Acute toxicity assessment of indoor dust extracts by luminescent bacteria assays with Photobacterium Phosphoreum T3

In the last decades, there has been an increasing concern about the human exposure to indoor dust. Therefore, it is imperative to assess the toxicity of indoor dust and associated dust extracts. In this study, the acute toxicity assessment of indoor dust was performed using a bioluminescence test, with Photobacterium phosphoreum T₃ (PPT₃) chosen as the test bacterium. The different indoor dust samples were collected from residences, offices, dormitories and laboratories in Shanghai, China. Our data reveal that PPT₃ is more active to water-soluble ions and organic contaminants at low concentrations, while extract solutions elicit increased bacterial toxicity at high concentrations. The results of a bioluminescence assay by PPT₃ indicated that the dust organic extracts exhibited increased toxicity compared with the water exacts. Dust extracts from the laboratory exhibited the greatest bacterial toxicity when compared with office, dormitory and residence samples. Moreover, office dust exhibited higher bacterial toxicity than residence dust. Furthermore, the comprehensive toxicity of dust on PPT₃ was assessed by extracts toxicity -addition (i.e. IR_addition). The calculated values were close to the corresponding experimental data. The bioluminescence test showed the indoor dust samples are weakly toxic to PPT₃, which are equivalent to 0.046–0.123 mg Hg• L⁻¹. Different dust extracts among the different sampling sites showed varying toxicity to PPT₃. This study provides some important information to understand the potential health risk from different indoor environment using a rapid bioluminescence assay.