Objective   To investigate the hazards of blowing sand and dust storm fine particulate matter(PM_2.5)on rat alveolar macrophage membranes.

  Methods   The ambient PM_2.5 samples were collected on normal, blowing sand and dust storm days in Wuwei city, Gansu province and Baotou city, Inner Mongolia Autonomous region.After rat alveolar macrophages(AM)were treated 4 h with particle suspensions of the samples, cytotoxicity was assessed using methyl thiazolyl tetrazolium(MTT)reduction assay.Also, activities of plasma membrane Ca²⁺ Mg²⁺-AT Pase and Na⁺ K⁺-AT Pase, activties of lactate dehydrog enase(LDH)and acid phosphatese(ACP)in culture meduim, and plasma membrane fluidity were examined.

  Results   Both the blowing sand and dust storm PM_2.5 could decrease cell viability, inhibit plasma membrane Ca²⁺ Mg²⁺-AT Pase and Na⁺ K⁺-AT Pase, increase leakage of cytosolic LDH and ACP, and elevate surface fluidity of plasma membranes in a dose-dependent manner as compared with the control saline.And the two-way ANOVA showed there was no significant difference on alterations of the measured indices between normal, blowing sand and dust storm groups.

  Conclusion   Blowing sand and dust storm PM_2.5 could make adverse effects on AM by increasing plasma membrane permeability and fluidity, leading to cytotoxicity.It suggested that appropriate attention should be focused on their to xicities.