Evidence map›Paper›PMID 41980636›Full record

SynthesisNeurotoxicology2026

Polychlorinated biphenyls (PCBs) exposure and cognitive function in adults: A systematic review of epidemiologic evidence and risk of bias assessment.

Zhenchun Yang, Jiayuan Hao, Hannah Nash, Wu Chen, Chenyu Qiu, Roksana Karim, Zhanghua Chen

Abstract readSystematic Review
In one paragraph

Synthesis in Neurotoxicology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Zhenchun YangDepartment of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
Jiayuan HaoDepartment of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
Hannah NashDepartment of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
Wu ChenDepartment of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
Chenyu QiuDepartment of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
Roksana KarimDepartment of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
Zhanghua ChenDepartment of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA. Electronic address: zhanghuc@usc.edu.

Funding

Translational Research Support CoreP30ES007048 · NIEHS · UNIVERSITY OF SOUTHERN CALIFORNIA · PI ROB S MCCONNELL · 1996 to 2026
$46.4M
Circulating levels of Persistent Organic Pollutants and Subclinical Atherosclerosis progression in Postmenopausal womenR01ES033705 · NIEHS · UNIVERSITY OF SOUTHERN CALIFORNIA · PI CHEN, ZHANGHUA, KARIM, ROKSANA · 2022 to 2025
$3.5M
The Long-term Influence of Persistent Organic Pollutants Exposure During and After Pregnancy on Metabolic Decline in Women After Pregnancies Complicated by Gestational DiabetesR01ES032247 · NIEHS · UNIVERSITY OF SOUTHERN CALIFORNIA · PI CHEN, ZHANGHUA · 2020 to 2023
$1.9M
NIEHS NIH HHS P30 ES007048NIEHS NIH HHS R01 ES032247NIEHS NIH HHS R01 ES033705
6 · The paper itself

Abstract

backgroundPolychlorinated biphenyls (PCBs) are persistent organic pollutants known for their environmental longevity and neurotoxicity. Although developmental exposure has been extensively studied, the cognitive impacts of PCBs exposure in adult and aging populations remain less understood.

objectivesThis systematic review evaluates the epidemiologic evidence linking PCBs exposure to cognitive function, with an emphasis on neurocognitive decline and dementia risk in adults.

methodsFollowing PRISMA guidelines, we searched PubMed and Web of Science for human epidemiological studies published in English up to November 2024. Inclusion criteria focused on empirical studies investigating associations between PCBs exposure and cognitive outcomes in elderly population. Data were synthesized narratively, and a domain-based risk of bias assessment was conducted using the Navigation Guide methodology.

resultsTwenty-four studies were included in the final analysis, spanning diverse populations and exposure contexts (occupational, environmental and dietary). Six studies examined the association between PCBs exposure and dementia or Alzheimer's disease, with overall mixed findings. Some studies reported associations in specific subgroups, particularly among individuals with higher exposure levels or among women, while others reported null relationships. For cognitive outcomes, memory, processing speed and executive functions were the frequently assessed domain; however, findings across studies were inconsistent and did not demonstrate a clear pattern of association. A smaller number of studies assessed cognitive decline, with similarly heterogeneous results. Risk of bias was generally low for exposure and outcome assessment but higher for confounding and other validity domains. Notably, inconsistent cognitive testing methods and limited longitudinal data constrained causal inference.

conclusionCurrent epidemiologic evidence is insufficient to support a consistent association between PCBs exposure and dementia or cognitive performance in aging populations. Further well-designed longitudinal studies using standardized cognitive assessments are needed to clarify potential relationships. PROSPERO REGISTRATION NUMBER: CRD420251003803.

Indexed as

CognitionCognitive DysfunctionEnvironmental ExposureEnvironmental PollutantsPolychlorinated BiphenylsAdultFemaleHumansRisk AssessmentEnvironmental PollutantsPolychlorinated BiphenylsAgingCognitive functionDementiaMemoryNeurotoxicityPolychlorinated biphenyls (PCBs)

Identifiers

PMID41980636
PMCPMC13289575

What Socratic holds

Textmetadata
LicenceTDM
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.