Cancer Risk of Human Intake of PAH-Contaminated Particles Based on Hand-to-Mouth Activities

Abstract

The health risk of residents exposed to PAH-contaminated outdoor soil and indoor dust particles via hand-to-mouth transfer was estimated by developing probabilistic risk models. The cancer risk was assessed by applying the Monte Carlo method. The results showed that toddlers, children, and teens were at greatest risk of exposure, followed by infants, adults, and seniors. The probability of exceeding the acceptable level 10-6 was 2% for infants, 5% for toddlers and teens (none of the values were larger than the upper limit 10-4), 15% for children (0.1% of the values were larger than 10-4); and 1% and 0.1% for adults and seniors, respectively. Indoor dust posed a more serious threat than outdoor soil, which accounted for 91% of the total risk; indoor hard surfaces were the main sources of indoor dust with a contribution of 65%. The most influential variables were the frequency of hand-to-mouth events (FQ), benzo[a]pyrene from indoor dust (PEFj), dust surface load on horizontal soft surfaces (DSLSS) and hard surfaces (DSLHS), and saliva extraction factor (SE).