In vitro toxicology of respirable Montserrat volcanic ash

摘要: OBJECTIVES—In July 1995 the Soufriere Hills volcano on the island of Montserrat began to erupt. Preliminary reports showed that ash contained a substantial respirable component and large percentage toxic silica polymorph, cristobalite. In this study cytotoxicity three volcanic (MVA) samples was investigated: M1 from single explosive event, M2 accumulated predominantly derived pyroclastic flows, M3 flow. These were compared with relatively inert dust TiO2 known quartz dust, DQ12. METHODS—Surface area particles measured Brunauer, Emmet, Teller (BET) adsorption method cristobalite content MVA determined by x ray diffraction (XRD). After exposure particles, metabolic competence epithelial cell line A549 assessed determine cytotoxic effects. The ability induce sheep blood erythrocyte haemolysis used assess surface reactivity. RESULTS—Treatment either MVA, quartz, or titanium dioxide decreased as reduce 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). On addition mannitol, effect significantly less M1, TiO2. All induced dose dependent increase in haemolysis, which, although than greater Addition mannitol superoxide dismutase (SOD) reduced haemolytic activity only but not M3, flow events. CONCLUSIONS—Neither nor correlated observed vitro reactivity. A role for reactive oxygen species could be shown which sample purely event. results suggest general bioreactivity is low pure mechanisms biological interaction may vary according source. Keywords: ash; cristobalite; reactivity