[Distribution, hazard evaluation, and control measures of allergenic airborne pollen]. / è‡´æ•æ€§æ°”ä¼ èŠ±ç²‰çš„åˆ†å¸ƒã€å±å®³è¯„ä»·åŠé˜²æ²»æŽªæ–½.

Allergenic airborne pollen can induce hay fever such as rhinitis and asthma. Many studies have been conducted on the allergenic pollution caused by airborne pollen. We synthesized available studies to summarize the temporal and spatial distributions of airborne pollen and influencing meteorological factors. We further summarized and discussed the hazards of airborne pollen sensitization on human health and evaluation indicators for classifying hazard levels. We described the research progress of prevention and control measures of airborne pollen induced pollution from the perspectives of source control, route monitoring, and prevention of susceptible population. Considering the limitations of current studies, we proposed some research directions on allergenic airborne pollen. The types of allergenic plants needed to be clearly identified and allergentic potential should be quantitatively identified. The methods of pollen collection and concentration monitoring needed to be improved and standardized. This review could provide a scientific guidance for the study on preventing and treating pollen allergies as well as optimizing urban green space planning.

[Seasonal Dynamics of Airborne Pollens and Its Relationship with Meteorological Factors in Beijing Urban Area].

The seasonal dynamics of airborne pollens and their relationship with meteorological conditions, which are considered to be important factors for appropriate construction of urban green system and reliable prevention of tropic pollinosis, were investigated in Beijing urban area. The airborne pollens were monitored from December 31st 2011 to December 31st 2012 by Burkard volumetric trap, and the data were analyzed. The results revealed that: (1) In 2012 the pollen dispersion period lasted 238 days from March 17 to November 18th, accounting for 65% of the year. There were two peaks of pollen amount in air, which occurred from March to May and from August to October, respectively. In the spring peak, tree pollens such as Oleaceae, Populus and Salix pollens were the dominant, accounting for 53% of the total annual pollens, while in the autumn period, weed pollens such as Compositae, Chenopodiaceae and Amaranthaceae pollens made up about 40% of the annual total value; (2) The highly allergenic weeds pollens dominated in autumn, which caused a high incidence of tropic pollinosis; (3) The airborne pollen amount of Beijing urban area was significantly affected by meteorological condition like the wind speed, temperature, humidity, precipitation and so on; (4) When temperature ranged from OC to 15 degrees C, the pollen amount showed positive relation with temperature; while in the temperature range of 18 degrees C to 30 degrees C, it showed negative relation; (5) The average temperature of spring and autumn season in 2012 was 17 degrees C, and 79% of airborne pollens were detected in these two seasons. This temperature condition was conducive to the pollen dispersion. (6) The pollen amount showed negative relation with relative moisture between 20% and 50% and larger than 70%, while in the moisture range of 50% to 60%, it showed positive relation; (7) The wind speed smaller than 3 m x s(-1) was good to pollen distribution, when it was larger than 4 m x s(-1) or the wind lasted for a long time, the pollen amount in the air would decrease; (8) The pollen release was decreased by the rain. The above results can be helpful to forecast the pollen amount in the air. monitoring; pollen amount

[Impacts of reclaimed water irrigation of urban lawn on groundwater quality].

Based on long-term monitoring of groundwater and irrigation water quality, the dynamics of the main physicochemical property and pollutant concentration of groundwater influenced by reclaimed water irrigation were examined in this study. The results of our five-year continuous study showed that the ammonium nitrogen concentration in reclaimed water ranged 0.05-65.4 mg x L(-1) with an average of 12.0 mg x L(-1), which exceeded the urban miscellaneous water quality standards for urban greening (GB/T 18920-2002). The total nitrogen in reclaimed water averaged at 28.3 mg x L(-1), ranging from 2.56 mg x L(-1) to 78.0 mg x L(-1), which was also relatively high. The groundwater quality indexes were normal with small fluctuations under tap-water irrigation. The influence of lawn irrigation with reclaimed water on the groundwater water quality was significant in the shallow well with a depth of 6 m, but not obvious in the deep well with a depth of 20 m. The greatest change was found in the enhanced value of nitrate concentration. The nitrate nitrogen concentration in shallow underground water had significantly positive correlation but lagging with the concentration of dissolved nitrogen in the irrigation reclaimed water, which indicated that lawn irrigation with reclaimed water might cause nitrate nitrogen pollution in shallow underground water. Therefore, considering the huge water consumption for the urban greening, it is suggested that the criteria of reclaimed water reuse should be further improved to avoid the risk of environmental pollution.