Research and Faculty

Environ Res. 2024 Sep 2;262(Pt 2):119910. doi: 10.1016/j.envres.2024.119910. Online ahead of print.

ABSTRACT

BACKGROUND: Organophosphate esters (OPEs), flame retardants and plasticizers found widely in consumer products, may impact vascularization processes in pregnancy. Yet, the association between maternal exposure to OPEs and both preeclampsia and blood pressure during pregnancy remains understudied.

METHODS: Within the LIFECODES Fetal Growth Study (N = 900), we quantified 8 OPE metabolites from maternal urine collected at up to 3 time points during pregnancy and created within-subject geometric means. Outcomes included diagnosis of preeclampsia and longitudinal systolic (SBP) and diastolic (DBP) blood pressure measurements (mean = 14 per participant). Cox proportional hazards models were used to estimate associations between OPE metabolites and preeclampsia. Associations between average OPE metabolite concentrations and repeated blood pressure measurements were estimated using generalized estimating equations.

RESULTS: Five OPE metabolites were detected in at least 60% of samples; 3 metabolites detected less frequently (5-39%) were examined in an exploratory analysis as ever vs. never detectable in pregnancy. There were 46 cases of preeclampsia in our study population. Associations between OPE metabolites and preeclampsia were null. We noted several divergent associations between OPE metabolites and longitudinal blood pressure measurements. An interquartile range (IQR) difference in average bis(2-chloroethyl) phosphate concentrations was associated with a decrease in SBP (-0.81 mmHg, 95% confidence interval [CI]: -1.62, 0.00), and, conversely, bis(1-chloro-2-propyl) phosphate was associated with a slight increase in SBP (0.94 mmHg, 95% CI: 0.28, 1.61). We also noted a decrease in SBP in association with several metabolites with low detection frequency.

CONCLUSIONS: We observed null associations between OPE metabolites and preeclampsia, but some positive and some inverse associations with blood pressure in pregnancy. While our study was well-designed to assess associations with blood pressure, future studies with a larger number of preeclampsia cases may be better poised to investigate the association between OPE metabolites and phenotypes of this heterogenous hypertensive disorder of pregnancy.

PMID:39233027 | DOI:10.1016/j.envres.2024.119910

Int J Biometeorol. 2024 Aug 14. doi: 10.1007/s00484-024-02737-y. Online ahead of print.

ABSTRACT

Allergic rhino-conjunctivitis (AR) is a globally relevant health disorder characterized by sneezing, rhinorrhea and sleep disturbance. Ragweed (Ambrosia artemisiifolia) is a plant common to North America and an important allergen. Coarse methods of measuring airborne pollen counts are used to predict seasonal allergy symptoms. This research used a longitudinal study design with a novel, model-based raster of predicted pollen counts to test associations with self-reported symptoms of AR collected from patients receiving immunotherapy for pollen allergies at an allergy clinic. Researchers visited a clinic six times over three weeks. Immunotherapy patients were asked to fill out a brief intake survey on allergic and symptomatic profiles, daytime sleepiness, housing quality, and demographics. Participants responded to a daily, emailed survey on sleepiness and asthma symptoms for 21 days. Using the date and location of responses, ragweed pollen counts were extracted from a prognostic, model based raster (25km pixels). Lag associations of pollen counts with sleepiness were tested using a logistic regression model , adjusted for housing and demographic characteristics, in a distributed lag non-linear model (DLNM) framework. 49 people participated in the study. 26 (52%) were female. The mean age was 37.9 years. Asthma/allergy symptoms were not associated with ragweed pollen but sleepiness was highest two days after exposure (Estimate: 0.33 [0.04,0.62]). Subjects traveled widely during the study period. Intense exposures to ragweed pollen may be associated with daytime sleepiness within small exposure windows. Model-based predicted pollen counts could be used to study health impacts of pollen in people with disease severe enough to receive immunotherapy. Daytime sleepiness can affect productivity and injury risk, and pollen season length and allergenicity may be increasing with climate change. Thus our results may have important implications for population health.

PMID:39141134 | DOI:10.1007/s00484-024-02737-y

Environ Health Perspect. 2024 Aug;132(8):87004. doi: 10.1289/EHP14008. Epub 2024 Aug 14.

ABSTRACT

BACKGROUND: Phenols and parabens are two classes of high production volume chemicals that are used widely in consumer and personal care products and have been associated with reproductive harm and pregnancy complications, such as preeclampsia and gestational diabetes. However, studies examining their influence on maternal blood pressure and gestational hypertension are limited.

OBJECTIVES: We investigated associations between individual phenols, parabens, and their mixture on maternal blood pressure measurements, including systolic and diastolic blood pressure (SBP and DBP) and hypertension during pregnancy (defined as stage 1 or 2 hypertension), among N=1,433 Puerto Rico PROTECT study participants.

METHODS: We examined these relationships cross-sectionally at two time points during pregnancy (16-20 and 24-28 wks gestation) and longitudinally using linear mixed models (LMMs). Finally, we used quantile g-computation to examine the mixture effect on continuous (SBP, DBP) and binary (hypertension during pregnancy) blood pressure outcomes.

RESULTS: We observed a trend of higher odds of hypertension during pregnancy with exposure to multiple analytes and the overall mixture [including bisphenol A (BPA), bisphenol S (BPS), triclocarbon (TCC), triclosan (TCS), benzophenone-3 (BP-3), 2,4-dichlorophenol (2,4-DCP), 2,5-dichlorophenol (2,5-DCP), methyl paraben (M-PB), propyl paraben (P-PB), butyl paraben (B-PB), and ethyl paraben (E-PB)], especially at 24-28 wk gestation, with an adjusted mixture odds ratio(OR)=1.57 (95% CI: 1.03, 2.38). Lower SBP and higher DBP were also associated with individual analytes, with results from LMMs most consistent for methyl paraben (M-PB) or propyl paraben (P-PB) and increased DBP across pregnancy [adjusted M-PB β=0.78 (95% CI: 0.17, 1.38) and adjusted P-PB β=0.85 (95% CI: 0.19, 1.51)] and for BPA, which was associated with decreased SBP (adjusted β=–0.57; 95% CI: –1.09, –0.05). Consistent with other literature, we also found evidence of effect modification by fetal sex, with a strong inverse association observed between the overall exposure mixture and SBP at visit 1 among participants carrying female fetuses only.

CONCLUSIONS: Our findings indicate that phenol and paraben exposure may collectively increase the risk of stage 1 or 2 hypertension during pregnancy, which has important implications for fetal and maternal health. https://doi.org/10.1289/EHP14008.

PMID:39140735 | PMC:PMC11323763 | DOI:10.1289/EHP14008

J Neurol Neurosurg Psychiatry. 2024 Aug 6:jnnp-2024-333978. doi: 10.1136/jnnp-2024-333978. Online ahead of print.

ABSTRACT

BACKGROUND: The pathogenesis of amyotrophic lateral sclerosis (ALS) involves both genetic and environmental factors. This study investigates associations between metal measures in plasma and urine, ALS risk and survival and exposure sources.

METHODS: Participants with and without ALS from Michigan provided plasma and urine samples for metal measurement via inductively coupled plasma mass spectrometry. ORs and HRs for each metal were computed using risk and survival models. Environmental risk scores (ERS) were created to evaluate the association between exposure mixtures and ALS risk and survival and exposure source. ALS (ALS-PGS) and metal (metal-PGS) polygenic risk scores were constructed from an independent genome-wide association study and relevant literature-selected single-nucleotide polymorphisms.

RESULTS: Plasma and urine samples from 454 ALS and 294 control participants were analysed. Elevated levels of individual metals, including copper, selenium and zinc, significantly associated with ALS risk and survival. ERS representing metal mixtures strongly associated with ALS risk (plasma, OR=2.95, CI=2.38-3.62, p<0.001; urine, OR=3.10, CI=2.43-3.97, p<0.001) and poorer ALS survival (plasma, HR=1.37, CI=1.20-1.58, p<0.001; urine, HR=1.44, CI=1.23-1.67, p<0.001). Addition of the ALS-PGS or metal-PGS did not alter the significance of metals with ALS risk and survival. Occupations with high potential of metal exposure associated with elevated ERS. Additionally, occupational and non-occupational metal exposures were associated with measured plasma and urine metals.

CONCLUSION: Metals in plasma and urine associated with increased ALS risk and reduced survival, independent of genetic risk, and correlated with occupational and non-occupational metal exposures. These data underscore the significance of metal exposure in ALS risk and progression.

PMID:39107037 | DOI:10.1136/jnnp-2024-333978

BMJ Paediatr Open. 2024 Jul 24;8(1):e002828. doi: 10.1136/bmjpo-2024-002828.

ABSTRACT

OBJECTIVE: To characterise applied force on the face and head during simulated mask ventilation with varying mask, device and expertise level.

DESIGN: Randomised cross-over simulation study.

SETTING: A quiet, empty room in the children’s hospital.

PARTICIPANTS: Neonatal healthcare providers, categorised as novices and experts in positive pressure ventilation (PPV).

INTERVENTIONS: PPV for 2 min each in a 2×2 within-subjects design with two masks (round and anatomic) and two ventilation devices (T-piece and self-inflating bag (SIB)).

MAIN OUTCOME MEASURES: Applied force (Newton (N)) measured under the head and at four locations on the manikin’s face (nasal bridge, mentum, left and right zygomatic arches) and symmetry of force applied around the mask rim.

RESULTS: For the 51 participants, force applied to the head was greater with the SIB than the T-piece (mean (SD): 16.03 (6.96) N vs 14.31 (5.16) N) and greater with the anatomic mask than the round mask (mean (SD): 16.07 (6.80) N vs 14.26 (5.35) N). Underhead force decreased over the duration of PPV for all conditions. Force measured on the face was greatest at the left zygomatic arch (median (IQR): 0.97 (0.70-1.43) N) and least at the mentum (median (IQR): 0.44 (0.28-0.61) N). Overall, experts applied more equal force around the mask rim compared with novices (median (IQR): 0.46 (0.26-0.79) N vs 0.65 (0.24-1.18) N, p<0.001).

CONCLUSION: We characterised an initial dataset of applied forces on the face and head during simulated PPV and described differences in force when considering mask type, device type and expertise.

PMID:39053968 | PMC:PMC11284901 | DOI:10.1136/bmjpo-2024-002828

Environ Int. 2024 Aug;190:108866. doi: 10.1016/j.envint.2024.108866. Epub 2024 Jul 2.

ABSTRACT

INTRODUCTION: Environmental phenols are endocrine disrupting chemicals hypothesized to affect early life development. Previous research examining the effects of phenols on fetal growth has focused primarily on associations with measures of size at delivery. Few have included ultrasound measures to examine growth across pregnancy.

OBJECTIVE: Investigate associations between prenatal exposure to phenols and ultrasound and delivery measures of fetal growth.

METHODS: Using the LIFECODES Fetal Growth Study (n = 900), a case-cohort including 248 small-for-gestational-age, 240 large-for-gestational age, and 412 appropriate-for-gestational-age births, we estimated prenatal exposure to 12 phenols using three urine samples collected during pregnancy (median 10, 24, and 35 weeks gestation). We abstracted ultrasound and delivery measures of fetal growth from medical records. We estimated associations between pregnancy-average phenol biomarker concentrations and repeated ultrasound measures of fetal growth using linear mixed effects models and associations with birthweight using linear regression models. We also used logistic regression models to estimate associations with having a small- or large-for-gestational birth.

RESULTS: We observed positive associations between 2,4-dichlorophenol, benzophenone-3, and triclosan (TCS) and multiple ultrasound measures of fetal growth. For example, TCS was associated with a 0.09 (95 % CI: 0.01, 0.18) higher estimated fetal weight z-score longitudinally across pregnancy. This effect size corresponds to a 21 g increase in estimated fetal weight at 30 weeks gestation. Associations with delivery measures of growth were attenuated, but TCS remained positively associated with birthweight z-scores (mean difference: 0.13, 95 % CI: 0.02, 0.25). Conversely, methylparaben was associated with higher odds of a small-for-gestational age birth (odds ratio: 1.45, 95 % CI: 1.06, 1.98).

DISCUSSION: We observed associations between some biomarkers of phenol exposure and ultrasound measures of fetal growth, though associations at the time of delivery were attenuated. These findings are consistent with hypotheses that phenols have the potential to affect growth during the prenatal period.

PMID:38968832 | PMC:PMC11349462 | DOI:10.1016/j.envint.2024.108866

Environ Health Perspect. 2024 Jul;132(7):77001. doi: 10.1289/EHP14647. Epub 2024 Jul 5.

ABSTRACT

BACKGROUND: Organophosphate esters (OPEs), used ubiquitously as flame retardants and plasticizers in consumer products, are suspected of having developmental toxicity.

OBJECTIVES: Our study aimed to estimate associations between prenatal exposure to OPEs and fetal growth, including both ultrasound (head circumference, abdominal circumference, femur length, and estimated fetal weight) and delivery [birth weight z-score, small-for-gestational age (SGA), and large-for-gestational age (LGA)] measures of growth.

METHODS: In the LIFECODES Fetal Growth Study (2008-2018), an enriched case-cohort of 900 babies born at the small and large ends of the growth spectrum, we quantified OPE biomarkers in three urine samples per pregnant participant and abstracted ultrasound and delivery measures of fetal growth from medical records. We estimated associations between pregnancy-averaged log-transformed OPE biomarkers and repeated ultrasound measures of fetal growth using linear mixed-effects models, and delivery measures of fetal growth using linear (birth weight) and logistic (SGA and LGA) regression models.

RESULTS: Most OPE biomarkers were positively associated with at least one ultrasound measure of fetal growth, but associations with delivery measures were largely null. For example, an interquartile range (IQR; 1.31 ng/mL) increase in bis(2-chloroethyl) phosphate concentration was associated with larger z-scores in head circumference [mean difference (difference): 0.09; 95% confidence interval (CI): 0.01, 0.17], abdominal circumference (difference: 0.10; 95% CI: 0.02, 0.18), femur length (difference: 0.11; 95% CI: 0.03, 0.19), and estimated fetal weight (difference: 0.13; 95% CI: 0.04, 0.22) but not birth weight (difference: 0.04; 95% CI: –0.08, 0.17). At delivery, an IQR (1.00 ng/mL) increase in diphenyl phosphate (DPHP) concentration was associated with an SGA birth (odds ratio: 1.46; 95% CI: 1.10, 1.94).

CONCLUSIONS: In a large prospective cohort, gestational OPE exposures were associated with larger fetal size during pregnancy, but associations at delivery were null. DPHP concentrations were associated with heightened risk of an SGA birth. These findings suggest that OPE exposure may affect fetal development. https://doi.org/10.1289/EHP14647.

PMID:38968089 | PMC:PMC11225970 | DOI:10.1289/EHP14647

Labor Stud J. 2023 Dec;48(4):336-362. doi: 10.1177/0160449×231196227. Epub 2023 Aug 30.

ABSTRACT

Precarious employment is an important social determinant of health inequities. Through in-depth qualitative interviews (n = 35), we examine precarious employment and labor exploitation, their potential impact on the working environment, and, ultimately, the health of farmworkers. We present results from the community-based participatory Michigan Farmworker Project. Our analysis identified dimensions of precarious employment and labor exploitation that involved lacking access to fundamental labor and social rights-including dehumanization-discriminatory occupational practices, and insufficient access to health care and social benefits. Policy reform is needed to address precarious employment and labor exploitation among farmworkers due to their potential long-lasting health effects.

PMID:38939876 | PMC:PMC11210576 | DOI:10.1177/0160449×231196227

Labor Stud J. 2023 Dec;48(4):336-362. doi: 10.1177/0160449×231196227. Epub 2023 Aug 30.

ABSTRACT

Precarious employment is an important social determinant of health inequities. Through in-depth qualitative interviews (n = 35), we examine precarious employment and labor exploitation, their potential impact on the working environment, and, ultimately, the health of farmworkers. We present results from the community-based participatory Michigan Farmworker Project. Our analysis identified dimensions of precarious employment and labor exploitation that involved lacking access to fundamental labor and social rights-including dehumanization-discriminatory occupational practices, and insufficient access to health care and social benefits. Policy reform is needed to address precarious employment and labor exploitation among farmworkers due to their potential long-lasting health effects.

PMID:38939876 | PMC:PMC11210576 | DOI:10.1177/0160449×231196227

Environ Int. 2024 Aug;190:108848. doi: 10.1016/j.envint.2024.108848. Epub 2024 Jun 22.

ABSTRACT

Preterm birth is a leading cause of neonatal mortality and presents significant public health concerns. Environmental chemical exposures during pregnancy may be partially to blame for disrupted delivery timing. Polycyclic aromatic hydrocarbons (PAHs) are products of incomplete combustion, exposure to which occurs via inhalation of cigarette smoke and automobile exhaust, and ingestion of charred meats. Exposure to PAHs in the US population is widespread, and pregnant women represent a susceptible population to adverse effects of PAHs. We aimed to investigate associations between gestational exposure to PAHs and birth outcomes, including timing of delivery and infant birth size. We utilized data from the PROTECT birth cohort where pregnant women provided spot urine samples at up to three study visits (median 16, 20, and 24 weeks gestation). Urine samples were assayed for eight hydroxylated PAH concentrations. Associations between PAHs and birth outcomes were calculated using linear/logistic regression models, with adjustment for maternal age, education, pre-pregnancy BMI, and daily exposure to environmental tobacco smoke. Models accounted for urine dilution using specific gravity. We also explored effect modification by infant sex. Interquartile range (IQR) increases in all averaged PAH exposures during the second trimester were associated with reduced gestational age at delivery and increased odds of overall PTB, although these associations were not statistically significant (p > 0.05). Most PAHs at the second study visit were most strongly associated with earlier delivery and increased odds of overall and spontaneous PTB, with visit 2 2-hydroxynapthalene (2-NAP) being significantly associated with increased odds of overall PTB (OR:1.55; 95 %CI: 1.05,2.29). Some PAHs resulted in earlier timing of delivery among only female fetuses, specifically 2-NAP on overall PTB (female OR:1.52 95 %CI: 1.02,2.27; male OR:0.78, 95 %CI: 0.53,1.15). Future work should more deeply investigate differential physiological impacts of PAH exposure between pregnancies with male and female fetuses, and on varying developmental processes occurring at different points through pregnancy.

PMID:38936064 | DOI:10.1016/j.envint.2024.108848