Evaluation of micronucleus induction of sand dust storm fine particles (PM(2.5)) in human blood lymphocytes

Sand dust storms are common phenomena in the arid and semi-arid regions. Previous studies have demonstrated that the airborne air fine particulate matter (PM_2.5, particulates with an aerodynamic diameter ≤2.5 μm) and its extracts can induce human genetic damage of lymphocytes such as micronucleus formation, chromosomal aberration and so on. However, little is known about the health risks associated with sand dust storm PM_2.5 and its extracts. The aim of the present study is to investigate the micronucleus induction of sand dust storm PM_2.5 (include its organic and inorganic extract) from two different towns on human lymphocytes. The samples of normal PM_2.5 and sand dust storm PM_2.5 were collected in Wuwei (Gansu Province) and Baotou (Inner Mongolia), China. The cytochalasin-B cytokinesis-block test was employed and the cells were treated with 0, 33, 100, 300 μg ml⁻¹ sand dust storm PM_2.5 or normal ambient air PM_2.5 suspension (physiological saline as solvent control), or inorganic extract (0, 75, 150, 300 μg ml⁻¹, physiological saline as solvent control) or organic extract (0, 20, 40, 80 μg ml⁻¹, DMSO as solvent control) at the beginning of the cell culture. Both sand dust storm and normal PM_2.5 and their extract treatment cultures revealed an increase in the frequency of micronucleus. With the increase of treatment concentrations the frequency of micronucleus increased and the nuclear division index (NDI) values declined in a dose–response manner (P < 0.01). In the same concentrates, the frequency of micronucleus of normal ambient air PM_2.5 and its extract were significant higher than those of sand dust storm PM_2.5 (P < 0.01) except the treatment of Wuwei sample at higher doses, the treatment of inorganic extract of PM_2.5 at the highest dose (300 μg ml⁻¹) and the treatment of organic extract of PM_2.5 at the higher dose (40 and 80 μg ml⁻¹) either in Baotou or in Wuwei (P > 0.05). The toxicity of sand dust storm PM_2.5 and its extract at high dose is very potent. The frequency of micronucleus of normal PM_2.5 (include its organic extract) from Baotou were higher than those of Wuwei especially in low and middle dose (P < 0.05), but the treatment results of sand dust storm PM_2.5 (include its all extract) was not significantly different between the towns (P > 0.05).