Study on the Relationship between Manganese Concentrations in Rural Drinking Water and Incidence and Mortality Caused by Cancer in Huai’an City

Table 3

The comparison of superscale ratio of Mn in drinking water.

Variable	Superscale		Qualified
		%		%
Counties
Chuzhou county	46	80.70	11	19.30	3.86	0.15
Jinhu county	46	77.97	13	22.03
Xuyi county	27	64.29	15	35.71
Periods
High flow period	45	53.57	39	46.43	45.62	0.00
Low flow period	74	100.00	0	0.00
Sources
Surface water	41	87.23	6	12.77	10.66	0.01
Shallow groundwater	44	80.00	11	20.00
Deep groundwater	34	60.71	22	39.29
All	119	75.32	39	24.68