Prenatal exposure to DDE and PCB 153 and respiratory health in early childhood: a meta-analysis

Chemical exposome and children health: Identification of dose-response relationships from meta-analyses and epidemiological studies

BACKGROUND

Health impact assessment studies quantifying the impact of the chemical exposome on children's health generally consider a small fraction of the exposome. Synthetizing available dose-response relationships is an essential step to fill this gap. We reviewed the literature for dose-response relationships relating the chemical exposome with children health.

METHOD

We focused on 78 substance-outcome pairs for which the level of evidence had previously been classified as 'likely' or 'very likely'. We searched for dose-response relationships for these pairs from meta-analyses and, if none was available, from single epidemiological studies, from which we conducted meta-analyses whenever possible.

RESULTS

We identified dose-response relationships for 50 of the 78 prioritized substance-outcome pairs (64%). Dose-response relationships stemmed from meta-analyses for 21 pairs, from de novo meta-analyses for 1 pair and single studies for 28 pairs. Dose-response relationships were available for tobacco (fetal and infant death, congenital heart defects, birth outcomes, orofacial clefts, respiratory health), lead (asthma, cognition, delayed puberty onset and iron deficiency anaemia), polychlorobiphenyls (PCBs) (cognition, respiratory infections and birth outcomes), bisphenol A (cognition), hexachlorobenzene (HCB) (respiratory health), Polybrominated diphenyl ethers (neurodevelopment), DDT (hypospadias, cryptorchidism, miscarriage), pesticides (neurodevelopment), methylmercury (cognition), PFAS (immune system, birth weight, behavior, miscarriage), arsenic (cognition, birth weight, death, respiratory health), cadmium (cognition, birth weight), manganese (behavior), sodium (blood pressure) and thallium (birth weight). For 28 of the 78 substance-outcome pairs (36%), no dose-response relationship was available from epidemiological studies in children.

CONCLUSIONS

We identified dose-response relationships for 50 substance-outcome pairs, corresponding to 20 chemicals and 17 health outcomes. These can be used to perform more comprehensive quantitative health impact assessment of the exposome on child health. We also identified 28 substance-outcome pairs corresponding to 'likely' or 'very likely' effects for which research generating dose-response functions in children would be relevant.

An Umbrella Review of Meta-Analyses Evaluating Associations between Human Health and Exposure to Major Classes of Plastic-Associated Chemicals

Background: Epidemiological research investigating the impact of exposure to plastics, and plastic-associated chemicals, on human health is critical, especially given exponentially increasing plastic production. In parallel with increasing production, academic research has also increased exponentially both in terms of the primary literature and ensuing systematic reviews with meta-analysis. However, there are few overviews that capture a broad range of chemical classes to present a state of play regarding impacts on human health. Methods: We undertook an umbrella review to review the systematic reviews with meta-analyses. Given the complex composition of plastic and the large number of identified plastic-associated chemicals, it was not possible to capture all chemicals that may be present in, and migrate from, plastic materials. We therefore focussed on a defined set of key exposures related to plastics. These were microplastics, due to their ubiquity and potential for human exposure, and the polymers that form the matrix of consumer plastics. We also included plasticisers and flame retardants as the two classes of functional additive with the highest concentration ranges in plastic. In addition, we included bisphenols and per- and polyfluoroalkyl substances (PFAS) as two other major plastic-associated chemicals with significant known exposure through food contact materials. Epistemonikos and PubMed were searched for systematic reviews with meta-analyses, meta-analyses, and pooled analyses evaluating the association of plastic polymers, particles (microplastics) or any of the selected groups of high-volume plastic-associated chemicals above, measured directly in human biospecimens, with human health outcomes. Results: Fifty-two systematic reviews were included, with data contributing 759 meta-analyses. Most meta-analyses (78%) were from reviews of moderate methodological quality. Across all the publications retrieved, only a limited number of plastic-associated chemicals within each of the groups searched had been evaluated in relevant meta-analyses, and there were no meta-analyses evaluating polymers, nor microplastics. Synthesised estimates of the effects of plastic-associated chemical exposure were identified for the following health outcome categories in humans: birth, child and adult reproductive, endocrine, child neurodevelopment, nutritional, circulatory, respiratory, skin-related and cancers. Bisphenol A (BPA) is associated with decreased anoclitoral distance in infants, type 2 diabetes (T2D) in adults, insulin resistance in children and adults, polycystic ovary syndrome, obesity and hypertension in children and adults and cardiovascular disease (CVD); other bisphenols have not been evaluated. Phthalates, the only plasticisers identified, are associated with spontaneous pregnancy loss, decreased anogenital distance in boys, insulin resistance in children and adults, with additional associations between certain phthalates and decreased birth weight, T2D in adults, precocious puberty in girls, reduced sperm quality, endometriosis, adverse cognitive development and intelligence quotient (IQ) loss, adverse fine motor and psychomotor development and elevated blood pressure in children and asthma in children and adults. Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) but not other flame retardants, and some PFAS were identified and are all associated with decreased birth weight. In general populations, PCBs are associated with T2D in adults and endometriosis, bronchitis in infants, CVD, non-Hodgkin's lymphoma (NHL) and breast cancer. In PCB-poisoned populations, exposure is associated with overall mortality, mortality from hepatic disease (men), CVD (men and women) and several cancers. PBDEs are adversely associated with children's cognitive development and IQ loss. PBDEs and certain PFAS are associated with changes in thyroid function. PFAS exposure is associated with increased body mass index (BMI) and overweight in children, attention deficit hyperactive disorder (ADHD) in girls and allergic rhinitis. Potential protective associations were found, namely abnormal pubertal timing in boys being less common with higher phthalate exposure, increased high-density lipoprotein (HDL) with exposure to mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) and reduced incidence of chronic lymphocytic lymphoma (a subtype of NHL) with PCB exposure. Conclusions: Exposure to plastic-associated chemicals is associated with adverse outcomes across a wide range of human health domains, and every plastic-associated chemical group is associated with at least one adverse health outcome. Large gaps remain for many plastic-associated chemicals. Recommendations: For research, we recommend that efforts are harmonised globally to pool resources and extend beyond the chemicals included in this umbrella review. Priorities for primary research, with ensuing systematic reviews, could include micro- and nanoplastics as well as emerging plastic-associated chemicals of concern such as bisphenol analogues and replacement plasticisers and flame retardants. With respect to chemical regulation, we propose that safety for plastic-associated chemicals in humans cannot be assumed at market entry. We therefore recommend that improved independent, systematic hazard testing for all plastic-associated chemicals is undertaken before market release of products. In addition because of the limitations of laboratory-based testing for predicting harm from plastic in humans, independent and systematic post-market bio-monitoring and epidemiological studies are essential to detect potential unforeseen harms.

[Pesticide exposure and chronic respiratory diseases]

INTRODUCTION

Pesticides are used worldwide, mainly in agriculture as a means of controlling pests and protecting crops. That said, the entire world population is ultimately subject to pesticide exposure (consumption of fruits and vegetables, living near treated fields…), with varying degrees of toxicity involved.

STATE OF THE ART

In recent decades, epidemiological studies have contributed to the identification of chemical pesticide families with detrimental effects on human health: cognitive disorders, Parkinson's disease, prostate cancer… and impairment in respiratory functioning. Current scientific evidence points to the implication of the active substances in insecticides, herbicides and fungicides in chronic respiratory diseases, two examples being chronic obstructive pulmonary disease (COPD) in exposed workers, and asthmatic wheezing in children during prenatal or postnatal exposure.

PERSPECTIVES

The safety of individuals exposed to pesticides is of key importance in public health. Further epidemiological investigations are needed to identify the chemical families affecting certain populations.

CONCLUSIONS

The scientific literature suggests strong links between pesticide exposure and respiratory health. Whether it be environmental or occupational, pesticide exposure can lead to respiratory disorders and symptoms of varying severity.

Carcinogenic, non-carcinogenic risk, and attributable cases to organochlorine pesticide exposure in women from Northern Mexico

This study aimed to estimate the carcinogenic and non-carcinogenic risk as well as the attributable cases due to exposure to organochlorine pesticides (OCPs): hexachlorobenzene (HCB), dichlorophenyltrichloroethane (DDT), hexachlorocyclohexane (HCH), heptachlor, and chlordane. From serum concentrations of pesticides of interest in a sample of 908 women from Northern Mexico, the risk for both cancer and non-cancer health effects was evaluated. The population attributable fraction (PAF) was also calculated based on summary association estimates between exposure to OCPs and different health events. Findings revealed that due to their OCP exposure slightly less than half of the women in the sample were at increased risk of developing non-cancerous diseases. Moreover, approximately 25% and 75% of participants were at risk of develop some type of cancer associated with their HCB and DDE concentrations, respectively. In addition, it was estimated that 40.5% of type 2 diabetes, 18.7% of endometriosis, and 23.1% of non-Hodgkin's lymphoma cases could have been prevented if women had not been exposed to these OCPs. Results suggest that the use of OCPs may have contributed to the disease burden in the study area and, based on the time required for these substances to be eliminated from the body, there are probably some women who are still at elevated risk of developing diseases associated to OCPs.

The plastic health map: A systematic evidence map of human health studies on plastic-associated chemicals

BACKGROUND

The global production and use of plastic materials has increased dramatically since the 1960s and there is increasing evidence of human health impacts related to exposure to plastic-associated chemicals. There is, however, no comprehensive, regulatory, post-market monitoring for human health effects of plastic-associated chemicals or particles and it is unclear how many of these have been investigated for effects in humans, and therefore what the knowledge gaps are.

OBJECTIVE

To create a systematic evidence map of peer-reviewed human studies investigating the potential effects of exposure to plastic-associated particles/chemicals on health to identify research gaps and provide recommendations for future research and regulation policy.

METHODS

Medline and Embase databases were used to identify peer-reviewed primary human studies published in English from Jan 1960 - Jan 2022 that investigated relationships between exposures to included plastic-associated particles/chemicals measured and detected in bio-samples and human health outcomes. Plastic-associated particles/chemicals included are: micro and nanoplastics, due to their widespread occurrence and potential for human exposure; polymers, the main building blocks of plastic; plasticizers and flame retardants, the two most common types of plastic additives with the highest concentration ranges in plastic materials; and bisphenols and per- or polyfluoroalkyl substances, two chemical classes of known health concern that are common in plastics. We extracted metadata on the population and study characteristics (country, intergenerational, sex, age, general/special exposure risk status, study design), exposure (plastic-associated particle/chemical, multiple exposures), and health outcome measures (biochemical, physiological, and/or clinical), from which we produced the interactive database 'Plastic Health Map' and a narrative summary.

RESULTS

We identified 100,949 unique articles, of which 3,587 met our inclusion criteria and were used to create a systematic evidence map. The Plastic Health Map with extracted metadata from included studies are freely available at https://osf.io/fhw7d/ and summary tables, plots and overall observations are included in this report.

CONCLUSIONS

We present the first evidence map compiling human health research on a wide range of plastic-associated chemicals from several different chemical classes, in order to provide stakeholders, including researchers, regulators, and concerned individuals, with an efficient way to access published literature on the matter and determine knowledge gaps. We also provide examples of data clusters to facilitate systematic reviews and research gaps to help direct future research efforts. Extensive gaps are identified in the breadth of populations, exposures and outcomes addressed in studies of potential human health effects of plastic-associated chemicals. No studies of the human health effects of micro and/or nanoplastics were found, and no studies were found for 26/1,202 additives included in our search that are of known hazard concern and confirmed to be in active production. Few studies have addressed recent "substitution" chemicals for restricted additives such as organophosphate flame retardants, phthalate substitutes, and bisphenol analogues. We call for a paradigm shift in chemical regulation whereby new plastic chemicals are rigorously tested for safety before being introduced in consumer products, with ongoing post-introduction biomonitoring of their levels in humans and health effects throughout individuals' life span, including in old age and across generations.

Systematic Review: Association of Pesticide Exposure and Child Wheeze and Asthma

BACKGROUND

The prevalence of wheeze and asthma has risen over recent decades for all age groups, especially children. These disorders can lead to decreased quality of life, missed school, urgent care and emergency department visits, hospitalizations, and increased health care costs. Environmental exposures, including pesticide exposure, are likely a contributing factor to this increased prevalence.

OBJECTIVE

To evaluate the association of pesticide exposure with childhood wheeze and asthma.

METHODS

We conducted a systematic review evaluating studies of pesticide exposure (measured objectively) and child respiratory outcomes. We searched PubMed, Embase (Elsevier), CINAHL (EBSCO), Scopus (Elsevier), Cochrane Database of Systematic Reviews (Wiley), and ClinicalTrials. gov from 1988 - 2021. Main search keywords included "pesticides", "insecticides", "herbicides", "respiratory", "asthma" and "wheeze".

RESULTS

Out of 5767 studies, 25 met the inclusion criteria; eight evaluated prenatal pesticide exposure (n=8407), twelve evaluated postnatal exposures (n= 50,488), and five evaluated pre-and postnatal exposures (n=20,919). Main pesticides investigated were dichlorodiphenyldichloroethylene (DDE) (14 studies) followed by organophosphates (7 studies). Primary methods of outcome assessment were questionnaire-based (84%), followed by spirometry (16%), registry data, and blood measures. Studies varied in the strength of evidence relating to study design and measures. Most studies (84%) reported a positive association of exposure with adverse child respiratory health.

CONCLUSION

The studies suggest an association of pesticide exposure and childhood wheeze and asthma. The varying results and methods reinforce the need for more research and standardized approaches to these studies to confirm the suggested association of pesticide exposure and childhood wheeze and asthma.

Effect of Gestational Pesticide Exposure on the Child's Respiratory System: A Narrative Review

BACKGROUND

In recent years, concern has arisen worldwide about the potential adverse effects that could result from early-life exposure to pesticides. Asthma, bronchitis, and persistent cough in children have been linked to gestational exposure to pesticides. The respiratory effects of gestational exposure to pesticides are controversial. The aim of this study was to determine the relationship between pesticide exposure in pregnant women and its effect on the respiratory system of their children.

METHODS

A narrative review was carried out by means of a search in the main databases.

RESULTS

Findings of studies confirmed the effects of pesticides on the child's health. These substances cross the placenta and become transmitters of exposure to the individual at the most sensitive stage of her development.

CONCLUSIONS

Chronic exposure to pesticides in fetuses is associated with chronic respiratory symptoms and disease.

Domestic Exposure to Chemicals in Household Products, Building Materials, Decoration, and Pesticides: Guidelines for Interventions During the Perinatal Period from the French National College of Midwives

INTRODUCTION

We are exposed to numerous pollutants inside our homes. The perinatal period represents a particular window of vulnerability during which these exposures can have negative health effects over a more or less long term. The objective of this article is to formulate guidelines for health care professionals and intended for parents to reduce exposure to chemical pollutants at home, based on the scientific literature and already existing guidelines.

METHODS

We have followed the methodological procedures set forth by the French authority for health (HAS) to establish guidelines to limit exposure to pollutants in homes. This narrative review of the scientific literature was conducted with two principal objectives: (1) to identify priority substances emitted within homes and that have a reprotoxic potential and (2) to identify measures to limit exposure to these residential pollutants. The guidelines were developed from the data in the literature and from advice already made available by diverse institutions about environmental health during the perinatal period.

RESULTS

Domestic pollutants are numerous and come from both common (that is, shared, eg, painting, cleaning, and maintenance work) and specific (use of household pesticides) sources. Numerous pollutants are suspected or known to produce developmental toxicity, that is, to be toxic to children during developmental stages. Removing some products from the home, protecting the vulnerable (ie, pregnant women and young children) from exposure, and airing the home are among the preventive measures proposed to limit exposure to these chemical substances.

CONCLUSION

Health care professionals can provide advice to parents during the perinatal period to diminish exposure to household pollutants. The lack of interventional studies nonetheless limits the level of evidence for most of these recommendations.

Sex specific associations between in utero exposure to persistent organic pollutants and allergy-related outcomes in childhood: The Rhea Mother-Child Cohort (Crete, Greece)

Accumulating evidence suggests that in utero exposures can influence the development of the immune system. Few studies have investigated whether prenatal exposure to persistent organic pollutants (POPs) is associated with allergy-related phenotypes in childhood, nor explored sex differences. We examined the association between prenatal exposure to POPs and offspring allergic outcomes in early and mid-childhood. We included 682 mother-child pairs from the prospective birth cohort Rhea. We measured dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB) and 6 polychlorinated biphenyl (PCB) congeners in maternal first trimester serum. Parents completed the questionnaires adapted from the International Study on Asthma and Allergy in Childhood (ISAAC) for allergy-related phenotypes when their children were 4 and 6 years old. We used Poisson regression models to estimate Risk Ratios. Prenatal HCB was associated with increased risk for rhinoconjunctivitis at 6 years (RR (95% CI): 2.5; (1.3, 4.8) for a doubling in the exposure). Among girls, prenatal DDE was associated with increased risk for current wheeze, current asthma and current rhinoconjunctivitis at 4 years (RR (95%CI): 1.4 (0.8, 2.6), 1.6 (1.1, 2.4) and 1.8 (1.0, 3.3) and p-interaction = 0.035, 0.027 and 0.059, respectively), with increased risk for current rhinoconjunctivitis at 6 years (RR (95%CI): 1.7 (0.7, 3.8) and p-interaction = 0.028) and total PCBs were associated with increased risk for current eczema at 4 years (RR (95%CI): 2.1 (1.1, 4.2) and p-interaction = 0.028). In boys, prenatal DDE was associated with decreased risk for current wheeze and current asthma at 4 years. Our findings suggest that even low levels of exposure to POPs prenatally may affect the development of childhood allergy-related outcomes in a sex and age-specific manner.

Respiratory and allergic health effects in children living near agriculture: A review

BACKGROUND

Exposure to pesticides and agricultural burning are likely to co-occur in agricultural communities, but these exposures have remained distinct bodies of research. We reviewed epidemiological studies to identify the respiratory health effects of children exposed to pesticides and agricultural burning through a systematic evaluation of peer-reviewed publications of children living in industrial agricultural areas.

METHODS

Two academic search databases (PubMed and Scopus) were queried for all available studies published in English before May 31st, 2021. The initial search combining both exposure metrics (pesticides and agricultural burning) yielded zero publications and thus the queries were performed and presented separately.

RESULTS

Studies were categorized based on main exposure of interest (i.e., pesticides or agricultural burning) and by respiratory health outcome assessment (i.e., self-reported asthma, acute respiratory symptoms, and lung function measurements). In total we identified 25 studies that focused on pesticide exposures and children's respiratory health, and 12 studies that focused on exposure to agricultural burning and children's respiratory health. A majority of the pesticide studies (18/25) reported a positive association between exposure to pesticides and adverse childhood respiratory health effects. Similarly, most (11/12) of the agricultural burning studies also reported a positive association between exposure to agricultural burning and adverse respiratory health effects.

CONCLUSION

The most frequently studied health outcomes in these publications were acute respiratory symptoms (n = 11 pesticides, n = 3 agricultural burning), followed by asthma (n = 9 pesticides, n = 3 agricultural burning), and lung function measurements (n = 5 pesticides, n = 6 agricultural burning). Although health outcome assessment differed between pesticide studies and agricultural burning studies, similar adverse respiratory health effects were observed across the majority of studies.

Maternal pesticide exposure and its relation to childhood cancer: an umbrella review of meta-analyses

This umbrella review summarizes the available meta-analyses elucidating the effects of maternal pesticide exposure on adverse health outcomes in children particularly the risk of childhood cancer. A literature search was conducted on PubMed and Scopus with 10-years temporal restriction and with search terms of ('pesticides') and ('maternal' or 'pregnancy' or 'gestational' or 'perinatal' or 'children' or 'infants' or 'birth weight' or 'gestational age' or 'cancer' or 'tumor' or 'malignancy' or 'carcinoma') and ('meta-analysis' or 'systematic review'). Using relative risk estimates, e.g., odds ratio (OR), relative risk (RR), ß coefficients, and 95% confidence interval (CI) as a prerequisite for inclusion/exclusion criteria a total of 19 eligible meta-analyses were included. The results showed that maternal domestic/occupational pesticide exposure increases the risk for childhood leukaemia. The overall OR regarding the risk of pesticide exposure and leukaemia was 1.23 to 1.57 with heterogeneity I2 values that varied between 12.9% and 73%. Some studies found that exposure to dichlorodiphenyldichloroethylene (p,p´-DDE) and polychlorinated biphenyls (PCB-153) pesticides appears to decrease infant birth weight to some extent [p,p´-DDE (ß = -0.007 to -0.008)] and [PCB-153 (ß = -0.15 to -0.17)]Needing more studies on this relationship, our study found that pesticide exposure is a risk factor for leukaemia in children.

Gestational exposure to PCB-118 impairs placental angiogenesis and fetal growth

Maternal exposure to polychlorinated biphenyls (PCBs) results in adverse effects on fetal development. However, the underlying mechanism has not been sufficiently explored in respect to particular PCBs. Placental angiogenesis plays a crucial role in feto-maternal substances transportation and fetal development. The present study was conducted to investigate the effects of prenatal PCB118 exposure on placental angiogenesis and fetal growth. The pregnant dam received PCB118 at environmentally relevant doses (0, 20, or 100 μg/kg/day) intragastrically from gestational day (GD) 7.5-18.5 to establish an in vivo model. Compared with the control group, the fetal body and placental weights of the PCB118 (100 μg/kg/day) group were significantly decreased and the intrauterine growth retardation (IUGR) rates were increased both in the female and male fetus. Furthermore, we found that placental histology was significantly impaired and the number of blood vessels was decreased in the PCB118 group. Additionally, gestational exposure to PCB118 caused anomalous mRNA expression of the genes in the placenta regarding angiogenesis. These findings indicate that PCB118 may contribute to the occurrence of IUGR by provoking placental angiogenesis dysfunction. This study clarified the adverse effects and potential mechanism of prenatal PCBs exposure on fetal growth, providing a new theoretical and experimental basis for future treatment and prevention.

Maternal pesticides exposure in pregnancy and the risk of wheezing in infancy: A prospective cohort study

INTRODUCTION

Pesticide exposure in pregnancy may have health effects in the offspring. We studied whether maternal pesticides exposure during pregnancy is associated with infant wheezing.

METHODS

The study involved 5997 children from the Italian NINFEA birth cohort, whose mothers were recruited during pregnancy between 2005 and 2016. We used questionnaires completed during pregnancy and 6 months after delivery to derive the following indirect measures of exposure: i) Self-reported pesticide use during the first and the third trimester of pregnancy; (ii) Agricultural activities during the same trimesters. We also evaluated the exposure to agricultural pesticides applied near home using the Corine Land Cover inventory to derive the proportion of a 200-metre buffer area around maternal home address covered by agricultural crops and specific crop types (arable land, fruit trees, heterogeneous cultivations). Questionnaires completed when the child turned 18 months reported information on wheezing between 6 and 18 months of age. We estimated the odds ratios of wheezing adjusting for the following maternal characteristics: age, education, parity, asthma, atopy, smoking in pregnancy, region and area of residence, pet ownership during pregnancy. Crops proximity analyses were restricted to residents in rural areas (N = 1674).

RESULTS

Agricultural activities during pregnancy were not associated with infant wheezing. Compared to no pesticide use, there was a weak positive association for self-reported use in the third trimester (POR: 1.30; 95 %CI 0.95-1.78) and a stronger association for use in both trimesters (POR: 1.72; 95 %CI 1.11-2.65). The relationship between the proportion of crops around the home address and the risk of infant wheezing, was J-shaped, in particular for fruit trees with the lowest risk for mid values and elevated risk for higher values.

CONCLUSION

We found some evidence of association for maternal pesticide use in pregnancy and residential proximity to fruit trees cultivations with infant wheezing.

Buy-now-pay-later: Hazards to human and planetary health from plastics production, use and waste

More than 8 billion tonnes of plastic were produced between 1950 and 2015, that is 1 tonne for every man, woman and child on our planet. Global plastic production has been growing exponentially with an annual growth rate of 8.4% since 1950, equating to approximately 380 million tonnes per annum. A further 50 kg of plastic is now being produced for each person every year with production continuing to accelerate. Here, we discuss the human and planetary health hazards of all that plastic. We consider each step in the journey of these complex and pervasive industrial materials: from their synthesis predominantly from fossil fuel feedstocks, through an often-brief consumer use as plastic products, and onto waste streams as fuel, permanent landfill or as unmanaged waste in our environment, food, air and bodies.

Environmental Risk Factors and Health: An Umbrella Review of Meta-Analyses

Background: Environmental health is a growing area of knowledge, continually increasing and updating the body of evidence linking the environment to human health. Aim: This study summarizes the epidemiological evidence on environmental risk factors from meta-analyses through an umbrella review. Methods: An umbrella review was conducted on meta-analyses of cohort, case-control, case-crossover, and time-series studies that evaluated the associations between environmental risk factors and health outcomes defined as incidence, prevalence, and mortality. The specific search strategy was designed in PubMed using free text and Medical Subject Headings (MeSH) terms related to risk factors, environment, health outcomes, observational studies, and meta-analysis. The search was limited to English, Spanish, and French published articles and studies on humans. The search was conducted on September 20, 2020. Risk factors were defined as any attribute, characteristic, or exposure of an individual that increases the likelihood of developing a disease or death. The environment was defined as the external elements and conditions that surround, influence, and affect a human organism or population's life and development. The environment definition included the physical environment such as nature, built environment, or pollution, but not the social environment. We excluded occupational exposures, microorganisms, water, sanitation and hygiene (WASH), behavioral risk factors, and no-natural disasters. Results: This umbrella review found 197 associations among 69 environmental exposures and 83 diseases and death causes reported in 103 publications. The environmental factors found in this review were air pollution, environmental tobacco smoke, heavy metals, chemicals, ambient temperature, noise, radiation, and urban residential surroundings. Among these, we identified 65 environmental exposures defined as risk factors and 4 environmental protective factors. In terms of study design, 57 included cohort and/or case-control studies, and 46 included time-series and/or case-crossover studies. In terms of the study population, 21 included children, and the rest included adult population and both sexes. In this review, the largest body of evidence was found in air pollution (91 associations among 14 air pollution definitions and 34 diseases and mortality diagnoses), followed by environmental tobacco smoke with 24 associations. Chemicals (including pesticides) were the third larger group of environmental exposures found among the meta-analyses included, with 19 associations. Conclusion: Environmental exposures are an important health determinant. This review provides an overview of an evolving research area and should be used as a complementary tool to understand the connections between the environment and human health. The evidence presented by this review should help to design public health interventions and the implementation of health in all policies approach aiming to improve populational health.

Gestational Pesticide Exposure and Child Respiratory Health

BACKGROUND

Childhood wheeze may be related to pesticide exposure, and diet and genetics (Paroxonase; PON1) may modify the effects of exposure.

METHODS

We analyzed data from the HOME Study, a prospective pregnancy and birth cohort, to examine the association of gestational urinary organophosphate (OP) and pyrethroid (3PBA) metabolite concentrations with child wheeze, forced expiratory volume in one second (FEV1) at ages 4 and 5 years, and wheeze trajectory patterns through age 8 years.

RESULTS

Among 367 singletons, the frequency of wheeze ranged from 10.6% to 24.1% at each measurement age. OP and 3PBA metabolite concentrations were not associated with wheeze at 8 years or from birth to 8 years, but there were three significant interactions: (1) maternal daily fruit and vegetable consumption (less than daily consumption and increasing 3PBA was associated with wheeze at age 8 years, OR = 1.40), (2) maternal PON1-108 allele (CT/TT genotypes and high DE was associated with wheeze at age 8 years, OR = 2.13, 2.74) and (3) PON1192 alleles (QR/RR genotypes with higher diethylphosphate (DE) and dialkyl phosphate (DAP) were associated with wheeze at age 8 years, OR = 3.84). Pesticide metabolites were not consistently related to FEV1 or wheeze trajectory.

CONCLUSIONS

Gestational OP and 3PBA metabolites were associated with child respiratory outcomes in participants with maternal dietary and genetic susceptibility.

Global trends in pesticides: A looming threat and viable alternatives

Pesticides are widely used chemical compounds in agriculture to destroy insects, pests and weeds. In modern era, they form an indispensable part of agricultural and health practices. Globally, nearly 3 billion kg of pesticides are used every year with a budget of ~40 billion USD. This extensive usage has increased the crop yield as well as led to significant reduction in harvest losses and thereby, enhanced food availability. On the other hand, indiscriminate usage of these chemicals has led to several environmental implications and caused adverse effects on human health. Epidemiological evidences have revealed the harmful effects of pesticides exposure on various organs including liver, brain, lungs and colon. Recent investigations have shown that pesticides can also lead to fatal consequences such as cancer among individuals. These chemicals enter ecosystem, thus hampering the sensitive environmental equilibrium through bio-accumulation. Due to their non-biodegradable nature, they can persist in nature for years and are regarded as potent biohazard. Worldwide, very few surveillance methods have been considered, which can bring awareness among the individuals, therefore the present review is an attempt to delineate consequences induced by various types of pesticide exposure on the environment. Further, the prospective of biopesticides use could facilitate the increase of crop production without compromising human health.

Prenatal pesticide exposure and respiratory health outcomes in the first year of life: Results from the infants' Environmental Health (ISA) study

BACKGROUND

Growing evidence suggests that pesticide exposure may influence respiratory health, but data in young children are very limited. We examined the association of prenatal pesticide exposure with lower respiratory tract infections (LRTIs) and wheeze at one year of age in children from the Infants' Environmental Health (ISA) study in Costa Rica.

METHODS

We measured seven pesticide metabolites, including ethylenethiourea (ETU, metabolite of mancozeb), in maternal urine samples collected repeatedly during pregnancy. For each woman, we averaged pesticide concentrations during each half of pregnancy (≤20 and >20 weeks of gestation) and across repeated samples collected over the course of pregnancy. We collected information about LRTIs (n = 355) and wheezing (n = 272) during the first year of life from mothers when their children were 11-19 months old. We fit multivariable logistic regression models using high (quartile 4) vs. low (quartiles 1-3) urinary pesticide concentrations as exposures and adjusted models for maternal age, education, parity, gestational age at birth, and child sex.

RESULTS

Ten percent of the children had at least one LRTI and 39% had at least one episode of wheezing during their first year of life. Median (25-75th percentile) specific gravity-corrected urinary ETU concentrations during the first half, second half, and over the course of pregnancy were 3.4 (2.1-5.0), 3.3 (2.2-4.7), and 3.4 (2.4-5.0) ng/mL, respectively. We observed that high urinary ETU concentrations during the first half of pregnancy were associated with increased odds of LRTI (OR = 2.45; 95% CI: 0.96, 6.26), whereas high urinary ETU concentrations during the second half of pregnancy were associated with decreased odds of wheezing (OR = 0.50; 95% CI: 0.26, 0.96). We found that the association between high urinary ETU concentrations during the first half of pregnancy and LRTIs persisted among mother-child pairs with either high or low ETU concentrations during the second half. In contrast, the association of high urinary ETU concentrations during the second half of pregnancy with wheezing was attenuated when we simultaneously adjusted for urinary ETU concentrations during the first half. We observed null associations between other pesticide metabolites measured during pregnancy and respiratory outcomes.

CONCLUSIONS

Our data indicate that exposure to mancozeb/ETU during the first half of pregnancy may be associated with respiratory outcomes in the first year of life.

Interactions between dietary habits and home environmental exposures on respiratory symptoms in Romanian school children: an analysis of data from the SINPHONIE project

In this study, we investigated the interactions between household pollutants and dietary habits on children's respiratory health. Our cross-sectional study collected self-reported information including health symptoms (allergy-like, asthma-like, and flu-like symptoms), home characteristics, dietary habits, and demographic information from questionnaires administered to parents of 280 school children in Romania. Unconditional logistic regression and stratified analyses were used to assess the interactions between dietary factors and environmental exposures on health symptoms among children, controlling for sociodemographic characteristics and co-exposures. We found that frequency of fruit consumption had significant interaction with residing near heavy traffic on allergy-like symptoms among children (p = 0.036). However, no association was observed by frequency of fruit consumption. Although no significant interaction was observed, we found that students with infrequent fruit consumption and residing near heavy traffic roads had elevated odds of asthma-like (POR 6.37; 95% CI 1.22, 33.29) and flu-like symptoms (POR 3.75; 95% CI 1.12, 11.86) than those who frequently consumed fruits. Likewise, low vegetable consumption was associated with increased asthma-like symptoms (POR 2.93; 95% CI 1.04, 8.24). Increased odds of asthma-like symptoms were observed among school children that resided near heavy traffic roads and frequently consumed milk (POR 2.80; 95% CI 1.24, 6.31) and yoghurt (POR 2.86; 95% CI 1.05, 7.75) compared to those that infrequently consumed dairy. Our findings suggest that frequent fruit and vegetable consumption may mitigate the negative effects of exposure to heavy traffic near dwelling on respiratory symptoms in Romanian children.

Prenatal exposure to organochlorine compounds and lung function during childhood

INTRODUCTION

Prenatal exposure to organochlorine compounds (OCs) can increase the risk of reported respiratory symptoms in children. It remains unclear whether these compounds can also impact on lung function. We assessed the association between prenatal exposure to OCs and lung function during childhood.

METHODS

We included 1308 mother-child pairs enrolled in a prospective cohort study. Prenatal concentrations of p,p'-dichlorodiphenyltrichloroethane [p,p'-DDT], p,p'-dichlorodiphenyldichloroethylene [p,p'-DDE], hexachlorobenzene [HCB], and seven polychlorinated biphenyls [PCBs] were measured in cord blood. Spirometry was performed in the offspring at ages 4 (n = 636) and 7 years (n = 1192).

RESULTS

More than 80% of samples presented quantifiable levels of p,p'-DDE, HCB, PCB-138, PCB-153, and PCB-180; p,p'-DDE was the compound with the highest median concentrations. At 4 years, prenatal p,p'-DDE exposure was associated with a decrease in forced expiratory volume in 1 s (FEV₁) in all quartiles of exposure (e.g., third quartile [0.23-0.34 ng/mL]: β for FEV₁ -53.61 mL, 95% CI -89.87, -17.35, vs. the lowest). Prenatal p,p'-DDE levels also decreased forced vital capacity (FVC) and FEV₁/FVC, but associations did not reach statistical significance in most exposure quartiles. At 7 years, p,p'-DDE was associated with a decrease in FVC and FEV₁ in only the second quartile of exposure (e.g. β for FEV₁ -36.96 mL, 95% CI -66.22, -7.70, vs. the lowest). Prenatal exposure to HCB was associated with decreased FVC and FEV₁, but in only the second quartile and at 7 years (e.g. [0.07-0.14 ng/mL]: β for FEV₁ -25.79 mL, 95% CI -55.98, 4.39, vs. the lowest). PCBs were not consistently associated with lung function.

CONCLUSION

Prenatal exposure to p,p'-DDE may decrease lung function during childhood, especially FEV₁ and at medium levels of exposure. Further and deeper knowledge on the impact of environmental chemicals during pregnancy on lung development is needed.

Exposure to Persistent Organic Pollutants and Birth Characteristics: The Upstate KIDS Study

BACKGROUND

Prenatal exposure to persistent organic pollutants (POPs) may be associated with obesogenic effects in offspring. Our study is the first to investigate associations between concentrations of POPs from newborn dried blood spots (DBS) and birth characteristics.

METHODS

Concentrations of 10 polychlorinated biphenyl congeners (PCBs), polybrominated diphenyl ether-47 (PBDE-47), and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) were measured from DBSs collected at birth from 2,065 singleton infants. DBS samples were pooled in groups of five and assayed together to reach limits of detection. Differences in risk of large for gestational age (LGA, defined as >90th percentile of birth weight for sex and gestational age), small for gestational age (SGA, <10th), and preterm birth (gestational age <37 weeks) were estimated using logistic regression per unit (ng/ml) increase in concentration of each chemical, adjusting for individual-level covariates, including maternal age, race/ethnicity, prepregnancy BMI, education, parity, smoking, and infant sex while assuming a gamma distribution and using multiple imputation to account for pools.

RESULTS

There were 215 (11.3%) singletons born LGA, 158 (7.5%) born SGA, and 157 (7.6%) born preterm. Higher concentrations of POPs were positively associated with slightly higher risk of LGA and higher birth weight.

CONCLUSIONS

Relationships between POPs measured in newborn DBS and birth size were mixed. Pooled analysis methods using DBS could address challenges in limits of detection and costs for population-based research.

Early-life exposome and lung function in children in Europe: an analysis of data from the longitudinal, population-based HELIX cohort

BACKGROUND

Several single-exposure studies have documented possible effects of environmental factors on lung function, but none has relied on an exposome approach. We aimed to evaluate the association between a broad range of prenatal and postnatal lifestyle and environmental exposures and lung function in children.

METHODS

In this analysis, we used data from 1033 mother-child pairs from the European Human Early-Life Exposome (HELIX) cohort (consisting of six existing longitudinal birth cohorts in France, Greece, Lithuania, Norway, Spain, and the UK of children born between 2003 and 2009) for whom a valid spirometry test was recorded for the child. 85 prenatal and 125 postnatal exposures relating to outdoor, indoor, chemical, and lifestyle factors were assessed, and lung function was measured by spirometry in children at age 6-12 years. Two agnostic linear regression methods, a deletion-substitution-addition (DSA) algorithm considering all exposures simultaneously, and an exposome-wide association study (ExWAS) considering exposures independently, were applied to test the association with forced expiratory volume in 1 s percent predicted values (FEV₁%). We tested for two-way interaction between exposures and corrected for confounding by co-exposures.

FINDINGS

In the 1033 children (median age 8·1 years, IQR 6·5-9·0), mean FEV₁% was 98·8% (SD 13·2). In the ExWAS, prenatal perfluorononanoate (p=0·034) and perfluorooctanoate (p=0·030) exposures were associated with lower FEV₁%, and inverse distance to nearest road during pregnancy (p=0·030) was associated with higher FEV₁%. Nine postnatal exposures were associated with lower FEV₁%: copper (p=0·041), ethyl-paraben (p=0·029), five phthalate metabolites (mono-2-ethyl 5-carboxypentyl phthalate [p=0·016], mono-2-ethyl-5-hydroxyhexyl phthalate [p=0·023], mono-2-ethyl-5-oxohexyl phthalate [p=0·0085], mono-4-methyl-7-oxooctyl phthalate [p=0·040], and the sum of di-ethylhexyl phthalate metabolites [p=0·014]), house crowding (p=0·015), and facility density around schools (p=0·027). However, no exposure passed the significance threshold when corrected for multiple testing in ExWAS, and none was selected with the DSA algorithm, including when testing for exposure interactions.

INTERPRETATION

Our systematic exposome approach identified several environmental exposures, mainly chemicals, that might be associated with lung function. Reducing exposure to these ubiquitous chemicals could help to prevent the development of chronic respiratory disease.

FUNDING

European Community's Seventh Framework Programme (HELIX project).

Associations of residential exposure to agricultural pesticides with asthma prevalence in adolescence: The PIAMA birth cohort

BACKGROUND

It has been suggested that children who are exposed to agricultural pesticides have an increased risk of asthma, but evidence for associations betweeen residential pesticide exposure and childhood asthma is inconsistent.

OBJECTIVES

To investigate the associations of residential pesticide exposure with the prevalence of asthma and related symptoms within a Dutch birth cohort study.

METHODS

In this cross-sectional analysis, we included participants of the PIAMA birth cohort study with data on residential pesticide exposure and asthma from parent-completed questionnaires at age 14, collected in 2012 (N = 1473). We used spatial data on the presence of individual crops (cereals, open field vegetables, commercial crops, open field floriculture/bulbs, corn and potatoes) and pesticide application on these crops to estimate residential exposure to pesticides with known irritant properties for the respiratory system within distances of 100, 500, and 1000 m of the participants' homes. Logistic regression was used to estimate associations between exposure and outcomes, adjusting for potential confounders.

RESULTS

No associations were found between living within 100, 500 and 1000 m of agricultural fields likely treated with pesticides and symptoms of asthma. For instance, for participants living within 100 m of fields with any crops likely treated with pesticides, the adjusted odds ratios (95% confidence interval) for the prevalence of asthma, shortness of breath and dry night cough at age 14 were 0.31 (0.07, 1.32), 0.61 (0.23, 1.57) and 1.26 (0.56, 2.80), respectively. No associations were found between estimated exposure to pesticides with known irritant properties for the respiratory system and asthma or related symptoms.

CONCLUSIONS

There was no association between living near agricultural fields likely treated with pesticides and asthma and related respiratory symptoms, among our study participants.

Fish and seafood consumption during pregnancy and the risk of asthma and allergic rhinitis in childhood: a pooled analysis of 18 European and US birth cohorts

Background

It has been suggested that prenatal exposure to n-3 long-chain fatty acids protects against asthma and other allergy-related diseases later in childhood. The extent to which fish intake in pregnancy protects against child asthma and rhinitis symptoms remains unclear. We aimed to assess whether fish and seafood consumption in pregnancy is associated with childhood wheeze, asthma and allergic rhinitis.

Methods

We pooled individual data from 60 774 mother-child pairs participating in 18 European and US birth cohort studies. Information on wheeze, asthma and allergic rhinitis prevalence was collected using validated questionnaires. The time periods of interest were: infancy (0-2 years), preschool age (3-4 years), and school age (5-8 years). We used multivariable generalized models to assess associations of fish and seafood (other than fish) consumption during pregnancy with child respiratory outcomes in cohort-specific analyses, with subsequent random-effects meta-analyses.

Results

The median fish consumption during pregnancy ranged from 0.44 times/week in The Netherlands to 4.46 times/week in Spain. Maternal fish intake during pregnancy was not associated with offspring wheeze symptoms in any age group nor with the risk of child asthma [adjusted meta-analysis relative risk (RR) per 1-time/week = 1.01, 95% confidence interval 0.97-1.05)] and allergic rhinitis at school age (RR = 1.01, 0.99-1.03). These results were consistently found in further analyses by type of fish and seafood consumption and in sensitivity analyses.

Conclusion

We found no evidence supporting a protective association of fish and seafood consumption during pregnancy with offspring symptoms of wheeze, asthma and allergic rhinitis from infancy to mid childhood.

Environmental health surveillance in a future European health information system

BACKGROUND

To date Health information (HI) in the European Union does not comprise indicators or other information related to impacts of hazardous chemicals in consumer products, food, drinking water or air on the health status of the population. Therefore, we inventorised and evaluated the potential of environmental health surveillance and research data sources in the European population to provide HBM-based indicators of internal human exposure and health impact of relevant chemicals.

METHODS

We established an up-dated inventory of European cross-sectional Human Biomonitoring (HBM) surveys and of birth cohorts, and compared chemicals and chemical groups addressed by HBM with indicators and health end points collected via European Core Health Indicators (ECHI), in birth registries, as well as in environmental and food data bases and health registries to see on how data collection could be aligned. Finally, we investigated study designs of HBM survey and health examination surveys for potential synergies.

RESULTS

The inventory covers a total of 11 European cross-sectional national programmes and a large number of birth cohorts and includes information on study population, age groups, covered substances, sampled matrices, and frequency. The comparison of data collections shows that there are many overlaps between environmental chemicals with environmental and health reporting. HBM data could be linked with ECHI indicators for work-related risks, body mass index (BMI), and low birth weight, with perinatal disease, neurologic disorders, and some chronic diseases, or with data bases for e.g. indoor air, food, or consumer products. Existing initiatives to link data collections at European Environment Agency (EEA) and Joint Research Center (JRC) or at World Health Organization (WHO) are good options to further develop linkage of HBM with exposures sources and health end points.

CONCLUSIONS

There is potential to use HBM based information in a number of public health policies, and this would help to align reporting to international commitments. Environmental health surveillance based on HBM and HBM-based indicators, is an excellent tool to inform public health policies about risks from environmental chemicals, and the EU health information system would benefit from additional HBM-based indicators for monitoring exposure burden from environmental chemicals. Considerable efforts are needed to align and establish routine data collections and to develop a surveillance system and indicators which may inform public health policies.

Pesticides exposure through environment and risk of pre-term birth: a study from Agra city

Pre-term birth is an increasingly prevalent complex condition with multiple risk factors including environmental pollutants. Evidences linking organochlorine pesticides with adverse pregnancy outcomes are inconsistent for link between organochlorine pesticides and adverse pregnancy outcomes. We performed a case-control study of 50 cases of full-term births and 40 cases of pre-term births in this study. Placental organochlorine pesticides like metabolites of dichlorodiphenyltrichloroethane that is, (p,p-DDE, p,p-DDT and o,p-DDD) and isomers of hexachlorocyclohexane (α, β, γ and δ HCH) were analyzed by gas chromatography. Although the mean levels of pesticide were found higher in the placenta of the women with pre-term delivery cases placentas, but only α-HCH, total-HCH, p,p-DDE and total-DDT were found statistically significant. It was observed that pesticide exposed women were approximately 1.7 times more likely to deliver pre-term baby as compare to pregnant women that were not exposed to any pesticides. We also observed that increasing maternal age reduced the risk of having pre-term birth (OR = 0.99). Among all pesticides, α-HCH was found to be strongest isomer to induce premature baby birth (p < 0.001). This study found that pregnant women's age and chronic disease, baby's weight at the time of birth and α-HCH were important risk factors for pre-term births.

Univariate predictors of maternal concentrations of environmental chemicals: The MIREC study

BACKGROUND

The developing fetus and pregnant woman can be exposed to a variety of environmental chemicals that may adversely affect their health. Moreover, environmental exposure and risk disparities are associated with different social determinants, including socioeconomic status (SES) and demographic indicators. Our aim was to investigate whether and how maternal concentrations of a large panel of persistent and non-persistent environmental chemicals vary according to sociodemographic and lifestyle characteristics in a large pregnancy and birth cohort.

METHODS

Data were analyzed from the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a cohort of pregnant women (N=2001) recruited over four years (2008-2011) in 10 cities across Canada. In all, 1890 urine and 1938 blood samples from the first trimester (1st and 3rd trimester for metals) were analysed and six sociodemographic and lifestyle indicators were assessed: maternal age, household income, parity, smoking status, country of birth and pre-pregnancy body mass index (BMI).

RESULTS

We found these indicators to be significantly associated with many of the chemicals measured in maternal blood and urine. Women born outside Canada had significantly higher concentrations of di-2-ethylhexyl and diethyl phthalate metabolites, higher levels of all metals except cadmium (Cd), as well as higher levels of polychlorinated biphenyls (PCBs) and legacy organochlorine pesticides (OCPs). Nulliparity was associated with higher concentrations of dialkyl phosphates (DAPs), arsenic, dimethylarsinic acid (DMAA), perfluoroalkyl substances (PFASs) and many of the persistent organic pollutants. Smokers had higher levels of bisphenol A, Cd and perfluorohexane sulfonate, while those women who had never smoked had higher levels of triclosan, DMAA, manganese and some OCPs.

CONCLUSION

Our results demonstrated that inequitable distribution of exposure to chemicals among populations within a country can occur. Sociodemographic and lifestyle factors are an important component of a thorough risk assessment as they can impact the degree of exposure and may modify the individual's susceptibility to potential health effects due to differences in lifestyle, cultural diets, and aging.

Prenatal exposure to persistent organic pollutants and offspring allergic sensitization and lung function at 20 years of age

BACKGROUND

Prenatal exposures to persistent organic pollutants (POPs) have been associated with asthma medication use and self-reported symptoms, but associations with lung function and allergic sensitization have been minimally explored. The aim of the study was to examine the associations between prenatal exposures to POPs and allergic sensitization and lung function in 20-year-old offspring.

METHODS

In a Danish cohort of 965 pregnant women established in 1988-1989, six polychlorinated biphenyl (PCB) congeners, hexachlorobenzene (HCB), and dichlorodiphenyldichloroethylene (p,p'-DDE) were quantified in archived maternal serum drawn in gestational week 30 (n = 872). Among those with available maternal exposure information, at age 20, 421 offspring attended attended a clinical examination including measurements of allergic sensitization (serum-specific IgE ≥ 0.35 kUA /L) (n = 418) and lung function [forced expiratory volume in one second (FEV1 ) and forced vital capacity (FVC)] (n = 414).

RESULTS

There were no associations between maternal concentrations of POPs and offspring allergic sensitization at 20 years of age. Maternal concentrations of POPs were, however, positively associated with offspring airway obstruction (FEV1 /FVC < 75%). Compared to offspring in the first tertile of exposure, offspring in the third tertile of dioxin-like PCB exposure had an OR of 2.96 (95% CI: 1.14-7.70). Similar associations for non-dioxin-like PCBs, HCB, and p,p'-DDE were 2.68 (1.06-6.81), 2.63 (1.07, 6.46), and 2.87 (1.09, 7.57), respectively. No associations were observed with reduced lung function (FEV1 % of predicted value < 90%).

CONCLUSION AND CLINICAL RELEVANCE

Our data indicate that prenatal exposure to POPs appears to be associated with airway obstruction but not allergic sensitization at 20 years of age. The findings support that chronic obstructive lung diseases may have at least part of their origins in early life.

Metabolic targets of endocrine disrupting chemicals assessed by cord blood transcriptome profiling

Early life exposure to endocrine disrupting chemicals (EDCs) has been frequently associated with impaired perinatal growth, an important risk factor for later onset of metabolic disorders. We analyzed whether the cord blood transcriptome showed early indications of alterations in metabolic processes in 195 human samples in relation to cord blood levels of dichlorodiphenyldichloroethylene (p,p'-DDE), polychlorinated biphenyl-153 (PCB-153), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonate (PFOS). Overall, 39 metabolically relevant transcription factors were significantly enriched (31 by p,p'-DDE, 10 by PCB-153, 8 by PFOA, and 2 by PFOS). These included the glucocorticoid receptor (p,p'-DDE and PCB-153) and the progesterone receptor (PFOA and PFOS). The 'insulin receptor signaling', 'acute phase response signaling', 'Interleukin(IL)-6 signaling', and 'prolactin signaling' pathways were significantly enriched in relation to p,p'-DDE. Transcriptional changes at birth suggest a role for specific metabolic targets as a link between prenatal EDC exposure and metabolic disorders later in life.

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.

Concentrations of persistent organic pollutants in maternal and cord blood from the maternal-infant research on environmental chemicals (MIREC) cohort study

BACKGROUND

Pregnant women are an especially important population to monitor for environmental exposures given the vulnerability of the developing fetus. During pregnancy and lactation chemical body burdens may change due to the significant physiological changes that occur. Developmental exposures to some persistent organic pollutants (POPs) have been linked with adverse health outcomes.

METHODS

First trimester maternal and cord blood plasma concentrations of several POPs including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCs), polybrominated diphenyl ethers (PBDE)s and perfluoroalkyl substances (PFASs) were measured in samples from 1983 pregnant women enrolled in the Maternal-Infant Research on Environmental Chemicals (MIREC) cohort. Predictors of exposure were also identified.

RESULTS

In maternal plasma, there was >90 % detection for the perfluoroalkyl substances (PFASs) perfluorooctanoic acid (PFOA), perfluoroctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), and dichlorodiphenyldichloroethylene (DDE), oxychlordane and PCB 138 and 153. Cord blood plasma had much lower detection rates with low or very limited detection for most PCBs and PBDEs. The PFASs were the most frequently detected (23-64 %) chemical class in cord plasma. In a subset of 1st and 3rd trimester paired samples, PFAS concentrations were found to be strongly correlated and had ICCs ranging from 0.64 (PFOA) to 0.83 (PFHxS). The cord:maternal plasma concentration ratios ranged from 0.14 (PFOS) to 0.87 (oxychlordane, lipid adjusted). Similar to other studies, we found parity, maternal age, income, education, smoking status, pre-pregnancy BMI and fish consumption to be significant predictors for most chemicals. Those participants who were foreign-born had significantly higher concentrations of organochlorinated pesticides and PCBs.

CONCLUSIONS

In the MIREC study, multiple chemical contaminants were quantified in the plasma of pregnant women. In cord plasma PFOA had the highest detection rate. However, compared to other Canadian and international population studies, the MIREC participants had lower contaminant concentrations of these substances.

Early-life Exposure to Widespread Environmental Toxicants and Health Risk: A Focus on the Immune and Respiratory Systems

Evidence has accumulated that exposure to widespread environmental toxicants, such as heavy metals, persistent organic pollutants, and tobacco smoke adversely affect fetal development and organ maturation, even after birth. The developing immune and respiratory systems are more sensitive to environmental toxicants due to their long-term physical development, starting from the early embryonic stage and persisting into early postnatal life, which requires complex signaling pathways that control proliferation and differentiation of highly heterogeneous cell types. In this review, we summarize the effect of early-life exposure to several widespread environmental toxicants on immune and lung development before and after birth, including the effects on immune cell counts, baseline characteristics of cell-mediated and humoral immunity, and alteration of lung structure and function in offspring. We also review evidence supporting the association between early-life exposure to environmental toxicants and risk for immune-related diseases and lung dysfunction in offspring in later life.

Maternal exposure to metals and persistent pollutants and cord blood immune system biomarkers

BACKGROUND

The fetal time period is a critical window of immune system development and resulting heightened susceptibility to the adverse effects of environmental exposures. Epidemiologists and toxicologists have hypothesized that persistent organic pollutants, pesticides and metals have immunotoxic properties. Immunotoxic effects may manifest as an altered immune system profile at birth. Immunoglobulin E, thymic stromal lymphopoietin (TSLP), and interleukin-33 (IL-33) may be implicated in the etiology of childhood allergy and are detectable at birth. The objective of this study was to examine the potential relationship between maternal concentrations of metals, persistent organic pollutants, and pesticides and elevated umbilical cord blood concentrations of IgE, TSLP, and IL-33 in a Canadian birth cohort.

METHODS

This study utilized data collected in the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a trans-Canada cohort study of 2,001 pregnant women. Of these women, 1258 had a singleton, term birth and cord blood sample. Logistic regression was used to determine associations between log-transformed continuous variables and immune system biomarkers.

RESULTS

Inverse relationships were observed between lead, DDE, PCB-118, and a summary index of organophosphorous metabolites and jointly elevated concentrations of IL-33 and TSLP. None of the environmental contaminants were associated with increased odds of a high cord blood immune system biomarker concentration.

CONCLUSIONS

In this primarily urban Canadian population of pregnant women and their newborns, maternal blood or urine concentrations of persistent organic pollutants, pesticides, and metals were not associated with immunotoxic effects that manifest as increased odds of elevated concentrations of IgE, TSLP or IL-33.

Prenatal exposure to environmental chemical contaminants and asthma and eczema in school-age children

BACKGROUND

Emerging evidence suggests that prenatal or early-life exposures to environmental contaminants may contribute to an increased risk of asthma and allergies in children. We aimed to the explore associations of prenatal exposures to a large set of environmental chemical contaminants with asthma and eczema in school-age children.

METHODS

We studied 1024 mother-child pairs from Greenland and Ukraine from the INUENDO birth cohort. Data were collected by means of an interview-based questionnaire when the children were 5-9 years of age. Questions from the ISAAC study were used to define asthma, eczema, and wheeze. We applied principal components analysis (PCA) to sixteen contaminants in maternal serum sampled during pregnancy, including perfluoroalkyl substances (PFASs), metabolites of diethylhexyl (DEHP) and diisononyl (DiNP) phthalates, PCB-153, and p,p'-DDE. Scores of five principal components (PCs) explaining 70% of the variance were included in multiple logistic regression models.

RESULTS

In a meta-analysis that included both populations, the PC2 score, reflecting exposure to DiNP, was negatively associated with current eczema (OR 0.71, 95% CI 0.52-0.96). Other associations were not consistent between the two populations. In Ukrainian children, the PC3 score (DEHP) was positively associated with current wheeze (adjusted OR 1.56, 95% CI 1.03-2.37), whereas the PC5 score, dominated by perfluorooctanoic acid (PFOA), was inversely associated with current wheeze (OR 0.64, 0.41-0.99). In Greenlandic children, a negative association of PC4 (organochlorines) with ever eczema (OR 0.78, 0.61-0.99) was found.

CONCLUSIONS

We found limited evidence to support a link between prenatal exposure to environmental chemical contaminants and childhood asthma and eczema.

Persistent organic pollutants and children's respiratory health: the role of cytokines and inflammatory biomarkers

Evidence of adverse effects of persistent organic pollutants (POPs) on the developmental respiratory and immune systems in children is still limited, and the biological mechanisms behind such effects are not fully understood. The aim of the present study is to evaluate the effects of prenatal DDE, HCB and ΣPCB exposure on children's respiratory health from birth to 14 years and to evaluate the role of immune biomarkers in these associations. We measured prenatal DDE, HCB and ΣPCB levels in 405 participants of the INMA-Menorca birth cohort (Spain) and collected information on wheeze, chest infections, atopy and asthma from birth until the age of 14 years. At age 4 years, 275 children provided serum samples and IL6, IL8, IL10, TNFα and C-reactive protein were measured. We applied linear and logistic regression models and generalized estimating equations. Prenatal DDE was associated with wheeze at age 4 years [RR (95% CI) per doubling of concentration=1.35 (1.07, 1.71)], but not thereafter. Prenatal HCB was associated with wheeze [1.58 (1.04, 2.41)] and chest infections [1.89 (1.10, 3.25)] at age 10years. No associations were found with ΣPCBs. IL10 levels increased with increasing POP concentration, with HCB showing the strongest association [β (95% CI)=0.22 (0.02, 0.41)]. IL8, IL10 and TNFα were associated with wheeze and/or chest infections and IL10 was associated with asthma. Prenatal DDE and HCB exposure was associated with respiratory health of children at different ages. This study further suggests a possible role of IL10, but not of the other immune biomarkers examined, as an early marker of chronic immune-related health effects of POPs.