Ecological Risk Due to Heavy Metal Contamination in Sediment and Water of Natural Wetlands with Tourist Influence in the Central Region of Peru

María Custodio,Edith Orellana-Mendoza,Anthony Fow,Samuel Pizarro,Deyvis Cano,Fernán Chanamé,Richard Peñaloza,Juan C Alvarado

doi:10.3390/w13162256

Abstract

In this study, the quality of sediment and surface water in two natural wetlands, Paca and Tragadero, in the central region of Peru was evaluated using pollution indices, including the geoaccumulation index, pollutant load index, modified pollution degree, potential ecological risk index, and site rank index, for four heavy metals. Principal component analysis was used to identify potential metal contaminant sources. The determination of Fe, Zn, Pb, and As was performed by flame atomic absorption spectrophotometry. The average concentrations of metals in the sediments of both lagoons decreased in the order Fe > Zn > Pb > As. The analysis of the contamination indices determined that As and Pb are the elements that contribute the most to environmental degradation in both wetlands. There is a strong correlation between the values of potential ecological risk and the modified degree of contamination, revealing that the Paca wetland has a moderate degree of contamination and potential ecological risk, while Tragadero presents a high degree of contamination and considerable potential ecological risk. The application of the site rank index showed that more than 50% of the sampling sites have between high and severe contamination. The principal component analysis presented 79.2% of the total variance. Finally, the results of this study are essential in order to carry out preventive actions for environmental protection in these lake ecosystems of great importance for many activities, such as bird watching.

Highlights

Contamination of aquatic ecosystems by toxic metals is a worldwide concern due to their toxicity, non-biodegradable nature, persistence, and accumulation in various habitats [1,2]
The results found in the sediment samples indicate that the contamination factors for Pb, Zn, Fe, and As in the Paca and Tragadero lagoons are classified as low, moderate, and very high
There is a strong correlation between the values of potential ecological risk and the modified degree of contamination

Summary

Introduction

Contamination of aquatic ecosystems by toxic metals is a worldwide concern due to their toxicity, non-biodegradable nature, persistence, and accumulation in various habitats [1,2]. Heavy metals have a low solubility, once released into the aquatic environment through various sources [3,4], they are deposited in bottom sediments. The release of heavy metals from sediments into the water column under favorable conditions makes the aquatic environment extremely vulnerable to contamination [1,6,7]. Heavy metals are readily absorbed by organisms, and can bioaccumulate and enter the food chain [8,9] and pose risk to human health and ecosystem integrity [10,11]. Some heavy metals such as iron (Fe) and zinc (Zn) are micronutrients and enzyme cofactors essential for the normal development of biological processes, and only pose a threat to health when they exceed permissible limits

Methods

Results

Conclusion