POLYCHLORINATED BIPHENYLS (PCB's) - Environmental Implications

SHIP BREAKING ACTIVITIES - SOURCE OF TOXIC/HAZARDOUS WASTE INCLUDING PCB's IN INDIA

Ship breaking activities involve breaking of old obsolete/damaged ships and recovery of construction material (mostly steel and other items) for recycling and reuse. Ship breaking had been regular commercial activity in some industrially advanced countries like UK, USA, Germany during first half of last century, but after 1960 the activity shifted from industrialized countries to other areas in Asia and Far East. Among Asian Countries, actively involved in Ship breaking activities are India, Bangladesh, Taiwan, China, South Korea, Japan and Pakistan. India has emerged as leading nation involved in Ship breaking activities because of demand of re-rollable and melting scrap steel and other items within the country.


Till 1960, ship breaking involves mainly dismantling of small-disused barges and coastal wretches but during seventies, the ship breaking activity registered commendable growth and later by the year 1979 it was recognized as full fledged small scale industry. The activity, which was confined to Mumbai and Kolkata, spread primarily on the western coast and other parts of the country. The major centres for ship breaking activities in the country are:

S. No.

State

Ship breaking Activity locations

1.

Andhra Pradesh

Vishakhapatnam

2.

Gujarat

Alang

Sachna

3.

Karnataka

Tadri

Mangalore

Malpe

4.

Kerala

Baypore

Cochin

Azhical

5.

Maharashtra

Mumbai

6.

Tamilnadu

Tuticorin

7.

West Bengal

Kolkata


Ship Breaking Process
Ship breaking activity is undertaken by private entrepreneurs and it is a labour intensive process, in which discarded ships are beached during high tide and dragged towards the shore by shore based winches. The material, which is physically removed from the discarded ships before its further breaking include:
  • Removal of Ballast water, fuel oil, lubricants, electrical items, loose cables, fire fighting equipments, ladders, window panel, frames etc.
  • Removal of moveable gear, electrical navigation equipments, nylon and steel ropes, shackles, pulley blocks, tarpaulin, paints and lubricant tins, machinery, spares etc.
  • Removal of auxiliary equipment of prime mover machinery like diesel generator sets, boilers, air compressors, pumps, valves etc.
  • Dismantling of main engine in parts - head, main block, piston, crankshaft and bore. Removal of propeller, its shaft etc.
After removal of material physically from the ship, the steel structure of vessel is cut vertically by Oxygen-LPG into large blocks. The cut blocks are dropped on the beach/ground on either side of vessel and large dismantled pieces are pulled up to onshore yard, where they are further cut up into small pieces for sorting and selling as steel scrap and rerollable steel for recycling to iron and steel industry.

Environmental Impact from Ship Breaking Activities

The shipping activities usually produce different organic and inorganic material, which pollute the area, if their removal is not controlled during dismantling. The potential source of toxic and hazardous pollutants during the ship breaking activity are:
  • Fuel oil and Lubricants
  • Oil sludge in oil tankers and oil/bulk ore carrier
  • Solid waste viz. hydrated/solidified cement
  • Heavy metals like Tin, Lead and chemical constituents of paints and coatings.
  • Remnants of toxic chemicals in cargo compartment of chemical carriers.
  • Bilge and ballast water.
Apart from the above, during breaking of ships several other pollutants are generated, which have considerable environment impact and hazards. Some of these are:
  • Inflammable gases from cargo tank of Oil/LPG/Naphtha, sometimes ammonia from chilling system of cold stores
  • Compressed carbon dioxide, freons etc.
  • Paint chips, which are the source of several heavy metals viz. Pb, Cr, Cu and Organic compounds like PCB's.
  • Solid waste - small scrap iron, metallic pieces, glass wool, rubber pipes, gaskets, PVC sheet and pipes, corks, wooden pieces, asbestos etc.
  • Oily material from cleaning of cargo hold, iron scales, rust during cutting and cleaning of scrap.
  • Cementing material, tiles, iron scales are dumped to low lying areas and at beaches contaminating land surface
  • PCB's laden oil, toxic material laden paints etc.
Preventive Actions Envisaged
  • Wastes containing PCB's and other toxic material generated from ship breaking activities should be reprocessed and reused as raw material.
  • PCB's contaminated transformers, PCB's laden articles, rags, soils and other debris contaminated with PCB's have to be incinerated at very high temperature.
  • Discarded items from ship suspected to contain PCB's should be stored in such confined area having impervious flooring to ensure containment of PCB's.
  • The presence of radioactive material on discarded vessels should be ascertained well in advance. The ships containing radioactive material should not be permitted to be broken.
  • Ship breaking activities site should be maintained properly to avoid land/water contamination. House keeping measures should be improved.
  • Bilge water and Ballast water should be appropriately treated before its final disposal.