|星期五, 11月 27|
对敏感人群不健康 150 美国 AQI
|星期六, 11月 28|
对敏感人群不健康 125 美国 AQI
|星期日, 11月 29|
对敏感人群不健康 145 美国 AQI
不健康 152 美国 AQI
|星期二, 12月 1|
对敏感人群不健康 125 美国 AQI
|星期三, 12月 2|
对敏感人群不健康 130 美国 AQI
|星期四, 12月 3|
对敏感人群不健康 139 美国 AQI
|星期五, 12月 4|
对敏感人群不健康 131 美国 AQI
|星期六, 12月 5|
对敏感人群不健康 132 美国 AQI
|星期日, 12月 6|
对敏感人群不健康 136 美国 AQI
After the capital city of Delhi, Ahmedabad recorded the worst air quality recently.
According to the Central Pollution Control Board, Ahmedabad was ranked as the 4th most polluted city in India, in 2001. This discovery led to the formation of the Bhure Lai committee to try to mitigate the situation. In 2019 the ranking stood at 69 with a figure of 59 PM2.5 µg/m³ which was slightly better than the 2018 figure of 76.1 µg/m³.
The PM10 particulate matter presently recorded consists mainly of fine dust and smoke which are large enough to become lodged in the mouth, throat and nose. The smaller PM2.5 particles are worse because they are small enough to enter the bloodstream after being inhaled into the lungs and trapped in the alveoli. Research conducted by the Air Pollution Knowledge Assessment city programme lists power plant emissions of 39 per cent and vehicle emissions and road dust make up 22 per cent.
Data recorded from 2016-2018 show that levels of Sulphur Dioxide (SO2) remain within acceptable levels in all cities where the tests were conducted. However, this was not the case for Nitrogen Oxide (NOx) and Sulphur Oxide (SOx) pollution, which are mainly produced by vehicle emissions. Over this period of time, 17 cities recorded an increase, 16 others noticed a decrease and a further 16 indicated fluctuating figures.
As far as Ahmedabad is concerned, it recorded increasing levels of Sulphur Dioxide since 2018 and the same trends applies to Nitrogen Dioxide which increased during 2016 and 2017 but remained at a constant level in 2018.
As with most large cities, the main source of air pollution within the city comes from vehicles and emissions from coal-fired power plants. The burning of rubbish and garbage at the Pirana dumping yard 24/7 also contributes to the dirty air as does the ceremonial burning of items of a religious nature.
Residents living near the Pirana site complain that their houses are covered in dust and that if they are not careful with their laundry, it becomes black due to the fine soot particles landing on it. A level of over 300 is often recorded for this area.
This soot is often referred to as Black Carbon (BC). It is formed by the incomplete combustion of organic matter and enters the air as PM2.5 Particles.
The fact remains that Ahmedabad is the most polluted city after Delhi has encouraged action to be taken by the local authorities. A decision has been made to turn Ahmedabad into a kerosene-free city and it has also been decided that not renew the license for commercial vehicles older than 15 years. All auto rickshaws will be converted to run on Condensed Natural Gas (CNG) and any new bus which is to be purchased will have to be CNG compatible.
A programme to generate energy from the mountain of waste at the Pirana dumping ground has also been given the “green light”. A ban on plastics of less than 10 microns will be implemented in the future. More air quality measuring stations are to be built at several locations in order to get a better understanding of how air quality differs in different places.
An unusual proposal has been put forward to wall-to-wall pave the inner city pavements to prevent dust blowing from the dry earth. New ones will be laid where there currently are none or where they are now broken.
The burning of straw and other organic material in order to prepare the ground for the next crop, is a great problem. Every year, after the rice harvest, the residual dry straw is burnt, creating a choking cloud of pollution which is carried by the wind towards the cities. Scientists are currently working on the development of a seeding machine which could sow the seeds directly into the ground over the top of the stubble. This new method would allow a 20 per cent increase in the crop yield and reduce the air pollution by as much as 78 per cent because the stubble no longer needs to be burnt off. The only downside to this would be the initial outlay of financing the machine, however it has been suggested that contractors are employed to sow the seed but that too costs money.
Living in any large metropolis exposes residents to many forms of pollution and Ahmedabad in no exception. It was, however the first city in India to operate Bus-rapid-transport system (BRT). This was inaugurated in late 2009 and has since been expanded to 89 kilometres. It is estimated that over 130,000 inhabitants use this service on a daily basis thus alleviating the need for private vehicles.
However, there is still a great risk from breathing in the heavily polluted air. Long term exposure can lead to strokes, lung cancer, chronic lung diseases, heart attacks and neo-natal diseases. In 2019, 1.67 million deaths were recorded as being a direct result of air pollution.
The air quality inside the home also can contribute to poor air quality by the use of charcoal, dried animal dung and wood when used as a fuel. In 2019 over 100,000 Indian infants lost their life due to poor air quality, mainly due to PM2.5.
It has recently been stated that the air quality is gradually improving but these improvements are only marginal, particularly on the Indo-Gangetic plains which are particularly susceptible to high levels of air pollution, especially during the winter months due to the lack of rain.
Sensitive groups and people with existing respiratory problems are advised to limit the amount of time they spend outdoors and to wear a good quality face mask. It is highly recommended to close all windows when inside to limit dirty outside air from entering. Indoor exercise can be taken in the form of walking through the large shopping malls or the use of exercise machines.