Abstract

Water used in maternity centres may contribute to environmental exposure through bathing, hand washing, cleaning and handling of reusable materials. This study assessed the physicochemical quality, including heavy-metal concentrations, of water used in selected maternity centres in Rivers State, Nigeria. Water samples were collected monthly for twelve (12) months from six maternity centres, comprising two centres in each of the Rivers East/Central, Rivers South East and Rivers West senatorial districts of Rivers State. Physicochemical parameters, heavy metals, seasonal and quarterly patterns, t-test comparisons and Pearson correlations were evaluated. Seasonal mean pH increased from 5.082 in the dry season to 5.780 in the wet season, while dissolved oxygen decreased from 1.857 to 1.306 mg/L. Electrical conductivity had similar seasonal means, 93.084 and 93.236 microS/cm, but a wider wet-season range. Nitrate increased from 0.424 to 0.442 mg/L, phosphate from 0.0049 to 0.0056 mg/L and total organic carbon from 0.052% to 0.054%. Out of 44 physicochemical ANOVA comparisons, 42 were significant at . Cadmium, chromium, arsenic and mercury were reported at 0.001 mg/L in the seasonal summaries, while iron and lead showed variation. Iron decreased from a dry-season mean of 0.0261 mg/L to 0.0253 mg/L in the wet season, and lead decreased from 0.0042 to 0.0034 mg/L. The highest monthly senatorial-district mean iron concentration occurred in Rivers South East in April (0.0835 mg/L), while the highest corresponding lead concentration occurred there in February (0.0155 mg/L), exceeding the WHO provisional guideline value of 0.01 mg/L. Heavy-metal ANOVA results were significant in 12 of 14 comparisons. Quarterly summaries showed that pH and nitrate were highest in Q3, electrical conductivity and total organic carbon in Q2, dissolved oxygen in Q1, and iron and lead in Q1. Significant t-test results were observed for iron, electrical conductivity and pH. Pearson correlation showed moderate positive relationships between electrical conductivity and total organic carbon (, ), iron and lead (, ), and dissolved oxygen and iron (, ), while dissolved oxygen and electrical conductivity were negatively correlated (, ). Rivers East/Central had the most favourable maximum monthly district-mean lead concentration (0.0070 mg/L), below the WHO benchmark, whereas Rivers West (0.0125 mg/L) and Rivers South East (0.0155 mg/L) exceeded it, with the greatest departure in Rivers South East. The water therefore did not consistently meet the lead benchmark, despite seasonal means below that value. Acidic water and episodic lead elevation support facility-specific monitoring and investigation of water supplies and plumbing; chemical results alone do not establish suitability for all maternity-care uses.