Air Quality Index Analysis of Dangote Cement in Obajana, Kogi State, Nigeria

Abstract

This study investigated the air quality index (AQI) and the associated environmental health risks in the vicinity of the Dangote Cement Plant, Obajana, Kogi State, Nigeria. Ambient concentrations of key air pollutants emitted from the plant including particulate matter (PM₂.₅, and PM₁₀,), sulphur dioxide (SO₂), nitrogen dioxide (NO₂), ammonia (NH₃), carbon monoxide (CO) and ozone (O₃) were monitored across multiple sampling stations over a six -months period, covering both the wet (August–October) and dry (November–January) seasons. AQI was computed using the Central Pollution Control Board (CPBP) method, and environmental risk was assessed by comparing pollutant levels to national and international standards. The results revealed that PM 2.5 concentration in December fell within the hazardous category, while ozone (O₃) levels were consistently in the very in the very unhealthy category throughout the six- months period. Carbon monoxide (CO) recorded unhealthy level category in December but remained in the good category from August to November and in January. Sulphur dioxide (SO₂) remained in the category of unhealthy for sensitive group throughout the study period. Ammonia (NH₃) and nitrogen dioxide (NO₂) were within the moderate category for August, September and October. Several pollutants exceeded recommended limits during the months. The findings underscore significant environmental and public health risks posed by emissions from the cement production process at Dangote cement factory Obajana, and highlighted the need for targeted mitigation strategies and stricter regulatory enforcement.