Title : Solar activity and its influence on human health: A multi-decadal ecological analysis (1950–2024)

Background: Solar activity has long been suspected to influence human physiological and epidemiological trends, yet empirical evidence spanning multi?decadal scales remains limited. This study explores how solar activity—measured through sunspot numbers and geomagnetic indices—correlates with cardiovascular, neurological, and heat?related health outcomes from 1950 to 2024.

Methods: A combined ecological and time?series analytical framework was applied using multi?decadal datasets including sunspot numbers, geomagnetic Kp index, temperature anomalies, and health outcome indicators. Analyses included correlation matrices, phase?space trajectories, lagged associations (0–5 years), and standardized z?score evolution to compare temporal co?variability. Visualizations were generated in R using ggplot2.

Results: Cardiovascular mortality showed a moderate positive association with sunspot activity, with stronger alignment during peak solar cycles (r ≈ 0.45). Lagged analysis demonstrated consistent trends up to a 5?year delay, suggesting cumulative physiological or environmental mediation pathways. Neurological and heat?related mortality also displayed cyclical co?variation with geomagnetic fluctuations. Standardized phase?time trajectories revealed parallel oscillatory patterns between solar indicators and health outcomes across decades. Country?level comparisons highlighted heterogeneity, with higher?latitude nations showing stronger associations.

Conclusion: Multi?decadal evidence indicates that solar variability may exert subtle but measurable effects on human health outcomes, particularly cardiovascular and neurological mortality. These findings support the emerging concept of heliobiology and underscore the importance of integrating solar–geomagnetic monitoring into global health surveillance frameworks.

Dr. Sagam Dinesh Reddy is a Family Physician with advanced expertise in Nutrition, Occupational Health, and Community Health. He has led multiple interdisciplinary research projects integrating epidemiology, chronobiology, and environmental health analytics. His work spans public health innovation, AI‑assisted clinical research, and long‑term health surveillance studies. He is currently the Director of LMR Hospital,NTR Distirct, Andhra Pradesh, India. He is also factory medical officer for Bharath petroleum corporation limited LPG/KTOP/AFS Vijayawada territory.