Assessment of Water Quality, Ecological and Health Risks of Inland Water Bodies in Mexico: A Case Study of Lake Chapala

Water security threatens the world's population, so the assessment of the quality of water in reservoirs is one of the priority issues and represents a challenge for the sustainability of ecosystems and the human population. The aim is to evaluate the physicochemical parameters and heavy metals of the water of Lake Chapala to evaluate its water quality, during the period 2010-2023, and to estimate the ecological and health risks. The results will provide valuable information on water quality management and protection of human health. The design is an ecological study, using water quality, pollution risk, ecological and health risk indices. The place and duration of the study is the Lake Chapala during the period 2010-2023. The methodology consisted of obtaining the quality data of the Water Lake Chapala through the State Water Commission, the National Water Commission and studies conducted by the University of Guadalajara. The analyses were conducted on a monthly basis from 2010 to 2023. Subsequently, the CWQI, WQI, NP, HPI, HEI, DC, PERI, HQ, HI, THI, CR and TCR indices were calculated to determine water quality and ecological and health risks. The results showed que the distribution of parameter concentration showed great spatial variation, but not temporal; the TDS, Turbidity, pH, Al, As, Cr, Cu, Mn, Pb and Zn with percentages above the CCME standard, but most of them within the NOM-001-SEMARNAT-2021. The heavy metals Al, As, Cr, Pb and Zn have concentration percentages 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 none of the trace elements have positive correlations with each other. Water quality according to the WQI of 178 was categorized as poor quality, while for the CWQI almost all uses except grazing, water quality is poor (20-35). According to the NP index (3.8 to 670), the concentrations of heavy metals showed high levels of contamination. The HPI index (88.6) showed moderate to high levels of heavy metal contamination. The HEI index showed <10 levels, indicating low contamination. The DC had a value of 0.2-18.2, classified as a high degree of contamination. The PERI index showed that the ecological risk from heavy metals is high. Non-carcinogenic risk indices indicate that lake water is not suitable for drinking, and poses a high health risk via ingestion, while dermal contact does not pose a health risk to residential and recreational recipients. The carcinogenic risk index is negligible to acceptable. The conclusion is according to the water quality, ecological and health risk indices, the water quality of Lake Chapala is poor, with a high degree of contamination and represents ecological and health risks (non-carcinogenic). It is recommended that the use of lake water does not include its ingestion to avoid health problems, and it is important to take measures to sanitize the lake to avoid ecological and health risks.