Description
Polycyclic aromatic hydrocarbons (PAHs) and their derivatives, oxygenated and nitrated PAHs, are ubiquitous atmospheric pollutants with toxic, mutagenic, and carcinogenic properties. One source of PAHs is tobacco smoke. Tobacco smoke residue that remains in the air and on surfaces and in settled dust in indoor environments is known as third-hand smoke (THS). The purpose of this study was to determine if concentrations of PAHs and oxy-PAHs were elevated in house dust samples from smokers’ homes as compared to non-smokers’ homes. Settled house dust samples were collected from San Diego County and characterized for 45 PAHs, oxy-PAHs and nitro-PAHs that are not among EPA’s commonly measured 16 PAHs using GCxGC/ToF-MS. None of the nitro-PAHs were detected. Among, 17 PAHs and 14 oxy-PAHs measured, 9 were not detected in any sample. Ten compounds were eliminated due to high blank levels. Among the 7 PAHs and 6 oxy-PAHs reported in the dust samples, the most abundant compounds were 2-methylphenanthrene and 1,2-naphthalenequinone. By loading, both 1-methylpyrene and 6-methylchrysene were significantly elevated in smokers’ homes as compared to non-smokers’ homes (geomean 456.5 vs. 148.1 ng/m 2 and 91.4 vs. 5.2 ng/m2, p<0.05). Levels of 1-methylpyrene were also significantly correlated with nicotine measured in the same dust samples (r = 0.524, p<0.05). The Σoxy-PAHs was also correlated with nicotine in the same samples (r = 0.468, p<0.05), adding to the evidence that these compounds may have arisen from tobacco smoke. Finally, the cancer risk assessment via ingestion, inhalation and dermal absorption of house dust was estimated for the most abundant PAHs and oxy-PAHs in the samples. Risks though the dermal and ingestion routes of exposure exceeded one in a million risk of cancer for the 7 compounds, and the highest risks were to infants and toddlers. In conclusion, oxy-PAHs and PAHs present in house dust may pose a risk to children, especially 1,2-naphthalenequinone. Thirdhand smoke in dust from smoking in the home may be a source of elevated levels of certain toxic PAHs and oxy- PAHs
