It is tiny but deadly and despite the focus on the Capital’s air quality in the last few months, particulate matter PM 1 has gone unnoticed. However, the Delhi government has now decided to set up five monitoring points across the Capital to measure PM 1 whose levels should be extremely low or none.
PM 1 is 70 times finer than human hair and a more dangerous pollutant compared to PM2.5 and PM10. Being a smaller particle, it can go deeper into the airways and lungs, and through the cell membranes it can enter the bloodstream and damage vital organs. Scientists say PM 1, which primarily emerges from combustion, is responsible for cardiovascular diseases, premature births and impacts foetal development.
According to a senior Delhi government official, the monitoring of PM 1 is expected to begin before next Diwali. “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,” the official told HT.
According to a Central Pollution Control Board 2010 study, small particulate matter penetrate deep into the lung 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 Polycyclic Aromatic Hydrocarbons (PAH) organic compounds containing high content of carbon, the study said.
These particles, byproducts of emissions from factories, vehicular pollution, construction activities and road dust, are not dispersed, and stay suspended in the air that we breathe.
Experts say the smaller the particle, the more harmful it is. Anumita Roychowdhury, who heads the Centre for Science and Environment’s Clean Air campaign, said that data of PM1 will be useful as globally there are no ambient standards yet.
“PM10 and PM2.5 have ambient standards. PM1 doesn’t yet. There have been studies in the UK that found 90% of diesel emissions to be PM1 particles.
“Euro 6, which will be implemented by 2020, is designed in such a way that it will begin to address ultrafine particles. This data will help you 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,” she said.
The city of about 20 million people, which ranks among the world’s top cities with foul air on a World Health Organisation list, has been struggling to clean up its air that contains a toxic cocktail of dust, smoke and gases from vehicles and factory exhausts. The condition worsens every autumn and winter as the city, buffeted by farmers burning crop stalks in neighbouring states and atmospheric changes, records higher levels of air pollution.
According to a Delhi government official, the process has also been started to put in place seven more fixed and one mobile air quality monitoring station by next year. “These will help us get a comprehensive picture of air pollution in Delhi, especially during winter, when the city’s air quality worsens,” the official said.
Adversely affects human health more than any other known pollutant
PM consists of sulphate, ammonia, nitrates, black carbon, mineral dust, water, sodium chloride.
Particulate matter with a diametre of 10 microns or less
Can seep into the lungs and lodge deep inside
Long term exposure to it develops risk of respiratory and cardiovascular diseases
Permissible limit: 100 µgm3
Particles with a diametre of 2.5 microns or less
Exposure to PM 2.5 particles leads to short term effects such as irritation in the eye, throat, nose, lung, shortness of breath, sneezing
Prolonged exposure increases risk of respiratory diseases.
Permissible limit: 60 µgm3
Microscopic particulate matter, with a diametre of 1 microns or less, is the tiniest class of pollution particles
Major contributor is transport sector, particularly diesel vehicles
Can easily penetrate very deep into the lungs
Can enter the blood and circulate, affecting the inner walls of arteries and causing cardiovascular problems
Permissible limit: No such standards yet
Sources of PM1: Emissions from factories, vehicular pollution, construction activities and road dust