Baseline concentrations of nitrogen dioxide in offices in residential areas of Benin City, Nigeria

• Published in: International journal of environmental studies 2007-10, Vol.64 (5), p.617-623
• Main Authors: Ukpebor, E.E., Ukpebor, J.E., Odiase, J.I., Uzoekwe, S.A.
• Format: Article
• Language: English
• Subjects: Diffusion tubes; Nitrogen dioxide; Principal component analysis; Work places
• ISSN: 0020-7233; 1029-0400
• DOI: 10.1080/00207230701553806

Baseline nitrogen dioxide (NO 2 ) concentration and distribution in 10 offices in Benin City, Nigeria have been evaluated. Palmes diffusion tubes were employed in capturing NO 2 data in this survey. The diffusion tubes were deployed at the specific offices at a height of approximately 2.0 m above the floor, and changed at two-week intervals. The survey was carried out between May and July 2005 in accordance with the Department for Environment, Food and Rural Affairs (DEFRA) UK NO 2 Diffusion Tube Network Instruction Manual - Version 1.5. A NO 2 range of 1.89 µgm −3 -24.83 µgm −3 was obtained for the offices studied which indicate good compliance with the available National and International regulatory limits for NO 2 . Significant spatial variations (p < 0.05) were noticed in the NO 2 distribution. The Principal Component Analysis (PCA) identified several clusters of NO 2 and different degrees of correlation between the monitoring sites. Outdoor sources were identified as the main source of NO 2 at these work places.