The concentration of air PM10 in six types of green lands in campus of Tsinghua university was measured. The results showed that PM10 concentration exhibited obvious daily and monthly variation,and also had remarkable difference among different seasons. However there was no remarkable difference in concentration of PM10 within the same season over all types of green lands. As for average concentration,the value was lower in arbor land of spring,autumn and winter,and in lawn of summer. The concentration of PM10 was 43% higher in cloudy days than that of sunny ones. Moreover,the difference increased to 137% between cloudy day after raining and sunny day after raining because of the clarification of rain.
Questionnaire survey was taken,the plant-caused pollution in 4 typical cities including Beijing,Hefei,Chengdu and Guangzhou was studied.Differences of three kinds of plant-caused pollution such as pollen,flying hair and catkin,and smell between different cities and different people were analyzed.The results are as follows:the plant-caused pollution has obviously regional distribution features.The rate of plant-caused pollution is 5.72% in Beijing,0.59% in Chengdu,2.12% in Hefei and 2.11% in Guangzhou.The order of the number of three kinds of plant-caused pollution allergen is pollen>flying hair and catkin>smell.The allergen caused by pollen and flying hair and catkin gathers largely in March to June.The allergen caused by smell gathers largely in summer.The whole condition of the allergen is female>male,and most of them are 20 to 50 years old.The results provide basis for the further research,and are also helpful for prevention of plant-caused pollution in urban area.
