The level of air and noise pollution in the city on Diwali this year was less as compared to the previous two years.

The announcement by radical Sikh organisations to observe “black” Diwali in protest against the recent incidents of desecration of Guru Granth Sahib seems to be one of the major factors for this.

As per the figures released by the Punjab Pollution Control Board, although the air and noise pollution levels were more than the permissible limits, these were low compared to the levels on the Diwali night in 2014 and 2013.

As fireworks lit up the skyline of the city, devices installed in major areas started monitoring noise pollution. The level of noise pollution was checked with a DV meter while that of air pollution with filter papers.

The city was divided into three zones, commercial, residential and sensitive, for the purpose of recording pollution levels. The sensitive zones include hospitals, educational institutions and religious places.

The noise pollution readings were taken by the officials from 6 pm to 12 midnight on Wednesday.

According to the national ambient air quality standards, the atmosphere must not contain more than 100 micrograms of respirable suspended particulate matter (RSPM) per cubic metre, 80 micrograms of oxides of nitrogen (NOx) per cubic metre and 80 micrograms of sulphur dioxide (SO2) per cubic metre.

On Diwali night this year, the average RSPM in commercial zone was 289 micrograms per cubic metre while it was 546 and 505 in 2014 and 2013, respectively. The average RSPM in residential zone this year was 148 micrograms per cubic metre as compared to 316 in 2014 and 335 in 2013. The RSPM level in sensitive zone was 179 micrograms per cubic meter this year while last year it was 412 and in 2013, it was 308.

Oxides of nitrogen recorded on the Diwali night this year were 40 micrograms per cubic metre in commercial zone, 31 in residential zone and 27 in sensitive zone while last year it was 50, 38 and 42 per cubic metre, respectively.

In sensitive zone, the sulphur dioxide recorded on Diwali night this year was 18 per cubic meter in commercial zone, 12 in residential zone and 11 in sensitive zone. In 2014, the readings were 24, 22 and 20 per cubic meter, respectively. In 2013, the presence of sulphur dioxide per cubic metre on Diwali night was 18, 22 and 15 in commercial, residential and sensitive zones, respectively.

As far as the normal range of sound is concerned, it is 75 decibels (dB) and 70 dB during the day and night time, respectively, for industrial area, 65 dB and 55 dB for commercial area, 55 dB and 45 dB for residential area and 50 dB and 40 dB for silence zone. As per the rules, the day time is from 6 pm to 10 pm and night time from 10 pm to 6 am.

The average noise pollution level in the residential zone this Diwali was 66.3 dB as compared to 75.48 dB last year and 70.86 dB in 2013. In the commercial zone, the sound level was 72.1 dB this year while it was 78.35 dB in 2014 and 78.6 dB in 2013.

In the sensitive zone, the average level this year was 69.1 dB while in 2014 it was 74.74 dB as against 72.95 dB in 2013.

Source: November 14, 2015, The Tribune