Environmental risk factors for cancer in childhood, adolescence, and young adults: A narrative review

Childhood, adolescent, and young adult cancers represent a significant global health burden, with an increasing incidence and a complex multifactorial etiology involving genetic susceptibility and environmental exposures. This narrative review provides a synthesis of current evidence on environmental risk factors associated with pediatric cancer, with the aim of guiding future research.Evidence indicates that several environmental exposures contribute to cancer risk in childhood and adolescence, although the strength and consistency of associations vary across factors. Air pollution, particularly exposure to benzene and fine particulate matter (PM₂.₅), has been consistently associated with an increased risk of childhood leukemia, especially acute myeloid leukemia. Prenatal and parental occupational exposures to hydrocarbons and industrial pollutants further support the role of early-life environmental insults. Ionizing radiation remains a well-established carcinogen in children, with increased risks observed following therapeutic and diagnostic exposures. Emerging evidence also suggests a potential association between extremely low-frequency magnetic fields and childhood leukemia, although findings remain modest and methodologically heterogeneous. Lifestyle-related factors, including alcohol consumption, are implicated primarily through cumulative lifetime exposure, while prenatal alcohol exposure may exert additional risk via epigenetic mechanisms. Dietary patterns, obesity, and early-life microbiome alterations are increasingly recognized as potential modulators of cancer susceptibility, although evidence remains partly inconclusive. Additional exposures, such as endocrine-disrupting chemicals and secondhand tobacco smoke, have been associated with specific pediatric cancer subtypes in epidemiological studies. Overall, while causality is firmly established only for a subset of exposures, growing evidence supports a role for modifiable environmental and developmental factors in pediatric oncogenesis. Further high-quality longitudinal studies are needed to clarify exposure–disease relationships and inform preventive public health strategies.