The shorthand for that is PM2.5, which are fine particles that are 2.5 microns or smaller across.

其简称为“ PM2.5”，即直径为 2.5 微米或更小的微粒。

And within hours to days, it converts to very fine particles, which scatters sunlight, causing that visible haze.

在几个小时到几天的时间里，它转化为极为细小的微粒，分散阳光，造成可见的雾霾。

Passive smoking exposes non-smokers to most of the same toxic gases, chemicals and fine particles that smokers inhale.

非吸烟者会接触到二手烟中的大部分有害气体，化学物质和细颗粒物。

The information is based on satellite data used to estimate the effects of increased airborne fine particles on life expectancy.

这些信息基于卫星数据，研究人员利用这些数据估计空气中细颗粒物增加对预期寿命的影响。

First, scientists melted the snow and then filtered it for fine particles.

首先，科学家们将雪融化，然后过滤掉细小的颗粒。

The greatest health risk comes from what is known as PM 2.5, the range of fine particles that are less than 2.5 microns in diameter.

其中，对健康威胁最大的是pm2.5，即直径小于2.5μm的细颗粒物。

According to Ginger Krieg Dosier, the firm's boss, the result is better than conventional cement at binding fine particles together.

根据该公司老板 Ginger Krieg Dosier 的说法，该产品在将细小颗粒粘合在一起方面优于传统水泥。

Those large, chunky, woody pieces and those are actually added back to the compost process and we'll continue to break those down until they're nice fine particles.

那些又大又粗的木块实际上会被添加到堆肥过程中，我们会继续分解它们，直到它们变成细小的颗粒。

These molecules oxidize to form sulfates, which condense with water vapor in the air to form a blanket of fine particles that impair visibility and cause severe lung damage.

这些分子会氧化，形成硫酸盐，并与空气中的水气结合，形成厚厚一层微粒子，降低能见度并造成严重的肺部损伤。