Esophageal Cancer
Copyright ©The Author(s) 2003.
World J Gastroenterol. Jun 15, 2003; 9(6): 1187-1190
Published online Jun 15, 2003. doi: 10.3748/wjg.v9.i6.1187
Figure 1
Figure 1 Time trend of nitrate nitrogen in relation to the farming use of nitrogen fertilizer in Cixian County and Chichen County.
Figure 2
Figure 2 Time trend of nitrite nitrogen in relation to the farming use of nitrogen fertilizer in Cixian County and Chichen County.
Figure 3
Figure 3 Time trend of ammonia nitrogen in relation to the farming use of nitrogen fertilizer in Cixian County and Chichen County.