The effects of particulate matters inhalation exposures of prallethrin and d-phenothrin mixture in mice (Mus musculus) against exhaled carbon dioxide concentration.

Particulate matter (PM) inhalation exposure affects exhaled CO2 concentration. Such exhaled CO2 refers to ventilation and perfusion of the cardiorespiratory system, the analysis of which is painless, non-invasive and simple to perform. This study examined the effect of prallethrin and d-phenothrin inhalation exposure on exhaled CO2 in mice using a simple method. Prallethrin and d-phenothrin were administered in male mice (Mus musculus) in a series of repeated inhalation exposures of lower and higher doses for 60 days. The lower dose was a mixture of 0.000141 mg/L prallethrin and 0.104 mg/L d-phenothrin, while the higher dose was a mixture of 0.00141 mg/L prallethrin and 1.04 mg/L d-phenothrin. The lower dose was based on a NOAEL value of prallethrin and d-phenothrin of 28 days exposure, while the higher one was ten times of the lower dose concentration. CO2 concentration was measured by means of the passage through NaOH 0.1 N, titrated by HCl 0.1 N. PMs were generated by the process of producing bubbles, inserted into the chamber containing mice. Mice were divided into four groups, namely: negative control (NC), positive control (PC), and lower- and higher-dose treatment groups, with three replicates for each group. Statistical difference analyses were observed in body weight and exhaled CO2 concentration between negative control and treatment groups, nevertheless, they did not differ significantly between the control and the treatment (lower and higher dose) groups. This study suggests that exhaled CO2 and body weight are not specific biomarkers to observe PMs inhalation exposure with respect to prallethrin and d-phenothrin mixtures. © Korean Society of Toxicology 2019.