According to a report published by the World Health Organisation (WHO), air pollution kills around 7 million people annually worldwide – making it the single biggest environmental health risk. There are lots of regulations and legislations put into place to help reduce this.
The WHO believes that particles are having a larger effect on people globally than any other pollutant, making this type of pollution important to measure and monitor. It is paramount for employers to protect their staff from exposure to harmful substance, making particulate monitoring an area of increasing importance in the workplace.
What is particulate pollution?
Particulate matter (PM), also known as particle pollution, is a mixture of extremely small solid and liquid particles suspended in the air. Classified into three different categories, this particulate can be coarse, fine or ultrafine.
Fine particles, categorised as those with a diameter of 0.1-2.5 µm, and ultra fine particles, <0.1 µm, remain suspended in the air for a long period time. Conversely, coarse particles are more likely to settle quickly and these have a diameter of between 2.5-10 µm.
To put this into more perspective – a grain of sand is around 90 µm in diameter.
PM10 particles are those that with a diameter smaller than 10 µm, such as dust and pollen. Similarly, PM2.5 particles are those with a diameter smaller than 2.5 µm like combustion particles and organic compounds.
Why do we need to monitor particulate?
There is an increasing awareness of the potentially damaging effect that can be caused by PM10 and PM2.5 particles on the human body and to the surrounding environment.
Once inhaled, these particles are so small that they are able to penetrate far into the respiratory system, having detrimental effects to health such as:
- Lung irritation, leading to an increased permeability of lung tissue;
- Aggravating the severity of chronic lung diseases, causing a loss of airway function;
- Inflammation of lung tissue, resulting in the release of chemicals that can impact heart function;
- Increased susceptibility to viral and bacterial pathogens, leading to pneumonia in vulnerable individuals.
These small particulates can also have an impact on the environment – changing the radiation balance of the planet, causing lakes and streams to become acidic, depleting nutrients in soil and contributing to reduced visibility and global warming.
Under the EU directive 89/391/EEC there is a requirement for employers to control and prevent the exposure of workers to harmful substance in the workplace. Using air quality alerts, it is possible to be alerted when particulate matter reaches harmful levels. The EU legislation is in place to limit exposure to air pollutants via ‘limit values’ (these are concentrations which cannot be exceeded).
Monitoring is necessary to assess compliance with workplace exposure limit values. Particulate matter monitoring is part of ‘Air quality monitoring’ which includes monitoring harmful gases and wind speed.
Larger particles, over 10um in diameter, are not usually covered by legislation as they are large enough to be filtered out by the nose and throat. Total Suspended Particles is the term which is used when referring all particle sizes. It is usual for Total Suspended Particles to be monitored alongside PM10 and PM2.5.
In next week’s blog, we will look at where particulate matter comes from and where it should be monitored.
Can you see the importance of monitoring particulate matter?