3International Tea Committee. Annual bulletin of statistics [ M ] London : International Tea Committee Ltd,2013.
4Han W Y, Zhao F J, ShiYZ, etal. Scale and causes of lead contamination in Chinese tea [ J ]. Environmental Pollution, 2006, 139(1) : 125 - 132.
5Han W Y, ShiY Z, Ma L F, et al. Effect of liming and seasonal variation on lead concentration of tea plant ( Ca- mellia sinensis ( L. ) O. Kuntze) [ J ]. Chemosphere, 2007, 66(1): 84-90.