Indoor environments: Evaluating air quality in Ulaanbaatar's traditional gers

Area of Science:

• Environmental Science
• Public Health
• Chemistry

Background:

• Ulaanbaatar faces severe air pollution, particularly in ger districts where coal heating is common.
• Approximately 60% of residents live in traditional gers, contributing to indoor air quality issues.
• This study focuses on polycyclic aromatic hydrocarbon (PAH) levels and health risks in ger dwellings.

Purpose of the Study:

• To investigate PAH concentrations and associated health risks in Ulaanbaatar's ger districts.
• To identify key PAH indicators and differentiate between high and low PAH level gers.
• To assess the Incremental Lifetime Cancer Risk (ILCR) from indoor PAH exposure.

Main Methods:

• Sampling and analysis of PAH concentrations in 6 gers.
• Utilized Gradient Boosting Machine algorithm for indicator identification.
• Applied Principal Component Analysis (PCA) and dissimilarity matrix for profile analysis.
• Conducted Incremental Lifetime Cancer Risk (ILCR) assessments for adults and children.

Main Results:

• High concentrations of PAHs, particularly 5- and 6-ring PAHs, were found in most gers.
• Gers 3 and 4 exhibited extremely high total PAH levels (38700 μg/g and 36200 μg/g).
• Pyrene, benzanthracene, and phenanthrene were identified as key PAH indicators; Gers 3 and 4 showed the highest cancer risks.

Conclusions:

• Traditional coal heating in Ulaanbaatar's gers leads to significant indoor PAH pollution and elevated cancer risks.
• Distinct PAH profiles were observed, with Ger 4 showing the most unique characteristics.
• Urgent interventions are needed in Mongolia and similar regions to address indoor air quality and long-term health risks associated with traditional heating.