Characterization, source apportionment, and human health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in road dust of a small island state in the Caribbean

ABSTRACT

Sixty-four and fifty-six road dust samples were collected over two seasons from various locations throughout the island of Trinidad and analyzed for the 16 priority PAHs. Total PAH concentrations ranged from 21 ng g⁻¹ to 4723 ng g⁻¹ (d.w.) for the rainy season and 36 ng g⁻¹ to 2428 ng g⁻¹ (d.w.) for the dry season. The Σ4–6 ring PAHs accounted for 88% and 63% of the 16 PAHs in road dust samples for the rainy and dry seasons, respectively. PAH diagnostic ratios, principal component analysis, and cluster analysis revealed both pyrogenic and petrogenic sources in road dust for the two seasons, with major contributions from vehicular emissions. Contributions from incomplete combustion and petroleum sources were also identified. The estimated Incremental Lifetime Cancer Risk (ILCR) associated with exposure to road dust PAHs in Trinidad for the rainy and dry seasons indicated no potential risk for both children and adults, as denoted by ILCR values lower than 10⁻⁶.

KEYWORDS:

• road dust
• polycyclic aromatic hydrocarbons
• principal component analysis
• health risk assessment
• Trinidad

Acknowledgments

The authors would like to thank the Department of Chemistry, The University of the West Indies for the resources and support throughout this project.

Disclosure statement

No potential conflict of interest was reported by the authors.