Abstract:
To clarify the influences of cement production on heavy metal contents in tobacco leaves and surrounding environment, two cement plants located in Huanghuai Plain and Southwest mountainous area were studied. The variations of deposition fluxes of heavy metals in the surrounding atmosphere and the heavy metal contents in surrounding farmland soil and tobacco leaves along with the distance from the cement plants were analyzed. The results showed that the effect of cement production on heavy metal contents in surrounding farmland soil was relatively light. The deposition fluxes of heavy metals in the atmosphere raised at 1.5-3.5 km and 1.0 km away from the cement plants in Huanghuai Plain and Southwest mountainous area, respectively. The maximum/minimum ratios of Pb, Cd, As, Cr and Ni deposition fluxes in the atmosphere were in the range of 1.7-2.8. Comparing with the upper tobacco leaves grown in the upwind direction, the highest contents of Pb, Cd, As, Cr and Ni in upper tobacco leaves in the downwind direction of the cement plant in Huanghuai Plain were 2.26, 3.09, 2.44, 3.72 and 1.78 times, respectively; and the peaks of heavy metal contents in upper tobacco leaves were at 1.0-4.0 km downwind of the cement plant. However, in places surrounding the cement plant in Southwest area, the maximum contents of Pb, Cd, As, Cr and Ni were 1.34, 1.19, 2.32, 3.41 and 4.66 times of the minimum in upper leaves, respectively; and the peaks were at 1.0-1.5 km away from the cement plant. In conclusion, tobacco is a sensitive indicator of atmospheric environment, and the influences of cement plant on plain at monsoon region are larger than those on mountainous area.