# Effect-Based Assessment of the Quality and Potential Presence of Hazardous Chemical Pollutants in Drinking and Potable Water in Mexico City

## TL;DR

This study assesses drinking water quality in Mexico City using bioanalytical tools, finding low levels of harmful chemical activity compared to international standards.

## Contribution

First application of effect-based methods to assess water quality in Mexico, comparing results to international benchmarks.

## Key findings

- Aryl hydrocarbon receptor activity and androgen receptor inhibition were detected in tap and filtered water.
- Estrogen receptor activity was highest in jug container water samples.
- Bioactivities were present but concentrations were below international thresholds and proposed trigger values.

## Abstract

Effect-based methods (EBMs) are bioanalytical tools detecting
bioactivity
of chemical mixtures on different toxicological end points. EBMs have
become increasingly important for water quality assessment and monitoring,
particularly in Europe and Australia. To date, their application has
not been reported for the assessment of water in Mexico, where tap
water is often not consumed as drinking water due to perceived concerns
of pollution from the distribution system. In this study, a battery
of EBMs was applied to assess the quality of drinking and potable
water from Mexico City and surrounding states. The results were compared
with international reports and proposed effect-based trigger (EBTs)
values. Aryl hydrocarbon receptor bioactivity and androgen receptor
(AR) inhibition were detected in tap water and household-filtered
water. Estrogen receptor activity was observed in most of the samples,
with the highest levels detected in water from the jug container.
No bioactivities were detected for AR activity, genotoxicity, or oxidative
stress. Although some of the samples were bioactive, the calculated
bioanalytical equivalent concentrations (BEQs) were generally below
the reported BEQs from other countries and below the proposed EBTs
for drinking water. These findings indicate that the tested drinking
and potable water sources in the surrounding states of Mexico City
are of good quality.