Table 1.

Sample number of different groups among the three areas

Area of incidence	County	Healthy (group I)	Gastric cancer (group II)	Other tumor (group III)
High	Changle	100	41	3
	Putian	52	39	14
Middle	Shaxian	95	14	15
Low	Fuan	49	15	16
Total		296	109	48