Genotoxicity of Organic Extracts of House Dust from Shanxi, China

Abstract

Indoor combustion of solid fuel such as coal may generate respirable particles containing polycyclic aromatic hydrocarbons (PAH) that may adhere to settled dust. Dust might therefore present a major source of PAH exposure in humans. This study evaluated the in vitro and in vivo genotoxicity of PAH mixtures extracted from house dust samples. Four dust samples (E1-4) were collected from houses in Shanxi, China, where coal is heavily used for heating and cooking. For comparison, a coal sample was also collected from one of the houses and included in the analyses. The samples were extracted with methylene chloride:acetone (95:5 v/v), dried, and redissolved in appropriate solvents for assessment in genotoxicity assays. Samples were evaluated for their ability to induce point mutations in bacteria and DNA adducts in vivo. DNA adduct levels were analyzed by nuclease P1-enhanced 32P-postlabeling. PAH were quantified using gas chromatography/mass spectrometry. Based on chemical analysis, sample E1 had the highest concentration by sampling area of benzo[a]pyrene (BaP) (181 microg/m2) and total PAH (10100 microg/m2). However, based on the microbial genotoxicity assay, sample E3, with the highest carcinogenic PAH/total PAH ratio (26%), produced the greatest number of revertants. In mice, administration of the extract of coal induced more adducts (9.81 adducts per 10(9) nucleotides) than dust extracts. The results of this study confirm the presence of genotoxic chemicals in residential dust. Inhalation of respirable particles containing similar mixtures of PAH represents a cancer risk for humans.

Indoor air pollution and the risk of orofacial clefts in a rural population in Shanxi province, China

“…These IAP factors are particularly prominent in Shanxi Province, where almost all rural households use coal for cooking and heating, and the male and female smoking rates are 52.9% and 2.4%, respectively (11). Furthermore, pregnant women in this region generally stay indoors during the day; therefore, they have substantial IAP exposure (Li et al, ; Naufal et al, ; Naspinski et al, ). However, little is known about the role of indoor exposure in the etiology of OFCs.…”

Biomarkers of exposure to combustion by-products in a human population in Shanxi, China

“…In an earlier report, elevated levels of genotoxic mixtures of PAHs were detected in the residential environments of a population located in Shanxi province, China (Naufal et al, 2007). The study described in this paper was directed at the analysis of biomakers of exposure, effect, and susceptibility in parents of children born with NTDs, and their matched controls.…”

Research Opportunities for Cancer Associated with Indoor Air Pollution from Solid-Fuel Combustion

“…IAP contaminates more than the air of closed structures; it may also settle onto the walls, floors, clothing, and food of the household inhabitants. A study conducted in Shanxi, China, confirmed the presence of genotoxic chemicals from indoor solid-fuel combustion in residential dust (Naufal et al 2007). Transdermal exposures to PAHs are well documented from a variety of sources (Kammer et al 2011).…”