PAHs in Size Fractionate Mainstream Cigarette Smoke, Predictive Deposition and Associated Inhalation Risk

ABSTRACT

Size fractionated mainstream cigarette smoke (MCS) samples were collected with variable configuration cascade impactor (VCCI). Samples were extracted ultrasonically and analysis of sixteen priority polycyclic aromatic hydrocarbons (PAHs) was performed using high performance liquid chromatography (HPLC) coupled with UV-visible detector. Identification of PAHs were also carried out using gas chromatography coupled with mass spectrometry (GC-MS) technique. Data of size fractionate PAHs in MCS were used to calculate size dependent deposition in different compartment of human respiratory tract using multiple path particle dosimetry (MPPD) model. All brand cigarette smoke showed similar trends of particle mass and PAHs size distribution peaked at two sizes 0.3–0.1 µm and 0.75–1.13 µm aerodynamic diameter. All tested brands of MCS recorded around 48.75% of two and three-ring PAHs, 23 to 25% four-ring PAHs and 26–27% five and higher rings PAHs of total analyzed PAHs. Benzo[a]pyrene equivalent (B[a]P_eq) PAHs emission in MCS was found to be 110 ± 12 (µ ± 1σ) ng per cigarette for tested brands. Total deposition fraction in respiratory tract was found to be 0.69 ± 0.26 for tested size ranges. Average 5th and 95th percentile values of incremental lifetime cancer risk (ILCR) for smoker due to PAHs exposure were found to be 1.3 × 10^–5 to 3.9 × 10^–5 respectively for tested cigarette brands.