GUWAHATI, July 31: The Pollution Control Board, Assam (PCBA) was monitoring only three of the twelve air pollutants notified by the Central Pollution Control Board (CPCB) for monitoring, thereby risking exposition of people and other wildlife in the State directly to air pollutants that could be detrimental to health. Besides, all monitoring stations were located in residential areas whereas there was no station in highly populated/vehicular density areas or in commercial, industrial and eco-sensitive areas.

The Comptroller and Auditor General (CAG) of India said this in its report on performance and audit on environmental degradation in the greater Guwahati area, with special emphasis on the role of the PCBA. The CAG’s report was tabled in the Assam Assembly recently.

The CPCB had notified the National Ambient Air Quality Standard (NAAQS) in November 2009 with 12 identified pollutants, including gaseous pollutants – sulphur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), carbon monoxide (CO) and Ammonia (NH3); two dust-related parameters PM10 and PM 25; three metals lead, nickel and arsenic; and two organic pollutants benzene and BaP-particulate.

However, during the audit, the CAG report said, it had been found that the PCBA had been monitoring only three pollutants – sulphur dioxide, nitrogen dioxide and Respirable Suspended Particulate Matter (RSPM/PM10) and Suspened Particulate Matter (SPM) regularly at all the 22 locations. It was also observed during the audit that the PCBA had not carried out any study regarding effects of air pollution on human health in Guwahati city.

On being pointed out, the CAG report said, the CPBA said in August 2015 that due to some technical difficulties, all prescribed parameters could not be monitored and the CPCB had been regularly accepting PCBA’s reports on four quality parameters. The PCBA further said that efforts had been to include more parameters.

The CAG report, however, said that the PCBA’s reply was not tenable as the fact remained that the PCBA could not monitor all the parameters prescribed by the CPCB even after a lapse of five years and on the basis of analysing three parameters, actual air quality could not be ascertained.

The PCBA has been carrying out ambient air quality under the National Air Monitoring Programme (NAMP) since 1991, and till date in Assam there are 22 stations, including six in Guwahati.

It was observed during the audit that –

* As per guidelines for Ambient Air Quality Monitoring, distribution of monitoring stations in a city depends on the distribution of pollution sources, and population in it. More stations should be located in areas according to population density, number of industries, and vehicular density. However, the physical verification of the six monitoring stations at Guwahati showed that all of them were located in places relatively with lesser population and vehicular density, the CAG report said.

* When this was pointed out, the PCBA said in August 2015 that all the stations were set up in urban and residential areas where the PCBA could assess the air quality with reference to human habitation. Besides, industries also regularly monitor ambient air quality, the report said. The report, however, said that the fact remained that the setting up of monitoring stations in residential areas ignoring the sensitive and industrial areas was not in compliance with the provisions of the guidelines. “Further, though industries monitor the ambience air quality, they are done on yearly basis with few exceptions being done on half-yearly/quarterly basis instead of daily basis as mandated,” the CAG report said.

* “The sampler, as per guidelines, should not be located in any confined place and must be (i) over 20 metres away from trees, (ii) more than two times the height of obstacles, and (iii) there should be unrestricted airflow in three of four quadrants. However, it was observed during the audit that one monitoring station was located at a distance of three/four metres from the three-storeyed office building of the PCBA and the State Public Health Laboratory. There were trees adjacent to the monitoring station,” the CAG report said, and added: “Another monitoring station was surrounded by buildings/trees on all sides.”

* On being pointed out, the PCBA accepted the audit observations and said in August 2015 that in the first case the tree was under the area of the state public health laboratory which was occasionally trimmed. It also said that the site had been selected long back and they were in search of an alternative location, the report said.