Maternal concentrations of perfluoroalkyl sulfonates and alterations in white matter microstructure in the developing brains of young children.

Background: Maternal exposure to per- and polyfluoroalkyl substances (PFAS) has been linked to child neurodevelopmental difficulties. Neuroimaging research has linked these neurodevelopmental difficulties to white matter microstructure alterations, but the effects of PFAS on children's white matter microstructure remains unclear. We investigated associations between maternal blood concentrations of six common perfluoroalkyl sulfonates and white matter alterations in young children using longitudinal neuroimaging data.

A field investigation of 3 masks proposed as respiratory protection for wildland firefighters: a randomized controlled trial in British Columbia, Canada.

Introduction: Wildland firefighters are exposed through the lungs and skin to particulate matter, fumes, and vapors containing polycyclic aromatic hydrocarbons (PAH). Wearing respiratory protection should reduce pulmonary exposure, but there is uncertainty about the most effective and acceptable type of mask.

Methods: Firefighters from 6 unit crews working with the British Columbia Wildfire Service were approached and those consenting were randomly allocated within each crew to a "no mask" control group or to use 1 of 3 types of masks: X, half-face respirator with P100/multi gas cartridge; Y, cloth with alpaca filter; Z mesh fabric with a carbon filter.

Sex-Specific Associations between Prenatal Exposure to Bisphenols and Phthalates and Infant Epigenetic Age Acceleration.

We examined whether prenatal exposure to two classes of endocrine-disrupting chemicals (EDCs) was associated with infant epigenetic age acceleration (EAA), a DNA methylation biomarker of aging. Participants included 224 maternal-infant pairs from a Canadian pregnancy cohort study. Two bisphenols and 12 phthalate metabolites were measured in maternal second trimester urines.

Maternal pre-pregnancy BMI influences the associations between bisphenol and phthalate exposures and maternal weight changes and fat accumulation.

Background: Bisphenols and phthalates are two classes of endocrine-disrupting chemicals (EDCs) thought to influence weight and adiposity. Limited research has investigated their influence on maternal weight changes, and no prior work has examined maternal fat mass. We examined the associations between exposure to these chemicals during pregnancy and multiple maternal weight and fat mass outcomes.

Maternal exposure to bisphenols, phthalates, perfluoroalkyl acids, and trace elements and their associations with gestational diabetes mellitus in the APrON cohort.

The increasing global prevalence of gestational diabetes mellitus (GDM) has been hypothesized to be associated with maternal exposure to environmental chemicals. Here, among 420 women participating in the Alberta Pregnancy Outcomes and Nutrition (APrON) cohort study, we examined associations between GDM and second trimester blood or urine concentrations of endocrine disrupting chemicals (EDCs): bisphenol-A (BPA), bisphenol-S (BPS), twelve phthalate metabolites, eight perfluoroalkyl acids (PFAAs), and eleven trace elements. Fifteen (3.

Sex-Specific Associations between Prenatal Exposure to Di(2-ethylhexyl) Phthalate, Epigenetic Age Acceleration, and Susceptibility to Early Childhood Upper Respiratory Infections.

Di(2-ethylhexyl) phthalate (DEHP) is a common plasticizer that can affect immune system development and susceptibility to infection. Aging processes (measured as epigenetic age acceleration (EAA)) may mediate the immune-related effects of prenatal exposure to DEHP. This study's objective was to examine associations between prenatal DEHP exposure, EAA at three months of age, and the number of upper respiratory infections (URIs) from 12 to 18 months of age using a sample of 69 maternal-child pairs from a Canadian pregnancy cohort.

An integrative and multi-indicator approach for wildlife health applied to an endangered caribou herd.

Assessing wildlife health in remote regions requires a multi-faceted approach, which commonly involves convenient samplings and the need of identifying and targeting relevant and informative indicators. We applied a novel wildlife health framework and critically assessed the value of different indicators for understanding the health status and trends of an endangered tundra caribou population. Samples and data from the Dolphin and Union caribou herd were obtained between 2015 and 2021, from community-based surveillance programs and from captured animals.

Associations between the chemical exposome and pregnancy induced hypertension.

Exposure to environmental chemicals has been linked to an increased risk of pregnancy-induced hypertension (PIH). This prospective cohort study examined the associations between PIH and maternal chemical exposure to four classes of chemicals (i.e.

Sex-specific associations between maternal phthalate exposure and neurodevelopmental outcomes in children at 2 years of age in the APrON cohort.

Background: There is inconsistent evidence regarding the sex-specific associations between prenatal phthalate exposure and children's neurodevelopment. This could be due to differences in the phthalate exposures investigated and the neurodevelopmental domains assessed.

Objective: To evaluate the associations between prenatal phthalate exposure and sex-specific outcomes on measures of cognition, language, motor, executive function, and behaviour in children 2 years of age in the Alberta Pregnancy Outcomes and Nutrition (APrON) cohort.

Maternal co-exposure to mercury and perfluoroalkyl acid isomers and their associations with child neurodevelopment in a Canadian birth cohort.

Background: Perfluoroalkyl acids (PFAAs) within the broader class of per- and polyfluoroalkyl substances (PFAS) are present in human serum as isomer mixtures, but epidemiological studies have yet to address isomer-specific associations with child development and behavior.

Objectives: To examine associations between prenatal exposure to 25 PFAAs, including perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) isomers, and child neurodevelopment among 490 mother-child pairs in a prospective Canadian birth cohort, the Alberta Pregnancy Outcomes and Nutrition (APrON) study. To consider the influence of a classic neurotoxicant, total mercury (THg), based on its likelihood of co-exposure with PFAAs from common dietary sources.

Associations between maternal folate status and choline intake during pregnancy and neurodevelopment at 3-4 years of age in the Alberta Pregnancy Outcomes and Nutrition (APrON) study.

Folate and choline are methyl donor nutrients that may play a role in fetal brain development. Animal studies have reported that prenatal folate and choline supplementation are associated with better cognitive outcomes in offspring and that these nutrients may interact and affect brain development. Human studies that have investigated associations between maternal prenatal folate or choline levels and neurodevelopmental outcomes have reported contradictory findings and no human studies have examined the potential interactive effect of folate and choline on children's neurodevelopment.

Exposures to Polycyclic Aromatic Hydrocarbons and Their Mitigation in Wildland Firefighters in Two Canadian Provinces.

Objectives: We aimed to characterize polycyclic aromatic hydrocarbons (PAHs) in the breathing zone and on the skin of wildland firefighters and to assess their contribution to urinary 1-hydroxypyrene (1-HP) over repeated firefighting rotations. We asked if improved skin hygiene or discretionary use of an N95 mask would reduce absorption.

Methods: In collaboration with wildfire services of two Canadian provinces, Alberta and British Columbia (BC), we recruited wildland firefighters from crews willing to be followed up over successive rotations and to be randomly assigned to normal practice, enhanced skin hygiene (ESH), or ESH plus discretionary use of an N95 mask.

Evaluating the use of hair as a non-invasive indicator of trace mineral status in woodland caribou (Rangifer tarandus caribou).

Trace mineral imbalances can have significant effects on animal health, reproductive success, and survival. Monitoring their status in wildlife populations is, therefore, important for management and conservation. Typically, livers and kidneys are sampled to measure mineral status, but biopsies and lethal-sampling are not always possible, particularly for Species at Risk.

Formation potential and analysis of 32 regulated and unregulated disinfection by-products: Two new simplified methods.

Water disinfection is an essential process that provides safe water by inactivating pathogens that cause waterborne diseases. However, disinfectants react with organic matter naturally present in water, leading to the formation of disinfection by-products (DBPs). Multi-analyte methods based on mass spectrometry (MS) are preferred to quantify multiple DBP classes at once however, most require extensive sample pre-treatment and significant resources.

A microelectric cell sensing technique for in vitro assessment of ocular irritation.

The animal-based Draize test remains the gold standard for assessment of ocular irritation. However, subjective scoring methods, species differences, and animal welfare concerns have spurred development of alternative test methods. In this study, a novel in vitro method for assessing ocular irritancy was developed using a microelectric cell sensing technology, real-time cell analysis (RTCA).

Laboratory medicine: The exemplar for value-based healthcare.

Value-Based Healthcare (VBHC) aims to improve the overall quality, safety, and sustainability of healthcare while reducing delivery costs of more effective care. Despite advantages associated with VBHC transformation, the road to its adoption has been lengthy. Laboratory Medicine (LM) is in a prime position to lead the transition to VBHC because of its key role in diagnosis and treatment of patients.

A hidden risk: Survival and resuscitation of Escherichia coli O157:H7 in the viable but nonculturable state after boiling or microwaving.

We report the existence and resuscitation of viable but nonculturable (VBNC) Escherichia coli O157:H7 cells in drinking water induced by the common point-of-use disinfection treatments of boiling or microwaving. Tap water and saline samples containing E. coli O157:H7 culturable cells from a bovine isolate or two clinical isolates were boiled (1, 10, or 15 min) on a hot plate or microwaved (1.

Similar names, different results: Consistency of the associations between prenatal exposure to phthalates and parent-ratings of behavior problems in preschool children.

Background: Environmental health research has reported mixed findings on the associations between prenatal exposure to phthalates and parent-ratings of child behavioral problems.

Objective: We examined the consistency of the associations between prenatal urinary phthalate concentrations and child behavior scores across two standardized instruments - the Behavior Assessment System for Children-Second Edition (BASC-2) and the Child Behavior Checklist (CBCL) - using two analytical approaches used to correct for urine dilution.

Method: A sample of 351 mother-child pairs were selected from a prospective birth cohort of pregnant women enrolled between 2009 and 2012.

Exposure and Absorption of PAHs in Wildland Firefighters: A Field Study with Pilot Interventions.

Objectives: There is limited knowledge of exposure to polycyclic aromatic hydrocarbons (PAHs) in wildland firefighters, or of the effectiveness of interventions to reduce this. This study of wildland firefighters assessed whether PAHs were present and considered respiratory protection and enhanced skin hygiene as possible interventions.

Methods: 1-Hydroxypyrene (1-HP) was measured in urine samples collected pre-shift, post-shift, and next morning from wildland firefighters in Alberta and British Columbia.

Cytotoxicity of Halogenated Tyrosyl Compounds, an Emerging Class of Disinfection Byproducts.

Halogenated amino acids and peptides are an emerging class of disinfection byproducts (DBPs), having been detected in drinking water and in washed food products. However, the toxicological significance of these emerging DBPs remains unclear. In this study, the cytotoxicity of eight halogenated tyrosyl compounds was investigated in Chinese hamster ovary (CHO) cells using real-time cell analysis (RTCA).

White matter microstructure mediates the association between prenatal exposure to phthalates and behavior problems in preschool children.

Background: Previous research reports associations between prenatal exposure to phthalates and childhood behavior problems; however, the neural mechanisms that may underlie these associations are relatively unexplored.

Objective: This study examined microstructural white matter as a possible mediator of the associations between prenatal phthalate exposure and behavior problems in preschool-aged children.

Methods: Data are from a subsample of a prospective pregnancy cohort, the Alberta Pregnancy Outcomes and Nutrition (APrON) study (n = 76).

Neurodevelopmental and Metabolomic Responses from Prenatal Coexposure to Perfluorooctanesulfonate (PFOS) and Methylmercury (MeHg) in Sprague-Dawley Rats.

Methylmercury (MeHg) and perfluorooctanesulfonate (PFOS) are major contaminants of human blood that are both common in dietary fish, thereby raising questions about their combined impact on human development. Here, pregnant Sprague-Dawley rats ingested a daily dose, from gestational day 1 through to weaning, of either 1 mg/kg bw PFOS (PFOS-only), 1 mg/kg MeHg (MeHg-only), a mixture of 0.1 mg/kg PFOS and 1 mg/kg MeHg (Low-Mix), or of 1 mg/kg of PFOS and 1 mg/kg MeHg (High-Mix).