Air pollution is a major public health concern, causing about 7 million premature deaths a year. According to the World Health Organization, air pollution is a bigger factor for mortality than HIV/AIDS, tuberculosis and malaria combined. Most of this pollution comes from big cities, and many of them are standing up and doing something about the hazard.
By reducing air pollution in their own city, people can impact the immediate local environment before it spreads out to affect the whole world. Air pollution can infect a lot of people who aren't even close to city limits. However, the first step to learning how to control and lessen air pollution is to monitor it. Setting up sensors is what cities around the globe are doing now to make a difference.
How Sensing Improves Air Quality
One of the first air pollutant sensor projects to come about was Breathe London, which measures people's daily exposure in and around this city. It creates a map that shows where the most harm, as well as good, is clearly visible. In a similar setup in West Oakland, California, it was discovered that air pollution levels could change up to eight-fold within just one city block. Making a comprehensive map with sensors on every street corner is an important step to understanding where problem areas are.
Once data is collected on where the most issues lie and what kind of pollutants there are, it's up to the city to take matters into its own hands by whatever means are available. This usually means cutting out industry in problem areas and planting more trees within city limits. In addition to finding areas with poor air quality, these sensors also find places with much cleaner air.
This allows cities to learn how to make improvements by what's being done different in those places and act on them.
By cutting out a fraction of the harmful pollution cities put out, the effects could be a big positive on a global scale. People around the world are affected by air pollution. Learning about how to contain and control it can help people everywhere. Before this happens, though, we need to learn about better sensors.
Implement Different Types of Sensors
There are a lot of different sensors that can measure a variety of things. Some of the sensors mentioned include temperature- and humidity-combined sensors, metal oxide-based volatile organic compound sensors, particulate matter sensors and gas-phase sensors. Depending on the type of pollution suspected to be in the area and the sort of health problems plaguing citizens, there are different sensors available for specific jobs.
The particulate matter, or PM, sensor is especially useful for finding materials too small to see with the human eye. With specially made optical systems for just this sort of situation, PM sensors can measure dust or particles in the air. Naturally, this task isn't exactly easy, as dust and optical systems famously don't get along. The technology includes fluid dynamics and management to study the flow of dust, which can then inform data analysts about what kind of particles these are.
Another popular type are gas phase sensors. Gas phase sensors are capable of measuring what cannot be seen but can still cause a lot of harm. However, since there are 500 different gases possible for monitoring, getting familiar with the ones that are problematic in the area will cut down on unnecessary information. By knowing what they're looking for before beginning analyses, cities can save time and money by initially looking through what they don't need. Regardless, the data gathered is vital for learning where safety and danger lie in the city.
Another project worthy of mention is the CAIRSENSE or the Community Air Sensor Network project in Denver, Colorado. This project focused on testing sensor performance in high-altitude, dry climate air conditions with a low temperature. The CAIRSENSE also monitored the sensors to make sure they gathered data similar information in comparison to reference measurements. Results from the study indicated that deployment was lower than lab-based results. This study demonstrates the need for more air pollution sensor studies in cities.
Measuring the Data
Since information can change so drastically from block to block, putting a sensor on every street corner is the ideal option, if not the most practical for potential monetary concerns. That said, it may be more possible than ever to put sensors where we want them to be by combining needs. Filtering data directly into the cloud can help save everyone a lot of hassle.
This cloud is referred to as the Array of Things, or the AoT for short. The AoT is an urban sensing network of nodes installed around a city to collect data on environment, infrastructure, noise, public activity and even air pollution. The point of the AoT is to keep citizens alerted at all times while also monitoring activity around the city for public safety concerns.
The data collected is then categorized and filtered to pick out averages in the areas of interest. Though the AoT is comprehensive, reading and understanding the data is all part of the process. Once divided correctly, the data is analyzed and processed down to come up with figures for people to work with such as what pollutants are prevalent in what areas.
Fight for Survival
Air pollution problems are a major concern. London's mayor Sadiq Khan declared the issue "now a matter of life and death" once children began having severe reactions. With recent advances in technology, we're finally getting around to wrangling air pollution, but the solution may have come a bit too late. Regardless, people are trying to get things under control — which is all we can do at this point. Setting up sensors and understanding the problem is the first step in combatting it and hopefully exterminating air pollution for good. Air quality can be improved if we learn more about the pollution cities are fighting against. To do so, sensors are being deployed in cities.