Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYBiodiversity, Conservation and Environmental Issues5 Marks
Question
How BS emission standards changed over time? Why is it essential?
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Answer
1. BS emission standards changed over the time due to changing city life and more vehicular traffic on the road, especially in the megacities.
2. Since capital city of Delhi was declared as worst polluted city as far as its air quality is concerned, various measures were taken by the Government of India. There was new fuel policy declared, in which Bharat stage emission standards (BS) were set.
3. These norms were set to reduce sulphur and aromatic content of petrol and diesel. Also the vehicular engines were upgraded.
4. Bharat stage emission standards (BS) are standards which are equivalent to Euro norms and have evolved on similar lines as Bharat Stage II (BS II) to BS VI from $2001$ to $2017$.
5. Since population of Delhi was to be saved, in $2001$, Bharat stage II emission norms were set for CNG and LPG vehicles.
6. This helped in reduced emission of sulphur which was controlled at $50$ ppm in diesel and $150$ ppm in petrol. Also aromatic hydrocarbons were reduced at $42 \%$ in concerned fuel according to norms.
7. Because, in spite of all the efforts, Delhi was declared as worst air-polluted city in the world in $2016$, therefore, Government of India directly adapted BS VI in the year $2018$, skipping BS V These efforts decreased the levels of $CO _2$ and $SO _2$ in Delhi.
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