1
|
Ha S, Abatzoglou JT, Adebiyi A, Ghimire S, Martinez V, Wang M, Basu R. Impacts of heat and wildfire on preterm birth. ENVIRONMENTAL RESEARCH 2024; 252:119094. [PMID: 38723988 DOI: 10.1016/j.envres.2024.119094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 04/30/2024] [Accepted: 05/07/2024] [Indexed: 05/12/2024]
Abstract
BACKGROUND Climate change continues to increase the frequency, intensity, and duration of heat events and wildfires, both of which are associated with adverse pregnancy outcomes. Few studies simultaneously evaluated exposures to these increasingly common exposures. OBJECTIVES We investigated the relationship between exposure to heat and wildfire smoke and preterm birth (PTB). METHODS In this time-stratified case-crossover study, participants consisted of 85,806 California singleton PTBs (20-36 gestational weeks) from May through October of 2015-2019. Birthing parent ZIP codes were linked to high-resolution daily weather, PM2.5 from wildfire smoke, and ambient air pollution data. Heat day was defined as a day with apparent temperature >98th percentile within each ZIP code and heat wave was defined as ≥2 consecutive heat days. Wildfire-smoke day was defined as a day with any exposure to wildfire-smoke PM2.5. Conditional logistic regression was used to calculate the odds ratio (OR) and 95% confidence intervals (CI) comparing exposures during a hazard period (lags 0-6) compared to control periods. Analyses were adjusted for relative humidity, fine particles, and ozone. RESULTS Wildfire-smoke days were associated with 3.0% increased odds of PTB (ORlag0: 1.03, CI: 1.00-1.05). Compared with white participants, associations appeared stronger among Black, Hispanic, Asian, and American Indians/Alaskan Native participants. Heatwave days (ORlag2: 1.07, CI: 1.02-1.13) were positively associated with PTB, with stronger associations among those simultaneously exposed to wildfire smoke days (ORlag2: 1.19, CI: 1.11-1.27). Similar findings were observed for heat days and when other temperature metrics (e.g., maximum, minimum) were used. DISCUSSION Heat and wildfire increased PTB risk with evidence of synergism. As the occurrence and co-occurrence of these events increase, exposure reduction among pregnant people is critical, especially among racial/ethnic minorities.
Collapse
Affiliation(s)
- Sandie Ha
- Department of Public Health, School of Social Sciences, Humanities and Arts, Health Science Research Institute, University of California, 5200 N Lake Rd, 95343, Merced, CA, USA.
| | - John T Abatzoglou
- Department of Management of Complex Systems, School of Engineering, University of California, Merced, USA
| | - Adeyemi Adebiyi
- Department of Life and Environmental Sciences, School of Natural Sciences, University of California, Merced, USA
| | - Sneha Ghimire
- Department of Public Health, School of Social Sciences, Humanities and Arts, Health Science Research Institute, University of California, 5200 N Lake Rd, 95343, Merced, CA, USA
| | - Valerie Martinez
- Department of Public Health, School of Social Sciences, Humanities and Arts, Health Science Research Institute, University of California, 5200 N Lake Rd, 95343, Merced, CA, USA
| | - Meng Wang
- Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, USA
| | - Rupa Basu
- Air and Climate Epidemiology Section, Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, Oakland, CA, USA
| |
Collapse
|
2
|
Picciotto S, Huang S, Lurmann F, Pavlovic N, Ying Chang S, Mukherjee A, Goin DE, Sklar R, Noth E, Morello-Frosch R, Padula AM. Pregnancy exposure to PM 2.5 from wildland fire smoke and preterm birth in California. ENVIRONMENT INTERNATIONAL 2024; 186:108583. [PMID: 38521046 DOI: 10.1016/j.envint.2024.108583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 02/23/2024] [Accepted: 03/15/2024] [Indexed: 03/25/2024]
Abstract
BACKGROUND Wildfires in the Western United States are a growing and significant source of air pollution that is eroding decades of progress in air pollution reduction. The effects on preterm birth during critical periods of pregnancy are unknown. METHODS We assessed associations between prenatal exposure to wildland fire smoke and risk of preterm birth (gestational age < 37 weeks). We assigned smoke exposure to geocoded residence at birth for all live singleton births in California conceived 2007-2018, using weekly average concentrations of particulate matter ≤ 2.5 µm (PM2.5) attributable to wildland fires from United States Environmental Protection Agency's Community Multiscale Air Quality Model. Logistic regression yielded odds ratio (OR) for preterm birth in relation to increases in average exposure across the whole pregnancy, each trimester, and each week of pregnancy. Models adjusted for season, age, education, race/ethnicity, medical insurance, and smoking of the birthing parent. RESULTS For the 5,155,026 births, higher wildland fire PM2.5 exposure averaged across pregnancy, or any trimester, was associated with higher odds of preterm birth. The OR for an increase of 1 µg/m3 of average wildland fire PM2.5 during pregnancy was 1.013 (95 % CI:1.008,1.017). Wildland fire PM2.5 during most weeks of pregnancy was associated with higher odds. Strongest estimates were observed in weeks in the second and third trimesters. A 10 µg/m3 increase in average wildland fire PM2·5 in gestational week 23 was associated with OR = 1.034; 95 % CI: 1.019, 1.049 for preterm birth. CONCLUSIONS Preterm birth is sensitive to wildland fire PM2.5; therefore, we must reduce exposure during pregnancy.
Collapse
Affiliation(s)
- Sally Picciotto
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, Berkeley, CA, USA
| | | | | | | | | | | | - Dana E Goin
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Rachel Sklar
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Elizabeth Noth
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, Berkeley, CA, USA
| | - Rachel Morello-Frosch
- Department of Environmental Science, Policy and Management, University of California, Berkeley, Berkeley, CA, USA
| | - Amy M Padula
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, San Francisco, CA, USA.
| |
Collapse
|
3
|
Bowman WS, Schmidt RJ, Sanghar GK, Thompson Iii GR, Ji H, Zeki AA, Haczku A. "Air That Once Was Breath" Part 2: Wildfire Smoke and Airway Disease - "Climate Change, Allergy and Immunology" Special IAAI Article Collection: Collegium Internationale Allergologicum Update 2023. Int Arch Allergy Immunol 2024; 185:617-630. [PMID: 38527432 DOI: 10.1159/000536576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 01/23/2024] [Indexed: 03/27/2024] Open
Abstract
BACKGROUND Population growth and climate change have led to more frequent and larger wildfires, increasing the exposure of individuals to wildfire smoke. Notably, asthma exacerbations and allergic airway sensitization are prominent outcomes of such exposure. SUMMARY Key research questions relate to determining the precise impact on individuals with asthma, including the severity, duration, and long-term consequences of exacerbations. Identifying specific risk factors contributing to vulnerability, such as age, genetics, comorbidities, or environmental factors, is crucial. Additionally, reliable biomarkers for predicting severe exacerbations need exploration. Understanding the long-term health effects of repeated wildfire smoke exposures in individuals with asthma and addressing healthcare disparities are important research areas. KEY MESSAGES This review discusses the need for comprehensive research efforts to better grasp wildfire smoke-induced respiratory health, particularly in vulnerable populations such as farmworkers, firefighters, pregnant women, children, the elderly, and marginalized communities. Effective mitigation would require addressing the current limitations we face by supporting research aimed at a better understanding of wildfire smoke-induced airway disease.
Collapse
|
4
|
Bowman WS, Schmidt RJ, Sanghar GK, Thompson Iii GR, Ji H, Zeki AA, Haczku A. "Air That Once Was Breath" Part 1: Wildfire-Smoke-Induced Mechanisms of Airway Inflammation - "Climate Change, Allergy and Immunology" Special IAAI Article Collection: Collegium Internationale Allergologicum Update 2023. Int Arch Allergy Immunol 2024; 185:600-616. [PMID: 38452750 DOI: 10.1159/000536578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 01/23/2024] [Indexed: 03/09/2024] Open
Abstract
BACKGROUND Wildfires are a global concern due to their wide-ranging environmental, economic, and public health impacts. Climate change contributes to an increase in the frequency and intensity of wildfires making smoke exposure a more significant and recurring health concern for individuals with airway diseases. Some of the most prominent effects of wildfire smoke exposure are asthma exacerbations and allergic airway sensitization. Likely due to the delayed recognition of its health impacts in comparison with cigarette smoke and industrial or traffic-related air pollution, research on the composition, the mechanisms of toxicity, and the cellular/molecular pathways involved is poor or non-existent. SUMMARY This review discusses potential underlying pathological mechanisms of wildfire-smoke-related allergic airway disease and asthma. We focused on major gaps in understanding the role of wildfire smoke composition in the development of airway disease and the known and potential mechanisms involving cellular and molecular players of oxidative injury at the epithelial barrier in airway inflammation. We examine how PM2.5, VOCs, O3, endotoxin, microbes, and toxic gases may affect oxidative stress and inflammation in the respiratory mucosal barrier. We discuss the role of AhR in mediating smoke's effects in alarmin release and IL-17A production and how glucocorticoid responsiveness may be impaired by IL-17A-induced signaling and epigenetic changes leading to steroid-resistant severe airway inflammation. KEY MESSAGE Effective mitigation of wildfire-smoke-related respiratory health effects would require comprehensive research efforts aimed at a better understanding of the immune regulatory effects of wildfire smoke in respiratory health and disease.
Collapse
Affiliation(s)
- Willis S Bowman
- UC Davis Lung Center, University of California, Davis, California, USA
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, School of Medicine, Sacramento, California, USA
| | - Rebecca J Schmidt
- Department of Public Health Sciences, School of Medicine, Sacramento, California, USA
| | - Gursharan K Sanghar
- UC Davis Lung Center, University of California, Davis, California, USA
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, School of Medicine, Sacramento, California, USA
| | - George R Thompson Iii
- UC Davis Lung Center, University of California, Davis, California, USA
- Division of Infectious Diseases, Department of Medicine, School of Medicine, Sacramento, California, USA
| | - Hong Ji
- UC Davis Lung Center, University of California, Davis, California, USA
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, Davis, California, USA
| | - Amir A Zeki
- UC Davis Lung Center, University of California, Davis, California, USA
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, School of Medicine, Sacramento, California, USA
| | - Angela Haczku
- UC Davis Lung Center, University of California, Davis, California, USA
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, School of Medicine, Sacramento, California, USA
| |
Collapse
|
5
|
Foo D, Stewart R, Heo S, Dhamrait G, Choi HM, Song Y, Bell ML. Wildfire smoke exposure during pregnancy and perinatal, obstetric, and early childhood health outcomes: A systematic review and meta-analysis. ENVIRONMENTAL RESEARCH 2024; 241:117527. [PMID: 37931734 DOI: 10.1016/j.envres.2023.117527] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 10/25/2023] [Accepted: 10/26/2023] [Indexed: 11/08/2023]
Abstract
BACKGROUND Maternal exposure to air pollution during pregnancy is associated with adverse birth outcomes, although less is known for wildfire smoke. This systematic review evaluated the association between maternal exposure to wildfire smoke during pregnancy and the risk of perinatal, obstetric, and early childhood health outcomes. METHODS We searched CINAHL Complete, Ovid/EMBASE, Ovid/MEDLINE, ProQuest, PubMed, Scopus, Web of Science, and Google Scholar to identify relevant epidemiological observational studies indexed through September 2023. The screening of titles, abstracts, and full-texts, data extraction, and risk of bias assessment was performed by pairs of independent reviewers. RESULTS Our systematic search yielded 28,549 records. After duplicate removal, we screened 14,009 studies, identifying 31 for inclusion in the present review. Data extraction highlighted high methodological heterogeneity between studies, including a lack of geographic variation. Approximately 56.5% and 16% originated in the United States and Brazil, respectively, and fewer in other countries. Among the studies, wildfire smoke exposure during pregnancy was assessed using distance of residence from wildfire-affected areas (n = 15), measurement of air pollutant concentration during wildfires (n = 11), number of wildfire records (n = 3), aerosol index (n = 1), and geographic hot spots (n = 1). Pooled meta-analysis for birthweight and low birthweight were inconclusive, likely due to low number of methodologically homogenous studies. However, the reviewed studies provided suggestive evidence for an increased risk of birthweight reduction, low birthweight, preterm birth, and other adverse health outcomes. CONCLUSIONS This review identified 31 studies evaluating the impacts of maternal wildfire smoke exposure on maternal, infant, and child health. Although we found suggestive evidence of harm from exposure to wildfire smoke during pregnancy, more methodologically homogenous studies are required to enable future meta-analysis with greater statistical power to more accurately evaluate the association between maternal wildfire smoke and adverse birth outcomes and other health outcomes.
Collapse
Affiliation(s)
- Damien Foo
- Yale School of the Environment, Yale University, New Haven, Connecticut, United States; Curtin School of Population Health, Curtin University, Perth, Western Australia, Australia.
| | - Rory Stewart
- Yale School of the Environment, Yale University, New Haven, Connecticut, United States
| | - Seulkee Heo
- Yale School of the Environment, Yale University, New Haven, Connecticut, United States
| | - Gursimran Dhamrait
- Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, Australia; School of Population and Global Health, The University of Western Australia, Perth, Western Australia, Australia
| | - Hayon Michelle Choi
- Yale School of the Environment, Yale University, New Haven, Connecticut, United States
| | - Yimeng Song
- Yale School of the Environment, Yale University, New Haven, Connecticut, United States
| | - Michelle L Bell
- Yale School of the Environment, Yale University, New Haven, Connecticut, United States
| |
Collapse
|
6
|
Aktoz F, Gunes AC, Yakin K. The effect of earthquake experience on pregnancy outcomes: A systematic review and meta-analysis. Eur J Obstet Gynecol Reprod Biol 2023; 291:70-75. [PMID: 37837936 DOI: 10.1016/j.ejogrb.2023.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 10/01/2023] [Indexed: 10/16/2023]
Abstract
OBJECTIVES Pregnant women are vulnerable to the health consequences of earthquakes, experiencing stress and limited access to healthcare. Despite the widespread impact of these events, knowledge about their effects on pregnancy outcomes is scarce and inconsistent. This systematic review and meta-analysis aimed to evaluate the available evidence, estimate the overall effect, and identify key research gaps about earthquake on pregnant women. STUDY DESIGN A comprehensive search of English-language peer-reviewed articles was conducted using PubMed and Web of Science Core Collection. Various combinations of keywords related to earthquakes and pregnancy outcomes were used. Studies comparing quantitative data on pregnancy outcomes between earthquake-affected and unaffected pregnant women were included. Random and fixed-effects models were used to estimate the pooled effect size. RESULTS The meta-analysis revealed no significant difference in preterm delivery rates (OR: 1.18; 95 % CI: 0.94-1.47; I2 = 75 %; five studies, 26,365 women) and low birth weight (LBW) infant delivery rates (OR: 1.19; 95 % CI: 0.83-1.71; I2 = 72 %; three studies, 16,127 women) between the earthquake-affected and control groups. However, a statistically significant increase in small-for-gestational-age (SGA) infants was observed in the earthquake-affected group (OR: 1.25; 95 % CI: 1.08-1.43; I2 = 0 %; two studies, 10,238 women). Data on miscarriage and stillbirth rates were not suitable for meta-analysis. CONCLUSIONS Limited evidence suggests that exposure to earthquakes may be associated with adverse pregnancy outcomes. Further studies are needed to confirm the increased risk of SGA in the affected population and to inform disaster management plans by enhancing our understanding of the adversities associated with earthquake exposure through more comprehensive epidemiologic research.
Collapse
Affiliation(s)
- Fatih Aktoz
- Women's Health Center, American Hospital, Istanbul, Turkey.
| | - Ali Can Gunes
- Department of Obstetrics and Gynecology, Mamak State Hospital, Ankara, Turkey
| | - Kayhan Yakin
- Women's Health Center, American Hospital, Istanbul, Turkey; Department of Obstetrics and Gynecology, Koc University, Istanbul, Turkey.
| |
Collapse
|
7
|
Bansal A, Cherbuin N, Leach L, Simmons RA, Nolan CJ. Wildfires and COVID-19: syndemic impact on maternal and child health. Trends Endocrinol Metab 2023; 34:779-782. [PMID: 37658035 DOI: 10.1016/j.tem.2023.08.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 08/09/2023] [Accepted: 08/10/2023] [Indexed: 09/03/2023]
Abstract
The prevailing COVID-19 pandemic and climate change-mediated wildfires can combine to impact maternal-child health, yet this connection remains understudied. To shape policies and design interventions to mitigate the combined effects of future global catastrophes, it is vital to holistically evaluate the impact of syndemics on maternal-child health.
Collapse
Affiliation(s)
- Amita Bansal
- School of Medicine and Psychology, College of Health and Medicine, Australian National University, Canberra, ACT 2601, Australia; John Curtin School of Medical Research, College of Health and Medicine, Australian National University, Canberra, ACT 2601, Australia.
| | - Nicolas Cherbuin
- National Center for Epidemiology and Population Health, Australian National University, Acton, ACT 2601, Australia
| | - Liana Leach
- National Center for Epidemiology and Population Health, Australian National University, Acton, ACT 2601, Australia
| | - Rebecca A Simmons
- Center for Research on Reproduction and Women's Health, University of Pennsylvania, Philadelphia, PA 19104, USA; Center of Excellence in Environmental Toxicology, University of Pennsylvania, Philadelphia, PA 19104, USA; Division of Neonatology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Christopher J Nolan
- School of Medicine and Psychology, College of Health and Medicine, Australian National University, Canberra, ACT 2601, Australia; John Curtin School of Medical Research, College of Health and Medicine, Australian National University, Canberra, ACT 2601, Australia; Endocrinology and Diabetes, The Canberra Hospital, Canberra Health Services, ACT 2601, Australia
| |
Collapse
|
8
|
Basilio E, Zlatnik MG. Extreme weather-Wildfires & pregnancy. Semin Perinatol 2023; 47:151839. [PMID: 37863677 DOI: 10.1016/j.semperi.2023.151839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2023]
Abstract
As described in the previous chapter, Chapter 4: Air pollution and pregnancy, there is robust literature on the adverse health impacts of ambient air pollution on perinatal outcomes. With climate change contributing to more extreme weather patterns, wildfire events are becoming more intense and frequent. Wildfire smoke is a major contributor to poor air quality and data are beginning to emerge with respect to the negative impact on perinatal outcomes. The aim of this chapter is to provide an overview of the current literature on wildfire smoke exposure in pregnancy and associated adverse outcomes.
Collapse
Affiliation(s)
- Emilia Basilio
- Department of Obstetrics, Gynecology, & Reproductive Sciences, University of California San Francisco
| | - Marya G Zlatnik
- Department of Obstetrics, Gynecology, & Reproductive Sciences, Western States Pediatric Environmental Health Specialty Unit, UCSF, University of California San Francisco.
| |
Collapse
|
9
|
Fernández ACG, Basilio E, Benmarhnia T, Roger J, Gaw SL, Robinson JF, Padula AM. Retrospective analysis of wildfire smoke exposure and birth weight outcomes in the San Francisco Bay Area of California. ENVIRONMENTAL RESEARCH, HEALTH : ERH 2023; 1:025009. [PMID: 37324234 PMCID: PMC10261910 DOI: 10.1088/2752-5309/acd5f5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 03/27/2023] [Accepted: 05/16/2023] [Indexed: 06/17/2023]
Abstract
Despite the occurrence of wildfires quadrupling over the past four decades, the health effects associated with wildfire smoke exposures during pregnancy remains unknown. Particulate matter less than 2.5 μms (PM2.5) is among the major pollutants emitted in wildfire smoke. Previous studies found PM2.5 associated with lower birthweight, however, the relationship between wildfire-specific PM2.5 and birthweight is uncertain. Our study of 7923 singleton births in San Francisco between January 1, 2017 and March 12, 2020 examines associations between wildfire smoke exposure during pregnancy and birthweight. We linked daily estimates of wildfire-specific PM2.5 to maternal residence at the ZIP code level. We used linear and log-binomial regression to examine the relationship between wildfire smoke exposure by trimester and birthweight and adjusted for gestational age, maternal age, race/ethnicity, and educational attainment. We stratified by infant sex to examine potential effect modification. Exposure to wildfire-specific PM2.5 during the second trimester of pregnancy was positively associated with increased risk of large for gestational age (OR = 1.13; 95% CI: 1.03, 1.24), as was the number of days of wildfire-specific PM2.5 above 5 μg m-3 in the second trimester (OR = 1.03; 95% CI: 1.01, 1.06). We found consistent results with wildfire smoke exposure in the second trimester and increased continuous birthweight-for-gestational age z-score. Differences by infant sex were not consistent. Counter to our hypothesis, results suggest that wildfire smoke exposures are associated with increased risk for higher birthweight. We observed strongest associations during the second trimester. These investigations should be expanded to other populations exposed to wildfire smoke and aim to identify vulnerable communities. Additional research is needed to clarify the biological mechanisms in this relationship between wildfire smoke exposure and adverse birth outcomes.
Collapse
Affiliation(s)
- Anna Claire G Fernández
- School of Public Health, University of California, Berkeley
- School of Medicine, University of California, San Francisco
| | - Emilia Basilio
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco
| | - Tarik Benmarhnia
- Scripps Institution of Oceanography, University of California, San Diego
| | | | - Stephanie L Gaw
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco
| | - Joshua F Robinson
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco
| | - Amy M Padula
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco
| |
Collapse
|
10
|
Basilio E, Ozarslan N, Buarpung S, Benmarhnia T, Padula AM, Robinson JF, Gaw SL. Gestational age-dependent decrease in fetal Hofbauer cells in placentas from pregnancies exposed to wildfire smoke in California. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.01.11.23284125. [PMID: 36712106 PMCID: PMC9882560 DOI: 10.1101/2023.01.11.23284125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVE Wildfires are more common over the last decade and the frequency of wildfire events has been accelerated by climate change. The existing body of literature suggests that exposure to wildfire smoke during pregnancy contributes to adverse perinatal outcomes such as preterm birth and fetal growth restriction. We hypothesize that exposures to wildfire smoke and its constituents triggers a fetal inflammatory response which contributes to pathological changes that underlie these adverse pregnancy outcomes. In this study, we quantified the presence of fetal macrophages (i.e., Hofbauer cells) in human placentas obtained between 2018 and 2020 to assess the relationship between fetal immune status and wildfire exposure. STUDY DESIGN We collected placentas from pregnancies from two hospitals in San Francisco over a two-year period that included two severe major wildfires. The average particulate matter < 2.5 μm (PM2.5) or wildfire specific PM2.5 levels were estimated over the gestational duration of each sample. Immunostaining against CK7 and CD68 was performed to identify intravillous fetal Hofbauer cells. We assessed the gestational-age dependent relationship between placental CD68+ cell density and mean daily PM2.5 or wildfire-specific PM2.5 via linear regression and Welch's t-test. Additionally, we compared placental CD68+ cell density with estimated peak wildfire exposures during the gestation to determine if timing of exposure during pregnancy may influence the occurrence of Hofbauer cells in the placenta. RESULTS The gestational ages ranged from 7-41 weeks (n = 67). The majority of samples were collected during one of two major wildfire events in Northern California (70%; n = 47). In general, we observed a significant inverse relationship between placental CD68 density and PM2.5 or wildfire specific PM2.5, however, these associations were only observed in first or second trimester samples, and not in term samples. For example, among first trimester samples (n=22), we observed lower mean CD68 density among samples likely to be exposed to wildfire events (mean = 1.42, SD = 0.8) as compared to those not exposed (mean = 3.73, SD = 1.983) (p = 0.0015). Based on our linear regression model results, we predicted that a one μg/m3 increase in daily mean wildfire PM2.5 was associated with a 0.457 decrease in CD68 density (ß =-0.457; 95% CI: -0.722, -0.193). This association was also significant for daily mean overall PM2.5, though smaller in magnitude (ß = -0.139; 95% CI: -0.218, -0.059). CONCLUSIONS Our results suggest that wildfire smoke exposures are associated with decreased presence of fetal Hofbauer cells in first and second trimester placentas, suggesting exposure may lead to impaired placental function via altered presence of fetal Hofbauer cells and changes in immune status.
Collapse
Affiliation(s)
- Emilia Basilio
- Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco
| | - Nida Ozarslan
- Center for Reproductive Sciences, Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco
| | - Sirirak Buarpung
- Center for Reproductive Sciences, Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco
| | - Tarik Benmarhnia
- Scripps Institution of Oceanography, University of California, San Diego
| | - Amy M. Padula
- Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco
| | - Joshua F. Robinson
- Center for Reproductive Sciences, Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco
| | - Stephanie L. Gaw
- Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco
- Center for Reproductive Sciences, Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco
| |
Collapse
|