients with Differences of Sex Development

STUDY QUESTION

What is the course of the LH/FSH ratio from infancy into adulthood in healthy individuals and in patients with Differences of Sex Development (DSD)?

SUMMARY ANSWER

The LH/FSH ratio had a marked overlap between the sexes after infancy and onwards throughout adulthood in healthy individuals and it was not a marker of hypogonadism in DSD patients.

WHAT IS KNOWN ALREADY

The LH/FSH ratio is a distinct marker of sex during minipuberty. No study has evaluated the LH/FSH ratio from infancy into adulthood.

STUDY DESIGN, SIZE, DURATION

This was a combined study of prospective longitudinal and cross-sectional cohorts of healthy individuals totaling 6417 males and females aged 0-80 years. Retrospective data from a single, tertiary center on 125 patients with DSD was also included.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Based on the healthy males (n = 3144) and females (n = 3273) aged 0-80 years, reference ranges for LH, FSH and the LH/FSH ratio were established from infancy (after minipuberty) and onwards. LH, FSH, and the LH/FSH ratio in 125 patients with DSD not undergoing treatment were compared to the reference ranges. Included DSD diagnoses were: Klinefelter syndrome including mosaic variants (males: n = 14), Turner syndrome including mosaic variants without Y-chromosome material (females: n = 48), 45,X/46,XY mosaicism (males: n = 24 and females: n = 6), partial androgen insensitivity syndrome (males: n = 11), complete androgen insensitivity syndrome (females: n = 13) and anorchia (males: n = 9).

MAIN RESULTS AND THE ROLE OF CHANCE

An overlap was observed in the LH/FSH ratio reference curves between males and females. However, when comparing the sexes at specific time points, the LH/FSH ratio was significantly higher in healthy males during childhood and adulthood and significantly higher in healthy females during puberty. When compared with healthy participants, male patients with anorchia and 45,X/46,XY mosaicism had significantly lower ratios, while patients with androgen insensitivity, regardless of sex, had significantly higher ratios.

LIMITATIONS, REASONS FOR CAUTION

The limitations of this study include that; (i) all healthy individuals were Caucasian, so conclusions may not apply to non-Caucasians; (ii) the calculated LH/FSH ratios were restricted to the specific analytical method used and may not be applicable to other laboratories; (iii) the samples from healthy individuals were stored for varying amounts of time up to 20 years which may affect the durability; and (iv) DSD diagnoses are heterogeneous thus making sturdy conclusions across diagnoses impossible.

WIDER IMPLICATIONS OF THE FINDINGS

In this study of combined cohorts of healthy participants, the largest normative ranges of LH, FSH, and the LH/FSH ratio to date were created. These reference ranges provide the opportunity for clinical as well as research use for all three markers. However, the previously rather undescribed LH/FSH ratio was not a distinct marker of sex after infancy nor a new marker of hypogonadism. Although there were significant differences between subgroups of DSD patients compared to healthy controls, the clinical significance of the LH/FSH ratio after infancy lacked. However, it can be speculated whether there are other areas of clinical application not investigated in this article, for example as a marker of fertility in select patient groups. As gonadotropin assays are readily available and gonadotropin measurements are part of regular workups, the LH/FSH ratio can easily be explored in further research without additional costs.

STUDY FUNDING/COMPETING INTEREST(S)

M.L.L. was funded by the Absalon Foundation. Cohort 1 was funded by the European Commission, through the Biomed 2 Program (BMH4-CT96-0314), Environmental Reproductive Health (QLK4-CT1999-01422) and EXPORED (QLK4-2001-00269), by the Danish Council for Independent Research (9700833 and 9700909), and by the Svend Andersens Foundation. Cohort 2 was funded by the Danish Environmental Research Program (96.01.015.16.05). Cohort 3 was funded by Kirsten and Freddy Johansens Foundation.

TRIAL REGISTRATION NUMBER

NA.

DATE OF FIRST PATIENT’S ENROLMENT

June 1990 (the launch of the department from which this project stems).

The effect of non-organophosphate household pesticides exposure during pregnancy on infants birth sizes and growth rate: a cohort study

Background

To date, there is limited evidence on the effect of antenatal exposure to non-organophosphate household pesticides on infant health. Our hypothesis is that antenatal exposure to non-organophosphate household pesticides will be associated with birth sizes and infant growth rate.

Methods

In this prospective cohort study, 284 mother-infant pairs were studied. Mothers were recruited at the third trimester in two primary care centers and one private hospital in Jakarta, Indonesia. Mothers filled out questionnaires about exposure to non-organophosphate household pesticides at the 3rd trimester of pregnancy. Birth weight and length were measured at birth. Afterwards, the weight, height, and head circumference (HC) were measured at 7 days, 1, 2, 4, and 6 months of age. Linear mixed modeling and linear regression was performed to calculate growth rate of each infant. Multivariable linear regression adjusted for confounders was used to assess the association between household pesticides exposure and birth sizes and infant growth rate.

Results

Based on self-report questionnaires, 133 (46.8%) mothers were exposed to household pesticides during pregnancy. The mean HC at day 7 in the exposed group was − 7.1 mm (95%CI -13.1;-1.2) lower than in the non-exposed group. The difference was more prominent in the non-mosquito pesticide group (linear regression coefficient: − 22.1 mm, 95%CI -36.5;-7.6). No material associations were found between antenatal exposure to household pesticides with other growth measures, including weight gain, length gain, HC increment and weight-to-length gain rates. No modification of effects by breastfeeding was found.

Conclusions

Our findings suggest that antenatal exposure to household non-organophosphate pesticides is associated with smaller head circumference at birth.

Association of prenatal pesticide exposures with adverse pregnancy outcomes and stunting in rural Bangladesh

BACKGROUND

Pesticide exposure during pregnancy is thought to adversely affect fetal growth, which in turn may impact child growth, but results have been inconsistent across studies and few have explored these effects in developing countries.

OBJECTIVES

To quantify urinary concentrations of pesticide biomarkers in early pregnancy (<16 weeks' gestation), and to estimate the association of these concentrations with preterm birth, low birth weight, small for gestational age, and stunting at ~1 and 2 years of age.

METHODS

Eight pesticide biomarkers were quantified in urine collected from 289 pregnant women (aged 18-40 years) participating in a birth cohort study in Bangladesh. Anthropometry measurements were conducted on the index child at birth and approximately 1 and 2 years of age. A directed acyclic graph was used to identify minimal sufficient adjustment sets. Log-binomial regression was used to estimate the relative risk (RR) with 95% confidence intervals (CI).

RESULTS

3,5,6-trichloro-2-pyridinol (TCPY), a metabolite of chlorpyrifos and chlorpyrifos methyl, and 4-nitrophenol, a metabolite of parathion and methyl parathion, were detected in nearly all women with geometric mean (95% CI) values of 3.17 (2.82-3.56) and 18.66 (17.03-20.46) µg/g creatinine, respectively. 3-phenoxybenzoic acid (3-PBA), a non-specific metabolite of several pyrethroids, and 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMPY), a diazinon metabolite, were detected in 19.8% and 16.1% of women, respectively. The remaining four pesticide biomarkers were detected in <10% of women. Women in the highest quartile of 4-nitrophenol were more than 3 times more likely to deliver preterm than women in the lowest quartile: unadjusted RR (95% CI), 3.57 (1.65, 7.73). Women in the highest quartile of 4-nitrophenol were also at increased risk of having a child born small for gestational age: RR (95% CI) adjusted for household income, maternal education, and maternal total energy and meat intake, 3.81 (1.10, 13.21). Women with detectable concentrations of IMPY were at increased risk of having a child born with low birth weight compared to women with non-detectable concentrations: adjusted RR (95% CI), 2.13 (1.12, 4.08). We observed no association between any of the pesticide biomarkers and stunting at 1 or 2 years of age.

DISCUSSION

Exposure to the insecticides parathion and diazinon during early pregnancy may increase the risk of adverse birth outcomes.

Para-occupational exposure to pesticides, PON1 polymorphisms and hypothyroxinemia during the first half of pregnancy in women living in a Mexican floricultural area

BACKGROUND

Adequate maternal thyroxine (T4) concentrations during the first half of pregnancy are fundamental to the embryo's or fetus' neural development. Organophosphate pesticides (OP) can act as thyroid disruptors and genetic polymorphisms for paraoxonase 1 (PON1), an enzyme that detoxifies OP, could be involved in individual's susceptibility to them. We assessed the association between para-occupational exposure to pesticides, including OP, during pregnancy and maternal hypothyroxinemia, as well as the potential genetic susceptibility conferred by PON1 polymorphisms.

METHODS

We analyzed information from 381 healthy pregnant women (< 17 gestational weeks), who lived in a floricultural region of Mexico where pesticides, including OP, are routinely used. Women who were para-occupationally exposed to pesticides were those whose partner had an occupation involving contact with these products. Thyroid-Stimulating Hormone (TSH) and free T4 concentrations were determined using ELISA, and hypothyroxinemia was defined as free T4 concentrations <0.76 ng/dL. PON1192QR, PON155LM and PON1-108CT polymorphisms were determined through Polymerase Chain Reaction (PCR). The association between para-occupational exposure and genetic polymorphisms and hypothyroxinemia was estimated using logistic regression models.

RESULTS

One hundred and sixty two women (42.52%) were classified as para-occupationally exposed to pesticides. Hypothyroxinemia prevalence was 54%, and it was not significantly associated with pesticide para-occupational exposure (OR: 1.21 95% CI 0.75-1.94). Independently of para-occupational exposure, the likelihood of hypothyroxinemia was higher among women who were carriers of PON155MM than in those with PON155LL genotype (OR _{MM vs LL}: 3.03; 95%CI 1.62, 5.70). PON1192 RR (OR _{RR vs QQ}: 1.72; 95%CI 0.93, 3.17) and PON1-108TT (OR _{TT vs CC}: 1.60; 95%CI 0.90, 2.70) genotypes were marginally associated with hypothyroxinemia. No significant interaction was observed between pesticides para-occupational exposure and PON1 polymorphisms.

CONCLUSIONS

These results suggest that PON1 polymorphisms could affect thyroid function during pregnancy in women living in areas where pesticides, including OP, are routinely used. Low exposure variability in this population, could be a possible explanation for the lack of association between para-occupational exposure and thyroid function.

Diet and Contaminants: Driving the Rise to Obesity Epidemics?

The obesity epidemic is spreading worldwide without reversal trend and despite specific policies oriented to dietary habits and lifestyle, which seem to have modest effects. Genetic factors only partly explain the rise, whereas environmental factors seem to play a key role, mainly by gene-environment interactions through epigenetic mechanisms. A number of animal and human studies point to maternal diet, intestinal microbiota and chemicals introduced as contaminants with food, all factors able to increase the risk of obesity. Widely diffused toxics (mainly BPA, phthalates, pesticides) are able to promote obesity in children and adults, mainly by acting on the differentiation pathway linking multipotent stromal stem cell to mature adipocyte, modulating epigenetic factors and influencing a series of mechanisms finally leading to altered dietary habits, increased adipocyte formation and fat storage. Furthermore, the adipose tissue is an important target for several chemicals (mainly POPs) which represent a threat to metabolic health. In conclusion, besides excessive individual energy intake and inadequate lifestyle, other broadly diffused and modifiable factors (mainly ingestion of toxic chemicals with food) seem to have a critical role in the rapid epidemiological growing of obesity, also considering trans-generational transmission of risk and later development of obesity due to exposure during early life. Further studies are needed, to better assess interactions between cumulative effects of toxic food contaminants and modification of diet and lifestyle, and to verify the efficacy of primary prevention strategies acting on all these factors and potentially able to reverse the continuous rising of the obesity epidemic.

Prenatal pesticide exposure associated with glycated haemoglobin and markers of metabolic dysfunction in adolescents

BACKGROUND

Pesticide exposure has been associated with increased risk of diabetes mellitus in adults, but potential effects of prenatal exposure on glucose regulation have not been investigated. The aim of this study was to investigate if maternal occupational pesticide exposure in pregnancy was associated with glycated haemoglobin A1c (HbA1c) in adolescents and whether an association was modified by sex and paraoxonase-1 (PON1) Q192R polymorphism.

METHODS

A prospective cohort study of children whose mothers were either occupationally exposed or unexposed to pesticides in early pregnancy. At age 10-to-16 years, the children (n = 168) underwent clinical examinations including pubertal stage assessment (accepted by 141 children) and blood sampling. PON1 Q192R genotype was available for 139 children and 103 mothers. The main outcome measure was HbA1c but other relevant biomarkers were also included.

RESULTS

Prenatal pesticide exposure was associated with a 5.0% (95% confidence interval: 1.8; 8.2) higher HbA1c compared to unexposed children after adjustment for confounders. After stratification, the association remained significant for girls (6.2% (1.6; 11.1)) and if the child or the mother had the PON1 192R-allele (6.1% (1.6; 10.8) and 7.1% (2.0; 12.6), respectively). Besides, an exposure-related increase was seen for the leptin-to-adiponectin ratio, for plasminogen activator inhibitor type-1 in girls, and for interleukin-6 in children whose mothers had the R-allele.

CONCLUSION

Prenatal pesticide exposure was associated with higher HbA1c and changes in related biomarkers in adolescents. Our results suggest an adverse effect on glucose homeostasis and support previous findings from this cohort of an exposure-associated metabolic risk profile with higher susceptibility related to female sex and the PON1 192R-allele.

Childhood Residential and Agricultural Pesticide Exposures in Relation to Adult-Onset Rheumatoid Arthritis in Women

Farming and pesticide exposure may influence risk of rheumatoid arthritis (RA); the role of early-life pesticide exposure is unknown. The Sister Study includes a US national cohort of women aged 35-74 years (enrolled 2004-2009); we examined childhood pesticide exposure in women in this cohort with adult-onset RA. Cases (n = 424) were compared with 48,919 noncases. Data included pesticide use at the longest childhood residence through age 14 years, farm residence of at least 12 months with agricultural pesticide exposure through age 18 years, and maternal farm experience. Odds ratios and 95% confidence intervals were adjusted for age, race or ethnicity, education, smoking, and childhood socioeconomic factors. Cases with RA reported more frequent and direct (personal) residential pesticide use in childhood (for infrequent/indirect pesticide use, odds ratio (OR) = 1.1; for frequent/direct use, OR = 1.8; P for trend = 0.013). Compared with women without residential farm history, odds of having RA increased for those reporting a childhood-only farm residence with personal exposure to pesticides used on crops (OR = 1.8, 95% confidence interval: 1.1, 2.9) or livestock (OR = 2.0, 95% confidence interval: 1.2, 3.3). Our findings suggest adult-onset RA may be related to childhood exposure to residential and agricultural pesticides, and support further investigations of lifetime pesticide use in RA.

Effects on metabolic parameters in young rats born with low birth weight after exposure to a mixture of pesticides

Pesticide exposure during fetal life can lead to low birth weight and is commonly observed in reproductive toxicology studies. Associations have also been found in low birth weight babies born from pesticide-exposed gardeners. Since low birth weight is also linked to metabolic disorders, it can be speculated that early life exposure to pesticides could increase the risk of becoming obese or developing diabetes later in life. We have analyzed potential long-term effects of gestational and lactational exposure to a low dose mixture of six pesticides that individually can cause low birth weight: Cyromazine, MCPB, Pirimicarb, Quinoclamine, Thiram, and Ziram. Exposed male offspring, who were smaller than controls, displayed some degree of catch-up growth. Insulin and glucagon regulation was not significantly affected, and analyses of liver and pancreas did not reveal obvious histopathological effects. Efforts towards identifying potential biomarkers of metabolic disease-risk did not result in any strong candidates, albeit leptin levels were altered in exposed animals. In fat tissues, the key genes Lep, Nmb and Nmbr were altered in high dosed offspring, and were differentially expressed between sexes. Our results suggest that early-life exposure to pesticides may contribute to the development of metabolic disorders later in life.

Human health implications of organic food and organic agriculture: a comprehensive review

This review summarises existing evidence on the impact of organic food on human health. It compares organic vs. conventional food production with respect to parameters important to human health and discusses the potential impact of organic management practices with an emphasis on EU conditions. Organic food consumption may reduce the risk of allergic disease and of overweight and obesity, but the evidence is not conclusive due to likely residual confounding, as consumers of organic food tend to have healthier lifestyles overall. However, animal experiments suggest that identically composed feed from organic or conventional production impacts in different ways on growth and development. In organic agriculture, the use of pesticides is restricted, while residues in conventional fruits and vegetables constitute the main source of human pesticide exposures. Epidemiological studies have reported adverse effects of certain pesticides on children's cognitive development at current levels of exposure, but these data have so far not been applied in formal risk assessments of individual pesticides. Differences in the composition between organic and conventional crops are limited, such as a modestly higher content of phenolic compounds in organic fruit and vegetables, and likely also a lower content of cadmium in organic cereal crops. Organic dairy products, and perhaps also meats, have a higher content of omega-3 fatty acids compared to conventional products. However, these differences are likely of marginal nutritional significance. Of greater concern is the prevalent use of antibiotics in conventional animal production as a key driver of antibiotic resistance in society; antibiotic use is less intensive in organic production. Overall, this review emphasises several documented and likely human health benefits associated with organic food production, and application of such production methods is likely to be beneficial within conventional agriculture, e.g., in integrated pest management.

Integration of in silico methods and computational systems biology to explore endocrine-disrupting chemical binding with nuclear hormone receptors

Thousands of potential endocrine-disrupting chemicals present difficult regulatory challenges. Endocrine-disrupting chemicals can interfere with several nuclear hormone receptors associated with a variety of adverse health effects. The U.S. Environmental Protection Agency (U.S. EPA) has released its reviews of Tier 1 screening assay results for a set of pesticides in the Endocrine Disruptor Screening Program (EDSP), and recently, the Collaborative Estrogen Receptor Activity Prediction Project (CERAPP) data. In this study, the predictive ability of QSAR and docking approaches is evaluated using these data sets. This study also presents a computational systems biology approach using carbaryl (1-naphthyl methylcarbamate) as a case study. For estrogen receptor and androgen receptor binding predictions, two commercial and two open source QSAR tools were used, as was the publicly available docking tool Endocrine Disruptome. For estrogen receptor binding predictions, the ADMET Predictor, VEGA, and OCHEM models (specificity: 0.88, 0.88, and 0.86, and accuracy: 0.81, 0.84, and 0.88, respectively) were each more reliable than the MetaDrug™ model (specificity 0.81 and accuracy 0.77). For androgen receptor binding predictions, the Endocrine Disruptome and ADMET Predictor models (specificity: 0.94 and 0.8, and accuracy: 0.78 and 0.71, respectively) were more reliable than the MetaDrug™ model (specificity 0.33 and accuracy 0.4). A consensus approach is proposed that reaches general agreement among the models (specificity 0.94 and accuracy 0.89). This study integrates QSAR, docking, and systems biology approaches as a virtual screening tool for use in risk assessment. As such, this systems biology pathways and network analysis approach provides a means to more critically assess the potential effects of endocrine-disrupting chemicals.

Combined exposure to low doses of pesticides causes decreased birth weights in rats

Decreased birth weight is a common effect of many pesticides in reproductive toxicity studies, but there are no empirical data on how pesticides act in combination on this endpoint. We hypothesized that a mixture of six pesticides (cyromazine, MCPB, pirimicarb, quinoclamine, thiram, and ziram) would decrease birth weight, and that these mixture effects could be predicted by the Dose Addition model. Data for the predictions were obtained from the Draft Assessment Reports of the individual pesticides. A mixture of equi-effective doses of these pesticides was tested in two studies in Wistar rats, showing mixture effects in good agreement with the additivity predictions. Significantly lower birth weights were observed when compounds were present at individual doses below their no-observed adverse effect levels (NOAELs). These results emphasize the need for cumulative risk assessment of pesticides to avoid potentially serious impact of mixed exposure on prenatal development and pregnancy in humans.

Interaction between prenatal pesticide exposure and a common polymorphism in the PON1 gene on DNA methylation in genes associated with cardio-metabolic disease risk-an exploratory study

BACKGROUND

Prenatal environmental conditions may influence disease risk in later life. We previously found a gene-environment interaction between the paraoxonase 1 (PON1) Q192R genotype and prenatal pesticide exposure leading to an adverse cardio-metabolic risk profile at school age. However, the molecular mechanisms involved have not yet been resolved. It was hypothesized that epigenetics might be involved. The aim of the present study was therefore to investigate whether DNA methylation patterns in blood cells were related to prenatal pesticide exposure level, PON1 Q192R genotype, and associated metabolic effects observed in the children.

METHODS

Whole blood DNA methylation patterns in 48 children (6-11 years of age), whose mothers were occupationally unexposed or exposed to pesticides early in pregnancy, were determined by Illumina 450 K methylation arrays.

RESULTS

A specific methylation profile was observed in prenatally pesticide exposed children carrying the PON1 192R-allele. Differentially methylated genes were enriched in several neuroendocrine signaling pathways including dopamine-DARPP32 feedback (appetite, reward pathways), corticotrophin releasing hormone signaling, nNOS, neuregulin signaling, mTOR signaling, and type II diabetes mellitus signaling. Furthermore, we were able to identify possible candidate genes which mediated the associations between pesticide exposure and increased leptin level, body fat percentage, and difference in BMI Z score between birth and school age.

CONCLUSIONS

DNA methylation may be an underlying mechanism explaining an adverse cardio-metabolic health profile in children carrying the PON1 192R-allele and prenatally exposed to pesticides.

Potential exposure to endocrine disrupting chemicals and selected adverse pregnancy outcomes: a follow-up study of pregnant women referred for occupational counselling

BACKGROUND

Experimental evidence indicates that fetal exposure to xenobiotics with the potential to interfere with the endogenous steroid hormone regulation of fetal development may reduce birth weight. However, epidemiological studies are limited. The aim of the study was to investigate whether potential occupational exposure to endocrine disrupting chemicals (EDC) of the mother during pregnancy is associated with preterm birth and low birth weight.

METHODS

Pregnant women referred to an Occupational Health Clinic (OHC) in two Danish regions (Copenhagen or Aarhus) between 1984 and 2010, suspected of being exposed to occupational reproductive hazards were included in the study. A job exposure matrix enabled estimation of potential occupational exposure to EDC on the basis of job title. Births by women potentially exposed to EDC (n = 582) were compared to births by women referred to an OHC on the suspicion of other exposures than EDC (n = 620), and to a sample of births by all occupationally active women in the same geographical regions (n = 346,544), including 1,077 births of the referred women's non-referred pregnancies.

RESULTS

No indications of reduced birth weight or increased risk of preterm birth were found among women potentially exposed to EDC. Women potentially exposed to EDC had children with a higher birth weight compared to the sample of occupationally active women but not compared to other women referred to an OHC.

CONCLUSIONS

Potential maternal exposure to EDC at Danish workplaces is not related to low birth weight or preterm birth among women referred to occupational counselling. Occupational exposures might be too weak on the average to cause these adverse effects or counselling at the OHCs is effective in preventing them.

Occupational Exposure to Endocrine-Disrupting Chemicals and Birth Weight and Length of Gestation: A European Meta-Analysis

BACKGROUND

Women of reproductive age can be exposed to endocrine-disrupting chemicals (EDCs) at work, and exposure to EDCs in pregnancy may affect fetal growth.

OBJECTIVES

We assessed whether maternal occupational exposure to EDCs during pregnancy as classified by application of a job exposure matrix was associated with birth weight, term low birth weight (LBW), length of gestation, and preterm delivery.

METHODS

Using individual participant data from 133,957 mother-child pairs in 13 European cohorts spanning births from 1994 through 2011, we linked maternal job titles with exposure to 10 EDC groups as assessed through a job exposure matrix. For each group, we combined the two levels of exposure categories (possible and probable) and compared birth outcomes with the unexposed group (exposure unlikely). We performed meta-analyses of cohort-specific estimates.

RESULTS

Eleven percent of pregnant women were classified as exposed to EDCs at work during pregnancy, based on job title. Classification of exposure to one or more EDC group was associated with an increased risk of term LBW [odds ratio (OR) = 1.25; 95% CI: 1.04, 1.49], as were most specific EDC groups; this association was consistent across cohorts. Further, the risk increased with increasing number of EDC groups (OR = 2.11; 95% CI: 1.10, 4.06 for exposure to four or more EDC groups). There were few associations (p < 0.05) with the other outcomes; women holding job titles classified as exposed to bisphenol A or brominated flame retardants were at higher risk for longer length of gestation.

CONCLUSION

Results from our large population-based birth cohort design indicate that employment during pregnancy in occupations classified as possibly or probably exposed to EDCs was associated with an increased risk of term LBW. Citation: Birks L, Casas M, Garcia AM, Alexander J, Barros H, Bergström A, Bonde JP, Burdorf A, Costet N, Danileviciute A, Eggesbø M, Fernández MF, González-Galarzo MC, Gražulevičienė R, Hanke W, Jaddoe V, Kogevinas M, Kull I, Lertxundi A, Melaki V, Andersen AM, Olea N, Polanska K, Rusconi F, Santa-Marina L, Santos AC, Vrijkotte T, Zugna D, Nieuwenhuijsen M, Cordier S, Vrijheid M. 2016. Occupational exposure to endocrine-disrupting chemicals and birth weight and length of gestation: a European meta-analysis. Environ Health Perspect 124:1785-1793; http://dx.doi.org/10.1289/EHP208.

Developmental Exposure to Environmental Chemicals and Metabolic Changes in Children

The incidence of childhood obesity, type 2 diabetes, and other forms of metabolic disease have been rising over the past several decades. Although diet and physical activity play important roles in these trends, other environmental factors also may contribute to this significant public health issue. In this article, we discuss the possibility that widespread exposure to endocrine-disrupting chemicals (EDCs) may contribute to the development of metabolic diseases in children. We summarize the epidemiological evidence on exposure to environmental chemicals during early development and metabolic outcomes in infants and children. Prenatal exposure to EDCs, particularly the persistent organic pollutant DDT and its metabolite DDE, may influence growth patterns during infancy and childhood. The altered growth patterns associated with EDCs vary according to exposure level, sex, exposure timing, pubertal status, and age at which growth is measured. Early exposure to air pollutants also is linked to impaired metabolism in infants and children. As a result of these and other studies, professional health provider societies have called for a reduction in environmental chemical exposures. We summarize the resources available to health care providers to counsel patients on how to reduce chemical exposures. We conclude with a discussion of environmental policies that address chemical exposures and ultimately aim to improve public health.

Organochlorine pesticides and female puberty in South Kazakhstan

The purpose of the study was to assess the puberty of females living in cotton-growing regions of South Kazakhstan, where organochlorine pesticides are widely used. The physical growth and sexual development were assessed; organochlorine pesticides, gonadotropic and steroid hormones, as well as insulin-like growth factor 1 in the peripheral blood were determined. 524 females (adolescents aged 10-17) were examined. They were divided into 2 groups, depending on their place of residence. The clinical research included the assessment of physical and sexual development. All examined females lived in rural areas, i.e. they were comparable in terms of social, welfare, and climatographic factors. A high concentration of organochlorine pesticides (lindane-18.51±0.16mg/l, dieldrin-169.16±3.13mg/l, DDT-177.78±2.71mg/l, endrin-37.57±0.9mg/l) in the blood of females living in regions exposed to pesticides compared to their peers (4.05±0.41mg/l, 30.8±3.7mg/l, 109.7±2.58mg/l, 4.85±0.69mg/l respectively) was found (p<0.001). The physical and sexual development of such females was delayed. The research established a correlation between the concentration of pesticides and the endocrine status, as well as with the insulin-like growth factor 1. This shows the adverse effect of organochlorine pesticides on the development of the female reproductive system during puberty.

Prenatal pesticide exposure and PON1 genotype associated with adolescent body fat distribution evaluated by dual X-ray absorptiometry (DXA)

Many modern pesticides have endocrine disrupting abilities and early-life exposure may affect growth and disease risk later in life. Previously, we reported associations between prenatal pesticide exposure and higher childhood body fat content measured by anthropometry. The associations were affected by child PON1 Q192R genotype. We aimed to study whether prenatal pesticide exposure was still associated with body fat content and distribution in the children at puberty and the potential impact of both maternal and child PON1 Q192R genotype. In this prospective cohort study of 247 children born by occupationally exposed or unexposed women (greenhouse workers and controls) two follow-up examinations (age 10-15 and 11-16 years) including simple anthropometry, skinfold measurements, pubertal staging and blood sampling were performed. Total and regional fat% was determined by dual X-ray absorptiometry (DXA) at age 10-15. Prenatal pesticide exposure was associated with increased total, android, and gynoid fat percentage (DXA) at age 10-15 years after adjustment for sex, socioeconomic status, and puberty (all β = 0.5 standard deviation score (SDS) p < 0.05). Stratified by sex, the associations were significant in girls (total fat: β = 0.7 SDS, android-gynoid ratio: β = 0.1, both p < 0.05), but not in boys. Carrying the R-allele (child or mother, separately, or both) augmented the differences between exposed and unexposed children (total fat: β = 1.0 SDS, β = 0.8 SDS, p < 0.05, respectively, and β = 1.2 SDS, p < 0.01). No exposure-related differences were found if either the child or mother had the QQ wild-type. At age 11-16, exposed children tended to have a higher total fat% estimated by skinfolds than unexposed children (p = 0.06). No significant associations between prenatal exposure and body mass index or waist circumference were found. Prenatal pesticide exposure was associated with higher adolescent body fat content, including android fat deposition, independent of puberty. Girls appeared more susceptible than boys. Furthermore, the association depended on maternal and child PON1 Q192R genotype.

Exposure to non-persistent pesticides and thyroid function: A systematic review of epidemiological evidence

Numerous pesticides are recognized for their endocrine-disrupting properties. Non-persistent pesticides such as organophosphates, dithiocarbamates and pyrethroids may interfere with thyroid function as suggested by animal studies. However, the influence of chronic exposure to these compounds on thyroidal functions in humans remains to be determined. The present study aimed to review epidemiological evidence for an association between exposure to non-persistent pesticides and circulating levels of thyroid hormones (thyroxin [T4] and triiodothyronine [T3]) and thyroid-stimulating hormone (TSH). A systematic review was conducted using MEDLINE, SCOPUS and Virtual Health Library (BVS) databases. Articles were limited to original studies and reports published in English, Portuguese or Spanish. Nineteen epidemiological studies were identified, 17 of which were cross-sectional, 14 were of occupationally exposed workers and 11 used exposure biomarkers. Fungicides and organophosphates (OP) insecticides were the most studied pesticides. Although methodological heterogeneity between studies was noted, particularly regarding study design, exposure assessment, and control of confounding, most of them showed associations with changes in T3 and T4, and/or TSH levels, while results from a few of these are consistent with experimental data supporting the findings that non-persistent pesticide exposure exerts hypothyroid-like effects. However, reporting quality was moderate to poor in 50% of the studies, particularly regarding method of selection of participants and discussion of external validity. Overall, current knowledge regarding the impact of non-persistent pesticides on human thyroid function is still limited. Given the widespread use of pesticides, future research should assess effects of exposure to currently-used pesticides in cohort studies combining comprehensive questionnaire-based assessment and biomarkers. Investigators need to pay particular attention to exposure during critical windows of brain development and exposure in agricultural populations.

Environmental pollutants and child health-A review of recent concerns

In recent years, many new studies have evaluated associations between environmental pollutants and child health. This review aims to provide a broad summary of this literature, comparing the state of epidemiological evidence for the effects of a wide range of environmental contaminants (air pollutants, heavy metals, organochlorine compounds, perfluoroalkyl substances, polybrominated diphenyl ethers, pesticides, phthalates and bisphenol A) on child health outcomes. The review addresses effects on foetal growth and prematurity, neurodevelopment, respiratory and immune health, and childhood growth and obesity. Findings of recent prospective studies and meta-analyses have corroborated previous good evidence, often at lower exposure levels, for effects on foetal growth of air pollution and polychlorinated biphenyls (PCBs), for neurotoxic effects of lead, methylmercury, PCBs and organophosphate pesticides, and for respiratory health effects of air pollution. Moderate evidence has emerged for a potential role of environmental pollutants in attention deficit hyperactivity disorder and autism (lead, PCBs, air pollution), respiratory and immune health (dichlorodiphenyldichloroethylene - DDE - and PCBs), and obesity (DDE). In addition, there is now moderate evidence that certain chemicals of relatively recent concern may be associated with adverse child health outcomes, specifically perfluorooctanoate and foetal growth, and polybrominated diphenyl ethers and neurodevelopment. For other chemicals of recent concern, such as phthalates and bisphenol A, the literature is characterised by large inconsistencies preventing strong conclusions. In conclusion, since most of the recent literature evaluates common exposures in the general population, and not particularly high exposure situations, this accumulating body of evidence suggests that the unborn and young child require more protection than is currently provided. Large, coordinated research efforts are needed to improve understanding of long-term effects of complex chemical mixtures.

[Impact on human health of endocrine disruptors present in environmental water bodies: is there an association with obesity?]

There is growing evidence that endocrine disruptors (ED) may adversely affect humans. Surface and underground water are the main sources for obtaining potable water, however they can be contaminated with ED, which are not completely removed by conventional water and sewage treatment processes. Some health problems are related to the exposure of humans to ED, obesity being one of them. There is currently an increase in the prevalence of obesity worldwide, a fact that is considered a concern in view of its potential impact on the health care system, since obesity is the major risk factor of the leading chronic diseases including diabetes and cardiovascular disease. By means of a review of the literature, this paper sought to gather scientific publications linking exposure to ED with obesity, in order to verify the importance of removal of ED from water bodies, thereby preserving the population's health and aquatic biota. Most of the selected studies suggest an association between ED and obesity in humans.

Putative Epimutagens in Maternal Peripheral and Cord Blood Samples Identified Using Human Induced Pluripotent Stem Cells

The regulation of transcription and genome stability by epigenetic systems are crucial for the proper development of mammalian embryos. Chemicals that disturb epigenetic systems are termed epimutagens. We previously performed chemical screening that focused on heterochromatin formation and DNA methylation status in mouse embryonic stem cells and identified five epimutagens: diethyl phosphate (DEP), mercury (Hg), cotinine, selenium (Se), and octachlorodipropyl ether (S-421). Here, we used human induced pluripotent stem cells (hiPSCs) to confirm the effects of 20 chemicals, including the five epimutagens, detected at low concentrations in maternal peripheral and cord blood samples. Of note, these individual chemicals did not exhibit epimutagenic activity in hiPSCs. However, because the fetal environment contains various chemicals, we evaluated the effects of combined exposure to chemicals (DEP, Hg, cotinine, Se, and S-421) on hiPSCs. The combined exposure caused a decrease in the number of heterochromatin signals and aberrant DNA methylation status at multiple gene loci in hiPSCs. The combined exposure also affected embryoid body formation and neural differentiation from hiPSCs. Therefore, DEP, Hg, cotinine, Se, and S-421 were defined as an “epimutagen combination” that is effective at low concentrations as detected in maternal peripheral and cord blood.

Persistent organic pollutants as risk factors for type 2 diabetes

Type 2 diabetes mellitus (T2DM) is a major and fast growing public health problem. Although obesity is considered to be the main driver of the pandemic of T2DM, a possible contribution of some environmental contaminants, of which persistent organic pollutants (POPs) form a particular class, has been suggested. POPs are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes which enable them to persist in the environment, to be capable of long-range transport, bio accumulate in human and animal tissue, bio accumulate in food chains, and to have potential significant impacts on human health and the environment. Several epidemiological studies have reported an association between persistent organic pollutants and diabetes risk. These findings have been replicated in experimental studies both in human (in-vitro) and animals (in-vivo and in-vitro), and patho-physiological derangements through which these pollutants exercise their harmful effect on diabetes risk postulated. This review summarizes available studies, emphasises on limitations so as to enable subsequent studies to be centralized on possible pathways and bring out clearly the role of POPs on diabetes risk.

Interaction between paraoxonase 1 polymorphism and prenatal pesticide exposure on metabolic markers in children using a multiplex approach

Prenatal environmental exposures may influence the risk of cardio-metabolic diseases later in life. This study used a multiplex approach to investigate non-fasting serum levels of metabolic markers in a cohort of school-aged children for whom associations between prenatal pesticide exposure and body fat content and blood pressure were previously found to be dependent on paraoxonase1 (PON1) Q192R genotype. In children with the PON1 192 R-allele, leptin, glucagon, and plasminogen activator inhibitor-1 (PAI-1) were positively associated with prenatal pesticide exposure. For PON1 192 QQ-homozygote children none of the biomarkers were significantly affected by prenatal pesticide exposure. In children with the R-allele, leptin was associated with both body fat measures and prenatal pesticide exposure and seems to mediate body fat accumulation in exposed children. These findings support our previous results of an adverse cardio-metabolic risk profile associated with prenatal pesticide exposure in children with the PON1 192 R-allele.

Perinatal exposure to low-dose methoxychlor impairs testicular development in C57BL/6 mice

Methoxychlor (MXC), an organochlorine pesticide, has adverse effects on male reproduction at toxicological doses. Humans and wild animals are exposed to MXC mostly through contaminated dietary intake. Higher concentrations of MXC have been found in human milk, raising the demand for the risk assessment of offspring after maternal exposure to low doses of MXC. In this study, pregnant mice (F0) were given intraperitoneal daily evening injections of 1 mg/kg/d MXC during their gestational (embryonic day 0.5, E0.5) and lactational periods (postnatal day 21.5, P21.5), and the F1 males were assessed. F1 testes were collected at P0.5, P21.5 and P45.5. Maternal exposure to MXC disturbed the testicular development. Serum testosterone levels decreased, whereas estradiol levels increased. To understand the molecular mechanisms of exposure to MXC in male reproduction, the F1 testes were examined for changes in the expression of steroidogenesis- and spermatogenesis- related genes. RT-PCR analysis demonstrated that MXC significantly decreased Cyp11a1 and increased Cyp19a1; furthermore, it downregulated certain spermatogenic genes (Dazl, Boll, Rarg, Stra8 and Cyclin-a1). In summary, perinatal exposure to low-dose MXC disturbs the testicular development in mice. This animal study of exposure to low-dose MXC in F1 males suggests similar dysfunctional effects on male reproduction in humans.

Self-reported parental exposure to pesticide during pregnancy and birth outcomes: the MecoExpo cohort study

The MecoExpo study was performed in the Picardy region of northern France, in order to investigate the putative relationship between parental exposures to pesticides (as reported by the mother) on one hand and neonatal parameters on the other. The cohort comprised 993 mother-newborn pairs. Each mother completed a questionnaire that probed occupational, domestic, environmental and dietary sources of parental exposure to pesticides during her pregnancy. Multivariate regression analyses were then used to test for associations between the characteristics of parental pesticide exposure during pregnancy and the corresponding birth outcomes. Maternal occupational exposure was associated with an elevated risk of low birth weight (odds ratio (OR) [95% confidence interval]: 4.2 [1.2, 15.4]). Paternal occupational exposure to pesticides was associated with a lower than average gestational age at birth (-0.7 weeks; p = 0.0002) and an elevated risk of prematurity (OR: 3.7 [1.4, 9.7]). Levels of domestic exposure to veterinary antiparasitics and to pesticides for indoor plants were both associated with a low birth weight (-70 g; p = 0.02 and -160 g; p = 0.005, respectively). Babies born to women living in urban areas had a lower birth length and a higher risk of low birth length (-0.4 cm, p = 0.006 and OR: 2.9 [1.5, 5.5], respectively). The present study results mainly demonstrate a negative correlation between fetal development on one hand and parental occupational and domestic exposure to pesticides on the other. Our study highlights the need to perform a global and detailed screening of all potential physiological effects when assessing in utero exposure to pesticides.

Association of placenta organotin concentrations with growth and ponderal index in 110 newborn boys from Finland during the first 18 months of life: a cohort study

BACKGROUND

Humans are exposed to tributyltin (TBT), previously used as an antifouling paint in ships, mainly through fish consumption. As TBT is a known obesogen, we studied the association of placenta TBT and other organotin compounds (OTCs) with ponderal index (PI) and growth during the first 18 months of life in boys.

METHODS

In a prospective Finnish study, 110 placenta samples were collected from mothers of boys born in 1997-1999 with (n = 55) and without (n = 55) cryptorchidism. To account for the original study design, linear regression, weighted for sampling fractions of boys with (121/55) and without (5677/55) cryptorchidism from the total cohort, was used to study the association between placenta OTCs and children's weight, length, growth rates and PI up to 18 months of age.

RESULTS

Placenta TBT concentrations were above the limit of quantification (LOQ) in 99% of the samples. However, monobutyltin (MBT), dibutyltin (DBT) and triphenyltin (TPhT) concentrations were below LOQ in 90%, 35% and 57% of samples, respectively. Placenta TBT was positively associated (p = 0.024) with weight gain during the first three months of life, but no other significant associations were observed for weight or length gain. Also, no significant associations between placenta OTC concentrations and child length, weight or PI at any time point were found.

CONCLUSIONS

We observed a trend towards higher weight gain from birth to 3 months of age with increasing placenta TBT concentration. These results should be interpreted with caution because obesogenic effects in animal experiments were seen after in-utero TBT exposures to doses that were orders of magnitude higher. Also the number of study subjects included in this study was limited.

Maternal cypermethrin exposure during the perinatal period impairs testicular development in C57BL male offspring

Numerous studies have demonstrated that endocrine-disrupting compounds (EDC) are a possible cause of male reproductive organ malfunction and malformation. Cypermethrin (CYP) is a widely used synthetic pyrethroid and a potential EDC. This study aimed to examine the effects of perinatal exposure to low-dose CYP on the development and function of the offspring testes. Pregnant mice were intragastrically administered 0.12 to 12 mg/kg/day CYP from embryonic day 0.5 (E0.5) to weaning (PD21.5, postnatal day 21.5). Maternal exposure to 0.12, 1.2, and 12 mg/kg/day CYP affected the body and organ weight of the offspring. Exposure of CYP led to a dose-dependent decrease in the male-to-female sex ratio. A histopathological analysis revealed a thinner seminiferous epithelium layer at PD21.5, interstitial hyperplasia at PD45.5, and germ cell vacuolization at PD90.5 in the 12 mg/kg/day CYP group. The TUNEL assay results revealed increased germ cell apoptosis in the 12 mg/kg/day CYP group. The serum testosterone (T) level decreased, whereas the estradiol level increased with age in the 1.2 and 12 mg/kg/day CYP groups. The RT-PCR analysis demonstrated decreased expression of T production-related, mitosis-related, and meiosis-related genes in the 1.2 and 12 mg/kg/day CYP groups. The in vitro experimental results demonstrated reduced expression of steroidogenesis genes and decreased T levels. It is concluded that perinatal exposure to low-dose CYP affects testes development and function in adults.

Currently used pesticides and their mixtures affect the function of sex hormone receptors and aromatase enzyme activity

The endocrine-disrupting potential of pesticides is of health concern, since they are found ubiquitously in the environment and in food items. We investigated in vitro effects on estrogen receptor (ER) and androgen receptor (AR) transactivity, and aromatase enzyme activity, of the following pesticides: 2-methyl-4-chlorophenoxyacetic acid (MCPA), terbuthylazine, iodosulfuron-methyl-sodium, mesosulfuron-methyl, metsulfuron-methyl, chlormequat chloride, bitertanol, propiconazole, prothioconazole, mancozeb, cypermethrin, tau fluvalinate, malathion and the metabolite ethylene thiourea (ETU). The pesticides were analyzed alone and in selected mixtures. Effects of the pesticides on ER and AR function were assessed in human breast carcinoma MVLN cells and hamster ovary CHO-K1 cells, respectively, using luciferase reporter gene assays. Effects on aromatase enzyme activity were analyzed in human choriocarcinoma JEG-3 cells, employing the classical [(3)H](2)O method. Five pesticides (terbuthylazine, propiconazole, prothioconazole, cypermethrin and malathion) weakly induced the ER transactivity, and three pesticides (bitertanol, propiconazole and mancozeb) antagonized the AR activity in a concentration-dependent manner. Three pesticides (terbuthylazine, propiconazole and prothioconazole) weakly induced the aromatase activity. In addition, two mixtures, consisting of three pesticides (bitertanol, propiconazole, cypermethrin) and five pesticides (terbuthylazine, bitertanol, propiconazole, cypermethrin, malathion), respectively, induced the ER transactivity and aromatase activity, and additively antagonized the AR transactivity. In conclusion, our data suggest that currently used pesticides possess endocrine-disrupting potential in vitro which can be mediated via ER, AR and aromatase activities. The observed mixture effects emphasize the importance of considering the combined action of pesticides in order to assure proper estimations of related health effect risks.

Levels of pesticides and their metabolites in Wistar rat amniotic fluids and maternal urine upon gestational exposure

Concentrations of pesticides and selected metabolites in rat urine and amniotic fluid were determined as biomarker upon oral administration of Wistar rats to two pesticide mixtures consisting of three to five pesticides (bitertanol, propiconazole, cypermethrin, malathion, and terbuthylazine). The pesticides and their metabolites were found in rat amniotic fluid and urine, generally in dose-response concentrations in relation to dosage. The measurement of the substances in the amniotic fluid indicated that the fetus was exposed to the pesticides as well as their metabolites. Moreover, the pesticides detected in urine demonstrated the exposure as well as the ability of the rat to excrete these compounds.

Paraoxonase 1 polymorphism and prenatal pesticide exposure associated with adverse cardiovascular risk profiles at school age

BACKGROUND

Prenatal environmental factors might influence the risk of developing cardiovascular disease later in life. The HDL-associated enzyme paraoxonase 1 (PON1) has anti-oxidative functions that may protect against atherosclerosis. It also hydrolyzes many substrates, including organophosphate pesticides. A common polymorphism, PON1 Q192R, affects both properties, but a potential interaction between PON1 genotype and pesticide exposure on cardiovascular risk factors has not been investigated. We explored if the PON1 Q192R genotype affects cardiovascular risk factors in school-age children prenatally exposed to pesticides.

METHODS

Pregnant greenhouse-workers were categorized as high, medium, or not exposed to pesticides. Their children underwent a standardized examination at age 6-to-11 years, where blood pressure, skin folds, and other anthropometric parameters were measured. PON1-genotype was determined for 141 children (88 pesticide exposed and 53 unexposed). Serum was analyzed for insulin-like growth factor I (IGF-I), insulin-like growth factor binding protein 3 (IGFBP3), insulin and leptin. Body fat percentage was calculated from skin fold thicknesses. BMI results were converted to age and sex specific Z-scores.

RESULTS

Prenatally pesticide exposed children carrying the PON1 192R-allele had higher abdominal circumference, body fat content, BMI Z-scores, blood pressure, and serum concentrations of leptin and IGF-I at school age than unexposed children. The effects were related to the prenatal exposure level. For children with the PON1 192QQ genotype, none of the variables was affected by prenatal pesticide exposure.

CONCLUSION

Our results indicate a gene-environment interaction between prenatal pesticide exposure and the PON1 gene. Only exposed children with the R-allele developed adverse cardiovascular risk profiles thought to be associated with the R-allele.

Smaller genitals at school age in boys whose mothers were exposed to non-persistent pesticides in early pregnancy

Endocrine disrupting chemicals are believed to play a role in the development of the testicular dysgenesis syndrome. Many pesticides are known to have endocrine disrupting abilities. In a previous study, sons of women who were occupationally exposed to non-persistent pesticides in early pregnancy showed signs of impaired reproductive function (reduced genital size and altered serum hormone concentrations) at three months of age. To assess the possible long-term effects of prenatal pesticide exposure, the boys were re-examined at 6-11 years. The 94 boys (59 exposed, 35 unexposed) underwent genital examinations including ultrasound of testicular volumes, puberty staging (Tanner), anthropometry, and blood sampling. Only a few of the boys had reached puberty (n = 3). Among prepubescent boys, testicular volume and penile length (age- and weight-adjusted) were reduced if mothers were exposed to pesticides. The effects were associated with the maternal exposure levels, so that high-exposed boys had smaller genitals than medium-exposed boys, who had smaller genitals than those who were unexposed. Boys of mothers in the high exposure group (n = 23) had 24.7% smaller testes (95% CI: -62.2; -10.1) and 9.4% shorter penile length (95% CI: -16.8; -1.1) compared with the unexposed. The testicular volume and penile length at school age could be tracked to measures from the same boys made at 3 months, e.g. those that had small testes at school age also had small testes at 3 months. Pituitary and testicular hormone serum concentrations did not differ between exposed and unexposed boys. Eight prenatally exposed boys had genital malformations (no unexposed). These boys had smaller testis, shorter penile length and lower inhibin B concentrations than prepubertal boys without genital malformations. The findings support the results obtained at three months of age and indicate that prenatal pesticide exposure has long-term effects on reproductive function in boys.