Laboratory tests on ponmo samples have revealed that cowhides roasted with tyres and plastic are unsafe for human consumption and pose severe health risks, DEJI LAMBO writes
The air over Agege Abattoir, one of Lagos’ busiest and biggest slaughterhouses, is thick with a strong, choky, acrid smell.
Last year, this reporter paid a visit to the abattoir to investigate the processing of ponmo, a popular Nigerian delicacy. Last week, when he paid a return visit, the air was still thick with the poisonous soot he breathed during his last visit.
The soot was emitted by the bonfire of plastic and sticks that ponmo traders used to roast cowhides at the abattoir.
“It is not only ponmo that they roast at the abattoir; they also roast cow horn as it is used in making breakable plates. When they are operating, the soot is always visible in the sky and mixes with the air we breathe in.
“The smell of the soot makes me feel irritated; I spit constantly and occasionally vomit when I smell it. But I have been trading in the community for about five years, so, the smell is now normal to me,” a trader, who does not want her name mentioned, said.
Her daughter, about two-year-old, was seen sleeping in her shop located on Wasiu Olaofe Road, popularly called Agric Road, Oko Oba, in the Ifako Ijaiye area of the state.
An expansive canal alongside a fence separated the Agege abattoir and structures on Agric Road. The road leads to the highly populated community where the trader’s shop is situated.
“Agric Road also leads to the Pipeline and Iju-Ishaga areas, and the smell of the soot also gets to some parts of these areas. When the people doing the roasting start operating, they don’t pity anybody; only the landlords can complain about the soot. I can’t, because I am just a trader who sells and goes home,” the trader said.
Resigned to fate
Over the years, landlords and residents in the affected area were said to have complained bitterly to the state government about the constant pollution caused by soot spreading through the community from the Agege abattoir ponmo processing facility.
But their complaints appeared to have fallen on deaf ears as the pollution in their community continued unabatedly, prompting them to resign to fate as they normalised the inhalation of the soot.
A resident, who gave his name only as Badejo, however, alleged that government officials, responsible for monitoring activities of the ponmo processors, ignored residents when they complained.
He added, “Before, they usually start roasting ponmo in the morning at the Agege abattoir, but a series of complaints to the government made the ponmo processors start operating in the afternoon.
“The government has tried to stop their operations but those in the business have spent a lot of money to remain there.”
However, it is not only residents of this community that are at the receiving end of the activities of the ponmo processors. Besides the residential buildings on Agric Road, the area also hosts shops of food sellers, petty traders, mechanic workshops, a pure and bottled water factory and schools.
Residents, school pupils, passersby, traders, and customers within and beyond the area usually inhale the soot emanating from the Agege abattoir almost every day.
According to experts, soot emitting from fire fuelled by plastic, tyres, used engine oil is dangerous as it contains harmful substances, some of which are carcinogenic.
Troubling discoveries
The Agege abattoir was one of the many abattoirs where our correspondent discovered that tyres, spoilt shoes, plastic, a blacky oily substance, and firewood were used in roasting cowhides.
But as lovers of ponmo in Nigeria are in their millions, most of them, including medical practitioners and researchers, are incurious about how their favourite meat delicacy is produced.
Some other consumers, who may be aware of the dangerous brown ponmo production practices, exhibit gross ignorance of the health complications that can arise from its consumption.
However, some ponmo traders are aware that the processing of ponmo with tyres, plastic, and used engine oil constitutes a serious health risk.
One of them, Ajibade, who accosted our correspondent as he was exiting her private ponmo processing facility on a wetland at the Adeniran Ogunsanya College of Education, said she was aware of the implications of the dangerous practice.
At tyre manufacturing and plastic plants, companies put safety mechanisms in place to protect factory workers whose works expose them to fumes and the toxic chemicals used in the production of plastic and tyres.
But at the ponmo processing facilities visited during the investigation, ponmo processors, traders and buyers breathe noxious gases without a care in the world.
Ponmo: Sample selection for testing
To determine whether ponmo roasted with tyres and plastic is safe or unsafe for human consumption, our correspondent purchased some roasted and fresh brown ponmo samples for a toxicological test.
The ponmo samples were purchased from two government-approved abattoirs and a private ponmo processing facility in Lagos. They were Ajibade’s facility, Agege abattoir, and the army barracks abattoir, along the Lagos-Badagry Expressway.
At Ajibade’s facility, the ponmo samples purchased had been roasted with tyres and re-roasted with spoilt shoes. The samples were tagged SAMPLE A.
The ponmo samples purchased from the Agege abattoir were roasted with firewood and ground plastic. The samples were tagged SAMPLE C.
Ground plastic, sticks, and small components of tyres were used in roasting the ponmo purchased at the barracks abattoir. They were tagged SAMPLE B.
The collection, consisting of roasted and washed ponmo, numbering about 12 samples, were put in transparent polythene bags for onward delivery to analysts at two government-approved laboratories for testing.
Sample submission for testing
Our correspondent tried to have the samples tested at the National Agency for Food and Drug Administration and Control. However, NAFDAC could not analyse the samples. Officials of the agency said the reference standards/materials to analyse the ponmo samples were unavailable.
At the Standards Organisation of Nigeria, the Director, Laboratory Services, SON, Dr Barth Ugwu, also said the government agency could not help because the reference standards were not available.
Our correspondent then approached Alfa Laboratories Limited and the Unilag Consult Limited, to analyse the samples to determine if they were safe for human consumption.
During negotiations, an observation was raised regarding Nigeria’s lack of a standard to benchmark ponmo testing and it was agreed that a foreign standard would suffice.
After payment, the ponmo samples were delivered to the labs and separate dates were set aside for result collection.
Disturbing findings
The results came in a few weeks after delivery, weeks after the laboratories had tested the ponmo for heavy metals and chemicals. The results were benchmarked against European and World Health Organisation standards.
The report issued by Alfa Laboratories Ltd, for samples A, B, and C revealed that “The pyrene, zinc and lead (in the ponmo) are higher than the European standards.”
These findings signified that the pyrene, zinc and lead found in the tested ponmo samples were beyond the permissible limit allowed in food items.
Also, results obtained from Unilag Consult Limited revealed the presence of polycyclic aromatic hydrocarbons in the analyzed ponmo samples.
The PAH (ug/g) found in SAMPLE A, which was the ponmo purchased immediately after it was roasted with tyre and spoilt shoes, was ‘105.0.’ In the same result, the PAH was reduced to ‘11.50’ when the purchased roasted but washed ponmo in SAMPLE A1 was analyzed.
A similar pattern was observed in tested SAMPLES B, B1 and C, C1, as the permissible limit sum of PAH specified in the result was “12.0”
The result went further to indicate that the health implications of parameters tested were, “eye irritation, diarrhoea, skin irritation, eye cataracts, kidney and liver damage, breathing problems, decreased immune functions, lung malfunction, asthma-like symptoms. The most significant end-point of PAH toxicity is cancer.”
It further noted that “plastic and tyres should not be used for the processing of cow skin.”
Expert interpretation
The results were presented to two experts to interpret independently.
Commenting on the results, Dr Amos Abolaji of the Department of Biochemistry, Drug Metabolism & Toxicology Unit, Faculty of Basic Medical Sciences, College of Medicine, University of Ibadan, said results from both labs indicated that the tested ponmo samples were unsafe for human consumption.
He said, “The study is of public health significance. The summary of what the Alfa Laboratories’ data indicates is that the roasted cow skin contained high levels of lead, zinc, pyrene.
“Pyrene is part of the polycyclic aromatic hydrocarbons. PAHs are the compounds generated when meat is roasted. So, when it is in excess in the system, it can cause cancer and other illnesses.
“We also have high levels of zinc; zinc is good in the system, but too much zinc can cause stomach cramps, loss of appetite, and some other health challenges. For an adult, the recommended daily allowance should not be more than 40 milligrams per day; for infants, it is four milligrams per day.
“In that particular data from the laboratory, the zinc level is very high. Apart from that, the lead is also higher than the European standards. Lead can attack the brain and the central nervous system, which can lead to coma and eventually death. Children who survive severe lead poisoning, as they go on in life, may have intellectual disabilities.
“In a nutshell, the results of the Alfa Laboratories indicated that lead, zinc, and polycyclic aromatic hydrocarbons were higher in the cow skin, especially the ones that were roasted with tyres. The results indicated that the ponmo roasted with tyres and plastic are not safe for consumption.”
Bioaccumulation risks
Commenting on the result presented by the Unilag Consult Ltd, Abolaji said it indicated that the tested ponmo samples were also unsafe for consumption.
He added, “Similar to what we found in the other laboratory (Alfa Laboratories), the result indicated that the ponmo is unsafe for consumption. It indicated the presence of polycyclic aromatic hydrocarbons. The cow skin roasted with tyres contained a very high amount of PAHs.
“Even after they washed the roasted ponmo, the level of the PAHs in the ponmo roasted with tyres was still high though close to the permissible limit by WHO standards.
“But the risk associated with this is the fact that if Mr A decides to take too much of this (ponmo) daily, of course, he will have a high level of PAHs in his system, compared to the other person that just takes a little as it can bioaccumulate in the system.
“The implication of the bioaccumulation is that over time, it can eventually lead to the process of carcinogenicity, which is the process by which cancer is formed. Some of them can initiate this process or make the process become pronounced in the system.
“The person may not know that something is going on in his/her system, but over time, he/she may just begin to see these diseases, including cancer, liver damage, among others.”
Occupational risks
Abolaji also cited occupational exposure as a pressing issue, explaining that people who roast ponmo with tyres and plastic daily would by means of their occupation become exposed to smoke from burning tyres and plastic.
“The gases generated as a result of the combustion of tyres and plastic include carbon monoxide, sulphur dioxide, and these gases are also toxic to the system.
“Also, some people can possibly suffer secondary exposure; they don’t work directly at the place where the ponmo is roasted with tyres and plastic, but they are close to the place or live in the same environment and despite having no business with the roasting of the cow skin, they can also get exposed to the gases.
“Several diseases that people go to the hospital to discuss with the doctor about can be prevented by preventing exposure to these chemicals.. For how long can you hold your breath passing through such an environment? As individuals, we need to be careful with what we allow ourselves to be exposed to. You don’t stay in such an environment for a long time.
“But if there can be a policy to indicate that roasting of the cowskin to make ponmo should not be carried out with tyres and plastic, it will reduce the spread of these toxic components.
“Concerning safety, the white ponmo is still better for consumption as it would have very low PAHs. Tyres and plastic should not be used in roasting ponmo. Anytime meat is roasted, the PAHs are generated but they won’t be as much as when you use tyres and plastic. People in the environment must also be aware that, when processors use only wood, the environmental contaminants will be reduced.”
A geneticist, Dr Olusola Sokefun, after reviewing the results, said the tested ponmo samples were unsafe for consumption.
He added, “If the results are standard, it means that there are dangers in eating the cowhide, especially that made with vehicle tyres. The reason is that most of the values obtained from the tests are above the permissible limits using the World Health Organisation, European and American standards. These are the three main standards used in food science.
“The apparent danger in having these residues above permissible limits is that most persons consume cowhide almost lifelong. So, these residues are known to bioaccumulate in human tissues. By bioaccumulation, I mean that it increases across time. So, it is 0.1mg today and in three years it may have become about 1.5 mg in some tissues. As we continue to consume, so does the amount in our system increase.
“There are several dangers. Some of these effects are short-termed while others can be long-termed. The most critical is the ability of these residues to damage the genetic material which is the deoxyribonucleic acid (DNA) either directly as genotoxic carcinogens or indirectly as promoters of existing damage (epigenetic carcinogens).
“Note that the cell is the unit of life that can exist independently, carrying out almost all of life’s processes. There should be very strong publicity and advocacy against the use of used tires for processing ‘Ponmo’ because of these findings.
“Less toxic alternatives should be used. I want to assume that the use of used tyres may not be unconnected with its being readily available and cheaper. But considering the long-term adverse effects on human health, I strongly advise the discontinuation of this practice. Ponmo can be termed the delicious silent killer with this amount of residues.”
Dangerous imports
Recently, the Director-General, NAFDAC, Prof. Mojisola Adeyeye, warned members of the public, particularly consumers of ponmo, against the activities of some unscrupulous businessmen and traders, who were selling imported industrial animal hides processed with chemicals as food items.
“These hides and skins are then sold to unsuspecting members of the public as a consumable animal skin product, otherwise called ponmo. Monitoring was also extended to some buyers, who patronised the sellers and custodians of the warehouse,” Adeyeye said in a statement.
She warned that cowhides that were pre-treated with industrial chemicals, which were not of food grade, would be toxic and injurious to human health.
However, aside from cowhide importation, locally sourced cowhides are surplus in various abattoirs in different states in Nigeria.
The cowhides are sourced through flaying before butchers cut the body of the cow into smaller pieces and sell to patronising customers.
Despite sourcing the cowhides locally or through importation, processors say the method of making the two types of ponmo: white and brown, is either through boiling or roasting.
Poor enforcement
After a six-month investigation revealed that Nigerian brown ponmo processors had been roasting the widely consumed delicacy with fire fueled by scrap tyres, plastic, spoilt shoes, among others, the illicit trade has continued unabated and without restriction.
Our correspondent confirmed this development after revisiting private and public ponmo processing facilities where the highlighted components were used in producing brown ponmo in Lagos State.
Despite experts’ admonitions against the practice of burning ponmo with tyres, plastic, black watery and oily substance, disused engine oil, among others, concerned regulatory agencies, including NAFDAC, SON, Lagos State Consumer Protection Agency, among others, have yet to wade in to put an end to these harmful practices.
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