Combined Neurodevelopmental and Neurodegenerative Burden: Lifetime DALYs from Pesticide Exposure in MENA Agricultural Communities

Combined Neurodevelopmental and Neurodegenerative Burden: Lifetime DALYs from Pesticide Exposure in MENA Agricultural Communities | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Combined Neurodevelopmental and Neurodegenerative Burden: Lifetime DALYs from Pesticide Exposure in MENA Agricultural Communities Aya Darwish, Aya Samy, Ahmed Amin, Jana Al-Nady, Shimaa Sami, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9086032/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 6 You are reading this latest preprint version Abstract Pesticide exposure in agricultural populations poses well-documented neurotoxic risks, yet comprehensive burden of disease assessments remain absent for the Middle East and North Africa (MENA) region—home to 450 million people with intensive agricultural practices. We quantified lifetime disability-adjusted life years (DALYs) attributable to pesticide-induced neurological disorders across 18 MENA countries from 2010–2023, focusing on prenatal neurodevelopmental impacts (intellectual disability from IQ decrements) and adult neurodegenerative disease (Parkinson's disease). Country-specific exposure prevalence was estimated from agricultural employment patterns (occupational pathway) and rural population distributions (environmental pathway), with pesticide application intensity derived from FAO statistics. We applied exposure-response coefficients from prospective birth cohort studies for neurodevelopment and meta-analytic relative risks for Parkinson's disease, calculating population attributable fractions and age-specific burden using Global Burden of Disease methodology. Regional burden reached 568,329 DALYs annually, with Egypt, Yemen, and Algeria accounting for 61% of total impact despite representing 32% of population. Neurodevelopmental burden dominated (90% of DALYs), challenging conventional adult-focused occupational health paradigms. Per-capita burden rates (229–235 DALYs per 100,000 in highest-burden countries) reached magnitudes comparable to lead exposure in contaminated populations, yet receive substantially less policy attention. An apparent inverse relationship between pesticide intensity and Parkinson's disease burden (ρ=-0.35, p = 0.14) was explained by agricultural mechanization confounding rather than causal dose-response: Gulf countries have high pesticide intensity (capital-intensive greenhouse systems) but minimal PD burden (young, urbanized populations with low baseline PD rates). Excluding these outlier countries eliminated the inverse relationship (ρ=+0.28, p = 0.36), though the positive association remained non-significant. These findings establish pesticide neurotoxicity as a major environmental health determinant in MENA, with prenatal and early-life exposure representing critical intervention windows requiring hazard-based chemical restrictions, spatial buffer zones, and occupational health programs targeting aging farmworker populations. Pesticides Neurodevelopmental disorders Parkinson's disease Disability-adjusted life years Intellectual disability Population attributable fraction Middle East North Africa Global burden of disease Full Text Additional Declarations No competing interests reported. Supplementary Files Supplementaryfiguresv2.docx Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 06 May, 2026 Reviewers invited by journal 05 Apr, 2026 Editor invited by journal 20 Mar, 2026 Editor assigned by journal 12 Mar, 2026 Submission checks completed at journal 12 Mar, 2026 First submitted to journal 10 Mar, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9086032","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":618676641,"identity":"01a198b5-b22a-41a8-9504-80701e672ce9","order_by":0,"name":"Aya Darwish","email":"","orcid":"","institution":"Benha University","correspondingAuthor":false,"prefix":"","firstName":"Aya","middleName":"","lastName":"Darwish","suffix":""},{"id":618676642,"identity":"75cd816a-0910-4516-9d1d-4bc21e6d6a69","order_by":1,"name":"Aya Samy","email":"","orcid":"","institution":"Benha 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We quantified lifetime disability-adjusted life years (DALYs) attributable to pesticide-induced neurological disorders across 18 MENA countries from 2010\u0026ndash;2023, focusing on prenatal neurodevelopmental impacts (intellectual disability from IQ decrements) and adult neurodegenerative disease (Parkinson's disease). Country-specific exposure prevalence was estimated from agricultural employment patterns (occupational pathway) and rural population distributions (environmental pathway), with pesticide application intensity derived from FAO statistics. We applied exposure-response coefficients from prospective birth cohort studies for neurodevelopment and meta-analytic relative risks for Parkinson's disease, calculating population attributable fractions and age-specific burden using Global Burden of Disease methodology. Regional burden reached 568,329 DALYs annually, with Egypt, Yemen, and Algeria accounting for 61% of total impact despite representing 32% of population. Neurodevelopmental burden dominated (90% of DALYs), challenging conventional adult-focused occupational health paradigms. Per-capita burden rates (229\u0026ndash;235 DALYs per 100,000 in highest-burden countries) reached magnitudes comparable to lead exposure in contaminated populations, yet receive substantially less policy attention. An apparent inverse relationship between pesticide intensity and Parkinson's disease burden (ρ=-0.35, p\u0026thinsp;=\u0026thinsp;0.14) was explained by agricultural mechanization confounding rather than causal dose-response: Gulf countries have high pesticide intensity (capital-intensive greenhouse systems) but minimal PD burden (young, urbanized populations with low baseline PD rates). Excluding these outlier countries eliminated the inverse relationship (ρ=+0.28, p\u0026thinsp;=\u0026thinsp;0.36), though the positive association remained non-significant. These findings establish pesticide neurotoxicity as a major environmental health determinant in MENA, with prenatal and early-life exposure representing critical intervention windows requiring hazard-based chemical restrictions, spatial buffer zones, and occupational health programs targeting aging farmworker populations.\u003c/p\u003e","manuscriptTitle":"Combined Neurodevelopmental and Neurodegenerative Burden: Lifetime DALYs from Pesticide Exposure in MENA Agricultural Communities","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-10 21:19:22","doi":"10.21203/rs.3.rs-9086032/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"225069702954914380526771386860383823710","date":"2026-05-06T17:54:47+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-06T02:37:40+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-03-20T04:33:43+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-12T07:33:18+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-12T07:33:11+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Public Health","date":"2026-03-10T15:40:10+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-public-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pubh","sideBox":"Learn more about [BMC Public Health](http://bmcpublichealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/pubh/default.aspx","title":"BMC Public Health","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"74944623-2819-483d-9d97-60742e1bd30d","owner":[],"postedDate":"April 10th, 2026","published":true,"recentEditorialEvents":[{"type":"reviewerAgreed","content":"225069702954914380526771386860383823710","date":"2026-05-06T17:54:47+00:00","index":95,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-10T21:19:22+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-10 21:19:22","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9086032","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9086032","identity":"rs-9086032","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}