Table 2.

Descriptive information on arsenic concentration (mg/L) in different water types and water used for consumption in years 2000 and 2008 of unmatched and matched case–control studies

Arsenic level in water variables	Unmatched case–control study				Matched case–control study
	Mean	SD	Min	Max	Mean	SD	Min	Max
Arsenic level (mg/L) in different water types in year 2000
Municipal tap	0.0058	0.0049	0.0009	0.0110	0.0057	0.0049	0.0009	0.0110
Well	0.5383	0.7636	0.0009	8.5830	0.5176	0.7619	0.0009	8.5830
Village tap	0.0402	0.0413	0.0009	0.0920	0.0421	0.0439	0.0009	0.0980
Rain	0.0217	0.0304	0.0009	0.0730	0.0173	0.0277	0.0009	0.0730
Bottleda	0.0000	0.0000	0.0000	0.0000	0.0000	0.0000	0.0000	0.0000
Arsenic level (mg/L) in different water types in year 2008
Municipal tap	0.0281	0.0426	0.0009	0.1120	0.0307	0.0429	0.0009	0.1050
Well	0.1214	0.1350	0.0009	0.3290	0.2264	0.2923	0.0009	1.1070
Village tap	0.0605	0.0588	0.0009	0.1500	0.0808	0.0915	0.0009	0.2470
Rain	0.0217	0.0304	0.0009	0.0730	0.0173	0.0277	0.0009	0.0730
Bottleda	0.0000	0.0000	0.0000	0.0000	0.0000	0.0000	0.0000	0.0000
Arsenic level (mg/L) of water used for consumption in year 2000
Drinking	0.0125	0.0208	0.0000	0.0670	0.0143	0.0225	0.0000	0.0670
Cooking	0.1532	0.3055	0.0000	1.0700	0.1010	0.1954	0.0000	1.0700
Teeth brushing	0.2772	0.3613	0.0000	1.3510	0.3685	0.4646	0.0000	1.3510
Arsenic level (mg/L) of water used for consumption in year 2008
Drinking	0.0495	0.0551	0.0000	0.1410	0.0433	0.0509	0.0000	0.1410
Cooking	0.1532	0.3055	0.0000	1.0700	0.0395	0.0497	0.0000	0.1410
Teeth brushing	0.0964	0.0951	0.0009	0.3020	0.1873	0.2224	0.0009	0.7270

Note:

^aPresumed, not measured.

Abbreviations: SD, standard deviation; Min, minimum; Max, maximum.