Hepatic alterations associated with fne particulate matter exposure

Abstract

Several studies have pointed to fne particulate matter (PM2.5) as the main responsible for air pollution toxic efects. Indeed, PM2.5 may not only cause respiratory and cardiovascular abnormalities but it may also afect other organs such as the liver. Be that as it may, only a few studies have evaluated the PM2.5 efects on hepatic tissue. Moreover, most of them have not analyzed the relationship between particles composition and toxicological efects. In this study, healthy rats were subjected to urban levels of PM2.5 particles in order to assess their structural and functional efects on the liver. During the exposure periods, mean PM2.5 concentrations were slightly higher than the value suggested by the daily guideline of the World Health Organization. The exposed rats showed a hepatic increase of Cr, Zn, Fe, Ba, Tl and Pb levels. This group also showed leukocyte infltration, sinusoidal dilation, hydropic inclusions and alterations in carbohydrates distribution. These histologic lesions were accompanied by serological changes, such as increase of total cholesterol and triglycerides, as well as genotoxic damage in their nuclei. We also observed signifcant associations between several biomarkers and PM2.5 composition. Ourresults show that exposure to low levels of PM2.5 might cause histologic and serological changes in liver tissue, suggesting that PM2.5 toxicity is infuenced not only by their concentration but also by their composition and the exposure frequency.