The last few decades mark rapid industrialization and urbanization around the world. With that, the demand for energy, transportation, and infrastructure development has skyrocketed. A number of studies have shown the detrimental effects of air pollution on human health and well-being. Among all the air pollutants, particulate matter (PM) pollution is of particular concern. Particulate matter (PM) is further classified into PM2.5 and PM10, based upon their particle diameter. However, various researches have shown that we still do not have enough PM2.5 and PM10 monitors to create a representative picture of PM pollution.
Due to their very small size, they can penetrate deep in the lungs and can also mix with the bloodstream. Chronic exposure to such a high level of particulate matter concentration is conducive to various cardiovascular and pulmonary diseases. The number of PM2.5 and PM10 monitors has increased in the past few years to accurately monitor particulate concentration.
WHY WE MONITOR PM2.5 AND PM10
You must have encountered this question about why we specifically monitor PM2.5 and PM10. In order to understand that, first we must address what is particulate matter and how it is measured. According to USEPA, particulate matter (or commonly referred to as PM), is a mixture of solid particles and liquid droplets found in the air. Some particles like dust and dirt are clearly visible with the naked eye and some are so small that they can only be observed with a microscope. Together they are responsible for all the particulate pollution that we experience every day. The health effects of microscopic particulate matter (PM) depends upon their particle diameter and that’s why they are further classified as PM2.5 and PM10.
PM10 and PM2.5 have less than an effective aerodynamic diameter of 10 micrometres and 2.5 micrometres respectively. All types of combustion activities including vehicular emission and forest fires are a major source of particulate matter (PM). Secondary PM can be indirectly generated by complex reactions with other pollutants such as sulfur dioxide and nitrogen oxides, present abundantly in the atmosphere. Construction and mining activities, unpaved roads, account for dust and particulate pollution. Dust monitoring at such sites is crucial to quantify the source contribution and PM size distribution.
It is important to formalize their particle diameter in order to develop control standards based on them. In order to do that samples collected from PM monitors were analysed for particle size distribution. The results showed that distribution patterns exhibit peaks around 2.5 and 10 micrometres. These are known as particle distribution modes of PM monitors.
PM MEASUREMENT TO UNDERSTAND THE PROBLEM OF AIR POLLUTION
There is a famous saying that – “you cannot manage what you cannot measure”. PM monitoring devices fulfill the requirement of measuring particulate matter concentration. However, the deployment of PM monitors does not solve the problem by itself. Monitoring of PM2.5 and PM10 concentrations serves as the basis of pollution abatement strategies. It provides important insights and relevant information that helps us define the pollution problem in order to solve it. PM monitors also enable us to track the progress of mitigation strategies by assessing the efficacy and efficiency of policy intervention. With such information, we can fine-tune our response to reduce exposure to PM2.5 and PM10.
Emission sources, topography and meteorological conditions are principle factors governing air pollution. Due to region-specific factors, the distribution and extent of pollution are different everywhere. To reduce PM concentration levels, it is imperative to define the pollution problem of the region of interest. Monitoring PM2.5 and PM10 concentration also enable us in carrying out long-term trend analysis. Recently CPCB’s National Ambient Air Quality Status & Trends report showed that while 78% of cities exceeded PM10 standards, PM2.5 concentrations have increased significantly in the last 3 years. Another report, named ‘Impact of Lockdown on Ambient Air Quality’ showed an unusually high ratio of PM2.5 to PM10 attributing the source of the pollution to biomass burning and cooking fuel.
Other studies have also attempted to accurately attribute percent increase in PM2.5 and PM10 concentration near roads by placing multiple PM monitors around roads and highways. Here, a robust PM monitoring system plays an important role as such analyses are only possible with the availability of accurate PM10 and PM2.5 monitoring data. Also, accurate data further enables an effective policy framework.
PM2.5 and PM10 MONITORS TO REDUCE POLLUTION EXPOSURE
Day-to-day activities result in majority of PM2.5 and PM10 emission which makes PM pollution a global issue. It is corroborated with a study carried out by the World Health Organization (WHO). It states that 9 out of 10 people worldwide breathe air containing high levels of particulate pollutants. As a result, air pollution (particularly PM2.5 and PM10) attributes to 7 million premature deaths worldwide. Out of which, 1.2 million Indians lost their lives prematurely according to the Global Burden of Disease Study 2015. This translates to global economic losses of US$ 3 trillion according to the OECD Report, of which India bear US$ 150 billion in monetary losses, according to Greenpeace Southeast Asia report.
Economic losses are due to lost productivity and increased expenditure in healthcare. Such analyses are carried out using concentration-response relationships. It shows the percent change to various changes in various health metrics brought by the percent change in pollution concentration. PM monitoring devices provide crucial datasets to develop such relationships. The study of the concentration-response relationship for PM2.5 and PM10 helps in understanding the economic co-benefits of PM pollution reduction.
It also helps in calculating return on investment (ROI) value during the economic feasibility of air pollution abatement plan. Highly accurate PM monitoring systems are prerequisite to facilitate such planning. Capacity building by increasing the number of PM monitors will pay back with improved productivity and reduced healthcare spending. Resultantly, the benefits of air pollution reduction will significantly outweigh costs as per TERI’s research. Such pollution abatement strategies which are built upon the data from PM monitors can effectively reduce people’s exposure to PM2.5 and PM10.
PM MONITORING TO ACHIEVE VARIOUS NATIONAL AND INTERNATIONAL GOALS
Particulate air pollution is a global issue. Existing networks of PM10 and PM2.5 monitors have shown that PM concentrations have increased manifold around the world in the past few years. Serious health and economic implications resulted in various international agreements. The Paris Agreement of 2015 is one of such very important international agreements. Member Countries agreed on the Sustainable Development Goals along with the agreement of reducing greenhouse gas emissions around the world. The SDG3 of healthy lives and wellbeing and SDG11 of sustainable cities mandates to increase the number of PM monitors around the world. The SDGs give well-needed emphasis on PM2.5 and PM10 monitoring and their reduction to achieve the overall target of sustainable development.
Similarly in India, the National Air Quality Monitoring Programme (NAMP) identified the limitation of inadequate PM monitoring systems. National Clean Air Programme (NCAP) is a target to attain targets of national ambient air quality standards (NAAQS). It has also allocated a budget to expand the networks of PM monitors. Along with monitoring of pollutants, it addresses the institutional and administrative aspects of air pollution reduction.
OIZOM’S PARTICULATE MATTER (PM) MONITORS
Oizom’s Dustroid, a dust monitoring device, specifically measures high particulate pollution loads experienced at mining and construction sites. Oizom’s Polludrone measures gaseous pollutants along with particulate pollutants (PM1, PM2.5, PM10). Both the PM monitors also measure meteorological parameters such as temperature, humidity, wind speed, and wind direction. OIZOM’s devices provide high-quality monitoring data at an economical cost. Further data integration with various platforms results in the generation of dynamic pollution maps.
OIZOM’s PM monitors are a perfect choice for monitoring PM2.5 and PM10 concentration at airports, roads and highways, and underground facilities such as tunnels and parking lots. Supplementary details on how to select monitoring location can be found in OIZOM’s Whitepaper on location selection.