About

Aimin Chen, MD, PhD, is a Professor of Biostatistics and Epidemiology at the Perelman School of Medicine at the University of Pennsylvania. He serves as the Co-Director of the Philadelphia Regional Center for Children's Environmental Health. Dr. Chen's educational background includes an MD in Preventive Medicine and an MS in Epidemiology from Nanjing Medical University, as well as a PhD in Epidemiology and Health Statistics from Fudan University. His research focuses on epidemiology and biostatistics, with a particular emphasis on environmental health, as evidenced by his extensive publication record on topics such as chemical exposures during pregnancy, childhood health outcomes, and the effects of environmental pollutants on development and disease. Dr. Chen's work involves investigating the impact of environmental chemicals like PBDEs, organophosphate esters, and other endocrine-disrupting compounds on various health parameters, including neurodevelopment, bone mineral density, sleep outcomes, and IQ in children, as well as epigenetic modifications related to chemical exposures.

Research topics

• Medicine
• Biology
• Endocrinology
• Environmental health
• Computer Science
• Obstetrics
• Machine Learning
• Statistics
• Internal medicine
• Mathematics
• Demography
• Environmental science
• Waste management
• Ecology
• Pediatrics
• Engineering

Selected publications

• Ligand-directed assembly of four new Ni(II)-based coordination polymers: structures, Hirshfeld surface analyses and electrochemical properties

  Inorganica Chimica Acta · 2026-01-28

  article
  PublisherDOI

• Estimating effects of longitudinal and cumulative exposure to PFAS mixtures on early adolescent body composition

  UNC Libraries · 2026-04-21

  articleOpen accessSenior author

  Few methods have been used to characterize repeatedly measured biomarkers of chemical mixtures. We applied latent profile analysis (LPA) to serum concentrations of 4 perfluoroalkyl and polyfluoroalkyl substances (PFAS) measured at 4 time points from gestation to age 12 years. We evaluated the relationships between profiles and z scores of height, body mass index, fat mass index, and lean body mass index at age 12 years (n = 218). We compared LPA findings with an alternative approach for cumulative PFAS mixtures using g-computation to estimate the effect of simultaneously increasing the area under the receiver operating characteristic curve (AUC) for all PFAS. We identified 2 profiles: a higher PFAS profile (35% of sample) and a lower PFAS profile (relative to each other), based on their average PFAS concentrations at all time points. The higher PFAS profile had generally lower z scores for all outcomes, with somewhat larger effects for males, though all 95% CIs crossed the null. For example, the higher PFAS profile was associated with a 0.50-unit lower (β = -0.50; 95% CI, -1.07 to 0.08) BMI z score among males but not among females (β = 0.04; 95% CI, -0.45 to 0.54). We observed similar patterns with AUCs. We found that a higher childhood PFAS profile and higher cumulative PFAS mixtures may be associated with altered growth in early adolescence. This article is part of a Special Collection on Environmental Epidemiology.

  PublisherDOI

• Associations between gestational polybrominated diphenyl ether (PBDE) serum concentrations and child sleep outcomes from ages 2–8 years

  Environmental Research · 2025-09-04 · 2 citations

  articleOpen accessSenior author
  PublisherOA PDFDOI

• Epigenetic signatures of maternal-fetal health: insights from cord blood and placenta

  Epigenetics · 2025-05-23 · 2 citations

  articleOpen accessSenior author

  = 67). Methylation patterns from the FP (6,021 CpGs) were significantly correlated with CBMC compared to the MP (2,862 CpGs). These CpGs were related to the biological (mitotic cell) process and molecular function (ribonucleoprotein complex binding). Our findings quantified CpG site correlation between cord blood and placenta, providing a valuable reference for future studies on placental health that rely on cord blood methylation in the absence of placental biospecimens.

  PublisherDOI

• Associations of endocrine disrupting chemical biomarkers and their mixture with vitamin D biomarker concentrations in childhood: The HOME Study

  Environmental Research · 2025-11-12 · 1 citations

  articleOpen access

  BACKGROUND: Children are universally exposed to endocrine disrupting chemicals (EDCs) which may disrupt the vitamin D system through several mechanisms, including competitive receptor binding. Current epidemiologic evidence is limited, especially in children. We cross-sectionally investigated the short-term associations of 24 EDC biomarkers with 3 vitamin D biomarkers measured at ages 8 and 12 years. METHODS: Among 236 children from the Health Outcomes and Measures of the Environment Study, we quantified serum concentrations of 4 per-/poly-fluoroalkyl substances (PFAS), 5 polybrominated diphenyl ethers (PBDEs), and 3 vitamin D biomarkers and urinary metabolites of 4 organophosphate esters (OPE), 9 phthalates/replacements, and 2 environmental phenols at ages 8 (n = 180) and 12 (n = 187) years. Using linear regression models with generalized estimating equations, we estimated cross-sectional covariate-adjusted associations of interquartile range (IQR)-scaled log2 EDCs with vitamin D biomarkers. We used g-computation models to estimate effects of class-based and overall mixtures. RESULTS: A simultaneous IQR increase in all 24 EDCs was associated with 6.6 ng/mL (95% CI: 2.7, 10.6) higher total 25-dihydroxyvitamin D [total 25(OH)D]. Class-based mixtures of PFAS (β: 3.1; 95% CI: 1.3, 5.0), PBDEs (β: 2.1; 95% CI: 0.3, 3.9) and OPEs (β: 2.6; 95% CI: 0.3, 4.8) were associated with higher total 25(OH)D whereas environmental phenols (β: 0.8; 95% CI: -0.8, 2.4) and phthalates/replacements (β: -0.8; 95% CI: -3.3, 1.8) were not. Results for 24,25-dihydroxyvitamin D were similar. The PBDE mixture was associated with 4.0 pg/mL (95% CI: 0.4, 7.6) higher 1α,25-dihydroxyvitamin D. DISCUSSION: Findings suggest that EDCs may alter the childhood vitamin D system. Associations with higher vitamin D biomarker levels may indicate competitive receptor binding and altered cellular transport with potential adverse downstream health impacts.

  PublisherDOI

• P-098 Impact of low-lactate culture medium on embryo development and euploidy rates in sibling oocytes

  Human Reproduction · 2025-06-01

  articleOpen access

  Abstract Study question Does low-lactate culture medium have any effects on embryo development and the euploidy rates of blastocysts? Summary answer Low-lactate culture medium appears to accelerate embryo development, resulting in a higher yield of Day 5 usable blastocysts in both age groups. What is known already Low-lactate culture medium have been shown to reduce stress and improve metabolic efficiency during embryo development. Study design, size, duration A total of 183 Intracytoplasmic Sperm Injection (ICSI) cycles from March 2024 to September 2024 were included in this study. Participants/materials, setting, methods Following ICSI, 2552 sibling oocytes were randomly assigned to two culture media: low-lactate (Group 1) or standard-lactate (Group 2) culture medium. The embryos were cultured to the blastocyst stage and categorized according to modified Gardner grading system: excellent (AA), good (AB, BA), fair (BB) and poor (BC, CB, CC). 514 blastocysts underwent trophectoderm biopsy for Pre-implantation Genetic Testing for Aneuploidy (PGT-A), while 649 blastocysts were vitrified without PGT-A. Main results and the role of chance Group 1 exhibited significantly higher Day 5 Blastocyst Utilization Rate (D5 BUR) (48.9% vs. 36.6%, p < 0.05) and Total BUR (TBUR) (64.8% vs. 57.6%, p < 0.05) compared to Group 2. This significant improvement in D5 BUR and TBUR also observed in embryos from both age groups, <38 and ≥38. The euploidy rates was marginally higher in Group 1 (23.3%) compared to Group 2 (18.5%), though this difference was not statistically significant. No difference was observed in the aneuploidy rates (37.3% vs. 37.0%) between the two groups. Although Group 1 demonstrated better D5 BUR, TBUR, and euploidy rates, the excellent-quality blastocyst rates (13.8% vs. 19.6%, p < 0.05) was significantly lower than that of Group 2. Limitations, reasons for caution The number of blastocysts that underwent PGT-A was small in this study, which may impact the statistical power of the analysis of euploidy rates. Further research into implantation and live birth rates is needed to assess the clinical outcomes of low-lactate culture medium. Wider implications of the findings The increased TBUR and euploidy rates in low-lactate culture medium may provide patients with more blastocysts available for embryo transfer. This could reduce the number of IVF cycles required for a successful pregnancy, thereby lowering overall costs for patients. Trial registration number No

  PublisherOA PDFDOI

• Does the timing of sample collection confound the association between prenatal serum PFAS concentrations and birthweight: results from two prospective cohort studies

  Environment International · 2025-12-06 · 1 citations

  articleOpen access

  BACKGROUND: Maternal serum concentrations of per- and polyfluoroalkyl substances (PFAS) during pregnancy have been consistently associated with reduced birthweight. However, these associations may be confounded by the timing of sample collection due to pregnancy-related changes in pharmacokinetics that impact both serum PFAS concentrations and birthweight. METHODS: We measured nine serum PFAS concentrations in each trimester among 728 women in the MABC Study (Ma'anshan, China, enrolled 2013-2014). We estimated covariate-adjusted differences in birthweight for individual PFAS and their mixture, as well as percent change in PFAS by infant birthweight. We repeated our analyses in 70 women-infant dyads from the HOME Study (Cincinnati, Ohio, enrolled 2003-2006) with repeated PFAS measures in 2nd trimester and at delivery. RESULTS: -transformed 1st and 3rd trimester PFOA was associated with a 6-gram (95 % CI:-35, 22) and 26-gram (95 % CI:-54, 3) decrease in birthweight, respectively. Concentrations of six PFAS declined more steeply among women who gave birth to larger vs. smaller infants. PFOA declined by 11.3 % (95 % CI:-12.7, -9.9) vs. 8.9 % (95 % CI:-10.3, -7.5) per 13 weeks among women who gave birth to infants born at the 90th vs. 10th birthweight percentiles, respectively. We observed similar findings in the HOME Study. CONCLUSIONS: These findings suggest that physiological changes in pregnancy may confound associations between serum PFAS and birthweight. Studies with PFAS measures later in pregnancy may overestimate the true effect of PFAS on fetal growth.

  PublisherDOI

• Associations of Urban Blue and Green Spaces With Coronary Artery Calcification in Black Individuals and Disadvantaged Neighborhoods

  UNC Libraries · 2025-04-05

  articleOpen access

  BACKGROUND: Proximity to urban blue and green spaces has been associated with improved cardiovascular health; however, few studies have examined the role of race and socioeconomic status in these associations. METHODS: Data were from the CARDIA study (Coronary Artery Risk Development in Young Adults). We included longitudinal measurements (1985-1986 to 2010-2011) of blue and green spaces, including percentage of blue space cover, distance to the nearest river, green space cover, and distance to the nearest major park. Presence of coronary artery calcification (CAC) was measured with noncontrast cardiac computed tomography in 2010 to 2011. The associations of blue and green spaces with CAC were assessed with generalized estimating equation regression with adjustment for demographics, individual and neighborhood socioeconomic status, health-related behaviors, and other health conditions. We conducted stratified analyses by race and neighborhood deprivation score to investigate whether the association varied according to social determinants of health. RESULTS: The analytic sample included 1365 Black and 1555 White participants with a mean±SD age of 50.1±3.6 years. Among Black participants, shorter distance to a river and greater green space cover were associated with lower odds of CAC (per interquartile range decrease [1.45 km] to the river: odds ratio [OR], 0.90 [95% CI, 0.84-0.96]; per 10 percentage-point increase of green space cover: OR, 0.85 [95% CI, 0.75-0.95]). Among participants in deprived neighborhoods, greater green space cover was associated with lower odds of CAC (per a 10 percentage-point increase: OR, 0.89 [95% CI, 0.80-0.99]), whereas shorter distance to the park was associated with higher odds of CAC (per an interquartile range decrease [5.3 km]: OR, 1.07 [95% CI, 1.00-1.15]). Black participants in deprived neighborhoods had lower odds of CAC with shorter distance to a river (per an interquartile range decrease: OR, 0.90 [95% CI, 0.82-0.98]) and greater green space cover (per a 10 percentage-point increase: OR, 0.85 [95% CI, 0.75-0.97]). There was no statistical interaction between the blue and green spaces and race or neighborhood characteristics in association with CAC. CONCLUSIONS: Longitudinally, shorter distance to a river and greater green space cover were associated with less CAC among Black participants and those in deprived neighborhoods. Shorter distance to a park was associated with increased odds of CAC among participants in deprived neighborhoods. Black participants residing in more deprived neighborhoods showed lower odds of CAC in association with greater exposure to river and green space cover.

  PublisherDOI

• Associations of Gestational and Childhood Urinary Triclosan Concentrations with Atopic and Allergic Symptoms in Health Outcomes and Measures of the Environment (HOME) Study Participants Ages 1–12 Years

  Environmental Health Perspectives · 2025-06-09 · 1 citations

  articleOpen access

  BACKGROUND: Triclosan, an antimicrobial chemical that was widely used in consumer products, may increase risk of allergic diseases in children, but prospective studies are needed to clarify the association. OBJECTIVES: To elucidate the associations of time-varying urinary triclosan concentrations with eczema, allergic rhinitis, and wheeze. METHODS: In the HOME Study, a prospective pregnancy and birth cohort, we quantified urinary triclosan concentrations in mother-child pairs up to ten times between 16 weeks’ gestation and age 12 years. Caregivers reported eczema, allergic rhinitis, and wheeze symptoms biannually until children were aged 6 years and again when they were aged 8 and 12 years. We used generalized estimating equations to estimate the covariate-adjusted association of gestational and childhood triclosan concentrations with the risk of reporting eczema, allergic rhinitis, or wheezing symptoms. RESULTS: Three hundred forty-seven mother-child dyads contributed >3,000 visits to the analysis of gestational exposures and >2,600 visits to childhood analyses. Each 2-fold higher childhood triclosan concentration was associated with 1.23 (95% CI: 1.04, 1.46) and 1.12 (95% CI: 1.01, 1.25) times higher risk of reporting eczema and allergic rhinitis, respectively, but not wheezing (RR = 0.98 [95% CI: 0.82, 1.16]). We did not observe modification by child sex. Associations of gestational triclosan with eczema, allergic rhinitis, or wheezing symptoms were null in the full sample. Child sex modified the association of gestational triclosan with allergic rhinitis and wheezing (p-interactionAllergy: 0.02; p-interactionWheezing:0.10), with 1.09 (95% CI: 1.00, 1.19) and 0.91 (95% CI: 0.83, 1.00) times the risk of allergic rhinitis symptoms among males and females, respectively. CONCLUSION: Childhood urinary triclosan concentrations were associated with caregiver reported eczema and more weakly with allergic rhinitis. Associations of gestational triclosan with allergic outcomes differed by child sex, suggesting heightened susceptibility to triclosan among males.

  PublisherDOI

• Hierarchical De@NiCo-LDH as high-efficiency catalyst for peroxymonosulfate activation toward enhanced ofloxacin degradation

  Inorganic Chemistry Communications · 2025-06-01 · 3 citations

  article
  PublisherDOI

Recent grants

• Environmental Health Informatics Core

  NIH · $16.5M · 2006–2030

• Developmental neurotoxicity of organophosphate and novel brominated flame retardants in children

  NIH · $3.4M · 2021–2023

• NIH Grant RC4ES01975501

  NIH · $1.7M · 2013

• NIH Grant R01ES020349

  NIH · $2.9M · 2017

Frequent coauthors

• Joseph M. Braun

  Providence College

  379 shared

• Kimberly Yolton

  Cincinnati Children's Hospital Medical Center

  309 shared

• Bruce P. Lanphear

  Child and Family Research Institute

  302 shared

• Kim M. Cecil

  Cincinnati Children's Hospital Medical Center

  155 shared

• Antonia M. Calafat

  Centers for Disease Control and Prevention

  155 shared

• Yingying Xu

  Cincinnati Children's Hospital Medical Center

  100 shared

• Heidi J. Kalkwarf

  71 shared

• Ann M. Vuong

  The University of Texas at Austin

  71 shared

Labs

• Aimin Chen's LabPI

Education

• M.D., Preventive Medicine

  Nanjing Medical University

  1994

• M.S., Epidemiology

  Nanjing Medical University

  1997

• Ph.D., Epidemiology and Health Statistics

  Fudan University

  2002