Research says PM0.5 air concentrations of number bigger than PM2.5 hazard accounted for about 90%

s fudan study found PM0.5 is likely to spread in the alveolar, sedimentary

s and accounted for about 90% of the number of air concentration

group

the

according to the Oriental morning post reported, in a certain city in north China was measured by 0.25 ~ 10 microns (namely PM0.25 ~ PM10) within the scope of 23 different size set of particle number concentration, analysis and comparison of their relationship to residents' health risks.


all kinds of fine particles of a harm to human body.

conclusion

grain size in the range of 0.25 ~ 0.50 microns particle number concentration and residents health hazard, especially the relationship between cardiovascular disease is the most significant, and the smaller the particle size, the greater the health hazards.

size is greater than 0.50 micron particle number concentration were not significantly associated with a resident health risks.

speculation

size is less than 0.50 microns particles mainly deposited in spreading way, run into the lungs. And a size greater than 0.50 micron particles mainly deposited in impact way, will stay in the respiratory tract.

PM2.5 has long been regarded as air pollution and human health caused by the culprit, but yesterday, according to the news of fudan university PM0.5 harm to human body health is very significant, and it accounts for about 90% of the number of air concentration.

yesterday, Shanghai fudan school of public health, atmospheric particulate matter pollution prevention and control of key laboratory of professor hai-dong kan team progress in the field of atmospheric particulate matter pollution and health studies, found that the diameter of less than or equal to 0.5 micron particles (PM0.5) very significant harm to human body health, the related papers have been published in the public health authority journal environmental health perspectives.

according to the paper, first the author Meng Xia introduction, more serious fog weather in our country in recent years, is one of the most often mentioned pollutants PM2.5. But the smaller particle size of particulate matter how health hazard, has not been determined. Group in a certain city in north China was measured by 0.25 ~ 10 microns (namely PM0.25 ~ PM10) within the scope of 23 different size set of particle number concentration, analysis and comparison of their relationship to residents' health risks. , says Yang Xin, a professor at the fudan university environmental science and engineering focuses on TSP to 2012 from 2000 PM10, now focus on PM2.5, following what size of particulate matter most harmful for people's health, is a question of the study.

professor hai-dong kan group residents total death risk of death compared with the relationship of different diameter particles, the results showed that particle size in the range of 0.25 ~ 0.50 microns particle number concentration and the residents' health hazards, especially the relationship between cardiovascular disease is the most significant, and the smaller the particle size, the greater the health hazards. And a size greater than 0.50 micron particle number concentration were not significantly associated with a resident health risks.

Meng Xia etc. The researchers speculate that the smaller the particle size, the number of the corresponding concentration and the total surface area is larger, the more likely it is adsorbed more harmful substances into the human body; May also be with different size particles in the respiratory tract of settling way, particle size is less than 0.50 microns particles mainly deposited in spreading way, run into the lungs; And more than 0.50 micron particles mainly deposited in impact way, will stay in the respiratory tract.

"PM7 can enter the nose, throat PM4.7 ~ 7 can arrive, PM2.5 can reach the bronchus, and PM1 can reach the alveoli, PM0.5 probably diffusion, deposition in the alveoli." Professor Yang Xin added. Automobile exhaust, mainly diesel exhaust emissions of black carbon particles, and sulfate, nitrate and other secondary pollutants are PM0.5 source.

from the perspective of the mass concentration in the air PM0.5 percentage is very low, but in terms of the number concentration, PM0.5 accounted for the proportion of very high, almost 90%. The findings suggest that particulate matter in the health hazard of the larger may be small particle size (e.g., less than or equal to 0.5 microns), part number, not part of the large particle size, mass.

professor hai-dong kan said, we can study in Canada and other countries the experience of prevention and cure, change the current air quality index (AQI) to air quality health index (AQHI), through the association between air quality and human health index, guiding the health behavior of the people.