A Study About Blood in Soil and Its Interactions

*Corresponding author: B Subashri Copyright © 2025 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0. A Study About Blood in Soil and Its Interactions B Suba Shri * and Keerthi S Master in Criminology and Forensic science, Department of Computer Science and Engineering, Faculty of Humanities and Science, MGR Educational and Research Institute, Chennai, Tamil Nadu. World Journal of Biology Pharmacy and Health Sciences, 2025, 22(01), 477-481 Publication history: Received on 05 March 2025; revised on 16 April 2025; accepted on 19 April 2025 Article DOI: https://doi.org/10.30574/wjbphs.2025.22.1.0407 Abstract This study investigates the interaction of blood with three soil types roadside soil, construction soil, and red soil under varying environmental conditions: cold, indoor (room temperature), and outdoor exposure. Using phenolphthalein reagent for blood decomposition and pH paper for chemical analysis, observations were made over ten days. Results show significant variations in pH levels and blood decomposition rates depending on soil type and environment. This research offers valuable insights for forensic science, particularly in crime scene reconstruction and estimation of bloodstain age. Keywords: Blood-soil interaction; Phenolphthalein test; Soil pH; Forensic science; Decomposition; Environmental exposure 1. Introduction Forensic biology serves as the bridge between biological sciences [3] and the justice system. Among the biological traces often encountered at crime scenes, blood is among the most critical due to its potential for DNA profiling, pattern analysis, and chronological interpretation.[2]. Simultaneously, soil often considered background evidence can preserve blood traces and provide environmental context. This study focuses on understanding how blood decomposes and affects soil chemistry under different environmental exposures. It addresses a gap in forensic literature where limited attention has been given to blood-soil interactions as a tool for post-event analysis and crime scene reconstruction. 2. Materials and Methods A controlled experimental setup was used to test three soil types: roadside soil, construction soil (M-sand), and red soil. Each type was exposed to three environmental conditions: cold storage, room temperature, and outdoor natural conditions. Fresh blood (source anonymized and ethically approved) was applied to each soil sample.[6] Phenolphthalein reagent was used at intervals to test for blood decomposition,[1] while pH strips were used to monitor chemical changes over a 10-day period.[4] Samples were collected and tested every 2 days. Control samples without blood were also included for baseline comparison. World Journal of Biology Pharmacy and Health Sciences, 2025, 22(01), 477-481 478 Figure 1 Chemical reaction of Phenolphthalein Assay [8] 3. Results Table 1 pH Readings Under Cold Conditions Soil types Day 0 Day 1 Day 3 Day 5 Day 7 Day 9 Roadside Soil 7 14 7 7 1 5 Construction Soil (M-Sand) 7 7 7 12 3 1 Red Soil 7 7 9 3 3 3 Figure 2 pH Readings Under Cold Conditions - Cold Conditions: Roadside soil reached a peak pH of 14 on Day 1 before dropping to 1 by Day 7. Construction soil peaked at Day 5 with pH 12. Red soil showed milder changes, peaking at pH 9. Table 2 pH Readings at Room Temperature Soil types Day 0 Day 1 Day 3 Day 5 Day 7 Day 9 Roadside Soil 7 9 8 5 3 3 Construction Soil (M-Sand) 7 12 9 3 1 6 Red Soil 7 8 12 3 1 3 World Journal of Biology Pharmacy and Health Sciences, 2025, 22(01), 477-481 479 Figure 3 pH Readings at Room Temperature -Room Temperature: pH generally increased early (Days 1–3) before dropping by Day 9 Table 3 pH Readings Under Outdoor Exposure Soil types Day 0 Day 1 Day 3 Day 5 Day 7 Day 9 Roadside Soil 7 12 12 1 1 1 Construction Soil (M-Sand) 7 10 8 1 1 1 Red Soil 7 7 9 9 1 1 Figure 4 pH Readings Under Outdoor Exposure - Outdoor Conditions: Exhibited rapid fluctuations in pH, likely due to environmental factors such as UV exposure and rainfall. World Journal of Biology Pharmacy and Health Sciences, 2025, 22(01), 477-481 480 Table 4 Phenolphthalein Test Readings Days Cold Conditions Room Temperature Outdoor Exposure 0 Present Present Present 1 Present Present Present 3 Absence Presence Present 5 Absence Absence Absence 7 Absence Absence Absence 9 Absence Absence Absence -Phenolphthalein tests showed positive results primarily on Days 1–3, indicating rapid early decomposition of Hemoglobin components. 4. Discussion Environmental conditions significantly influence the rate of blood decomposition and soil pH changes. Cold environments delayed decomposition, while room temperature and outdoor exposure accelerated it.[7] Red soil exhibited the highest absorption and least visible staining, while construction soil showed prolonged visibility of blood stains. Table 5 Blood Absorption in Different Soils Soil Type Absorption Rate Surface Staining Red Soil High Absorbs quickly, stains less Roadside Soil Moderate Can alter blood colour Construction Soil (M-Sand) Low Blood remains visible longer High Absorption: Red soil (iron content affects binding); Medium Absorption: Roadside soil (due to organic matter and mixed particles).; Low Absorption: Construction soil (M-sand lacks organic matter). Table 6 Blood Decomposition in Different Soils Soil Type Decomposition Speed Colour Changes Odour Red Soil Medium Remains same Absence Roadside Soil Fast Dark Colour Presence Construction Soil (M-Sand) Slow Dark Colour Presence Fastest Decomposition: Roadside soil (high microbial activity); Moderate Decomposition: Red soil (due to iron and mineral interactions); Slowest Decomposition: M-sand (low bacterial growth). Table 7 Physical Changes in Soils Soil Type Early Stage (0-3 Days) Intermediate Stage (4-7 Days) Late Stage (8-10 Days) Red Soil Stainless, no moist appearance. Stainless, no moist appearance. Stainless, no moist appearance. Roadside Soil Dark red stains, slightly moist. Hardening due to protein coagulation brittle or slightly crusty. Construction Soil (MSand) Dark red stains Clumping Dark red stains 0–3 Days: Blood is fresh; easy to detect; 4–7 Days: Hemoglobin begins degrading; pH shifts in soil are noticed; 8-10 Days: Decomposition byproducts develop World Journal of Biology Pharmacy and Health Sciences, 2025, 22(01), 477-481 481 These findings are critical for forensic investigations, as they suggest that blood's persistence and detectability can vary greatly based on soil type and climate. Understanding these dynamics aids forensic experts in determining time since deposition and potential movement of a suspect or victim. 5. Conclusion The interaction between blood and soil is complex and highly sensitive to environmental variables.[5] Phenolphthalein tests are effective for early detection of blood, but their utility diminishes after a few days. pH analysis provides a promising supplementary tool for forensic timing and environmental profiling. The study confirms that soil-blood interaction analysis can support crime scene reconstruction and contribute meaningfully to forensic science. Compliance with ethical standards Disclosure of conflict of interest No conflict of interest to be disclosed. Acknowledgement I would like to express my sincere gratitude to all those who have supported and contributed to the successful completion of this research article. References [1] District of Columbia Department of Forensic Sciences. (2014). FBS02 - Phenolphthalein presumptive chemical test for the presence of blood. In District of Columbia Department of Forensic Sciences. https://dfs.dc.gov/sites/default/files/dc/sites/dfs/page_content/attachments/FBS02%20KM%20Testing.pdf [2] Bloodstain Pattern Analysis: Principles. (n.d.). https://www.forensicsciencesimplified.org/blood/principles.html [3] Science, F. (n.d.). Forensic Biology and Serology. SGTB Khalsa College. [4] Soil ph. (n.d.). https://lter.kbs.msu.edu/protocols/163 [5] Chouhan, R., 1*, Mali, B., 2, Tekam, V., 3, Nishad, P., 4, Holkar Science College, Devi Ahilya Vishwavidyalaya, Institute of Forensic Science, Mumbai University, Institute of Sciences, & SAGE University. (2024). EXPLORING THE INTERACTION OF BLOOD AND SOIL [Journal-article]. [6] Badu-Boateng, A., Twumasi, P., Salifu, S. P., & Afrifah, K. A. (2018). A comparative study of different laboratory storage conditions for enhanced DNA analysis of crime scene soil-blood mixed sample. Forensic Science International, 292, 97–109. https://doi.org/10.1016/j.forsciint.2018.09.007 [7] Janaki, M. C., & Kumar, S. A. (2023). A forensic study on lifespan of blood stains on different soil in different temperature [Forensic Science]. Research Journal of Forensic Sciences, 1–6. https://www.isca.in [8] Li, R. & John Jay College of Criminal Justice. (2015). Forensic biology (Second). CRC Press.