Evaluation of the impacts of abattoir activities on ambient air quality of Ilorin, Nigeria

Abstract

This study assessed the impact of the Ilorin Central Abattoir on air quality of its immediate environment. A mixed-methods approach was employed, involving systematic air quality monitoring at 18 fixed sites, ten (10) sites within the abattoir premises and eight (8) in the surrounding environment at distance 50m and 100m north, south, east, and west of the abattoir premise. Particulate Matter (PM_2.5), Carbon Dioxide (CO₂), Formaldehyde (HCHO), and Total Volatile Organic Compounds (TVOCs) were monitored using standard methods in the morning, afternoon, and evening for twenty-eight (28) consecutive days. Results revealed severe pollution hotspots within the facility, particularly during morning operations. Critically elevated level of PM_2.5 recorded at the by-product processing area (438.86 ± 3.84 µg/m³) and slab (179.14 ± 3.85 µg/m³), exceeding WHO guidelines by up to 29 times. CO₂ concentrations similarly peaked in these areas (>4000 ppm), indicating intense biological activity. A dramatic afternoon spike of HCHO (71.96 µg/m³) at the waste site pointed to specific chemical use or waste burning. A sharp pollutant gradient observed from the interior to exterior, with PM_2.5 remaining elevated at 50-100m distances (71-75 µg/m³), while gaseous pollutants like HCHO and TVOCs dropped to near-background levels outside the premises. The study concludes that the abattoir is a major point source of air pollution, creating hazardous occupational exposure inside the premises and contributing significantly to ambient particulate matter in the local community. The findings underscore the urgent need for improved ventilation, worker protection, and cleaner operational protocols to mitigate health risks.