Contamination of the Conchos River in Mexico: Does It Pose a Health Risk to Local Residents?

Abstract: A Water Quality Index (WQI) is a simple numeric expression reflecting the quality of water in any ecosystem at a given time. The objective of this study was to develop a WQI for the man-made dam Francisco I. Madero located in Chihuahua, Mexico. Eight points were randomly selected in the dam area and at each point water samples were collected monthly from March 2011 to February 2012 at three depths; 0.30 m, 5 m and 10 m. The following physical-chemical variables were measured: potential hydrogen (pH), electrical conductivity (EC), dissolved oxygen (DO), temperature (T), turbidity, total dissolved solids (TDS), total hardness (TH) and chlorides (Cl-). In a first step for data analysis, an analysis of variance (ANOVA) was performed for each variable considering a factorial treatment design 12 × 3 in which factor A was the month with 12 levels (sampling months) and factor B was the depth with three levels (0.30 m, 5 m and 10 m). In a second statistical step, the WQI was calculated for each month only for the surface sampling (0.30 m) and the resulting value was classified under three categories; 2.5 as excellent water. The results showed the following ranges for single variables: pH of 7.63 - 10.65, EC of 190 - 320 μS·cm-1, DO of 1.30 - 12.1 mg·L-1, T of 11.30°C - 30°C, Turbidity of 0-1, 120 NTU, TDS of 170 - 220 mg·L-1, TH of 240 - 900 mg·L-1 and Cl- of 7.28 - 7034 mg·L-1. The calculated WQI demonstrated that water quality varies seasonally and was classified as poor in the rainy season to good in winter season. We conclude that in general the water from the dam is acceptable and suitable for ecological and a broad spectrum of other purposes.

TL;DR: Overall, it is possible that swimmers are exposed to risk via the dermal route when carrying out water-related activities, and it is recommended that necessary precautions and management should be taken in other similar locations around the world.

TL;DR: A positive correlation of arsenic contents was found through all sampling seasons in fish samples and the samples of sediment and water and the contribution of the weekly intake of inorganic arsenic was found lower than the acceptable weekly intake suggested by FAO/WHO.

TL;DR: In this paper, the authors evaluated the concentration of Pb, Cd, and Cu in surface waters of the Cotaxtla-Jamapa basin in Veracruz, Mexico.

TL;DR: The literature has been critically reviewed in order to assess the attenuation processes governing contaminants in leachate affected aquifers as discussed by the authors, focusing on dissolved organic matter, xenobiotic organic compounds, inorganic macrocomponents as anions and cations, and heavy metals.

TL;DR: The Integrated Risk Information System (IRIS) is a human health assessment program that evaluates quantitative and qualitative risk information on effects that may result from exposure to environmental contaminants.

TL;DR: Chromium is an essential nutrient required for sugar and fat metabolism and given to people with impaired glucose tolerance or diabetes leads to improved blood glucose, insulin, and lipid variables as well as improving lean body mass in humans and swine.

TL;DR: It is shown that the addition of trace amounts of copper to water given to cholesterol-fed rabbits can induce β-amyloid accumulation, including senile plaque-like structures in the hippocampus and temporal lobe, and can significantly retard the ability of rabbits to learn a difficult trace conditioning task.