Immaculata Ngozika Nwaoziri1*, Micheal Abimbola Oladosu2**, Moses Adondua Abah3, Mesoma Princess Onyekwere4 and Angel Ojimaojo Ekel3

 1Department of Dentistry, Faculty of Dentistry, College of Medicine, University of Nigeria Nsukka, Enugu, Nigeria.

2Department of Chemical Sciences, Faculty of Science, Anchor University Lagos, Ayobo, Lagos, Nigeria.

3Department of Biochemistry, Faculty of Pure and Applied Sciences, Federal University of Wukari, Wukari, Taraba State, Nigeria.

4Department of Dentistry, Faculty of Dentistry, College of Medicine, University of Nigeria, Enugu Campus, Enugu State, Nigeria

 () Corresponding Author

Received: Apr 20, 2026/ Revised: May 29 2026/Accepted: June 8, 2026

Highlights

  • Reviews how environmental exposures alter the epigenome and influence disease risk.
  • Examines mechanisms involving DNA methylation, histone modifications, and non-coding RNAs.
  • Links environmental factors to cancer, cardiovascular, metabolic, and neuropsychiatric disorders.
  • Highlights emerging epigenetic biomarkers for disease prediction and biological aging assessment.
  • Discusses advances in epidrugs, epigenome editing, and precision epigenetic medicine.

 Abstract

The human epigenome serves as a molecular interface between genome and environment, dynamically orchestrating gene expression without altering DNA sequence. Over the past decade, high-resolution epigenomic technologies and large-scale cohort studies have established that external exposures, including air pollutants, dietary patterns, endocrine-disrupting chemicals, psychological stressors, and early-life adversity, induce lasting, sometimes transgenerational, alterations in DNA methylation, histone post-translational modifications, and non-coding RNA profiles. These environmentally driven epigenetic changes underpin a spectrum of non-communicable diseases, including cancer, cardiovascular disease, metabolic syndrome, and neuropsychiatric disorders. Critically, the reversibility of epigenetic marks has catalysed a new class of pharmacological agents, epidrugs, several of which hold regulatory approval, with an expanding pipeline targeting BET bromodomains, EZH2, and locus-specific methylation via CRISPR-dCas9 fusions. Epigenetic clocks and circulating cell-free DNA methylation signatures are emerging as powerful translational biomarkers for biological ageing, cancer screening, and disease prognostication. This review synthesises current mechanistic understanding, catalogues evidence linking environmental exposures to epigenome perturbation, and charts a roadmap toward precision epigenetic medicine, where pharmacological, lifestyle, and gene-editing interventions are tailored to individual exposome histories.

Keywords: Environmental epigenetics, DNA methylation, histone modifications, non-coding RNA, transgenerational inheritance, disease susceptibility, personalized medicine.

How to cite this article

Nwaozirii, I. N., Oladosu, M. A., Abah, M. A., Onyekwere, M. P., & Ekel, A. O. (2026). Environmental epigenetics: How external factors shape the epigenome and influence disease risk. Science Archives, 7(2), 213–225. https://doi.org/10.47587/SA.2026.7220

This work is licensed under a Creative Commons Attribution 4.0 International License

 

View Details