Water quality and heavy metal levels in the Sinú River, a drinking water source in the Colombian Caribbean

Abstract

The objective of this work was to evaluate water quality in the Sinú River in northern Colombia, duringits dry and rainy seasons. The water quality index (WQI), the heavy metal pollution index (HPI),the heavy metal evaluation index (HEI), the heavy metal toxicity load (HMTL), and the degree ofcontamination (Cd) were calculated based on analyses of water samples taken along the entire lengthof the river at sixteen sampling sites. Comprehensive and in some cases punctual samplings wereperformed depending on the morphology of the current. Five samplings were carried out in the dry andrainy periods from March 2008 to April 2009. All samples were taken in triplicate at each samplingsite. For the determination of metals, a Thermo electron atomic absorption spectrometer, modelS4AA System was used. Of the metals monitored, only zinc, iron, and manganese were identified atquantifiable levels, with average values of 8.5 x 10⁻⁵ kg m-3, 0.004 424 kg m-3 and 8.5x10⁻⁵ kg m-3,respectively in the rainy season. The obtained index values altogether (WQI =63.5, HPI=145, HEI=24, HMTL=0.1329, and Cd= 20.8) revealed the presence of contamination by heavy metals in the Sinú River, although the observed toxicity level does not imply a hazard to human health.