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    ThesisItemOpen Access
    Active biomonitoring of heavy metals in the ambient air by mosses in the tarai region of U.S. Nagar, Uttarakhand
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2016-07) Negi, Vrinda; Singh, Vir
    Heavy metals, viz. Hg, Pb, Cu, Cd and Zn were monitored actively employing Thuidium cymbifolium (Dozy & Molk.) Dozy & Molk. in and around the Pantnagar University (15 km radius) for a period of one year (2014-15), at an interval of 4 months, for each season i.e. from March to June for summer, July to October for monsoon season, and November to February for winter. Prior to the monitoring work, Thuidium was screened out of ten mosses collected from Naina Peak, Nainital on the basis of its biochemical activity. It gave very good results for total chlorophyll, superoxide dismutase (SOD), peroxidise (POD) and catalase (CAT) enzymes upon being subjected to various concentration (10, 20, 50 and 100 ppm) and time period (7th, 14th, 21st and 28th day) of a concoction of aforesaid heavy metals under laboratory conditions. The highest total chlorophyll (5.74±0.39 mg/g FW) was observed at 10 ppm on 7th day. Highest SOD activity (6.00±0.02 Unit/min/g FW) was observed at 50 and 100 ppm on 28th day while CAT activity was just 4.93±0.12 Unit/min/g FW at 20 ppm on 28th day. POD activity (13.37±0.12 Unit/min/g FW), the highest amongst all the enzymes, was recorded at 100 ppm on 14th day. Heavy metals were determined by Atomic Absorption Spectrophotometer (AAS) and spatio-temporal maps were drawn using Quantum GIS software. The results suggested that summer was more prone to heavy metal pollution as compared to winter and rainy season. The average concentration of Hg, Pb, Cu, Cd and Zn in the air in summer was 8.60±0.11, 7.31±0.23, 1.05±0.06, 0.050±0.004 and 3.16±0.15 ppm respectively; in monsoon 4.15±0.09, 2.22±0.192, 0.60±0.29, 0.017±0.002 and 0.866±0.053 ppm respectively; and in winter 6.10±0.11, 4.08±0.222, 0.61±0.03, 0.030±0.003 and 1.99±0.106 ppm respectively. A high concentration of the aforesaid heavy metals was detected in the corresponding soil samples with positive correlation except for Cd. The highest Air Pollution Index (API) value was recorded for SIDCUL (1.67336) followed by Jha colony (1.029536), BSP gate-Pantnagar (0.989741), Matkota (0.762641, VRC (0.794992), Lalkuan station (0.695607), Petrol pump-Pantnagar (0.553984), Rudrapur market (0.51653), MRDC–fields (0.531072), Lalkuan market (0.581977) and Nagla gate (0.356864). Though heavy metal pollution might attain alarming proportions in the Tarai region in future with proliferation of polluting industries, the study area, fortunately, does not so far lie in the danger zone.