With increasing industrialization outpacing investment in pollution control technology (such as newer dust collector filter technology) and pollution control regulations , New Delhi has now replaced Beijing as the national capital city with the worst air quality in the world.
November 25, 2011 | Baghouse.com – The 16 million inhabitants of New Delhi, India on a normal day can raise their eyes to look over their beautiful city, only to have it obscured by a think layer of smog and haze that hangs over the city. With a rapidly industrializing economy, increasing numbers of cars on its roads, and extensive construction taking place within its borders, the city’s air quality has become so polluted that it is now classified from hazardous to so severe that a public health emergency needs to be declared.
According to measurements taken by US and Indian governmental agencies, the AQI (Air Quality Index) for Particulate Matter 2.5 was over 300 on Monday. According to US EPA (Environmental Protection Agency) anything 201 on the scale, which rates pollution concentrations on a scale of 0 to 500, is termed “very unhealthy” and should be considered dangerous for older persons, and children to be outside. In India the levels found on Monday of over 300 are currently classified only as “very poor” as opposed to “hazardous” by the standards of most other countries.
The main troublesome pollutant in the city (and throughout the country) is PM 2.5, a term for small dust particles that measure less than 2.5 microns in size. These particles have been proven to have a detrimental effect on the health of those exposed to them, due to their ability to penetrate deep into the lungs. Depending on the exact source material (coal-fired power plants, metals, plastics, chemicals, etc.) a myriad of illnesses such as cancers, asthma, brain and neurological damage can result.
At a time when the United States, and most other developed countries are tightening clean air regulations and mandating large investments in newer pollution control technologies such as newer PTFE membrane dust collector filter technology, countries like China and India are making only minimal investments in such areas.
With lower environmental clean air standards than other industrialized nations, China and India both are suffering the effects. Most nations enforce tough regulations for PM 2.5, requiring extensive pollution control equipment known as dust collection systems to be installed and maintained at most facilities that generate even small amounts of dust pollution. A common dust collection system, known as a baghouse, works by passing the dirty exhaust (or dirty air collected from various points throughout the facility) through a series of fabric dust collector filters that capture the dust particles down to the sub-micron level. The now dust free air is then exhausted into the atmosphere.
Until recently, China’s capital of Beijing held the dubious title of world’s most polluted capital, with regular pm 2.5 concentrations in the hazardous range. Monday marks the first time that Beijing has been surpassed by New Delhi in AQI levels. However, unlike India, which publishes figures for PM2.5 regularly, and whose numbers are trusted by most international sources, China still measures its air quality on the outdated PM 10 (particles 10 microns in size) standard, and their reported levels are often questions by locals and others alike. This has lead the US embassy in Beijing to install a monitoring station on the roof of ht embassy. It maintains a Twitter feed with its readings (which are PM 2.5) for the public to view.
Whether or not the famously polluted air in Beijing is only going to earn the city the number 2 spot on the list, or if this is merely a one time occurrence will depend upon the resolve of these respective cities’/nations’ to take the necessary steps to improve air quality.
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