Multi-pathway human exposure risk assessment using Bayesian modeling at the historically largest mercury mining...

Area of Science:

• Environmental Health
• Toxicology
• Risk Assessment

Background:

• Almadén, Spain, hosts the world's largest mercury (Hg) mining district.
• Significant environmental impacts are known, but human health risks remain under-documented.
• Mercury contamination poses a potential threat to local inhabitants' well-being.

Purpose of the Study:

• To conduct a probabilistic human health risk assessment for mercury exposure in Almadén residents.
• To estimate non-carcinogenic health risks via multiple exposure pathways using Bayesian modeling.
• To compare probabilistic and deterministic risk assessment approaches.

Main Methods:

• Analysis of mercury (Hg) levels in environmental samples: vegetables, mushrooms, fish, soil, water, and air.
• Collection of survey data from adult residents to tailor risk models.
• Application of Bayesian modeling for probabilistic human health risk assessment.

Main Results:

• Unacceptable non-carcinogenic risk levels identified through ingestion of Hg-contaminated vegetables (HQ 20x threshold) and fish (HQ 3x threshold) at the 97.5th percentile.
• Risks from mushroom ingestion, soil/water dermal contact, water ingestion, and air inhalation were below safety limits for the 97.5th percentile.
• Probabilistic and deterministic approaches yielded comparable risk estimations.

Conclusions:

• The Almadén population faces significant human health risks from historical mercury mining legacy.
• Dietary intake, particularly of vegetables and fish, is a primary pathway for concerning mercury exposure.
• This study provides crucial data on mercury's health impact on residents, highlighting the need for mitigation strategies.