Pollution status, ecological risk assessment and source identification of heavy metals in road dust from an Industrial Estate in Trinidad, West Indies

Road dust in an industrial estate could potentially contain toxic heavy metals as a result of various anthropogenic sources. This study investigated sixteen samples from various locations throughout the Point Lisas Industrial Estate in Trinidad, West Indies. Samples were acid-digested and analysed by Flame Atomic Absorption Spectroscopy, which revealed that concentrations for Cd, Cr, Cu, Mn, Ni, Pb and Zn ranged from 2.48-5.45g/g, 14.2-70.5g/g, 15.3-130g/g, 219-1330g/g, 20.0-62.1g/g, 43.5-113g/g and 105-1154g/g, respectively. Different methods (Geoaccumulation index, pollution index, integrated pollution index, enrichment factor and ecological risk assessment) of assessing heavy metal contamination in road dust indicated negligible to moderate degrees of pollution, in which the associated potential ecological risk was considered low. Principal component analysis (PCA) and Cluster analysis (CA) grouped the heavy metals according to potential sources and indicated that the accumulation of heavy metals in the road dust of the Estate were influenced mainly by vehicular and industrial processes.