Considering the mounting evidences of the effects of air pollution on health, the present study was undertaken to assess the ambient air quality status in Sonepat region. The PM 10 aerosol samples were collected from three sampling sites (DCRUST: Deenbandhu Chhotu Ram University of Science and Technology, University campus, Sector 14: residential cum commercial area, and traffic intersection along National Highway number 1) during January to July 2014 and studied for air quality, metal concentrations and their monthly variations. In addition, free fall dust samples were studied for soluble cations. PM 10 concentration was found to be ranging from 120.00 μg/m 3 to 569.59 μg/m 3, 66.56 μg/m 3 to 312.45 μg/m 3 and 80.95 μg/m 3 to 262.47 μg/m 3 at NH-1, Sector-14 and DCRUST respectively. The concentrations of Na +, , K +, Ca 2+, Mg 2+ at sector 14 Sonepat were 52.115 ppm, 6.755 ppm, 13.989 ppm, 105.845 ppm and 72.574 ppm, respectively. At DCRUST site, the concentrations of Na +, , K +, Ca 2+, Mg 2+ were 207.583 ppm, 0.550 ppm, 50.573 ppm, 90.659 ppm and 85.024 ppm, respectively. The heavy metals concentrations of Zn, Cu and Cr at NH-1 was 36 ppm, 17.5 ppm and 95.7 ppm, respectively. The concentration of Zn, Cu and Cr at NH-1 was found to be varying from not detected to 19.7 ppm, 2.1 ppm to 16.54 ppm and 7.24 ppm to 24.1 ppm, respectively. Thus, it was recommended that an integrated assessment of air pollution and health risk should be carried out in Sonepat region at regular intervals of time.
Air quality is getting deteriorated day by day and is of a great concern not only in mega cities but developing cities. Numerous studies have been conducted on determination of chemical composition of aerosols and pollution source in mega cities. Atmospheric aerosol is termed as tiny liquid or solid particulate matter suspended in air. The atmospheric aerosol plays direct and indirect role in various atmospheric phenomenons [
Anthropogenic emissions of air pollutants (like Particulate Matter and heavy metals) that are linked with rapid urbanization and industrialization in developing countries are severely affecting the environment and human health [
Sonepat is located at 28.98˚N 77.02˚E in the National Capital Region about 40 km from Delhi. The Yamuna river flows along the eastern boundary. The climate of Sonepat is dry with a hot summer and a cold winter. The weather becomes milder during the monsoon period (July to September). The post-mon- soon months of October and November constitute a transition period prior to the onset of winter.
The winter starts in December when day and night temperatures fall rapidly. January is the coldest month when the mean daily minimum temperature is 6˚C to 7˚C. The district experiences high humidity only during the monsoon period. The period of minimum humidity (less than 20%) is between April and May. Sonepat is becoming a growing industrial town due to its proximity with Delhi. There is a remarkable growth in export of rice, stainless steel products, paper products, electrical goods and auto parts in the district.
The environment of Sonepat has degraded in the past few years due to rapid urbanization, industrialization, and increase in population, vehicles and commercialization of land available within the town. Three sampling sites which have been selected include NH-1 (S1) which is a National Highway connecting North India to New Delhi, DCRUST (S2) and sector 14 (S3) (
The samples of PM10 were collected at all three sites NH-1, DCRUST and Sector 14 from January 2014 to July 2014. PM10 samples were collected for 24 h at three different sites twice a week. PM10 samples were collected using a high volume air sampler (Model: Lata Envirotech India, APM 154) fitted with a fiberglass filter. All the collected samples were packed in polyethylene covers and transported immediately to the laboratory and analysed for PM10 and heavy metals in PM10 using standard laboratory procedures. In the laboratory the filter papers obtained after sampling were weighed again to determine the mass concentration of PM10.
Aerosols samples of free fall dust were collected from the sampling sites using plastic trays filled with a layer of glass marble balls kept at a height of 15 meters above the ground level using the phenomena of gravity settling. The purpose of using the marble balls in tray was to trap the freely falling dust particles in between the marbles. Dried sample was removed from the trays with the help of a scrapper and the tray as well as marble balls were washed with distilled water to remove the sticky particles, the solution was evaporated at 70˚C in order to get the sample in dried form and was stored in plastic vials for analysis.
After sampling, one-fourth of the exposed fiberglass filter, was cut and put in a Teflon crucible, then a mixture of 5 ml of Hydroflouric acid (HF), 10ml of conc. Nitric acid (HNO3) and 1 ml of Perchloric acid (HClO4) was taken in the same crucible and was kept on a hot plate at a temperature range of 85˚C - 90˚C with the lid on for 4 hours to ensure complete reaction. After 4 hours the lid was removed and the solution was evaporated to dryness. In next step, 10 ml HF, 5 ml HNO3 and 1 ml HClO4 was added to above and then heated to dryness. After cooling, in the next stage, 5 ml concentrated Nitric acid was added and heated to dryness. In next step, 20 ml of 1 N Hydrochloric acid (HCl) was added to about 100˚C to bring the digested sample into solution and then transferred to 50 ml flask. This sample was cooled and raised up to 100 ml by adding milli-Q water [
2 g of free fall dust was weighed and transferred to 100 ml conical flask and then 20 ml of milli-Q was added. Solution was thoroughly mixed by shaking conical flask for at least half an hour. Solution was filtered through 0.2 µm filter. Now the sample was ready to be inserted in ion exchange chromatography.
The data of aerosol load was collected to record seasonal variation in the status of air-borne PM10 and to correlate them with anthropogenic activity. The knowledge of aeorsol load is important as it affects the climate change in local area. A continuous monitoring is required to know the seasonal effect in developing cities due to local factors.
The monthly average of 24 hourly average value of PM10 are shown in
The high PM10 concentration at highway is as a result of various commercial activity and high traffic density, as this is National Highway-1 connecting Delhi to North India. This sampling site is actually a crossroad between Sonepat and NH-1, where sometimes a congestion of vehicle occurs due to traffic bottlenecks and absence of signals. In addition to this aerosol particles are also emitted into atmosphere due to abrasion process of automobiles components such as brake or tire wear [
The second sampling station was a university campus with adequate vegetation and better maintenance but it is not far away from NH-1. The comparatively less concentration of particulate matter in the university campus may be attributed to the good vegetation in campus.
The concentration of PM10 in Sonepat city indicates that the level of particulate matter has increased significantly. This is due to urbanisation, increase traffic density, construction activity, biomass burning and poor condition of roads. The concentration of PM10 in Sonepat city was found to be exceeding the permissible limit. An interesting relationship has been observed, between population density and suspended particulate matter which shows that particulate matter concentration hardly depends on the local meteorology and climate of the place; rather it depends upon the local polluting sources [
Road dust resuspension is also a major contributor to PM10 during all seasons. There is found to be significant variation in aerosol load with season. The dry deposition of aerosols is a effect of both natural and anthropogenic sources. The entire data of various months was grouped to know the seasonal variation. The season from January to March is spring and is associated with low wind speed and less rain resulting in increase of air pollution. High concentration of particulate matter in February may be due to calm wind conditions, moderate temperature and scanty rainfall. Whereas high concentration of particulate matter in summer from April to June, is associated with strong winds and low humidity. This may also be attributed to the harvesting period as the area is surrounded by fields and burning of paddy takes place in April-May despite ban from Govt. of Haryana.
In contrast July is monsoon season with low wind speed and medium to high precipitation which reduces air pollution due to scavenging effects of rain and is reflected in PM10 concentration in July. Rain in the area in July makes atmosphere clean from dust particles. This suggests that monsoon has a cleansing effect on atmosphere. Particulate matters are potentially dangerous for human health. These small particles can penetrate deep in to the lungs and causes various health problems like asthma, bronchitis etc.
The heavy metals are associated with respirable dust particles in urban air and penetrates deep into lungs and cannot be flushed out easily. The presence of heavy metal in particulate matter can be attributed to anthropogenic as well as geological origin in the city. The heavy metal concentration was determined only at one station i.e. NH-1 which was having highest PM10 load. The concentration of heavy metals in the atmosphere ranged as Zn (ND-25.6 µg/m3), Copper (1.4 - 22.85 µg/m3), and Chromium (5.21 - 27.42 µg/m3). The order of average concentration of heavy metals was in the order Cr > Cu > Zn. Pb concentration was found to be below detection limit in all months and this could be attributed to use of unleaded petrol in vehicles, which used to be a major contributor of lead in urban areas [
In cities the major components of airborne particulate matter are inorganic ions, metallic constituents and organic compounds [
Month | Zinc (Zn) | Copper (Cu) | Chromium (Cr) |
---|---|---|---|
January | 13.8 ± 2.35 | 16.5 ± 3.11 | 24.1 ± 3.89 |
February | 19.7 ± 1.51 | 16.54 ± 2.17 | 18.74 ± 4.21 |
March | Below detection limit | 2.1 ± 1.87 | 7.24 ± 1.69 |
April | 5.46 ± 1.47 | 11.1 ± 5.60 | 19.7 ± 3.32 |
According to Yusuf and Rashid [
anthropogenic origin. K+ is a useful tracer for pyrogenic aerosols in plants; it is an important component that originates from burning of vegetative material [
In the present study, the chemical characterisation of PM10 was done on samples collected from developing city Sonepat. As this was the first study done in the region concerning anions, heavy metal and PM10 load, we could not compare it with previous studies. The PM10 concentration in the region shows that it was season specific and wind direction and humidity plays a crucial role. The PM10 concentration was higher than permissible limit of Central Pollution Control Board, India. The three metals Zn, Cu and Cr were also quantified from PM10 concentration. The concentrations of heavy metals were substantial in traffic area and so might be correlated with traffic density. The gaseous pollutants serves as precursors of ionic particle so were studied along with. There is need of study of source apportionment along with aerosol study to avoid health problems due to exposure of heavy metals.
The first author is a thankful to University Grant Commission, New Delhi for Start Up Grant provided.
Chaudhary, S. and Kumar, N. (2017) Qualitative and Quantitative Analysis of Aerosols in Sonepat-A National Capital Region-India. Open Journal of Air Pollution, 6, 65-75. https://doi.org/10.4236/ojap.2017.62006