The Buddhist cave temple complex at Yungang in northern China is affected by rapid accumulation of airborne particles that settle onto the thousands of statues contained within those caves. Experiments have been conducted that seek to identify the most important air pollution sources that contribute to that dust deposition problem. The spatial distribution of the deposition rate of airborne particles within a 2 km by 2 km area surrounding the grottoes was measured during a 2-day period in April, 1991. Peak particle deposition rates of over 60 µg/m2-sec were found at locations within the village of Yungang itself and along the adjacent coal-haul highway. Moving away from the village and coal-haul highway, deposition rates decline to much lower values, indicating that the village and highway are significant sources of airborne particles. Comparison of the mineralogical composition of the dust deposits in the caves to the composition of local soil dust, paved road dust from the coal-haul highway, and deteriorated cave ceiling rock material indicates that the dust deposits in the caves are a combination of the above sources, with the paved road dust from the coal-haul highway providing the closest match to the largest quantity of the material deposited in the caves.
Lynn Garry Salmon <>{