Indian Journal of Geo Marine Sciences Vol. 48 (01), January 2019, pp. 137-142

An appraisal of pollution level in the sediments of forthcoming Vizhinjam port zone, Southwest coast of

Silpa B.L1, Aneesh T.D2, Reji Srinivas2*, Krishna.R.Prasad2, Arun T.J2 & Sajan K1 1Department of Marine Geology and Geophysics, School of Marine Sciences, Cochin University of Science and Technology, Cochin, 682016, India 2National Centre for Earth Science Studies, Earth System Science Organisation, Ministry of Earth Sciences, , , Pin: 695011, India [Email: [email protected]]

Received 06 March 2017; revised 07 July 2017

A pilot study on the granulometry and geochemical distribution of major and trace elements were carried out in the surface sediments of the port zone. Granulometric studies inferred the dominance of sand fractions in this high energy regime. Heavy metal concentrations in the area are below the threshold levels associated with the toxicological effects and the regulatory limits and this confirms the lithogenic origin of metals. Metal enrichments observed at , an international tourist destination specifies the anthropogenic influence. Present study reveals that as of now there is no distinctiveness either in the distribution of sediments or the heavy metals signifying an immaculate coastal environment.

[Keywords: Vizhinjam port, Granulometry, Geochemistry, Pollution.]

Introduction Adimalathura to Kovalam (6km) has earthy/rocky Pollution by heavy metals in natural environments cliffs fronted by narrow sandy beaches (Figure 1). has become a global problem1. The concentration of The coastal stretch of Adimalathura which is at the heavy metals in the aquatic environment needs south of the proposed port is a sandy beach whereas considerable ecological concern due to their toxicity, the Vizhinjam to Kovalam coastal stretch possesses non biodegradable properties and accumulative rocky headlands. The cenozoic sedimentary behaviours. Several studies on heavy metal formations of Kerala unconformably overlie the contamination were conducted on port zones of Precambrian crystalline rocks7, comprising mainly of different parts of the world and majority of them charnockite and khondalite group of rocks and these recorded toxicity of heavy metals in and around the structures have played a significant role in graben zone2, 3, 4, and 5. With the rapid industrialization and subsidence and in the formation of sedimentary basins economic development in coastal region, heavy in the west coast8. metals are introduced to the estuarine and coastal environment where metals are produced as by- Materials and Methods products6. Since the operating activities of the port The nearshore surface samples were collected from terminals/harbours are recognized to be extremely 3 transects T1 (Adimalathura), T2 (Mullur) and T3 harmful to the coastal environment an Environmental (Kovalam) at a depth of 3m, 5m, 10m, 15m and 20m Impact Assessment (EIA) is inevitable. As the (Figure 1). A total of 14 surficial sediment samples maximum transportation of the state is through sea, it were collected using van Veen grab and were is inevitable for the state to develop a container subjected to pre-treatment. Textural studies on the terminal to crater traded goods. To sustain an sediments were performed for sand, silt and clay international seaport at Vizhinjam a serious distributions9. Organic carbon (OC) was determined assessment on environmental pollution should be by wet oxidation method10. Analysis of major and taken before the development of the seaports. Hence trace elements was done using XRF facility which the present study proposes to investigate the heavy consists of a Bruker Model S4 Pioneer sequential metal contamination in and around the upcoming wave length dispersive X-ray fluorescence and Vizhinjam port zone. The study area extending from sample preparation units. Major and trace metal 138 INDIAN J. MAR. SCI., VOL. 48, NO. 01, JANUARY 2019

Table 1 — Percentage of sand, silt and clay of nearshore sediments of Vizhinjam Port area Locations Sand % Silt % Clay % Sediment type T1 (3m) 99.63 0.69 0.02 Sand T1 (5m) 99.30 0.97 0.05 Sand T1 (10m) 99.40 1.24 0.75 Sand T1 (15m) 99.73 0.83 0.07 Sand T2 (3m) 99.33 1.18 0.03 Sand T2 (5m) 99.67 0.88 0.02 Sand T2 (10m) 89.99 8.62 1.39 silty Sand T2 (15m) 90.92 7.69 1.39 silty Sand T2 (20m) 97.43 1.92 0.65 Sand T3 (3m) 98.72 1.34 0.04 Sand T3 (5m) 99.51 1.06 0.13 Sand T3 (10m) 97.99 1.34 0.67 Sand T3 (15m) 98.11 0.95 0.94 Sand T3 (20m) 99.32 0.45 0.24 Sand

Table 2 — Concentration of C-org and major elements (%) in the nearshore sediments of Vizhinjam Port area Locations C-org Na K Ca Mg Fe Mn Ti Si Al P T1 (3m) 0.67 1.23 0.75 3.67 0.14 0.99 0.03 0.39 38.22 3.69 0.03 T1 (5m) 0.78 1.33 0.84 3.89 0.24 1.07 0.04 0.29 37.59 3.75 0.03 T1 (10m) 0.65 1.10 0.82 3.57 0.16 1.06 0.05 0.92 37.32 4.14 0.03 T1 (15m) 0.63 1.13 0.52 0.69 0.12 0.65 0.04 0.15 42.80 2.83 0.02

Fig. 1—Study Area: Vizhinjam Port zone. T2 (3m) 0.82 1.15 0.73 3.43 0.03 1.16 0.01 0.94 38.06 3.61 0.03 T2 (5m) 0.76 1.24 0.77 3.03 0.09 1.04 0.04 0.52 38.82 3.56 0.03 contamination and its relation with organic carbon in T2 (10m) 0.10 1.39 1.09 3.23 0.46 1.76 0.07 0.86 36.41 4.69 0.04 the samples were studied using contamination factor T2 (15m) 0.15 1.31 0.92 3.02 0.41 1.93 0.07 1.09 35.97 4.75 0.05 (CF)11, Pollution load index (PLI) 12 and T2 (20m) 0.53 1.16 0.71 1.80 0.21 1.12 0.05 0.55 39.95 3.54 0.03 T3 (3m) 0.30 1.19 0.61 2.69 0.07 0.73 0.02 0.65 39.42 3.42 0.03 Geoaccumulation index (I ) 13. geo T3 (5m) 0.44 1.13 0.53 1.53 0.08 1.15 0.03 1.29 39.54 3.88 0.03 T3 (10m) 0.17 1.19 0.72 2.99 0.33 2.62 0.02 2.45 35.06 4.39 0.07 Results T3 (15m) 0.14 1.17 0.61 0.09 0.08 1.17 0.06 1.66 40.70 3.87 0.02 The sand, silt and clay proportions are given in T3 (20m) 0.62 1.10 0.52 0.33 0.11 0.90 0.06 0.69 42.26 3.28 0.02 table 1 and majority of the sediments exhibit sandy nature. Percentage of sand ranges from 99.3% to all the measured metals in the Vizhinjam nearshore 99.7% at Adimalathura, 89.9% to 99.6% at Mullur surface sediments are depicted in table 2. Percentage and 97.4% to 99.5% at Kovalam respectively. Mean of Na content at Adimalathura, Mullur and Kovalam values indicated a predominant distribution of fine to varies from 1.10 to 1.39%, while the concentration of very fine sand in the area. Sediments are moderately K is of 0.02 to 0.59% indicating detrital origin. well sorted to very well sorted and are symmetrical to Sodium and potassium mainly comes into sediments coarse skewed. Percentage of organic carbon varies as a weathering product of minerals like feldspars, from 0.10 to 0.82% (Table 2) and the low value feldspathoids, amphiboles and pyroxenes from the signifies the predominance of sand. Low organic source rock. Maximum concentrations of Ca and Mg carbon content in the study area can be attributed to are observed at Adimalathura and Mullur which is the coarse nature of the sediments and high tidal and due to the leaching of dead shelled organisms. Fe in wave activity. the study area can be attributed to detrital mineral Natural concentrations of major and trace elements composition in particular to heavy minerals. The are strongly influenced by the nature of the inorganic distribution of Fe and Ti shows maximum percentage matter that results from physical and chemical at Kovalam where heavy mineral assemblages weathering. The concentrations and the averages of dominate. Heavy minerals are highly enriched in the SILPA et al.: AN APPRAISAL OF POLLUTION LEVEL IN THE SEDIMENTS 139

beach sand along the west coast of India. From Most of the trace metals analysed show positive Adimalathura to Kovalam the average concentration correlation with mud than organic carbon (Table 4) of Si is 38.72% and it can be attributed to the higher which indicates that finer particles are the main sand content in the study area. The phosphorus carriers of elements. Al and Fe are positively content in the study area also reflects the supply of correlated with majority of the elements studied. detrital minerals and the biogenic materials found in Hydrous oxides of Al and Fe readily sorbs and co the form of shell fragments. precipitate elements when they sink to the bottom of Average concentrations of trace elements in the water. This association may be due to the large nearshore sediments of Vizhinjam port zone are surface area, extensive cation exchange and wide provided in the table 3. availability of the elements. In the present study trace The maximum concentration of Cu is observed at elements show positive correlation with Fe than Mn. Adimalathura where intense fishing activities are Correlation of Cr with clay indicates that illite traps going on. Boating activities in particular, paint chips Cr in a reducing environment. Cu enrichment is or flakes resulting from the annual cleaning or generally found associated with clay as well as the scraping of automobiles may increase the high organic content and this proves the negative concentration of Cu in sediments. Even though the correlation of these elements in the area. Correlation values of Ni are of low concentration in the present of Ni with Cr and mud indicates that these elements study, they show a maximum range in Kovalam are either absorbed/adsorbed by mud rather than suggesting the anthropogenic contribution due to organic carbon. tourism. The concentration of Cu and Ni does not Contamination Factor (CF) is used to evaluate the show much variation in the study area designating the extent of metal contamination and also anthropogenic source of these metals either from detrital minerals or inputs (Table 5). The values of CF for almost all the fishing activities. Lower concentrations of Pb and Zn trace elements except Zr in the study area are less in the study area reflect the source as detrital mineral than one indicating low contamination. Zr shows composition, vehicle emissions and antifouling paints. highest value due to the presence of zircon in the Zr is a strong transition metal and is observed at heavy minerals of Kovalam. Concentration of heavy Kovalam due to the presence of heavies. The presence mineral assemblages in Kovalam is the result of of Cr in the study area is from the dyes, tanning strong winnowing action of waves rather than agents, anticorrosive agents, welding fumes, selective transport by longshore currents. Moreover, lubricating oils and greases etc. Rare earth elements the rocky headlands is the another source for these like La, Nb, Sm and Ce are of very negligible minerals. The pollution load index values (PLI) (<1) concentration and as of now it is not at all alarming. also supports the CF values indicating no pollution in the Vizhinjam seaport area (Figure 2). The obtained Table 3 — Concentration of trace elements (ppm) in the nearshore sediments of Vizhinjam Port area Igeo value for the trace elements shows that the Vizhinjam port area is not at all polluted (Table 6). Locations Cu Ni Pb Zn Zr Cr Also from the result, it isinferred that Kovalam is T1 (3m) 38 12 3 8 251 50 T1 (5m) 57 28 8 14 122 29 Table 4 — Inter-elemental correlation matrix of minor elements T1 (10m) 26 38 13 37 2897 88 in the nearshore sediments of Vizhinjam port area T1 (15m) 29 33 16 31 111 15 C- Sand Silt Clay Cu Ni Pb Zn Zr Cr T2 (3m) 12 16 7 21 974 60 org % % % T2 (5m) 37 23 4 29 477 38 C-org 1.00 T2 (10m) 29 45 16 61 2467 97 Sand % 0.68 1.00 T2 (15m) 27 42 12 53 3643 93 Silt % -0.60 -0.99 1.00 T2 (20m) 40 22 9 51 1786 48 Clay % -0.75 -0.86 0.80 1.00 T3 (3m) 17 31 11 24 1597 62 Cu 0.29 0.04 -0.08 -0.03 1.00 T3 (5m) 9 46 15 53 2509 92 Ni -0.78 -0.36 0.30 0.58 -0.28 1.00 T3 (10m) 25 62 18 74 8550 136 Pb -0.69 -0.24 0.16 0.51 -0.27 0.86 1.00 T3 (15m) 31 51 23 66 4518 86 Zn -0.76 -0.47 0.38 0.71 -0.24 0.84 0.79 1.00 T3 (20m) 37 30 14 48 697 56 Zr -0.71 -0.28 0.20 0.56 -0.30 0.84 0.62 0.79 1.00 Average 30 34 12 40 2096 66 Cr -0.72 -0.44 0.39 0.62 -0.47 0.77 0.53 0.74 0.89 1.00 140 INDIAN J. MAR. SCI., VOL. 48, NO. 01, JANUARY 2019

Table 5 — Contamination factor (CF) and pollution load index under moderately polluted condition compared to (PLI) of minor elements of nearshore sediments in Vizhinjam other stations and this is due to the anthropogenic port area influence owing to tourism activities. Location Cu Ni Pb Zn Zr Cr PLI Discussions T1 (3m) 0.84 0.24 0.15 0.08 1.57 0.56 0.35 The wave energy regime along the Kerala coast T1 (5m) 1.27 0.56 0.40 0.15 0.76 0.32 0.46 exhibits distinct patterns, with highest energy T1 (10m) 0.58 0.76 0.65 0.39 18.11 0.98 1.12 observed off Thiruvananthapuram region14. T1 (15m) 0.64 0.66 0.80 0.33 0.69 0.17 0.48 Winnowing action of the waves aided by the steep T2 (3m) 0.27 0.32 0.35 0.22 6.09 0.67 0.55 bathymetry may be a reason for the high T2 (5m) 0.82 0.46 0.20 0.31 2.98 0.42 0.55 15 T2 (10m) 0.64 0.90 0.80 0.64 15.42 1.08 1.31 concentration of sand in the region . Southern Kerala coast (Paravur and Veli) recorded low organic carbon T2 (15m) 0.60 0.84 0.60 0.56 22.77 1.03 1.26 16 T2 (20m) 0.89 0.44 0.45 0.54 11.16 0.53 0.91 with high percentage of sand and the low organic T3 (3m) 0.38 0.62 0.55 0.25 9.98 0.69 0.78 carbon values might be related with the poor T3 (5m) 0.20 0.92 0.75 0.56 15.68 1.02 1.04 absorbability of organics by sand dominant regions T3 (10m) 0.56 1.24 0.90 0.78 53.44 1.51 1.84 and constant flushing activity by tides along with the 17 T3 (15m) 0.69 1.02 1.15 0.69 28.24 0.96 1.57 input of waves . Carbonate materials have a coarse T3 (20m) 0.82 0.60 0.70 0.51 4.36 0.62 0.88 texture and as a result the Ca contents are very high in

18 coarse sediments . The Ca is abundant in the Table 6 — Geo accumulation index of minor elements of southern side of Tuticorin, East coast of India where nearshore sediments in Vizhinjam port area the shelf is widest and shell debris is main 19 Location Cu Igeo Ni Igeo Pb Igeo Zn Igeo Zr Igeo Cr Igeo constituent . Another source of Ca is the plagioclase 20 T1 (3m) 0.17 0.05 0.03 0.02 0.31 0.11 mineral . Mg concentrations reveal a higher average T1 (5m) 0.25 0.11 0.08 0.03 0.15 0.06 in the surface sediments of Gulf of Mannar (Mg: T1 (10m) 0.12 0.15 0.13 0.08 3.63 0.20 1.12-8.32%) than for other coastal regions along the T1 (15m) 0.13 0.13 0.16 0.07 0.14 0.03 southeast coast of India due to the abundance of T2 (3m) 0.05 0.06 0.07 0.04 1.22 0.13 skeletal components19. Abundance of heavy mineral T2 (5m) 0.17 0.09 0.04 0.06 0.60 0.08 assemblages in Kovalam reveals that the T2 (10m) 0.13 0.18 0.16 0.13 3.09 0.22 morphodynamics of the coast and the hydrodynamics T2 (15m) 0.12 0.17 0.12 0.11 4.57 0.21 of the region are the major factors that determine the T2 (20m) 0.18 0.09 0.09 0.11 2.24 0.11 distribution patterns of these minerals in the area21. T3 (3m) 0.08 0.12 0.11 0.05 2.00 0.14 Atomic minerals directorate for exploration and T3 (5m) 0.04 0.18 0.15 0.11 3.15 0.21 research (2001) reported an average total heavy T3 (10m) 0.11 0.25 0.18 0.16 10.72 0.30 mineral concentration of 21.33% at Vizhinjam- T3 (15m) 0.14 0.20 0.23 0.14 5.67 0.19 Kovalam stretch. Higher percentage of sand implies T3 (20m) 0.17 0.12 0.14 0.10 0.87 0.12 that Si is related to terrestrial input of quartz22. The concentration of Cu (48.8µg/g) and Ni (71.1µg/g) at the nearshore sediments of Ennore, south east coast of India may be due to the industrial and petroleum related activities23. Cu and Ni enrichment are commonly observed in a region where harbour and petroleum-related activities are intense24. Presence of Pb and Zn can be due to the heavy input of industrial effluents from the industrial regions23 and also from the vehicle emissions, municipal refuse and automobiles25, 26, 27. Trace metals do not seem to constitute a threat to the marine environment of central south west coast of India28 and this supports the results of our study. Chromium is an essential

nutrient for plants and animal metabolism and it Fig. 2 — Spatial distribution of PLI in the Vizhinjam port area indicate the anthropogenic influence in the marine

SILPA et al.: AN APPRAISAL OF POLLUTION LEVEL IN THE SEDIMENTS 141

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