Bioavailability and potential carcinogenicity of polycyclic aromatic hydrocarbons from wood combustion particulate matter in vitro

• Published in: Chemico-biological interactions 2013-11, Vol.206 (2), p.411-422
• Main Authors: Gauggel-Lewandowski, Susanne, Heussner, Alexandra H., Steinberg, Pablo, Pieterse, Bart, van der Burg, Bart, Dietrich, Daniel R.
• Format: Article
• Language: English
• Subjects: 3T3 Cells; adverse effects; Animals; BALB/c 3T3 cell transformation assay; Benzoflavones - chemistry; Benzoflavones - pharmacology; bioavailability; carcinogenicity; carcinogens; cell transformation assay; combustion; energy; fossil fuels; Genes, Reporter - drug effects; humans; in vitro studies; Luciferases - metabolism; Mice; PAH CALUX; Particulate matter; Particulate Matter - analysis; Particulate Matter - toxicity; particulates; Polycyclic aromatic hydrocarbons; Polycyclic Aromatic Hydrocarbons - analysis; Polycyclic Aromatic Hydrocarbons - toxicity; Receptors, Aryl Hydrocarbon - antagonists & inhibitors; Receptors, Aryl Hydrocarbon - metabolism; renewable energy sources; reporter genes; wood; Wood - chemistry; Wood combustion
• ISSN: 0009-2797; 1872-7786
• DOI: 10.1016/j.cbi.2013.05.015

•Analysis of PAH bioavailability in wood combustion particulate matter.•A differential PAH bioavailability was detected.•Results suggest higher PAH bioavailability in PM from more efficient combustion.•Samples with high PAH amount showed higher tumor initiation potential. Due to increasing energy demand and limited fossil fuels, renewable energy sources have gained in importance. Particulate matter (PM) in general, but also PM from the combustion of wood is known to exert adverse health effects in human. These are often related to specific toxic compounds adsorbed to the PM surface, such as polycyclic aromatic hydrocarbons (PAH), of which some are known human carcinogens. This study focused on the bioavailability of PAHs and on the tumor initiation potential of wood combustion PM, using the PAH CALUX® reporter gene assay and the BALB/c 3T3 cell transformation assay, respectively. For this, both cell assays were exposed to PM and their respective organic extracts from varying degrees of combustion. The PAH CALUX® experiments demonstrated a concentration–response relationship matching the PAHs detected in the samples. Contrary to expectations, PM samples from complete (CC) and incomplete combustion (IC) provided for a stronger and weaker response, respectively, suggesting that PAH were more readily bioavailable in PM from CC. These findings were corroborated via PAH spiking experiments indicating that IC PM contains organic components that strongly adsorb PAH thereby reducing their bioavailability. The results obtained with organic extracts in the cell transformation assay presented the highest potential for carcinogenicity in samples with high PAH contents, albeit PM from CC also demonstrated a carcinogenic potential. In conclusion, the in vitro assays employed emphasize that CC produces PM with low PAH content however with a general higher bioavailability and thus with a nearly similar carcinogenic potential than IC PM.