Abstract: Semi-mechanized abattoirs are central to Nigeria’s meat supply, yet their slaughter halls remain largely unregulated zones, with workers exposed to a range of airborne contaminants daily. This study investigates the air quality inside one of the busiest semi-mechanized abattoirs in Akure, southwestern Nigeria. A low-cost, precisely calibrated sensor system was deployed to monitor PM₂.₅, PM₁₀, ammonia (NH₃), and hydrogen sulfide (H₂S) every thirty minutes over a ten-week period. After data cleaning, 1,900 reliable observations were obtained. Findings were striking. Average concentrations of PM₂.₅ and PM₁₀ exceeded both WHO and NESREA guidelines, at times by three to five times the recommended limits. Additionally, ammonia and hydrogen sulfide levels peaked during periods of intense slaughter activity, when wastewater accumulated, humidity increased, and air movement was minimal. Random Forest Regression analysis indicated that the number of animals processed, humidity, and ventilation rates were the primary drivers of pollution, collectively accounting for up to half of the observed variability. The most severe pollution episodes including PM₂.₅ above 120 µg/m³ or ammonia over 6 ppm sustained for at least one hour were consistently recorded on the busiest market days, particularly when humidity exceeded 80% and the air was stagnant. A decision-matrix approach identified improved cross-ventilation as the most effective and practical mitigation, reducing pollution by approximately 28–30%. More frequent removal of paunch contents and adjustments to work schedules also contributed to reductions, but to a lesser extent. While biofilters could theoretically offer superior air cleaning, their costs remain prohibitive for facilities of this type. This study goes beyond pollutant measurement, demonstrating how high-resolution sensor data and advanced analysis can inform interventions aligned with NESREA standards. The main conclusion is clear: enhanced ventilation, real-time air quality monitoring, and strengthened health policies are essential to protect workers and the surrounding community. These measures represent meaningful progress for public health and advance Nigeria’s efforts toward achieving SDG 3 and SDG 11.
Keywords: semi-mechanized abattoir; indoor air quality; particulate matter (PM₂.₅, PM₁₀); ammonia (NH₃); hydrogen sulfide (H₂S); low-cost sensors; Random Forest Regression; ventilation mitigation; occupational exposure; NESREA guidelines; high-resolution monitoring; environmental engineering.
Title: HIGH-RESOLUTION MULTI-SENSOR ASSESSMENT OF INDOOR AIR QUALITY IN A SEMI-MECHANIZED NIGERIAN ABATTOIR AND ENGINEERING-BASED EVALUATION OF MITIGATION STRATEGIES
Author: Olatunji Omoniyi, Christopher O. Akinbile
International Journal of Interdisciplinary Research and Innovations
ISSN 2348-1218 (print), ISSN 2348-1226 (online)
Vol. 13, Issue 4, October 2025 - December 2025
Page No: 103-114
Research Publish Journals
Website: www.researchpublish.com
Published Date: 09-December-2025
