Severe Particulate Pollution in Lanzhou China

摘要

Concentrations of total suspended particles (TSP) and PM(sub 10) in Lanzhou China have been kept high for the past two decades During intensive observational period from October 1999 to April 2001, the concentrations of TSP and PM(SUB 10) are even increasing and becoming major air pollutants; the temporally total mean PM(SUB 10) concentration is 2%56 mg m(exp -3)(exp -3) The rate of PM(SUB 10) polluted-day occurrence to is 71% in a year, 89% in the winter, and 79% in the spring. Starting from November, the PM(SUB 10) pollution intensifies, and reaches mid to high alert level of air pollution, continues until April next year, and is at low alert level in the summer. The temporally total mean TSP concentration is 5.92 mg m(exp -3). In the winter and spring, the TSP concentration is 2-10 times higher than the third-level criterion of air quality (severe pollution). Intrinsic factors (sources of pollution) and exterior preconditions (propagation of dust storms) for severe PM(SUB 10) and TSP pollution are investigated.