ML-Assisted Olfactory Epidemiology Survey Urbanizing China: A Population-Based Study in Yancheng

Area of Science:

• Environmental Health
• Otorhinolaryngology
• Epidemiology

Background:

• Urbanization in China is associated with increasing air pollution, a potential risk factor for olfactory dysfunction (OD).
• Population-based studies investigating the link between urbanization, air pollution, and OD in China are scarce.
• Understanding OD prevalence and risk factors in diverse populations is crucial for public health initiatives.

Purpose of the Study:

• To investigate the association between urbanization-related factors and olfactory dysfunction in a Chinese population.
• To identify dominant risk factors and distinct phenotypes of olfactory dysfunction.
• To analyze the impact of aging and environmental exposures on olfactory abilities.

Main Methods:

• A cross-sectional study involving 1500 participants in urbanizing Yancheng, China (2023-2025).
• Olfactory function assessed using the Sniffin' Sticks test.
• Machine learning algorithms (XGBoost, k-means clustering) employed for risk factor and phenotype analysis.

Main Results:

• Head trauma (OR=163.04) and chronic rhinosinusitis (CRS, OR=161.39) were identified as the primary risk factors for OD (p<0.001).
• Rural residence showed a significantly lower OD risk (OR=0.011, p<0.0001) compared to urban residence.
• Four OD subtypes were identified: sinusitis-linked, age-related, neurological disorder-associated, and child-specific mild dysfunction. Olfactory ability declined significantly after age 63, with anosmia quadrupling from childhood to elderly age.

Conclusions:

• Head trauma and sinusitis are the most significant risk factors for OD in urbanizing China.
• Urban residence (as a proxy for air pollution) and aging are substantial contributors to olfactory dysfunction.
• Phenotypic stratification of OD is essential for developing targeted interventions and informing environmental and clinical management strategies.