Rainwater chemistry as influenced by atmospheric deposition of pollutants in Southern Nigeria

Examines rainwater chemistry as it relates to atmospheric pollution in Southern Nigeria. Rainwater samples were collected and analysed for major cations and anions in Lagos, Ibadan and Port Harcourt, these sites reflecting industrial, residential and oil flaring regions respectively. In general, water samples from Ibadan were about neutral. Correlation studies revealed that HCl and H₂SO₄ dominated the slightly acidic rainwater in the Lagos and Port Harcourt areas respectively. The effect of marine spray from the Gulf of Benin was observed with trace of NaCl. The reaction of the much emitted NH₃ with the available SO₄^2– in the atmosphere produced (NH₄)₂SO₄ which acted as a neutralizer for samples from the Lagos area. The findings suggest that rainwater from most industrial cities of Nigeria are tending towards acidity and if oil flaring activities are not checked, there is a tendency of increasing acidic rainwater in the delta regions. The observation and findings are useful for preliminary assessments of the influence of rapid industrial and urban development on atmospheric pollution and indirectly rainwater constituents.