A Systematic Review and Meta-analysis of Pesticide Exposure and Alzheimer’s Disease Risk

Abstract No:

1687 

Abstract Type:

Student Poster 

Authors:

S Azeez Salami1, S Khuder1

Institutions:

1University of Toledo, Toledo, OH

Presenter:

Shakira Azeez Salami, BPharm  
University of Toledo

Faculty Advisor:

Sadik Khuder, PhD  
University of Toledo

Description:

This updated meta-analysis evaluates the relationship between pesticide exposure and risk of Alzheimer's disease (AD) by incorporating recent literature and assessing study heterogeneity and potential moderators. This study supports a statistically significant association between pesticide exposure and AD, particularly for organochlorines and agriculture settings.

Situation/Problem:

Alzheimer's disease is a progressive (AD) neurodegenerative disorder that has been increasingly linked to environmental exposures, particularly pesticides. Organochlorine and organophosphates pesticides are known neurotoxins which cross the blood-brain barrier and induce the mechanisms implicated in AD pathogenesis. Although many epidemiological studies indicate a potential association between chronic pesticide exposure and AD, some studies have failed to establish a definitive direct correlation between pesticides and the occurrence of AD. This updated meta-analysis aims to evaluate the relationship between pesticide exposure and risk of Alzheimer's disease by incorporating recent literature and assessing study heterogeneity and potential moderators.

Methods:

A systematic search was conducted across electronic databases MEDLINE/PubMed, Medscape, and Google Scholar for studies published between 1985 and August 2025. Key words used in the search included: pesticides, herbicides, insecticides, organochlorine, organophosphate, DDT, DDE, Alzheimer's disease, dementia, neurodegenerative disease, and cognitive decline. The focus of the inclusion criteria was on peer-reviewed observational studies involving human subjects that reported associations between pesticide exposure and AD. Twelve (12) eligible studies comprising 22,971 cases and 27,987 controls were extracted and analyzed using the R statistical software (version 4.4.3). The pooled odds ratios and 95% confidence intervals were calculated under both fixed and random effects models. Cochran's Q and I² was used to assess the heterogeneity

Results / Conclusions:

Results:

Of the 12 studies that were selected to be in this meta-analysis, seven were case-control studies, three were cohort studies, one was a cross-sectional study, and one was an ecological study. Three of the studies were carried out in the United States, three studies in Canada, two each in Spain and India, one study was conducted in France, and one study was completed in Australia.

The combined OR under the random effects model was 2.01 (95% CI: 1.39-2.91), indicating a significant association between pesticide exposure and increased AD risk. Two groups of pesticide analysis were conducted, which revealed stronger associations for organochlorine pesticides (OR =3.35; 95% CI: 1.65-6.85) and agriculture exposures (OR=1.63, 95% CI: 1.31-2.04). Sensitivity analyses confirmed the robustness of the findings. Publication bias assessments showed no significant asymmetry.

Conclusions:

This study supports a statistically significant association between pesticide exposure and AD, particularly for organochlorines and agriculture settings. Future research should prioritize longitudinal studies with refined exposure metrics and explore gene–environment interactions to deepen our understanding and inform preventive strategies.

Core Competencies:

Toxicology / Human Disease

Secondary Core Competencies:

Chemical Hazards

Keywords

Choose at least one (1), and up to five, (5) keywords from the following list. These selections will optimize your presentation's search results for attendees.

Occupational epidemiology

Targeted Audience (IH/OH Practice Level)

Based on the information that will be presented during your proposed session, please indicate the targeted audience practice level: (select one)

Practitioner: Practitioner is a job title given to persons in various occupational fields who are trained to assist professionals but are not themselves licensed or certified at a professional level by a certification body recognized by the National Accreditation Recognition (NAR) Committee of IOHA. The IH/OH practitioner performs tasks requiring significant knowledge and skill in the IH/OH field, such as conducting worker exposure monitoring and, in some cases, may even function independently of a professional IH/OH but may not be involved in the breadth of IH/OH practice nor have the level of responsibility of a professional IH/OH certified by examination. The IH/OH practitioner requires a certain level of education that can be obtained from an accredited university or equivalent. Additional training in specific skill sets that provide additional career paths to the IH/OH practitioner can also be obtained. IH/OH practitioners may also serve as team leaders or project managers.

Volunteer Groups

Was this session organized by an AIHA Technical Committee, Special Interest Group,  Working Group, Advisory Group or other AIHA project Team?  

No

Worker Exposure Data and/ or Results

Are worker exposure data and/or results of worker exposure data analysis presented?

No

Practical Application

How will this help advance the science of IH/OH?

This research strengthens the evidence that links pesticide exposure to neurodegenerative disease risk, especially Alzheimer's disease. This work will also support IH/OH professionals in identifying high-risk exposures, inform risk management practices, and guide future research on occupational neurotoxins and worker health protection.

Presentation History

Have you presented this information before?

Yes

For each type of submission: Please Check All That Apply

Another conference: (please list conference name and year)  -   University of Toledo College of Medicine & Lifesciences symposium

Student Poster Agreement

I have read and agree to these guidelines.

Yes