Objective        To explore the characteristics of the main harmful factors in tank cabins during marching

and to provide scientific data for further protective studies.       Methods        Three tanks with the same conditions were subjected randomly and run at 20 km/h over 60 min on sandy path. The concentrations of main gases in the cabin including oxygen (O

2

)

hydrogen sulfide (H

2

S)

carbon monoxide (CO)

hydrocyanic acid (HCN)

chlorine gas (Cl

2

)

carbon dioxide (CO

2

)

sulfur dioxide (SO

2

)

ammonia (NH

3

)

nitrogen dioxide (NO

2

)

combustible gas (represented by CH

4

) and total volatile organic compounds (TVOC) were monitored with Draeger X-am portable gas detectors during marching. Volatile organic gases (VOCs) were sampled with vacuum SUMMA cans at 0

20

40 and 60 min during marching and measured qualitatively and quantitatively with GC/MS. The concentration of the dust

the level of noise and intensity of electromagnetic radiation in the tanks were monitored with LB-FC hand-held dust detector

TES 1352H sound level meter and TES-92 Electro Smog Meter

respectively.        Results        CO

2

NH

3

NO

2

and TVOC were detected

and the concentrations increased significantly along with the marching time (P0.01). There were 122

122

155 and 154 kinds of VOCs at above 4 time points

respectively

and 66 kinds of VOCs had been detected at each time point

in which alkanes and benzenes were major constituents. The concentration of toluene at 60 min were significantly higher than that at 0 min (23.6±4.3 vs 11.1±2.0  g/m

3

P0.01)

and the concentrations of ethyl benzene at 40 and 60 min were significantly higher than that at 0 min (28.1±14.3 vs 12.2±0.5  g/m

3

P0.05; 31.7±2.1 vs 12.2±0.5  g/m

3

P0.05). Dust concentration increased along with the marching time and the peak concentration was 194.28 mg/m

3

. The intensities of noise at 20

40 and 60 min were significantly higher than that at 0 min (105.4±4.8 vs 91.4±7.1 dB

P0.05; 104.9±5.6 vs 91.4±7.1 dB

P0.05; 105.4±5.2 vs 91.4±7.1 dB

P0.05). The intensity of electromagnetic radiation at each state was quite low

and the intensity at the state with all instruments running was significantly higher than that at the rest state (525.8±365.3 vs 3.7±0.2 mV/m

P0.01).       Conclusion        There are many kinds of harmful occupational factors in tanks during marching

and in which harmful gases

noise and total dust pollute were most seriously. The concentrations of main harmful gases and total dust increase along with marching time

and the combined effects of them may influence soldiers’ health and work ability.