Concentrations and predictors of select nutrients in Canadian human milk samples from the Maternal-Infant Research on Environmental Chemicals pregnancy cohort.

Background: Human milk (HM) composition data are widely used in clinical, regulatory, and public health initiatives. The existing HM profiles in United States and Canadian nutrient databanks are outdated and now considered inappropriate to estimate current nutrient intakes. Recent reviews have underscored the limited North American data available to generate a new profile.

Gestational urinary concentrations of glyphosate and aminomethylphosphonic acid in relation to preterm birth: the MIREC study.

Background: Few high-quality studies have evaluated associations between urinary glyphosate or its environmental degradate (aminomethylphosphonic acid (AMPA)] and preterm birth (PTB).

Objectives: To quantify associations between urinary glyphosate and AMPA and preterm birth in the pan-Canadian Maternal-Infant Research on Environmental Chemicals (MIREC) study and determine if associations differ by fetal sex.

Methods: We measured first trimester urinary glyphosate and AMPA concentrations in MIREC participants who were recruited between 2008-2011 from 10 Canadian cities.

A cohort study of the multipollutant effects of PM, NO, and O on C-reactive protein levels during pregnancy.

Background: PM NO, and O contribute to the development of adverse pregnancy complications. While studies have investigated the independent effects of these exposures, literature on their combined effects is limited. Our objective was to study the multipollutant effects of PM, NO, and O on maternal systemic C-reactive protein (CRP) levels.

Density and proximity of oil and gas wells and concentrations of trace elements in urine, hair, nails and tap water samples from pregnant individuals living in Northeastern British Columbia.

Background: Oil and gas exploitation can release several contaminants in the environment, including trace elements, with potentially deleterious effects on exposed pregnant individuals and their developing fetus. Currently, there is limited data on pregnant individuals' exposure to contaminants associated with oil and gas activity.

Objectives: We aimed to 1)measure concentrations of trace elements in biological and tap water samples collected from pregnant individuals participating in the EXPERIVA study; 2)compare with reference populations and health-based guidance values; 3)assess correlations across matrices; and 4)evaluate associations with the density/proximity of oil and gas wells.

Using in vitro data to derive acceptable exposure levels: A case study on PBDE developmental neurotoxicity.

Background: Current acceptable chemical exposure levels (e.g., tolerable daily intake) are mainly based on animal experiments, which are costly, time-consuming, considered non-ethical by many, and may poorly predict adverse outcomes in humans.

Cohort profile update: The Canadian Maternal-Infant Research on Environmental Chemicals Child Development study (MIREC-CD PLUS).

Background: The pan-Canadian Maternal-Infant Research on Environmental Chemicals (MIREC) study was established to determine whether maternal environmental chemical exposures were associated with adverse pregnancy outcomes in 2001 pregnant women.

Objectives: The MIREC-Child Development (CD PLUS) study followed this cohort with the goal of assessing the potential effects of prenatal exposures on anthropometry and neurodevelopment in early childhood.

Population: MIREC families with children between the ages of 15 months and 5 years who had agreed to be contacted for future research (n = 1459) were invited to participate in MIREC-CD PLUS which combines data collected from an online Maternal Self-Administered Questionnaire with biomonitoring and neurodevelopment data collected from two in-person visits.

Measurement of 24 phthalate metabolites in 1st trimester urine samples: The MIREC study.

Phthalates are non-persistent chemicals measured as metabolites in urine. Over time, new metabolites have been identified. In the original Maternal-Infant Research on Environmental Chemicals (MIREC) study (2008-2011), we measured 11 phthalate metabolites in first trimester urine samples.

Prenatal and concurrent blood mercury concentrations and associations with IQ in canadian preschool children.

Background: Prenatal and childhood mercury (Hg) exposures have been associated with negative impacts on child neurodevelopment. It is unclear if associations persist at the low Hg exposures typical in Western countries.

Objective: To examine associations between prenatal/childhood blood Hg concentrations and child IQ in Canadian male and female children while considering the potential modifying role of prenatal fish consumption.

Computerized Cognitive Test Batteries for Children and Adolescents-A Scoping Review of Tools For Lab- and Web-Based Settings From 2000 to 2021.

Objective: Cognitive functioning is essential to well-being. Since cognitive difficulties are common in many disorders, their early identification is critical, notably during childhood and adolescence. This scoping review aims to provide a comprehensive literature overview of computerized cognitive test batteries (CCTB) that have been developed and used in children and adolescents over the past 22 years and to evaluate their psychometric properties.

Descriptive analysis of organophosphate ester metabolites in a pan-Canadian pregnancy cohort.

Organophosphate esters (OPEs) are widely used in numerous consumer products for their flame retardant and plasticizing properties. Despite potential widespread exposure, biomonitoring data during critical windows of development are scarce and limited to the most widely studied metabolites. We quantified urinary concentrations of multiple OPE metabolites in a vulnerable Canadian population.

Urinary concentrations and determinants of glyphosate and glufosinate in pregnant Canadian participants in the MIREC study.

Background: Glyphosate is the most widely applied herbicide in agriculture. Glufosinate is a broad spectrum herbicide used to manage glyphosate-resistant weeds. Despite the widespread use of these herbicides, biomonitoring data - which inform risk assessment and management - are sparse.

Volatile organic compounds (VOCs) in indoor air and tap water samples in residences of pregnant women living in an area of unconventional natural gas operations: Findings from the EXPERIVA study.

Background: Northeastern British Columbia (Canada) is an area of unconventional natural gas (UNG) exploitation by hydraulic fracturing, which can release several contaminants, including volatile organic compounds (VOCs). To evaluate gestational exposure to contaminants in this region, we undertook the Exposures in the Peace River Valley (EXPERIVA) study.

Objectives: We aimed to: 1) measure VOCs in residential indoor air and tap water from EXPERIVA participants; 2) compare concentrations with those in the general population and explore differences related to sociodemographic and housing characteristics; and 3) determine associations between VOC concentrations and density/proximity to UNG wells.

Concentrations of Lead, Mercury, Selenium, and Manganese in Blood and Hand Grip Strength among Adults Living in the United States (NHANES 2011-2014).

Exposure to lead and mercury can cause deficits in neuromotor function. Selenium and manganese are essential elements, hence both deficiency and excess could result in decreased neuromotor function. We aimed to examine hand grip strength, a marker of neuromotor function, and blood concentrations of lead, mercury, selenium, and manganese in the general U.

Urinary phthalates and body mass index in preschool children: The MIREC Child Development Plus study.

Childhood exposure to phthalates, a class of chemicals with known reproductive and developmental effects, has been hypothesized to increase the risk of obesity, but this association is not well understood in preschool children. We examined the association between urinary concentrations of phthalate metabolites and concurrently measured body mass index (BMI) and skinfolds among children between the ages of two and five years. We collected anthropometric measures and biomonitoring data on approximately 200 children enrolled in the Maternal-Infant Research on Environmental Chemicals Child Development Plus study.

Prenatal exposure to polybrominated diphenyl ethers (PBDEs) and cognitive ability in early childhood.

Background: Prenatal exposure to polybrominated diphenyl ethers (PBDEs) has been associated with adverse neurodevelopmental outcomes in children, but evidence remains mixed regarding sex differences in this association.

Objective: To examine the prospective association between prenatal PBDE exposure and cognitive ability in young children, as well as potential sex differences.

Methods: The study was conducted in a multi-site Canadian pregnancy cohort recruited in 2008-11.

Associations among urinary triclosan and bisphenol A concentrations and serum sex steroid hormone measures in the Canadian and U.S. Populations.

Exposure to triclosan, an antimicrobial agent, and bisphenol A (BPA), the monomer of polycarbonate plastics, is widespread. Endocrine-disrupting impacts of these chemicals have been demonstrated in in vitro studies, rodent toxicology studies, and some human observational studies. Here we compared urinary concentrations of triclosan and BPA in the Canadian and U.

Concentrations of urinary parabens and reproductive hormones in girls 6-17 years living in Canada.

Background: Parabens are chemical substances used as preservatives for their antibacterial and antifungal properties in many personal care products, and sometimes in pharmaceutical and food products. Concerns for adverse human health effects arise from animal studies showing endocrine disrupting effects, such as changes in the timing of puberty and alterations in reproductive hormone activity. Our objective was to examine the association between urinary concentrations of parabens and serum concentrations of estradiol, progesterone, follicle stimulating hormone [FSH], and luteinizing hormone [LH]) in girls from the general population.

Organophosphate pesticides exposure during fetal development and IQ scores in 3 and 4-year old Canadian children.

Background: Organophosphate pesticides are widely used in agriculture and for other purposes, leading to ubiquitous exposure in human populations. Some studies reported cognitive deficits in children exposed prenatally to organophosphate pesticides, but findings from recent studies were inconsistent. Furthermore, recent biomonitoring studies suggest exposure levels have decreased.

Gestational Exposures to Phthalates and Folic Acid, and Autistic Traits in Canadian Children.

Background: The etiology of autism spectrum disorder is poorly understood. Few studies have investigated the link between endocrine-disrupting chemicals and autistic traits. We examined the relationship between gestational phthalates and autistic traits in 3- to 4-y-old Canadian children.

Multi-exposures to suspected endocrine disruptors in electronic waste recycling workers: Associations with thyroid and reproductive hormones.

Electronic waste recycling (e-recycling) exposes workers to substances such as flame retardants and metals. Some of them are known or suspected endocrine disruptors that could affect hormonal homeostasis and eventually result in adverse health outcomes. Our aim was to measure biological concentrations of organophosphate ester (OPE) metabolites, polybrominated diphenyl ethers (PBDEs), mercury, lead and cadmium in e-recycling workers, and to explore associations with thyroid and sexual hormones.

Blood metal levels and early childhood anthropometric measures in a cohort of Canadian children.

Fetal exposure to some toxic metals has been associated with reduced fetal growth, but the impact of contemporary, low-level metals on anthropometric measures in childhood is not well understood. Our primary objective was to quantify associations between childhood levels of toxic metals and concurrently measured body mass index (BMI) in a population of Canadian preschool-aged children. We collected biomonitoring data and anthropometric measures on 480 children between the ages of two and five years in the Maternal-Infant Research on Environmental Chemicals (MIREC) Child Development Plus study.