Delhi Half Marathon’s use of radio waves to try to curb air pollution leaves experts sceptical

On October 21, nearly 35,000 people participated in the Airtel Delhi Half Marathon. As the city’s air quality deteriorated in the week leading up to the race, the organiser aerially sprayed water and swept the route to settle the dust. They also used machines emitting ultra high frequency radio waves to “purify the air”. “It made a huge difference,” claimed Vivek Singh, managing director of Procam International, the organiser.

Two of these machines were installed along the race route, one at Jawaharlal Nehru Stadium and the other outside Le Meridien hotel on Janpath. “They brought down pollution by 30% and provided a safe corridor for the runners,” Singh claimed.

Pollution experts are not convinced. “This is just marketing,” claimed Mukesh Khare, a professor at the Indian Institute of Technology, Delhi. This technology originated in Russia during the Cold War, Khare added, but it was more for improving visibility than air quality.

“We received a proposal for a similar machine a few months back,” he said, referring to the central Department of Science and Technology’s Technical Review Committee of which he is a member. “It was a different vendor and they said the machine could clear PM 2.5. But there were so many questions and they never came back with the answers.”

An official at the Delhi Pollution Control Committee claimed the machines were installed without clearance. As for their efficacy and safety, he said the radio waves are supposed to create a “virtual chimney” but there is no data to show if and how this works. “They have exposed the runners and the local ecology to unknown things,” the official said. “We asked for peer-reviewed research papers but we did not get any. This has not been cleared by any of us. It is an uncalled-for step.”

This isn’t the first time the Delhi Half Marathon has been the subject of controversy. In November 2017, the event went ahead despite the Indian Medical Association urging the High Court to stop it as pollution levels had increased alarmingly, and outdoor physical activity in such conditions heightened the risk of asthma and heart attacks and worsened lung ailments.

This year, the marathon was held in October. The pollution levels were still high, but Singh claimed the athletes did not complain. “Running builds immunity and runners can combat the impact of pollution,” he said.

Mean machines?

The machines in questions, called Pure Skies, are made by Devic Earth, a Bengaluru company which, The Telegraph reported this week, received Rs 5.5 lakh as “seed capital” from the central environment ministry in 2009.

Pure Skies accelerates the “natural phenomena” of settling dust and the particulate matter PM 2.5 and PM 10 – tiny particles that can penetrate deep into human lungs and bloodstream – by pulsing out ultra high frequency radio waves, said Dr Srikanth Sola, a cardiologist who founded Devic Earth. “It’s like Wi-Fi,” he said. “These waves give energy to the matter to move faster.”

Radio waves from Pure Skies are of “far lower” frequency than those emitted by mobile phone towers and are “highly regulated”, Sola claimed. He said a “formal study” to assess the technology’s impact on people as well as honey bees, butterflies, fruit bats and migratory birds was conducted at the Sri Sathya Sai Institute of Higher Medical Sciences in Andhra Pradesh from October 2016 to February 2017. “There was no negative impact on them,” he said. “The side effects are still a big question, but the energy being given out is very controlled.”

Sola claimed the machine clears the air within a 10-km radius. “After 10 kilometres, we notice the benefits of the machine clearly decline,” he added.

But Khare was sceptical. “This is the first time I am hearing of such phenomena,” he said. “If these waves are pushing the particles, then they will still be suspended in the atmosphere. PM 10 may be able to settle faster but PM 2.5 is very fine and takes much longer.”

Not quite clean

In Delhi, the machines were installed on October 18. By the morning of the half marathon, which lasted from 5 am to 10 am, they had helped make the air cleaner by 30%-40%, Procam International claimed.

However, Prashant Gargava of the Central Pollution Control Board said the organiser did not have permission to set up the machines. “They haven’t been approved by us,” he said.

Sola admitted that was the case, but claimed there are “no regulations” in place for seeking permission. “We take the onus on our side to make sure that the machines are safe,” he added.

Sola said he could not share any data about the performance of the machines because his company has a “confidentiality agreement” with Procam.

But data from a monitoring device run by the Delhi Pollution Control Committee at the Jawaharlal Nehru Stadium, where one of the Pure Skies was installed, would seem to undermine Procam’s assertion. It shows PM 2.5 and PM 10 levels from October 18 to October 21 were far above permissible limits, going beyond 200 micrograms per cubic metre on most days. The permissible limit for PM 2.5 is 40 micrograms per cubic metre and for PM 10 is 60.

Though the particulate matter levels dropped significantly on the morning of October 19 compared to the previous morning, they rose steadily thereafter, peaking around noon. Between 5 am on October 20 and 5 am the next day, PM 2.5 registered a slight drop of around 6.2%, but PM 10 rose by 60.8%. In the 5 am-10 am period, the average PM 2.5 was the highest on October 20, at 196, while the average PM 10 was the highest on October 21, at 436.

On all these days, the particulate matter levels declined from 5 am until noon. This is what happens naturally, the Pollution Control Committee official said. “With sunrise, as the temperature rises, the particulate matter starts to disperse,” he explained.

Damaging ecology

Khare is worried the technology was used even though its effects on flora and fauna, wind velocity, the flow of pollen are not yet known. “We know how mobile towers have affected sparrows; they have disappeared from Delhi,” he said. “It is a matter of study but we know no other country is using this technology to purify air. They come to India because there are no regulations here.”

How radio waves affect the environment usually depends on their wavelength, said CR Babu, a professor emeritus at Delhi University. High frequency waves can cause blood cancer, brain tumours, neurological disorders and allergies in human beings. They could harm animals as well. “They impact navigational skills in bats,” he said. “They are not able to hunt for food or find their mates which could lead to infertility”

In amphibians such as frogs, Babu said, prolonged exposure to high frequency radio waves caused high mortality among tadpoles. In migratory birds, they affected brain cells. “Research shows that eggs in nests located on mobile towers do not hatch,” he added. “There will be a change in the ecosystem if it is being exposed to such waves. Before we use such instruments, we need to check for their environmental impact.”