Polycyclic aromatic hydrocarbons in dust from the indoor environment of Qatar

Abstract

Polyaromatic Hydrocarbons (PAHs) concentrations in dust trapped on air conditioning unit filters operating in residential and workplace locations in Doha, Qatar were sampled and measured. Fourteen samples were collected and their PAH congener profile were quantified using gas chromatography–mass spectrometry (GC-MS). The results showed that the medians of ΣPAH16, which include seven carcinogenic components (ΣPAH7), were 214.7 ng g− 1 and 129.2 ng g− 1 of dust respectively for the residential samples, and 224.4 ng g− 1 and 137.9 ng g− 1 respectively for dust samples collected in an office workplace environment. Among all samples, benzo (b) fluoranthene (BBF) and benzo (a) pyrene (BAP) were the dominant congeners in both the residential and workplace samples, representing 18.2% and 16.9% of the ΣPAH16, respectively. Factors of correlation were calculated for various PAHs, and showed that lighter molecular weight PAHs have a significant positive correlation with heavier congeners within the residential samples, while workplace samples showed a negative correlation with BAP, Indeno (1,2,3-cd) pyrene (IND), and Dibenz (a,h) anthracene (DBA). Benzo (a) pyrene equivalent (BAPe) was used to assess the risk of human exposure to PAH inhalation. BAPe estimates for residences sampled averaged 0.019 μg g− 1, with a maximum of 0.063 μg g− 1 of dust, while workplace estimates averaged at 0.056 μg g− 1 with a maximum of 0.148 μg g− 1. Source apportionment assessment indicated that most residential and workplace PAHs samples have a pyrogenic origin with few showing evidence of petrogenic origins. All quantified PAHs concentrations and estimated BAPe in Qatar indoor dust samples are well below reported values elsewhere in the world.