Microbiological Assessment of Rainwater and Air Quality of Some Areas in Port Harcourt

Abstract

The microbiological quality of Rainwater and air of the market, hospital, and residential area was evaluated. Roof-harvested and direct rainwater samples were collected from the three aforementioned locations. The air quality was investigated using the plate sedimentation method. Culture-based techniques were used for the enumeration and isolation of microorganisms in water samples, while the identities were confirmed using morphological, microscopic, and biochemical tests. The range of the total heterotrophic bacterial counts (THBC) of rainwater was 1.2±7.1x106 to 6.1±1.1 x106 cfu/ml, total coliform count (TCC) ranged between 8.0±0.00 x103 to 30.5 ±2.1 x103 cfu/ml, faecal coliform counts (FCC) ranged between 1.0±0.00×103 to 6.0±0.00×103 cfu/ml, fungal counts ranged from 2.0±0.00x103 to 11.0±0.00x103 cfu/ml.  The THB, TCC, and FCC of the air samples, ranged between 0.04±0.02 to 0.13±0.04 cfu/min-m2, 0.01±0.00to 0.03±0.00 cfu/min-m2, and 0.01±0.00 to 0.02±0.00 cfu/min-m2, respectively. There was a significant difference (P≤ 0.05) in the total heterotrophic bacterial load of the roof-harvested rainwater and the direct rainwater of the residential area, roof-harvested and direct rainwater of the hospital. Statistically, there was a significant difference (P≤ 0.05) in the total coliform counts of the water with the coliform counts of the roof-harvested rainwater of the market being significantly higher than the coliform counts recorded in other locations. Seven bacterial genera belonging to Micrococcus sp, Staphylococcus, Escherichia coli, Proteus sp, Pseudomonas sp, Enterobacter sp, and Bacillus sp were isolated. The fungal isolates were Candida sp, Mucor sp, Rhizopus sp, Penicillium sp, Aspergillus niger, and Aspergillus flavus. The results showed that rainwater is not fit for consumption due to its components and can cause harm to individuals if consumed without treatment. proper treatment is recommended before consumption. The results also showed that the microbiological quality of the air samples was influenced by their environment.