Arsenic originates from both geochemical and numerous anthropogenic activities. Exposure of the general public to significant levels of
arsenic is widespread.
Arsenic is a well-documented human
carcinogen. Long-term exposure to high levels of
arsenic in
drinking water has been linked to bladder, lung, kidney, liver, prostate, and
skin cancers. Among them,
lung cancer is of great public concern. However, little is known about how
arsenic causes
lung cancer and few studies have considered effects in normal human lung cells. The purpose of this study was to determine the cytotoxicity and genotoxicity of
arsenic in human primary bronchial fibroblast and epithelial cells. Our data show that
arsenic induces a concentration-dependent decrease in cell survival after short (24h) or long (120h) exposures.
Arsenic induces concentration-dependent but not time-dependent increases in chromosome damage in fibroblasts. No chromosome damage is induced after either 24h or 120h
arsenic exposure in epithelial cells. Using neutral comet assay and gamma-H2A.X foci forming assay, we found that 24h or 120h exposure to
arsenic induces increases in
DNA double strand breaks in both cell lines. These data indicate that
arsenic is cytotoxic and genotoxic to human lung primary cells but lung fibroblasts are more sensitive to
arsenic than epithelial cells. Further research is needed to understand the specific mechanisms involved in
arsenic-induced genotoxicity in human lung cells.