0188-4999 0188-4999 S0188-49992005000400171 Mexico 00 12 2005 00 12 2005 21 4 171 181

2002 Kwangju, South Korea 1-11 2003 1-11 ASTM 1999 ASTM 2002 1996 416 127-38 2004 1999 96 3427-31 2004 15 y 18 2000 34 87-92 Hach 1997 3 1997 123 800-7 2005 12 271-6 2000 45 1430-4 1977 2 333-45 1995 103 79-88 2001 2 1-16 2004 11 211-6 2001 9 302-5 1997 123 453-9 2005 Puente de Ixtla, Morelos 1997 4 153-6 NMX 2001 OID 2004 1-5 2000 7 261-4 2003 8 16-8 2000 9 25-32 2005 88 237-43 1997 2003 30 1-20 2001 1-3 1992 124 79-110 1992 41 159-67 2002 24 1031-41 WHO 2001