It is 70 times finer than the thickness of a human hair, goes directly into the bloodstream and is potentially more dangerous than the pollutants made notorious by Delhi’s recent smog nightmare. And no one knows how much of it is in the air we breathe.
PM1 (particulate matter 1) is fast emerging as a pollution threat that needs urgent attention, according to scientists, and the government has now decided to install the capital’s first meters that will measure its concentration in the air.
“The process is on and sites for these monitoring points are yet to be finalised. PM1 is a fairly recent discovery and there are no standards set for it. Monitoring of this particulate matter can help address a major source of pollution. Unlike PM10 (comparatively larger particulate matter) which can increase because of dust, PM1 is entirely because of combustion,” a Delhi government official told HT.
According to the official, the monitoring of PM1 is expected to begin before next year’s Diwali.
Experts say the smaller the particle, the more harmful it is. Anumita Roychowdhury, head of Centre for Science and Environment’s Clean Air campaign, said data of PM1 will be key since there are no ambient standards globally yet.
According to a Central Pollution Control Board 2010 study, small particulate matter penetrates deep into lungs and can reach the alveolar region, causing heart ailments. These fine particles cover a large surface area, absorb toxic compounds such as heavy metals and organic compounds with high carbon content, the study said.
These particles — spewed primarily from vehicles, factories and construction sites — are not dispersed and stay suspended in the air.
“Euro 6 emission standard, which will be implemented by 2020, is designed in a way that it will begin to address ultrafine particles. This data will help understand the risk and facilitate in calibrating diesel emission standards. It is not monitored regularly anywhere in the world, but it is important from the perspective of setting emission norms,” Roychowdhury said.
The city of about 20 million people, among the world’s most polluted according to the World Health Organisation, has been struggling to clean up a toxic cocktail of dust, smoke and gases from its air. The day after this Diwali, the capital and its neighbourhood saw one of the worst spells of smog that prompted alarm among people.
Such conditions recur every autumn and winter as the city is buffeted by farmers burning crop stalks in neighbouring states and atmospheric changes inhibit dispersion of regular pollution.