Air pollution results from a combination of natural and manmade substances. Exposure to harmful particles in the air can have an impact on health, from respiratory diseases to cardiovascular diseases. There are particular ways to monitor air pollution and limit exposure to pollutants. Let’s look at five methods that can be used to monitor air pollution.
This form of air pollution monitoring uses a simple and cost-effective method of monitoring air quality in a particular environment. A diffusion tube is often used to absorb a particular pollutant from the atmospheric air without the use of a power supply source. The passive monitoring period generally lasts for 2-4 weeks at a time, and the tubes are required to undergo an air quality analysis in a lab to uncover the level of pollution that has been detected. This method allows sampling at several points in the area being monitored and can identify ‘hot spots’ of high concentrations of pollutants.
Active (Semi Automatic) Sampling
With active sampling, the pollutant samples are either collected by physical or chemical means, either the gravimetric method for PM 10 or the PM2.5 monitoring method. The process involves the use of an established volume of air that is pumped through a filter for a particular period of time, and the mass of particulate matter collected on the filter is later sent to a laboratory for analysis to determine the ambient concentration of PM10 or PM2.5. It is also possible to analyze the collected material for metals and gases. A sampler is capable of holding several days’ or weeks’ worth of filters, and particular active sampling methods can be labor intensive, with long data turn around times.
Automatic Point Monitoring
Though generally more expensive and sophisticated than other systems, automatic analysers pull in outdoor ambient air, and the pollutant in the sampled air is calculated to determine its concentration. Automatic monitoring techniques are used for monitoring oxides of nitrogen, sulphur dioxide, carbon monoxide, ozone, and other pollutants such as hydrocarbons. One advantage of this monitoring method is that it produces high-resolution measurements, sending data from the site directly to your computer, and it requires a high standard of operation to ensure that the data produced are accurate and reliable.
Photochemical and Optical Sensor Systems
As portable monitoring tools, these air pollution monitoring systems can provide continuous monitoring of a range of pollutants, including carbon monoxide, nitrogen dioxide, sulphur dioxide. These systems have low sensitivity sensors and are ideally suited for identifying hotspots near point sources and some are developed for personal exposure monitoring applications. These electrochemical or solid-state sensor-based systems either rely on battery or mains for operation, and portable sensors that utilize the light scattering principle are generally applied to PM10 monitoring.
Remote Optical/Long-path Monitoring
This method of air pollution uses a long-path spectroscopic technique to detect pollution between a light source and a detector, which are placed separately at a site. The concentration of a range of pollutants is measured in real-time. Instruments using the Differential Optical Absorption Spectroscopy (DOAS) system can be employed in monitoring data for nitrogen dioxide, sulphur dioxide, and benzene. The data collected can be sent from the analyser directly to a computer for instant evaluation.
It’s important to have clean air to breathe. There are effective ways of monitoring air pollution and in the process, improve air quality. Hazardous pollutants can have a huge impact on health, and so, good air quality is essential.