Parmar, D. K.Khatkar, Ameesh2019-08-202019-08-202019-07http://krishikosh.egranth.ac.in/handle/1/5810122562The unique geographical position and special climate environment have attracted more and more tourists to Himachal Pradesh and consequently, affecting the environment gradually by vehicular exhaust because environment in this state is rarely affected by other anthropogenic activities. The present study entitled “Studies on heavy metals contamination along national highway soils and plants ecosystem in Himachal Pradesh” was therefore, designed to assess the extent of heavy metals concentration in roadside soils and plants along NH-21 and to characterize soil and plant samples into safe/toxic levels. The selected study sites of current study were Dadour, Nagchala, Takoli, Nagwain and Jhiri in Mandi district and Kais, Kararsu, Raison, Katrain and Patlikuhal in Kullu district. One rural road in each district was also taken as a background sampling site (Rahala in Mandi and Dobhi in Kullu) to compare the extent of heavy metals with that of NH-21. Soil and fruit samples of commercially grown tomato and apple were collected at 0 m, 50 m, 100 m, 200 m, 300 m, 400 m and 500 m on both sides of NH-21. The sampling was done during peak tourist season starting from first week of May, 2018 till last week of July 2018. Surface soil samples collected at above mentioned sites were processed, digested and analyzed for heavy metals following standard methods. Similarly, fruit samples of tomato from each site in Mandi district and apple fruits in Kullu district were processed, digested and analyzed for heavy metals using standard techniques. Means were used to assess the contamination levels of heavy metals in soil and fruit samples at each site and comparison was done with maximum permissible limits set by WHO/FAO. Correlation carried out to determine the relationships between sampling locations from road and soil properties and heavy metal in both soil and edible plant parts. The results of current study revealed that samples taken next to the road were characterized by higher values of soil pH, EC and heavy metals in soil as well as in tomato and apple fruits. Decreased values of measured variables in soils and plant were recorded along with an increase in the distance from the national highway. The concentration of heavy metals were in sequence Fe > Mn > Zn > Cu > Pb > Cr > As > Hg for soil and Mn > Zn > Cu > Fe >Pb > As > Cr > Hg for plant. However, Hg in soil was detected only at Dadour and Nagchala sampling sites in Mandi, whereas it was below the detection limit in other sampling sites of Mandi and Kullu district. The roadside surface soil as well as tomato and apple fruit samples were relatively contaminated with heavy metals. The results of this study revealed elevated values of heavy metals e.g. Fe, Zn, Pb and As in soil and Cu, Zn, Pb and As in plant. On the other hand, Cu, Mn, Cr and Hg in soil and Fe, Mn, Cr and Hg in plant were below the maximum permissible limits as set by WHO/FAO. The results of correlation analysis between the levels of the heavy metals and varying sampling distances from road along two sides (left and right) from each of the sampling sites revealed a significant (p ≤ 0.01) but negative correlation. The observed negative correlation values depicted that concentration of heavy metals in soil and plant decreased with increase in sampling distances from the road. These heavy metals are cumulative poisons and their values need to be below the proposed maximum tolerable levels fixed by the FAO/WHO. It is therefore, recommended that the levels of heavy metals in soils and plants should be constantly monitored.enThesis