One of the chief culprits was a humongous increase in particulate matter such as soot , whose presence in air is linked to a range of health issues .
主要起因之一是煤烟等微粒物质大量增加,空气中的煤烟与一系列健康问题有关。
Scientists have known for a long time that aerosols such as soot , dust and other small particulate matter , alter cloud density and the radiative balance of the atmosphere .
科学家们很早之前就发现,诸如煤烟、灰尘和其他细小的微粒,能改变云体的密度及大气的辐射平衡。
But studies have shown that high-efficiency particulate air ( hepa ) filters on most jets today can capture 99.97 % of bacterial and virus-carrying particles .
但研究表明,如今大部分飞机上的高效微粒空气过滤器能够滤掉99.97%的细菌和病毒微粒。
Steps include frequently washing bedding and stuffed toys in hot water , maintaining low humidity , regularly using a vacuum with a fine filter such as a high-efficiency particulate air ( hepa ) filter , and replacing carpeting with hard flooring .
While anthracite , a purer , cleaner coal sends out little particulate in the air , the increase in coal burning -- along with increased wood burning , including green wood -- has raised pollution concerns in some communities .