Citizens Sense!


Until recently, measuring air pollution was a task that could be performed only by trained scientists using very sophisticated – expensive equipment. Environmental Sensors are now getting advanced, miniaturized and cheaper, opening up new methods of collecting environmental data.

Environmental data capture is no more left to the regulatory agencies today. Its now led by the citizens. Citizen can “sense” the environment using readily available sensor devices with smart phones, and share this information using existing cellular and internet communication infrastructure.


“Democratization” of technology and Do-It-Yourself (DIY) hardware platforms, have the potential to enable citizens to sense. It is estimated that by 2019, “citizen environmentalists” will have more personal sensors, measuring air and water pollution, energy consumption, health parameters etc. than the governments.

US EPA is challenging communities across the country to collect data using hundreds of air quality sensors as part of the Smart City Air Challenge. The agency just offered up to $40,000 apiece to two communities to help them develop and implement plans for collecting and sharing data from air quality sensors. The award money only covers part of the program costs, so communities will need to partner with sensor manufacturers, data management companies or others to get resources and expertise to implement their plans.

The State Pollution Control Boards in India should think of taking up such initiatives.

I came across the Air Quality Egg.  This is a network of about 1,300 CO2 and NO2 sensors, which cost $240 each. Another popular device is the Smart Citizen Kit.   Here data is uploaded to the Smart Citizen Website which shows about 800 kits deployed across the world, with more than half deployed in Europe. The basic kits cost about $170, before tax and shipping. There are dozens of such sensor packs and gateways now available and the number is constantly growing.


Air Quality Egg Sensor

We don’t have such devices and networks established in India.


Forty Air Quality Eggs in Georgia

The Do-It-Yourself Mantra

EnviroDIY in the US is a community of enthusiasts sharing Do-It-Yourself Ideas for environmental monitoring. All EnviroDIY members can showcase their environmental sensing gadgets or describe their own homegrown approaches to monitoring, sensor calibration, installation hardware, radio communication, data management, training or any number of other topics. Members can pose and answer questions and can network within interest groups to collectively develop new devices, tutorials, or other useful products.

Empowering the Youth

The Kids Making Sense program empowers youth to drive positive change and improve public health by collecting credible air quality data around their neighborhoods. Students participate in hands-on science tasks, discuss their findings with an air quality scientist, and share their data with the global air quality community. They can even use their data to identify local sources of air pollution and take actions to be part of the solution. DIY is the strategy.


Students in Bangkok participating in Air Quality Sensing

Market forces and consumer convenience are driving the growth of DIY sensor market. Whatever the motivation, these sensors are being used now by many organizations, including concerned citizen advocacy groups, and to some extent by the regulatory community. Regulators are interested in the low cost sensor technologies because they can cheaply expand measurement capacity. But at the same time, they are cautious because of uncertainties about measurements that do not comply with narrowly prescribed measurement methods.

Many environmental sensors are still in an early stage of technology development, and many sensors have not yet been evaluated to determine the accuracy of their measurements. So there are important concerns about how well and how accurately these sensors work.

The latest version of EPA’s Air Sensor Toolbox provides a variety of resources on using air sensor technologies, including new sensor performance reference tables. One of the most popular resources is the Air Sensor Guidebook, a how-to for using of air sensors and what to consider before getting started with a citizen science project. In addition, the Toolbox includes scientific reports on air sensor monitors that undergo testing and evaluation by EPA. Technical documents on operating procedures also are available.

But low-cost air monitoring does have merits. It is not hard to build a $30 sensor to measure carbon monoxide, although such a device probably will not be able to measure concentrations less than, say, one part per million. In many advanced countries, where pollution levels are relatively low, such a device would not produce meaningful measurements. But on a busy street in New Delhi, or near a brick kiln in Patna, it could be quite useful because pollution levels are significantly higher that citizens would like to sense.

Sensors of Tomorrow

The team, led by Professor Giacinta Parish, has come up with a new kind of sensor. It’s made from gallium nitride, a material that can perform in extreme heat and at high power levels, unlike the materials silicon and gallium arsenide that are often used in sensor chips.

Parish’s team along with engineers from CSIRO, Australia have used the gallium nitride to build a single sensor chip that can detect many different ions without the need for a reference electrode that would add to its size and weight.

Plants have amazing and significant sensing capabilities. For instance, each single root apex can simultaneously and continuously monitor many chemical and physical parameters. A digital network and a powerful algorithm transforms each tree into an environmental informer. A group of Italian, British and Spanish researchers are working on developing a network of micro sensors that can be embedded in plants, sending us information on how plants respond to changes in temperature, humidity, air pollution, chemicals and many other changes in their environment. A project called PLEASED (PLants Employed As SEnsing Devices)  has been launched with €1.07 million ($1.46 million) funding by the EU.

I am a strong advocate of citizen monitoring. To encourage the citizens to sense our environment, engage into science based discussions and action, we should probably consider launching a nation-wide program on “citizen sensing”.

The Central Pollution Control Board (CPCB) should take the task of setting a Toolbox like US EPA did to ensure quality entry of the sensors, guide correct use and provide tips and training for the interpretation of this data.

Department of Science & Technology should sponsor research on low cost environmental sensors that can be indigenously manufactured and serviced and promote entrepreneurship in this area. Our venture capitalists should seriously consider investing and come up with innovative business models.

Some may say that involving citizens in “sensing” will increase the Public Interest Litigations (PILs) and appeals to the National Green Tribunal (NGT). But whether the regulators like or not, citizens and especially the youth – are going to get more involved – since the environment matters.

Citizens are now interested to know more about the state of environment they are living and not solely depend on the monitoring reports of the regulators. Don’t you think it makes a pretty good sense!

You may want to read my following previous posts

Participatory Air Quality Monitoring

Why Monitor Environmental Quality – Why not Generate Random Numbers?

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One comment

  1. Nice to know about easy to use air pollution monitor. Monitoring particulates used to be faulty due to inadequate vacuum and improper filter.Hope these new finds are foolproof/ediotproof.

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