At a time when the Delhi-NCR is already gasping for breath on account of the extremely poor air pollution levels, a damning study conducted by researchers at Bose Institute, Kolkata, paints a grim picture for yet another silent killer, aerosol pollution, for multiple East and North Indian states in the coming years.
The study reveals that in 2023, aerosol pollution in West Bengal is anticipated to rise by 8% and continue to remain in the “highly vulnerable” red zone, second only to Bihar which is the highest forecasted aerosol pollution level state in the country.
While the study specifies three North Indian states – Punjab, Haryana and Uttar Pradesh – also falling within this category, it adds that most South Indian states would alarmingly exhibit a shift from “less vulnerable/safe” to “vulnerable” zones in 2023.
The study, A Deep Insight Into State-Level Aerosol Pollution in India, by researchers Dr Abhijit Chatterjee, Associate Professor, and his PhD scholar Monami Dutta from the Bose Institute, provides a national scenario of aerosol pollution with the long-term (2005–2019) trend, source apportionment, and future scenario (2023) for various Indian states.
High aerosol amounts include particulate matter (PM2.5 and PM10), among other pollutants, as well as sea salt, dust, black and organic carbon. If inhaled they can be harmful to people’s health. Aerosol Optical Depth (AOD) is the quantitative estimate of the aerosol present in atmosphere and can be used as a proxy measurement of PM2.5.
The study shows that Bengal currently falls under the red category, which is the highly vulnerable zone with AOD over 0.5. With aerosol pollution expected to rise by 8%, the AOD would be further pushed to over 0.75 within the vulnerable (red) zone in 2023.
The values of AOD range from 0 and 1. While 0 indicates a crystal-clear sky with maximum visibility, a value of 1 indicates extremely hazy conditions.
Division of categories for AOD:
Based on these percentiles, there are four different colour zones:
● Green (Safe Zone)- AOD value less than 0.3
● Blue (Less Vulnerable Zone)- AOD value between 0.3-0.4
● Orange (Vulnerable zone)- AOD value between 0.4-0.5
● Red (Highly Vulnerable zone)- AOD value greater than 0.5
In the research paper, the threshold for aerosol pollution vulnerability has been considered as a value of 0.4.
“Due to its strategic location, West Bengal receives Indo-Gangetic Plain air pollution outflows and its local emissions have put West Bengal in the highly vulnerable zone. A nominal increase of around 8% in AOD can cause a disastrous impact on the health and life of the people residing in this state,” said Dr Abhijit Chatterjee, principal author of the study.
From 2005 to 2014, vehicular emissions (40-42%) remained the top source of aerosol pollution in big cities in West Bengal, followed by vehicle driven dust (18-20%) and solid fuel burning (13-15%).
“Lack of proper maintenance of national and state highways and unpaved roads are the major factors for excessive vehicular dust,” said Monami Dutta, first-author of the study.
Interestingly, the study finds that, since 2015, solid fuel burning (35%) became the largest emission source while vehicular emissions (18%) dropped to becoming the least contributor to aerosol pollution.
“The reason for the drop in vehicular emissions could be due to the introduction of Bharat VI emission standards and upgradation of engines, ban on 15-year-old vehicles etc. At the same time, vehicular driven dust was replaced by construction driven dust which is a result of over urbanisation,” said Dutta.
“The dominance of solid fuel burning in recent years could be because of the unregistered and overabundant roadside eateries and restaurants across major cities in Bengal,” he added.
Chatterjee explained that another reason for rise in solid fuel burning was due to hike in LPG prices, which prompted economically weaker sections to shift back to wood or other polluting fuels.
“The government should increase the subsidy rate, at least for underprivileged people, which might give some relief to this situation. However, since we do not have any specific data for solid waste burning in India, we could not quantify the amount of reduction for this source of aerosol pollution,” Chatterjee said.
Dutta added that fast-paced urbanisation in recent times has resulted in increase in construction rate across cities in states like West Bengal.
“Proper management during construction like increasing green cover and sprinkling of water is required to reduce the dust from construction and demolition,” she said.
Read all the Latest India News here
Comments
0 comment