Comparative Study of Lead Pollution at Velankanni, Nagapattinam and Kodiakarai during Flag Hoisting Festival

Keywords: Lead, Lead Deposits, Total Lead, Marine Sediments

Introduction

Lead (Pb) is one of the oldest metals known to man. It is found naturally on the earths crust (about 20 mg/kg) in the form of Sulfide Galena (PbS). Several lines of evidence implicate high-level lead exposure as a cause of many of pathological conditions such as renal insufficiency, gout and hypertension (Wedeen et al., 1979; Batuman, 1993; Ding et al., 2001).

Adaikpoh et al. (2005) studied heavy metals concentration in coal and sediments from river Ekulu in Enugu, Coal City of Nigeria. This research established the presence of toxic metals in the area and called for a follow up study to determine how the human and aquatic lives have been affected.

Okoye (1994) in a survey of Pb and other metal contents of dried fish from Nigerian markets remarks that the Pb content is high. He observes that the high Pb content in fish from Nigerian markets indicates serious Pb contamination in Nigeria. He attributes this mainly to heavy automobile traffic and the high lead content of the local automobile fuels.

Exposure to Pb can occur through multiple pathways, including inhalation of air and ingestion of Pb in food, water, soil or dust. Excessive Pb exposure can cause seizures, mental retardation and behavioural disorders. The danger of Pb is aggravated by low environmental mobility even under high precipitations (Mench et al., 1994).

Industrial discharges containing toxic and hazardous substances, including heavy metals contribute tremendously to the pollution of aquatic ecosystems (Gbem et al., 2001; Woodling et al., 2001). Metals enter the environment and oceans by two means: natural processes (including erosion of ore-bearing rocks, wind-blown dust, volcanic activity and forest fires); and processes derived from human activities by means of atmospheric deposition, rivers and direct discharges of dumping (Clark, 2001). Materials and Methods.

Sampling Sites

All sampling was done in the Nagapattinam district on the Coromandel Coast of Tamil Nadu state in southern India.

1. Nagapattinam
   Coordinates: latitude 10°46’N longitude 79°50’E
   A prominent seaport and an important centre of trade and commerce that dates back to the Sangam period. The large fishing Industry was severely damaged by the Tsunami that struck its coast on 26 December 2004.
2. Velankanni
   Coordinates: latitude 10°42’N longitude 79°48’E
   Once a port that traded with Rome and Greece, home to a significant Roman Catholic shrine dedicated to Our lady of Good Health.
3. Kodikarai
   Coordinates: latitude 10°17’16.08”N longitude 79°51’54.36”E
   The apex of the Cauvery River delta, with the Point Calimere Wildlife Sanctuary and its three natural habitat types: dry evergreen forests, mangrove forests, and wetlands.

Sampling Method

Surface sediment samples were collected using Ekman sediment grab. Soft sediment samples were collected in polyethylene plastic covers from coastal sampling stations, on monthly basis. Firstly the sediment samples were shade dried under room temperature. After the removal of debris and large stones, the samples were sieved >2mm size. Then the samples were weighed and processed for Lead extraction. The extraction procedure for total lead and particulate lead extraction from the sediments was adopted following the method of Loring and Rantala (1992).Detailed sample preparation extraction procedures are given in fig. 1 & 2

Sample Analysis

Lead concentrations in the sediment extracts were determined using Atomic Absorption spectrophotometer. The concentrate was directly aspirated into the air acetylene flame of Atomic Absorption Spectrophotometer (A.A.S), Thermo Jarrell Ash (AASCAN – I USA).

Stock Standard Solution

Standard stock solution was prepared by dissolving 0.1598 g of lead nitrate [Pb(NO₃)₂] in 1 per cent (V/V) nitric acid and diluted to 1 litre with 1 per cent (V/V) HNO₃. 1.00 ml = 1 mg. The working standard solution was prepared by making up 2 ml of standard stock solution to 100 ml using double distilled water. The sediment samples were analysed in PPM level.

Figure 1 · Sediment Sample Preparation for Lead Estimation

Figure 2 · Extraction Procedure for the Detrital and Non Detrital Fractions of Lead in the Coastal Sediments

For some metals, natural and anthropogenic inputs are of the same order (for sample Hg and Cd), whereas for others (for example Pb) inputs due to human activities dwarf natural inputs (Clark, 2001). As said in the above reference, a high concentration of total and loosely bounded lead concentration was observed in places like Velankanni and Nagapattinam. A hike in lead concentration was observed in the month of August, September and January due to heavy tourist vehicle movements for attending the Flag Hoisting Festival, Christian holidays and New Year celebrations at Velankanni, and during the month of December the Kandhuri festival at Nagapattinam. As a renowned Bird Wild Life Sanctuary, Kodikarai encountered extensive tourist vehicle traffic that resulted in increased lead levels.

In these study areas we have seen higher concentrations of lead in both Velankanni and Nagapattinam which are nearby areas. A hike in concentration was noticed in the month of August and September because of the Velankanni flag hoisting festival. The flag hoisting festival falls in the month of August last due to the arrival of very high tourist population. Nagapatinam recorded a high concentration of Pb during Kandhoori festival time i.e. in the month of December. Kodiakarai recorded a very high concentration during all seasons because it is one of the important tourist attractive site and due to its boat industry and fishing area. As is the same case in most coastal towns, wastewater and industrial sewage is directly discharged into the sea (Rasoanandrasana, 2006).

Summary

Velankanni attracts most tourists during the flag hoisting festival period in the last week of August of every year, and in December for Christmas and the New Year celebration. Nagapattinam Kandoori festival during December of every year these tourist impacts make a raise in the level of Lead pollution in these areas. As Kodikarai is a well known tourist place it attracts people who visits festivals as well as the pollutants. The Kodikarai becomes most polluted due to the adjacent tourist sites ie. Velankanni and Nagapattinam as pollutants get transported by sea water and due to the flow of tourist vehicle. 

References

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