Assessment of atmospheric sulphur dioxide (SO₂) levels and associated health risks at selected industrial and urban sites in Akure and Okitipupa, Ondo state, Nigeria

Nigeria has experienced significant air pollution, with sulphur dioxide (SO₂) being one of the primary pollutants due to rapid industrialization and urbanization. SO₂ contributes to acid precipitation, haze formation, reduced visibility, and increased respiratory and cardiovascular diseases. This study measured atmospheric SO₂ concentrations across five locations—Welding Workshop (A), Busy Road (B), Generator House (C), Mechanic Workshop (D), and Metal Works and Welding Industry (E)—in Akure and Okitipupa, Nigeria. The highest SO₂ concentration was recorded at location E (30.4 mg/m³; ~30,368 µg/m³), while the lowest was observed at location C (3.6 mg/m³; ~3,640 µg/m³). Meteorological parameters, including temperature, wind speed, and humidity, were analyzed to assess their influence on SO₂ levels. Health risk assessments were conducted for both adults and children, evaluating exposure through inhalation, ingestion, and dermal contact. The findings indicate elevated non-carcinogenic health risks, particularly at location E, although hazard indices remain below 1. These results highlight potential respiratory risks based on screening-level exposure modeling.