PCBs: The silent killer

Vegetable oil is one of the highly used cooking oils in the country.Its uses range from the domestic front to commercial usage where it is used to fry bean cake popularly called akara, and all sort of snacks which are consumed by both the high and low in society.But a recent base line survey, conducted […]

Vegetable oil is one of the highly used cooking oils in the country.
Its uses range from the domestic front to commercial usage where it is used to fry bean cake popularly called akara, and all sort of snacks which are consumed by both the high and low in society.
But a recent base line survey, conducted by the Federal Ministry of Environment, has shown that most of the cheap vegetable oils sold across the country are mixed with Polychlorinated Biphenyl (PCB).
PCBs are a class of synthetic organic chemicals used in electrical transformers and capacitors as dielectric fluids worldwide, whose production was banned globally at the inception of the Stockholm Convention, along with other members of the ‘dirty dozen’.
Because of PCBs ability to penetrate human skin without difficulty and its non-degredable nature and the ability to travel long distances by air and water and its high toxicity, it was classified as persistent organic pollutant after being triggered as a carcinogenic agent. Its production was banned by the United States Congress in 1979 and the Stockholm Convention on Persistent Organic Pollutants in 2001.
According to health experts, PCBs have shown toxic and mutagenic effects by interfering with hormones in the body. “They, depending on the specific congener, have been shown to both inhibit and imitate estradol – the main sex hormone in females. Inhibition of estradol can lead to serious developmental problems for both males and females including sexual skeletal and mental developmental issues,” the experts concluded in a meeting in Abuja recently.
“Extreme high level of PCBs can manifest in humans as rashes, changes in blood and urine, liver damage, dermal lesions, irregular menstrual cycles, lowered immune responses, fatigue, headaches, coughs, unusual skin sores while children may exhibit cognitive development issues,” the experts said.
 Mr Kazeem Bayero, Acting Director of Pollution Control and Environmental Health Department, Federal Ministry of Environment, said that a pilot inventory has been conducted in some power installations. “The inventory, among others, revealed that there is very little knowledge of the full concept of PCBs among workers in the energy sector, occasioning unprotected handling of PCB, improper storage and attendant exposure risks.
It was specifically observed that personnel who engaged daily in the retro-filling, filtration, recycling and storage of transformer oil were quite oblivious to hazards of PCB-contaminated equipment and waste PCB-rich oils. Some people are also known to procure/use discarded transformer oil as fuel in cooking, roasting animal hides, and burning farm lands.”
Dr.  John-Paul Unyimadu, a technical consultant to the Federal Ministry of Environment, has declared that no part of the Lagos Lagoon, particularly the Ijora axis, is safe for the fish and other living organisms in the water.
Dr. Unyimadu also raised similar alarm about the Onitsha part of the River Niger where findings, he said, have shown, a huge concentration of a harmful chemical that could cause cancer, reproductive and development toxicity, impaired immune function, life changes and affects the central nervous system as well as other deadly health problems to both humans and other living organisms that come in contact with it.
Delivering a public lecture entitled, “PCBs: Concentrations in sediments, fish and surface water in selected locations in Nigeria,” at a one-day training workshop in Enugu, Dr. Unyimadu said due to the high level of a certain chemical called Polychlorinated Biphenyl (PCB) in the Ijora area of the Lagoon and Onitsha axis of the River Niger, fish and other living things in the water there have become endangered species.
“No part of Lagos Lagoon is safe now, when you talk of the levels of the PCBs in the water,” said Dr. Unyimadu, who added that “in the  Ijora Power Station area of the lagoon, any living organism in that water is in danger depending on the level of PCBs and if an organism is endangered, it means that man is also endangered.”
He also said: “The two locations: Ijora is much polluted. Then in River Niger, the Onitsha axis of the river is also polluted because manufacturers of plastic products and paints, dump certain things that contain PCBs inside the river.”
Dr. Unyimadu recalled that way back in 1881, some chemists discovered and began manufacturing a certain chemical element known as Polychlorinated Biphenyls, also known as PCBs which are in the class of “organic compound found to be fire resistant, stable, non-conductive to electricity and of very low volatility under normal conditions.”
He explained that due to its characteristics, the chemical was used in the manufacture of certain oils that became vital in the operation of power conductors and electric equipment, especially “electricity transformers became most efficient, running on the oil laced with PCBs.”
“With the discovery and manufacture of PCB containing oils, electricity processing and distribution process became more efficient and manufacturing industries also started running more efficient machinery. PCBs and PCB-based oils were therefore of immense value and benefits to mankind, since 1881, through the years to recent time. In fact, by early 1929 the characteristics associated with PCBs made it ideal for many industrial applications and for the manufacture of many consumer products. The use became more predominant in the years between 1950 and 1970s,” the participants were told.
However, in the early 1980s, it was discovered that the all-important PCBs contain toxic properties that are harmful to every living thing – man, animal and even the environment. “Due to all of these dangerous effects of PCBs, it was banned world-wide, in the early 1980s. PCBs were classified among the 21 most dangerous chemicals marked for complete elimination from among mankind, at the Stockholm Convention of 2001,” the lecturer informed participants.
“The transformer oil we were using in those days, has become harmful today; people should be very careful about what they eat and how they live,” he warned.