Monitoring of Suspended Particulate Matter (SPM) in ambient air in the campus of Lady Keane College, Shillong.

· Articles
Authors

D.G. Marbaniang*, Carefullydaris L. Nonglait, Naris Thabah, Zeralovinia Wahlang &
Peltisha L. Mawlong
Department of Chemistry, Lady Keane College, Shillong
*Corresponding author: D.G. Marbaniang, email: deswyn1@yahoo.com

Abstract

Clean air is necessary for healthy life. Air is one of the five vital basic natural ingredients of life system. A first ever study on the ambient air quality in the campus of Lady Keane College, Shillong was undertaken during the month of November, 2013. The findings indicate that the ambient air in the campus possess light air pollution. The current mean concentration of total suspended particulate matter (SPM) in the vicinity of Lady Keane College was found to be 97.42µgm-3 which is much lower than the NAAQ Standard limit (200µgm-3). Also, the mean respirable suspended particulate matter (RSPM) was observed to be 54.40µgm-3 which is also lower that the NAAQ Standard limits (100µgm-3). The low concentration of RSPM can be attributed to the immediate and important green surrounding in and around the college.

Keywords Air, health, monitoring, particulate, respirable

Introduction

Clean air is necessary for healthy life. Nevertheless, many essential human activities related to economic and social development pollute the air where most people live. Air is one of the five vital basic natural ingredients of life system. The immediate environment of humanbeing comprises of air on which depends all forms of life. The major anthropogenic sources of air pollutants are industrial emissions, domestic fuel burning, emissions from power plants and transportation activities etc. The advent of technological and scientific innovations in various fields and diverse activities of human race for its sophistication have put extra load on the atmosphere by way of releasing air pollutants like suspended particulate matter (SPM), respirable suspended particulate matter (RSPM), sulphur dioxide (SO2), oxides of nitrogen (NOx), carbon monoxide (CO), unburned hydrocarbon (HC), hydrogen fluoride (HF) and other organic as well as inorganic pollutants including trace metals responsible for causing health consequences. (Panda et al., 2012)

Air Pollution indeed is now a serious worldwide public health problem. The short term health impacts of air pollution have been studied extensively since the London fog in the mid 20th Century and subsequent series of dreaded incidents in industrialized countries. The compatibility between ecology and economy is one of the most burning issues of the present times. Developmental activities for example industrial expansion, mining exploration, transportation and constructional works etc. cause degradation and drastic changes in every component of environment namely: hydrosphere, lithosphere, atmosphere and biosphere through pollution. Air pollution has emerged in the past few decades as the most crucial problem to the mankind and a large number of studies in this regard have been undertaken all over the world (Panda et al., 2012).

Monitoring is a general term for the on-going collection and use of measurement data or other information for assessing performance against a standard or status with respect to a specific requirement. Ambient air quality monitoring refers to collecting and measuring samples of ambient air to evaluate the status of the air pollutants in the atmosphere as compared to clean air standards and historical information. Ambient air monitoring evaluates the status of the atmosphere and provides air quality information to regulators, scientists, industry, and the public. Ambient air quality monitoring is required to determine whether a geographical region or area is meeting the National Ambient Air Quality Standards (NAAQS) for criteria pollutants. In addition to determining areas where air quality standards are not being achieved (non-attainment areas), the monitoring data are used to assess trends in air quality, and to assess the impact of pollution generated by various activities. The emissions from stationary sources (and other types of sources, e.g., mobile sources such as automobiles) directly impact the ambient air quality of a region and the pollutant levels detected by ambient monitoring (USEPA, 2013a).

Airborne contaminants can present a significant threat to worker health and safety. Thus, identification and quantification of these contaminants through air monitoring is an essential component of a health and safety program at a hazardous waste site. Reliable measurements of airborne contaminants are useful for:

  • Selecting personal protective equipment.
  • Delineating areas where protection is needed.
  • Assessing the potential health effects of exposure
  • Determining the need for specific medical monitoring.

This chapter delineates the factors to consider when conducting air monitoring at a hazardous waste site. It presents strategies for assessing airborne contamination at hazardous waste sites and describes instruments and methods for measuring exposures. (OSHA, 2013).

Suspended particulate matter (SPM) in air generally is a complex, multi-phase system of all airborne solid and low vapor pressure liquid particles having aerodynamic particle sizes from below 0.01-100µm and larger. Historically, SPM measurement has concentrated on total suspended particulates (TSP), with no preference to size selection. Research on the health effects of TSP in ambient air has focused increasingly on particles that can be inhaled into the respiratory system, i.e., particles of aerodynamic diameter less than 10µm. The health community generally recognizes that these particles may cause significant adverse health effects. Recent studies involving particle transport and transformation strongly suggest that atmospheric particles commonly occur in two distinct modes: the fine (<2.5µm) mode and the coarse (2.5-10.0µm) mode. The fine or accumulation mode (also termed the respirable particulate matter) is attributed to growth of particles from the gas phase and subsequent agglomeration, while the coarse mode is made of mechanically abraded or ground particles. Ambient air SPM measurements are used (among other purposes) to determine whether defined geographical areas are in attainment or non-attainment with the national ambient air quality standards (NAAQS) for PM10 (USEPA, 2013b).

Sampling locations

Lady Keane College, Shillong a pioneer in Women’s education in the North Eastern Region was established in the year 1935. It is located in the heart of Shillong City which is the Capital of the State of Meghalaya. The college is surrounded on the North by congested G.S. Road which is the main road of the City, on the East by busy M.G. Road, on the South by the National Highway 44 and on the west by another main road which links it to the main market (Figure 1). Because of its immediate surroundings, the college was deemed ideal to conduct this study so as to ascertain the level of total Suspended Particulate Matter concentration in the campus.

Objectives

The objectives for carrying out this study are;

  1. To check the air quality relative to standard limit values and
  2. Monitor current levels as a baseline for future assessment.

Period of sampling, frequency and duration

Sampling was carried out for 8h day-1 for five working days during the time when activities in the college is at its peak. Measurement was performed during the month of November, 2013.

Instrumentation

A high volume air sampler attached with an SPM filter manifold, air flow monometer to measure flow rate and Glass fibre Filter (8“× 10″) (Model Type: APM 400BL without Blower, Envirotech) was used for the study. This equipment is a High Volume Sampler with a cyclone attachment which fractionates the dust into respirable and non-respirable fractions (Figure 2).

Method of Measurement

The method employed for collection of suspended particulate matter is by volumetric filtration and gravimetric weighing, where sampling of air through a filter medium at a known flowrate for a specified time is performed. The sampler whose height is around 1.3 m is kept at the ground level so as to mimic the average height of the average human respiratory organ i.e., the nose. A conditioned and pre weighed glass fibre filter and a cyclone cup are placed in their appropriate mounting in the air sampler. The sampler timer is set for eight hours. The monometer is also adjusted for the right flow rate (i.e., 1Lmin-1) and the initial flow rate is noted down after 5 min of starting. The suspended particles enter the cyclone where coarse non-respirable dust (NRSPM) is separated from the air stream by centrifugal force. It falls through the cyclone’s conical hopper and gets collected in the pre-weighed cyclonic cup. The fine dust comprising the respirable fraction (RSPM or PM10) of the suspended particulate matter is collected on a pre-weighed Whatman glass microfibre filter paper (GF/A 20.3 × 25.4 cm). At the end of the sampling process, the final flow rate is again noted down and the RSPM collected over the GF filter paper and the NRSPM collected in the cyclonic cup are weighed using an electronic top loading weighing balance. The concentration of the particulate matter is estimated on the net mass collected divided by the volume of air sampled. The amount of non-respirable suspended particulate matter (NRSPM) is added to the amount of respirable suspended particulate matter (RSPM) for calculation of SPM (Suspended Particulate Matter). (Panda et al., 2012)

Table 1: Concentration of Suspended Particulate Matter in Ambient Air in Lady Keane College, Shillong.

SL. No.

Location/ Date

Starting Time/ Date

Stopping Time

Total Time in Hrs

Monometer Reading

Filter paper Weight

Cyclone Cup Weight

Conc. Of RSPM (µgm-3)

Conc. Of NRSPM (µgm-3)

Total SPM Conc. (µgm-3)

Activities in and around the college campus

Initial m3min-1

Final m3min-1

Initial g

Final g

Initial g

Final g

1.

LKC Campus, Near DG Set15.11.2013

10:30 am

6:30 pm

8

1.04

1.05

2.799

2.830

12.580

12.601

61.80

41.87

103.78

Plying of Vehicles Construction Work in the college campus. Use of Generator for 2 hours

2.

LKC Campus, Near DG Set18.11.2013

11:00 am

7:00 pm

8

1.06

1.05

2.793

2.836

12.610

12.624

84.9

27.65

112.56

Plying of Vehicles. Construction Work in the college campus

3.

LKC Campus, Near DG Set20.11.2013

9:00 am

5:00 pm

8

1.07

1.04

2.784

2.801

12.618

12.647

33.57

39.50

90.84

Plying of Vehicles Construction Work in the college campus. Use of Generator for 3 hours

4.

LKC Campus, Near DG Set21.11.2013

10:00 am

6:00 pm

8

1.07

1.04

2.800

2.823

12.319

12.350

45.42

61.22

106.64

Plying of Vehicles Construction Work in the college campus

5.

LKC Campus, Near DG Set22.11.2013

10:00 am

6:00 pm

8

1.08

1.08

2.783

2.807

12.635

12.635

46.30

27.00

73.30

Plying of Vehicles Construction Work in the college campus

Result and Discussion

The fact that air pollution is hazardous to human health is well known. WHO estimates that worldwide, at least two million people every year die prematurely due to health effects caused by lack of clean air. Air is the basic necessity of human life but the quality of air is deteriorating continuously and it is being constantly polluted from different sources. One of the major sources of air pollution are automobiles and industries, as per estimates vehicular pollution is the primary cause of air pollution in urban areas (60%), followed by industries (20-30%) in India. (Panda et al., 2012)

From Table 1, it can be seen that the concentration of the total suspended particulate matter (SPM) during different sampling periods was found to be different. The reason for this fluctuation can be attributed to the different activities that occur during the sampling period. As can be seen from Table 1, apart from the student population that crowds the college every day, the other recorded activities in the campus of Lady Keane College include plying of Vehicles (two wheelers; light motor vehicles; Heavy motor Vehicles; both diesel and petrol engines), construction work within the campus of the college and use of a generator for some hours in specific days. The frequency of such activities may fluctuate during different sampling days. These activities may directly or indirectly contribute to the lowering or increased in the concentration of the SPM values. Also, being located at the heart of the City and surrounded by four major high density roadways, this strategized location may also be responsible for the observed concentration of SPM. The concentration was found to vary from a minimum value of 73.30µgm-3 to a maximum value of 112.56µgm-3 with a mean value of 97.42µgm-3. The respirable suspended particulate matter (RSPM) varies from 33.5µgm-3 to 84.9µgm-3 with a mean of 54.40µgm-3 whereas the nonrespirable suspended particulate matter (NRSPM) varies from 27.00µgm-3 to 61.22µgm-3 with a mean value of 39.45µgm-3. From (Figure 3), it can be seen that there is variation in the minimum and maximum values of SPM and RSPM. Unlike SPM which shows a minimum concentration on the 22.11. 2013 sampling, RSPM minimum values was observed on the 20. 11.2013. The maximum values were however observed on the 18.11.2013 sampling date.

Comparing the mean SPM values (97.42µgm-3) with the National Ambient Air Quality Standards (NAAQS; Table 2 & Table 3), it can be seen that the SPM concentration in the campus of Lady Keane College is below the standard prescribed values of 200µgm-3. The measured RSPM mean value (54.40µgm-3) was also lower than the standard prescribed limit of 100µgm-3. However, it is important to mention that in this study, sampling was performed only for eight hour per day. Had the duration been increased the values might also be higher. Throughout the sampling period, there was no rainfall and since the sampling month (i.e., November) is the start of the winter season in which anti-cyclonic condition prevailed which was characterized by calm or very slow wind, there was little dispersion or dilution of pollutants which caused higher levels of SPM.

Table 2:National Ambient Air Quality Standards in µgm-3 (Suspended Particulate Matter)

Averaging Period

Industrial Areas

Residential,Rural & other areas

Sensitive areas

24 Hours

Annual

500

360

200

140

100

70

Table 3:National Ambient Air Quality Standards in µgm-3 (Respirable Suspended Particulate Matter; PM-10 & PM-2.5) (CPCB, 2004).

Averaging Period

Industrial Areas

Residential,Rural & other areas

Sensitive areas

24 Hours

Annual

150

120

100

60

75

50

Conclusion

The current mean concentration of suspended particulate matter in the vicinity of Lady Keane College was found to be 97.42µgm-3 which is much lower than the NAAQ Standard limit (200µgm-3). Also, the mean RSPM was observed to be 54.40µgm-3 which is also lower that the NAAQ Standard limits (100µgm-3). This is the first ever study on the ambient air quality in the campus of Lady Keane College, Shillong. The findings indicate that the ambient air in the campus possess light air pollution. This study allows us to understand the baseline concentration of SPM and RSPM in the campus of the college. At present, the concentration of SPM and RSPM are lower than the prescribed limit. This can be attributed to the immediate and important green surrounding that the college is blessed with. It may be because of the presence of this green coverage, that the concentration of SPM which include both respirable as well as non-respirable particulate matter which may pose a serious health concern to the residents as well as the students pursuing their career in this prestigious institution was observed to be lower that the safety limit.This finding will serve as a reference for the management of the institution to take precaution so as not to disturbed the greenery but strive to enrich it further.

This study in itself is not complete. It requires further research into other air pollution indicators so as to have a comprehensive understanding of the quality of the ambient air within the borders of Lady Keane College, Shillong.

Acknowledgement

The author and co-workers wish to extend their sincere gratitude to the Principal, Lady Keane College for her encouragement, and for Sponsorship to the project, to the Head of the Chemistry Department for allowing the work to be carried out in the Departmental Laboratory and to the staff of the department for their active participation in this research work.

References

CPCB, 2004. National Ambient Air Quality Standard, Central Pollution Control Board, New Delhi.

Google Maps, https://maps.google.co.in/maps?ie=UTF8&q =Lady+Keane+College&fb=1&gl=in&hq=lady+keane+college+shillong&cid=609216305257764311&ei=UCT7UpDBGs2nrgf99YBo&sqi=2&ved=0CJABEPwSMA4

OSHA, 2013. Occupational Safety and Health Administration, United States Departmnt of Labor.

Panda B.K. and Panda C.R. 2012. Estimation of ambient air quality status in Kalinga Nagar industrial complex in the district of Jajpur of Odisha, International Journal of Environmental Sciences 3(2): 767-775.

USEPA, 2013a. United States Enviornmental Protection Agency (http://cfpub.epa.gov/oarweb/mkb/faq.cfm)

USEPA, 2013b. United States Enviornmental Protection Agency (http://www.epa.gov/ttnamti1/files/ambient/inorganic/mthd-2-1.pdf)

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