MAJOR AND TRACE ELEMENTS IN RAIN WATER COLLECTED FROM INDUSTRIAL AND NON-INDUSTRIAL AREAS OF OGUN STATE, NIGERIA

Abstract

Many people rely on collected rainwater for consumption and other daily needs because of non-availability or inadequate supply of pipe borne water in most Nigerian semi-urban settlements. A total of 30 rain water samples were collected from industrial and non-industrial areas of Ogun State Southwest Nigeria. The sampling was done during raining season between June – October, 2013. The rain water samples were analyzed for trace elements using inductively coupled plasma mass spectrometry (ICP/MS). The values of pH, total dissolved solid (TDS) and electrical conductivity (EC) varied widely over five months period. The major elements from non-industrial and industrial areas with exceptionally high mean values are  K (1055 ± 464 µgL-1, 1513 ± 1143 µgL-1 ), Mg (339 ± 123 µgL-1, 309±266 µgL-1), Ca (13125 ± 6173 µgL-1, 11375±8641 µgL-1 ) and Fe (72.5 ± 19.2 µgL-1, 225±81.7 µgL-1) are respectively. The percentage of rain water samples collected from industrial areas which contains Cd and Al concentration in excess of WHO limit in drinking water are 16 % and 50 % respectively. The source of metallic elements recorded in rain water collected from the study area are, different roof types as well as atmospheric suspension of particulate matter containing metals. For rainwater to be suitable for human consumption, at least the pH of such water must be known.