Particulate matter (PM2.5), refers to particles in the air that cause pollution. These particles are from a variety of sources, both indoors and outdoors.

Even at moderate levels, it can still be harmful to sensitive people and the use of a pollution mask is recommended.

Though the atmosphere will always have PM2.5, certain levels are dangerously high. A guide from AIRNow shows that exposure levels above 151 are very unhealthy and dangerous for everyone.

1) Why is it called 2.5?

The ‘2.5’ in PM 2.5 refers to the size of the pollutant in micrometers. Additionally, particulate pollutants vary in size and the smaller they are, the more damage they cause to your health. PM10 is particulates that have a diameter of 10 micrometers or less. Dust particles are the main source of PM10.

PM2.5 is comparatively much smaller in size as compared to other particles and pollutants.

Meanwhile, PM 2.5 is particulates that have a diameter of 2.5 micrometers or smaller. These particles are so small that they can only be viewed under a microscope. Therefore, their small size makes them much deadlier than PM10.

2) Where does it come from?

PM2.5 is produced through:

• Combustion in vehicles and machinery
• Industrial processes, particularly those involving coal
• Emissions from power plants
• Chemical processes in the atmosphere which happen when gasses and other pollutants from power plants interact
• Sources inside the home, such as candles, lamps, and fireplaces
• Forest fires and coal burning.

3) Exactly how bad is PM2.5 in China?

According to reports released by the World Bank and the Chinese government, China is one of the countries with the highest levels of PM2.5 in the world. 16 of the world's 20 cities with the highest air pollution are in China. A fifth of Chinese people in urban areas breathes air that’s heavily polluted. Because of this, the Chinese government has been actively putting in measures to improve pollution in China, but given the scope of the problem, the effects of these won’t be visible for the next 15-20 years.

4) What are the negative effects of exposure to PM2.5

Complications arising from exposure to PM2.5 depend on the health of an individual. However, even healthy, active people are still in danger when the exposure of PM2.5 is too high. Effects of exposure to your health include:

• Shortness of breath
• Eye, nose and throat irritation
• Excessive coughing and wheezing
• Diminished lung function and lung disease
• Diminished heart function, sometimes resulting in a heart attack
• Asthmatic attacks
• Death.

PM2.5 also damages the environment by increasing acidity in the soil and water bodies, which in turn affects their ability to produce food and support life.

5) How can I protect myself against PM2.5?

Going inside the house will limit exposure but does not eliminate the risks associated with breathing in PM2.5. Wearing a DIY mask or a surgical mask will also not protect you because normal masks do not have effective filters for capturing micro-particles.

The material and technology used in making Cambridge masks™ make it effective for filtering PM2.5 and even particles as small as bacteria and viruses. This means that Cambridge masks™ are your best defense against PM2.5.

Who will benefit from wearing a Cambridge Mask™?

Everyone will benefit from wearing a Cambridge mask™ but if you fall in the following groups, your health is more at risk and you should, therefore, take immediate steps to get yourself one:

• People with respiratory complications such as asthma or lung disease
• If you are obese or have diabetes
• If a doctor has diagnosed that you have a cardiovascular disease
• Children, teenagers and the elderly
• Expectant women and new mothers.