Groundwater arsenic in Chimaltenango, Guatemala

Area of Science:

• Environmental Science
• Public Health
• Hydrogeology

Background:

• Groundwater contamination by inorganic arsenic is a global health concern.
• The Municipality of Chimaltenango, Guatemala, relies on groundwater for its drinking water supply.
• Naturally occurring arsenic in tertiary volcanic rock layers can contaminate water sources.

Purpose of the Study:

• To assess total inorganic arsenic concentrations in groundwater within the Municipality of Chimaltenango.
• To evaluate potential health risks associated with arsenic exposure from drinking water.
• To identify the geological source of elevated arsenic levels.

Main Methods:

• Collected 42 groundwater samples from 27 wells across the municipality for spatial representation.
• Analyzed samples for total inorganic arsenic concentration.
• Conducted a health risk assessment and geological source identification using US Geological Survey and GPS data.

Main Results:

• One site, Cerro Alto, exceeded the World Health Organization's guideline (10 μg/L) with an average concentration of 47.5 μg/L.
• Health risk assessment indicated increased noncarcinogenic and carcinogenic risks for residents in Cerro Alto.
• Cerro Alto was the only sampled site located within a tertiary volcanic rock layer, a known arsenic source.

Conclusions:

• Groundwater in Cerro Alto presents a significant health risk due to elevated arsenic levels.
• The tertiary volcanic rock layer is identified as the source of naturally occurring arsenic.
• Recommendations were made to mitigate arsenic levels in the community's drinking water to manage health risks.