Abstract: Atmosphere, soil and vegetable samples (56 for each) were collected along 4 highway profiles in Guilin suburbs to analyze the mercury (Hg)concentration, aimed to understand the situation of Hg pollution from automobile exhaust in the suburbs. The Hg concentration along the highway profiles all exhibited a symmetrical single-peaked distribution, and the diffusion range of automobile exhaust Hg was approximately 200 m. The soil and vegetable Hg had close relations with atmosphere Hg, and the automobile exhaust Hg contamination degree of the highway profiles increased with increasing road age and vehicle flow. The Hg contamination of the highway profiles was considered to be mainly come from the Hg in fuel oil. According to the National Soil Environmental Quality Standard of China for non-pollution vegetables, the Hg concentration in 48% of the soil samples was above its maximum allowable concentration. The Hg concentration in the vegetables along the Guiyang highway profile was 10-70% times higher than the threshold value (0.29±0.03 μg·g^-1) of the National Standard for non-pollution agricultural products. This study showed that the highway profiles in Guilin were moderately contaminated by mercury.

Key words: Hybrid tilapia, Growth, Ration level, Body weight