Evaluation of Water Quality and the Potential Ecological and Health Risk in the Cajititlán Lagoon

Water security threatens the world's population, so the evaluation of the water quality of water bodies is one of the critical issues and is a current challenge to ensure the sustainability of ecosystems and human population.

Objective: The aim is to estimate the physicochemical parameters and heavy metals of the water of the Cajititlán Lagoon during the period 2009-2023, to evaluate its water quality, ecological and health risks. The results will supply valuable information on water quality management and human health protection.

Study Design: Ecological study, using water quality, pollution, ecological and health risk indices.

Place and Duration of the Study: Cajititlán Lagoon during the period 2009-2023.

Methodology: The water quality data of Lagoon Cajititlán were obtained through the State Water Commission of the government of the State of Jalisco. The analyses were performed monthly from 2009 to 2023. CWQI, WQI, NP, HPI, HEI, DC, PERI, HQ, HI, THI, CR and TCR indices were then calculated to find water quality and ecological and health risks.

Results: The distribution of parameter concentration showed a drastic spatial variation, but not temporal. The TDS, Turbidity, pH, F, Al, As, Cr, Cu, Mn, Ni, Pb and Zn showed percentages above the CCME regulations, however most are within the NOM-001-SEMARNAT-2021. The heavy metals Al, Cr, Ni, Pb, Zn and As are those that present the % concentration of more than 100% with respect to the international standard. The remaining 14 parameters are within both national and international standards. Pearson's correlation analysis showed that most heavy metals have positive correlations with each other, except for Cr, Pb and Cu. Water quality according to WQI of 112 was categorized as poor-quality, while for CWQI all uses except livestock, water quality is poor (20-35). According to the NP index (0.19 to 670), heavy metal concentrations showed high contamination levels. The HPI index (89) showed moderate to elevated levels of heavy metal contamination. The HEI index showed levels <10, showing low pollution. The DC presented a value of 4, classified as a high degree of contamination. The PERI index showed that the ecological risk from heavy metals is high. Non-carcinogenic risk indices show that lagoon water is not suitable for drinking, and poses a high health risk via ingestion, while dermal contact poses no health risk to residential and recreational recipients. The results say that As would not pose a carcinogenic risk to residents and recreational receptors in different surface waters, while Cr may pose a slight carcinogenic risk to recreational receptors.

Conclusions: According to the indices of water quality, ecological risk and health, the water quality of the Cajititlán Lagoon is poor, with a high degree of contamination and stands for ecological and health risks (non-carcinogenic).