The stay-at-home culture fostered during the pandemic to mitigate the worst impacts of COVID-19 has reduced traffic congestion and cleaned up city air. A report by the National Bureau of Economic Research calculated that the reduction in air pollution due to fewer personal vehicles traveling in US cities has led to a drop of about 25 percent in air-quality related illnesses such as asthma, lung disease, and heart disease across the country.
But there is no room for complacency. As cities open up in the post-pandemic world, congestion is returning. That accompanying traffic continuously pumps out noxious emissions, including the deadly 2.5µm diameter (and less) atmospheric particulate matter (PM). This “PM2.5” pollution penetrates deep into the lungs, making it the most hazardous pollutants to health.
The poverty-stricken suffer the most from the global problem of poor air quality. For example, Mumbai, India, subject to crippling congestion from poorly-maintained vehicles, often suffers from appalling air quality. The Times of India newspaper reported the city ranked the 63rd most polluted from a list of 859 worldwide and the fourth most polluted ‘megacity.’ This is a conurbation where, according to the newspaper, twenty percent of the population live below the poverty line, which the United Nations (U.N.) defines as a person who lives on less than US$1.90 per day.
The rapidly-maturing Internet of Things (IoT) provides a long-term solution to poor air quality for developed and developing nations alike. Widespread deployment of commercial air-quality sensors—wirelessly connected to the IoT via low-power wide-area networks (LPWANs) like LoRaWAN®—promises to generate the fine-grained data that city planners need to address the challenges of atmospheric pollution.
Taking Action to Protect the Vulnerable
Mumbai is far from unique. The U.N. says that, globally, more than one billion city dwellers live in slums, and they suffer disproportionally from the impact of poor air quality. According to the World Health Organization (WHO), air pollution is mainly responsible for non-communicable diseases, causing around 24 percent of all adult deaths from heart disease, 25 percent from stroke, 43 percent from chronic obstructive pulmonary disease, and 29 percent from lung cancer.
The U.N. recognizes we need urgent action to improve this at-risk group’s quality of life and safety. In 2015, the U.N.’s members adopted the 2030 Agenda for Sustainable Development. Comprising 17 Sustainable Development Goals (SDGs), the plan included making cities safe, resilient, and sustainable. Part of that objective consists of a commitment to improving air quality.
IoT technology providers willingly support the U.N.’s agenda. Among these is the LoRa Alliance, an open, nonprofit association whose members closely collaborate to promote the LoRaWAN protocol. The alliance’s members are developing several air pollution mitigation initiatives under the “LoRaWAN for Good” umbrella.
The IoT’s capacity to quickly generate, collate, and analyze data from compact, inexpensive wireless sensors—connected to the cloud via LoRaWAN—enables city planners to take advantage of “big data” to improve air pollution control. The systems comprise the following elements:
- Wireless air quality sensors to monitor and report pollution levels in real time
- LoRaWAN connectivity to transmit data from short-range wireless sensor networks to the cloud
- Cloud servers with the power to analyze the continuous data stream from tens of thousands of wireless sensors
- Predictive algorithms to suggest measures to prevent air pollution from building to hazardous levels
Wireless air quality sensors can be “tuned” to pick up the nitrogen dioxide (NO2) and carbon monoxide (CO) prevalent in exhaust gases and give an overall indication of the air pollution created by vehicles. Because these PM2.5 and gas sensors are inexpensive and unobtrusive, they can be widely distributed across a city to monitor air pollution.
LoRaWAN-enabled end-devices are incorporated into these wireless air-quality sensor networks, and these, in turn, are connected to a LoRaWAN network of gateways. They can transmit data to 5km in urban areas and up to 15km across rural line-of-sight connections, using end devices with batteries lasting ten years. Thus, LoRaWAN can provide a backbone for the rapid and inexpensive deployment of wireless sensor networks in any city area.
The Importance of Reliable Infrastructure
To ensure reliable, long-term performance, the LoRaWAN must be built from industrial-grade equipment. Therefore, the gateways are the critical link in the communication chain, and fortunately, there are many proven industrial options. One example is the Advantech WISE-6610 Industrial LoRaWAN Gateway, which ensures reliable LoRaWAN connectivity for industrial environments. The Advantech gateways support private and public LoRaWAN networks and feature MQTT, the lightweight network protocol that forms part of the Internet Protocol (I.P.) Suite.
The hardware and software flexibility of the WISE-6610 gateways support edge-computing systems and include redundancy-enhanced functions to prevent connection loss. In addition, high levels of security are underpinned by VPN tunnel creation for safe communication and a network server that can locally encrypt and convert LoRaWAN data. Other features include an 868-to-915MHz frequency range, a power input range of 9-to-36VDC, DIN rail or wall mounting, and an IP30 enclosure rating.
Data sent to the cloud by the LoRaWAN gateway can be aggregated and analyzed to build an almost real-time, fine-grained picture of how air pollution is changing throughout a city. As the historical database develops, algorithms can refer to past events to accurately predict how future patterns will play out—enabling authorities to take preventative measures if needed. Such information will allow for measured and proactive interventions such as regulating traffic flows, temporarily lowering road tolls for cleaner vehicles, and quickly advising citizens via the cellular network or internet to avoid areas that might soon become hazardous.
Moving closer to Sustainable Development Goals
While cities remain wedded to diesel and gasoline vehicles, PM2.5 emissions from tailpipes will be a potential hazard to human health. But major conurbations are wising up to the loss of productivity and the increased load on the health system caused by respiratory ailments, and they are now turning to the IoT and LoRaWAN to address the weaknesses of traditional monitoring systems. Networks of wireless sensors generating continuous streams of accurate data in near real time enable planners to make informed decisions such as cutting traffic flows to limit pollution on days with particularly adverse conditions.
With engineers now rolling out the next generation of wireless sensor networks, backed by city-wide LoRaWAN infrastructure, the U.N.’s eleventh Sustainable Development Goal to make cities safe, resilient, and sustainable is much closer. Moreover, it’s a perfect example of how LoRa technology can be harnessed for good.
Conclusion
Across the globe, cities are suffering from air pollution, and the poor are particularly vulnerable. The increasing use of the IoT, coupled with the availability of inexpensive wireless sensors tuned to measure NO2 and CO, offers an opportunity to address this growing problem. Wireless air-quality sensors supported by LoRaWAN infrastructure provide the rapid, fine-grained data needed to tackle both long-term and transient episodes of high-particulate pollution.
Source: Mouser Electronics
