Appraisal of polycyclic aromatic hydrocarbons (PAHs) in indoor dust of Eastern Nigeria and its implications in the COVID-19 years

The risk assessment of PAHs in settled indoor dusts from different localities of Awka, Ekwulobia, and Rumuodomaya–Ogale, Eastern Nigeria, were investigated. Settled dust samples (n = 144) were collected from the windows and floor using brush and analyzed for PAHs with GC- FID. Dust from the windows showed higher total PAHs concentrations than the floor in the order; Rumuodomaya–Ogale > Ekwulobia > Awka. The 3- and 4-ring PAHs were dominant in the window and floor dust of Awka in all the months, while the 3-ring PAHs were the dominant compound in Ekwulobia. The concentrations of total PAH in the window and floor dusts of Ekwulobia, showed a significant difference across the months (p < 0.05). In Rumuodomaya–Ogale, the 3, 4, and 5-ring PAHs supersede in the window and floor dust. This showed that dust is a major sink for 3–5-ring PAHs. The compounds; BaA, DahA, Ant, BaP, and DBA were the major contributors to benzo(a)pyrene as toxicity equivalence ($Ba{P}_{TEQ}$) values of the window and floor dust. The total incremental life cancer risk was < 1.0 × 10⁻⁰⁴ in all the study area; hence, the increased indoor activities during COVID-19 lockdown had no significant cancer effect on human health of the populace.