Sequential Extractions and Toxicity Potential of Trace Metals Absorbed into Airborne Particles in an Urban Atmosphere of Southwestern Nigeria

Table 1

Monitoring locations, their characteristics, and coordinates at Akure.

	Site code	Coordinate	Description	value	Pollution index
(1)	AKEX	N07°17′06.2′′​; E005°10′34.0′′	Created along Ilesa-Akure-Owo/Benin road, an expressway, close to the NNPC station	2.0 < < 3.0	Moderate
(2)	AKOA	N07°14′25.3′′​; E005°11′15.0′′	Oke-Aro monitoring site, a residential area with many local buildings, close to furniture workshops	> 3.0	Highly contaminated
(3)	AKOB	N07°15′12.7′′​; E005°11′43.8′′	Created at the Oja Oba, a market square with heavy traffic	> 3.0	Highly contaminated
(4)	AKAL	N07°14′55.1′′​; E005°12′54.4′′	Alagbaka monitoring site, the site of many government offices	2.0 < < 3.0	Considerably contaminated
(5)	AKOR	N07°49′47.2′′​; E005°09′37.9′′	Ondo road park monitoring site, a bus terminus with a cluster of petrol dispensing stations	2.0 < < 3.0	Considerably contaminated
(6)	AKBR	N07°13′47.6′′​; E005°09′37.9′′	Aponmu monitoring site, a small community and a background site for the study	1.0 < < 2.0	Low contaminated