Study on environmental etiology of high incidence areas of liver cancer in China

Table 1 The organic pollution indicators of drinking water and death rate from cancer

The drinking water type	Qidong in Jiangsu					Fusui in Guangxi
	Pond	Channel	River	Shallow well	Deep well	Pond	River	Deep well
Death rate	61.53	58.17	41.99	18.80	0.0	115.05	37.49	0.0
Number of samples	20	18	22	21	16	7	18	25
COD	4.66	3.85	3.55	3.20	1.28	48.27	0.75	0.197
Humic acid	0.43	0.36	0.28	0.18	0.08	0.58	0.18	0.042
NO3-	14.52	18.20	21.46	67.91	1.53	0.74	0.75	0.480
NO2-	0.54	0.48	0.38	0.28	0.04	0.061	0.008	0.0096

The death rate is 1/10⁵ and the unit of NO₃^-, NO₂^- is ppm.