Polychlorinated Biphenyls (PCBs) belong to a group of pollutants known as “Persistent Organic Pollutants” or POPs. Often called “Dirty Dozen,” POPs are twelve in number and are considered the most hazardous substances in nature. The two most important characteristics that make POPs so dangerous is the fact that these don’t degrade readily and can travel thousands of miles. In the arctic, traces of POPs have been reported despite their no use or manufacturing in the area.

Introduced in 1929, polychlorinated biphenyls (PCBs) became a big success for industry due to their chemical nature. The first person to recognize PCBs as being dangerous was the Danish born chemist Soren Jensen. While trying to measure the amounts of DDT in blood he kept seeing an unknown chemical compound. It took him two years to identify the substance as PCBs. Ten years later, in 1976, the United States banned the manufacturing of PCBs and other countries followed. However, the problem is that since its production, the world has produced 3.4 billion pounds of PCBs and much of it had already been let loose into the environment. Once in wildlife and human organisms, PCBs cause disastrous effects. Organisms become less fertile, less immune, slower, have lower IQs and have higher rates of cancer. A new study has shown that PCBs are also endocrine disrupters, which means that they block hormone messages.

However, due to its chemical characteristics, PCBs are suitable for a broad range of applications. PCBs are available under several trade names such as Clophen, Arocler, Kanechlor, Santotherm, Phenoclor and Pyralene. These were heavily used in the beginning as a nonflammable cooling compound in transformers and capacitors, thus becoming popular in the chemical industry. Other uses of PCBs have been lubricants, hydraulic fluids, cutting oils, adhesives, liquid seals, making wood and plastics nonflammable, protecting rubber, as ingredients in paints, varnishes, inks and pesticides and carbonless copy paper.

There are many activities that produce PCBs wastes. Industrial, automotive and electric machinery are the main sources of PCBs contaminated oils. Lakes, rivers and sea contain PCBs due to industrial discharges where they absorb into sediments. Inadvertently, PCBs laden materials are also produced through a number of chemical processes in the organic pigments, pesticides, chemical and aluminum refining industries.

Human populations have been exposed to PCBs via three major pathways: accidental, occupational, and environmental. The ingestion of food, particularly meat, fish, and poultry however is considered to be the main path of exposure. PCBs pass through the placenta, as well as being transferred into human breast milk fat.

We risk exposure when PCBs enter waterways through various means. PCBs enter directly through discharge of a facility, or through improperly managed waste disposal sites. Humans can also get exposure through natural deposition in waterways. It is here where the beginning of the food chain occurs. Being fat-soluble it accumulates as it goes up the food chain. PCBs levels in fish can exceed 100,000 times that of the water.

Occupational exposure occurs via skin absorption and inhalation. Three accidental exposures have taken place. The first took place in Japan when a case of contaminated cooking oil containing PCBs was used. This event named Yusho, affected 1770 people. In 1979, Taiwan had a similar event that occurred killing 200 people. The third population that had accidental exposure was in Seveso Italy. In 1976, accidental release of PCBs occurred in a manufacturing plant. The main route of exposure to residents was by inhalation and contact of the skin and eating contaminated foods. Worldwide PCBs exposure has led to conditions such as skin rashes, itching and burning, eye irritation, skin and fingernail pigmentation changes, disturbances in the liver function and immune system, irritation of the respiratory tract, headaches, dizziness, depression, memory loss, nervousness, fatigue, and impotence. Chronic effects of low-level PCBs exposure include liver damage, reproductive and developmental effects and possibly cancer.

Total PCBs in human tissue ranged from 14 to 1,77ng/g (0.014-1.7 ppm) (lipid basis)” The amounts however are much larger in those countries such as Pakistan that have PCBs still in use. PCBs have become a vital issue to mankind due to their most hazardous chemical nature and these must be regulated towards reduction, leading to their total elimination.

The Stockholm convention on persistent organic pollutants deals with the twelve most hazardous persistent organic pollutants, including PCBs, which pose major and increasing threats to health and environment. For the protection of human health and environment, the convention was adopted at Johannesburg during the 5th session of international negotiating committee (INC), in December, 2000 and was opened for signature in Stockholm, Sweden on May 22, 2001. So far 151 countries have signed the convention and 37 countries ratified it.

Article 3 of Stockholm convention on POPs describes the measures to reduce or eliminate releases from intentional production and use of POPs and states that each state shall (a) prohibit and /or take the legal measures necessary to eliminate (i) production and use of the chemicals listed in Annex A (which includes PCBs) and (ii) their import and export. Specific measures to reduce/eliminate PCBs are described in Part 2 of Annex A, binding each state to make determined efforts to identify, label and remove from use equipment containing more than the specified amounts of PCBs.

Pakistan participated in all sessions of INC and all along strongly supported reduction of POPs (including PCBs) production and use, leading to its total elimination. Pakistan signed the Stockholm Convention on Persistent Organic Pollutants on December 6, 2001. In Pakistan, Persistent Organic Pollutants (POPs) problem including PCBs, has not been a priority environmental issue. In the national environmental action plan (NEAP) approved by Pakistan environmental protection council (PEPC) in 2001, the given four areas of immediate concerns are clean air, clean water, disposal of solid wastes and eco-system management. Toxic and hazardous substances, including PCBs, are one of the additional areas of concerns of NEAP. However, as a result of signing of Stockholm Convention on POPs, in December 2001 by Pakistan, an “Enabling Activity Project,” with support from GEF/UNDP, has been launched to strengthen capacity in the country for meeting its obligations under the convention. Among others, the envisaged project activities include compilation of baseline inventory database on PCBs situation in the country, setting up priorities for PCBs phase out, manage contaminated sites and finalization of national implementation plan (NIP) for meeting Pakistan obligation under Stockholm convention.

The release of PCBs into the environment is generally expected to be due to (a) leakage from PCBs containing electrical equipment (transformers, capacitors, circuit breakers, voltage regulators etc. and (b) handling and processing of wastes containing PCBs. In Pakistan little documented information is available in any form on PCBs containing electrical equipment, use and wastes. Of many uses/applications of PCBs in other parts of the world, in Pakistan the main use seems to be in different PCBs formulations, generally termed as “Transformer Oil,” used in power and distribution transformers for cooling and insulation purposes. Sealed or compact transformers, distribution transformers and power transformers of different capacities (average life of 8 – 10 years) are in use and mostly they are locally manufactured. For transformer installation both the Pole and Pad systems are in practice. Among the damaged transformers received at the repairing/recycling workshops the number of Pole transformers have been reported to be higher than the Pad transformers and hence the former type are more likely source of PCBs releases into the environment. Generally, employing a large number of small size transformers within small areas has been preferred over employing small number of big size transformers in large areas. Whereas, both these system have their merits and demerits in terms of cost, consumers’ convenience, installation, maintenance and supervision, both may be as much environmental un-friendly due to possible PCBs releases.

Transformer oils are used for the multiple roles of dielectric, heat transfer agent and arc-quencher. Both paraffin and mineral based transformer oils have been/are being used in the country, probably containing some PCBs. A survey carried out by the Sustainable Development Policy Institute (SDPI) has indicated that the oil content in 15, 100 and 200 KVA capacity transformers as declared on the transformer label was 48.5, 114 – 152 and 198.5 kg, respectively. However, different volumes of oil are used in distribution transformers according to their voltage rating and range from 40 liters in 10 KVA to 270 liters in 200 KVA. Reported synthetic oils, which have been/are being used, include Silicon, Ester and Askarrel. The transformer oil has been imported from a number of countries as well as produced locally. Pak-HY Oils Limited is one of the main suppliers of transformer oil to WAPDA. It is claimed that Pak-HY Oils Limited have been producing PCBs free oil from the mineral based feedstock for the past 25 years. However, the oil containers at different WAPDA storehouses are not labeled, “PCBs Free” or “NO PCBs” by the company.

Askarels synthetic transformer oils are considered to be the main source of PCBs release and their use has been prohibited in many countries, including Pakistan. However, it could not be ascertained by which government department and since when the use was prohibited in Pakistan. The reclaimed Askarels from discarded old transformers could still be a source of PCBs release to the environment. Even if the PCBs free transformer oil has been in use in the country for quite some time, PCBs contamination of in-service transformer oil may have occurred due to use of reclaimed Askarels oils (from old/discarded transformers) in transformer oil reprocessing (refilling, oil level top up). The country’s fresh transformer oil demand has been estimated at 4000 M.T/ annum and the quantity of collected used transformer oil < 1500 M.T/ annum.

SDPI survey also indicated that only physical damage might cause any leakage/release of the oil to the environment. The largest source of contamination from PCBs with reference to capacitors and transformers is when these are either old or have leaked. Transformer repair workshops therefore are potential sources of PCBs contamination, affecting workers and wildlife. There are repairing workshops in some main cities in the country with facilities for recycling (dehydration followed by filtration) of transformer oil contaminated with moisture/impurities. The drainage water and soil messed up with some oily stuff was observed all around the workshop near WAPDA Field Store, Defence Colony, Peshawar. Damaged distribution transformers are generally not recycled but disposed off, whereas power transformers are preferably recycled. A repair/recycling workshop may receive as many as 250 damaged transformers in a year. Damaged transformers, if un-repairable are auctioned by WAPDA from time to time. These discarded transformers are dismantled and different parts are used to rebuild transformers or the scrap is sold to steel mills. The unused oil from the dismantled transformers is sold to small scale welding plants and industries. The carbonized discarded transformer oil is also reportedly used by elderly village people as remedy for joints-pain and is supplied to them free of cost in small quantities by repair/recycling workshops.

The transformers in Pakistan have not been operating without fault and there has been a reported case of five WAPDA officials sustaining burn injuries at the Saidpur Grid Station in Lahore due to bursting of a transformer because of some technical fault. Transformers are damaged due to overload, manufacturer’s fault, and loose connection or short-circuiting inside the transformer. Besides the transformer installation sites in the country, the other potential sites of PCBs releases into the environment could be oil reclamation plants, repair and maintenance workshops, vendors workshops, welding plants, small industries and furnaces.

The production, supply and use of PCBs are not specifically regulated in any way in Pakistan. Sections 13 and 14 of Pakistan Environmental Protection Act 1997 (PEPA-97) deal, in general, with prohibition of import of hazardous wastes and handling of hazardous substances. PEPA-1997, Section 11 prohibits discharges/emissions of any oil/grease into environment above National Environmental Quality Standards (NEQS). However, PCBs have not been specifically included in the list of NEQS but as “Phenolic Compounds.” Under the recently introduced “Self-Monitoring and Reporting/SMART ” program for industry in the country, only petrochemicals, petroleum, oil and gas, tanning and leather finishing industries are required to periodically report Phenolic Compounds” levels (measured as phenol) in their industrial liquid discharges/effluents. PCBs are not given as “Banned Items” (Negative List) or “Restricted Items” in the “Import Trade and Procedures Order, 2000.” Nor are PCBs mentioned in “Hazardous Substances Rules 1999.” Due to the adverse health and environmental impacts caused by PCBs, it is essential that PCBs specific regulations for its complete phase out be developed and implemented in the country.

When dealing with PCBs Pakistan should have two main goals: (a) elimination of PCBs in the environment and (b) environmentally sound management of existing PCBs throughout their life cycle. Pakistan should seek to achieve no measurable release of PCBs into the environment. There should also be a phase-out of open system PCBs use. It is also important to prevent through regulations the formation of new materials contaminated with PCBs during manufacturing processes.

As mentioned earlier, “POPs Enabling Activity Project” has been launched to strengthen capacity in Pakistan for meeting its obligation under the Stockholm Convention on POPs. In addition to the enabling activities envisaged in this project, the following activities as part of the project may also be considered:

• Carrying out a survey on the health effects of PCBs using local incidences through a survey of contaminated sites and epidemiological studies.
• Setting up of a process for people reporting, verification of and accessibility to information regarding PCBs.
• Promotion of literature on alternative products and processes to reduce and eliminate PCB generation, use and releases
• Regulatory actions to support implementation of ban on PCBs. There should be a national program for phasing out and destruction of contaminated equipment.
• Some kind of incentive for industries to support this action, economic or otherwise. Some kind of compensation for machinery lost.

There is a dire need to develop capacity in the country for trained personnel for conducting surveys and establish PCBs inventories, for maintaining “PCBs Release and Transfer Registers” (PRTRs), to collect PCBs data from a wide range of national sources and its interpretation and comparison with national and international requirements, protocols and treaties.