Tuesday, August 19, 2014

Taming Aflatoxin, The Silent Killer in Food: The Case of Malawi

Is it not ironic that the moulds that produce aflatoxin are more
visible than the prescription of death they pronounce on humankind? In legumes such as groundnuts, moulds wear their guts on the outside,
their colour laid out like a map to death. 

The Webster’s New World Medical Dictionary defines aflatoxin as “a
toxin produced by moulds that can damage the liver and may lead to liver cancer. Aflatoxins cause cancer in some animals. The fungi that produce aflatoxin grow on crops such as peanuts and wheat, corn,   beans, groundnuts and rice. Aflatoxin is a problem particularly in  undeveloped and developing countries”. 

Malawi, as one of the ‘developing’ countries, is not immune to aflatoxin fateful pangs. For example, a 2010 study titled ‘Aflatoxins in Sorghum Malt and Traditional Opaque Beer in Malawi’,   indicates that the problem is wide-spread in the country.

Researchers - Deliwe Lakudzala of the Department of Physics and Bio-chemical Sciences at the Polytechnic, a constituent College of the University of Malawi, Elenimo Khonga of the Faculty of Agriculture at Botswana College of Agriculture, Maurice Monjerezi of the Chemistry Department at Chancellor College and a researcher from Chitedze Agriculture Research Station - took part in the study. 

“Samples of sorghum grain and malt, traditional opaque sweet beverage (thobwa) and beer prepared from sorghum malts were collected from the southern region of Malawi during the humid month of January. The samples were analysed for total aflatoxins using aflatest vicam fluorometry procedure. All malt and beer samples, 15 percent and 43 percent of the sorghum and thobwa samples, respectively, were contaminated with aflatoxin,” reads the research report.

It adds: “The sorghum malt prepared for beer brewing had significantly higher total aflatoxin content than any other type of sample. The average aflatoxin content in the beer was 22.32 μg/litre (a mode of measuring toxic content in liquids), which is higher than the permissible maximum level in ready to eat foods set by Codex Alimentarius Commission (10 μg/kg). Thus consumption of opaque sorghum-based traditional beer poses a risk of aflatoxin exposure.”

Fatal laxity

 Some cancers in Malawi may therefore be as a result of exposure to aflatoxin.

That the prominence of cancer as one of the leading killers is rising is a fact that we all accept and yet we continue to look at the problem from a distance.

In spite of this knowledge, Malawi's response to the problem has
been lukewarm. Cancer awareness remains low with research
interventions into cancer being either non-existent or very little.

The Environmental Health Trust says aflatoxin is a naturally-occurring
contaminant produced by moulds, particularly Aspergillus flavus and
Aparasiticus. These moulds grow on crops, especially peanuts, maize, wheat and seed oils (i.e. cotton seed) that are stored in conditions of warmth and humidity.

It adds that aflatoxin are carcinogenic and, as such, are dangerous
to both humans and other animals and have been associated with various human health-related conditions, including the high incidents of liver cancer, growth retardation in children, reproduction impairment and immunity suppression.

Exposure to aflatoxin is known to cause both chronic and acute hepatocellular injury. 

According to the Centre for Disease Control in Kenya, acute aflatoxin
poisoning results in liver failure and death in up to 40 percent of

What is worrying though is that knowledge and awareness about
aflatoxin is minimal in Malawi. Very few people in Malawi know that a dietary exposure to aflatoxin-contaminated groundnuts and other legume-based products - even maize - can result in all the above-listed health complications. 

Very few people know how to control aflatoxin; there is virtually  no political will to address this knowledge gap. Consequently, Malawians may be dying silently from the very same produce that is  supposed to make them proud and give them the energy and nutrients that oil life. 

In real terms, how many farmers in this country know about  aflatoxin? Do our hospitals have aflatoxin testing kits? What is the  country doing on the groundnuts and other crops that cannot be  exported due to high aflatoxin levels? Are these consumed by  unsuspecting Malawians?

Or do we have procedures of disposing off aflatoxin-infested crops? Is there any evidence or records for such dispositions?

The Agricultural Development and Marketing Corporation  (Admarc), the country’s grain marketer established by an Act of Parliament of 1971, says it has always treated the issue of aflatoxins "with the seriousness it deserves", citing the existence of a factory and  laboratory specialising in the same at Liwonde in Machinga. 

Admarc spokesperson Agnes Ndovi says the corporation realises the  importance of meeting international standards, hence its commitment  to ensuring that consumers are not exposed to hazardous substances.

"There are international standards put in place to control the  concentration of aflatoxins and, in Malawi, these aflatoxin largely  affect groundnuts,” she explained. “To meet these standards, we established the factory and laboratory at Liwonde in Machinga, a development that has guaranteed that our groundnuts remain fit for human consumption."

Adds Ndovi: "For your own information, our export consignments have  never been turned back. This is because we work hand in hand with  the Malawi Bureau of Standards which monitors the activities at the  laboratory and factory and issues an Aflatoxin Certificate that  accompanies our groundnut exports. It is mandatory that, apart from  the other permits, consignments of groundnut exports should be
accompanied by this certificate."

Questions, no answers

  Be that as it may, it is known within research institutions that dietary exposure to aflatoxins has been one of the causes of stunted growth. Would it be fair therefore to conclude that low knowledge on aflatoxins and the impact they have can be one of the causes of the 50 percent of stunting growth rates that we have in districts such as Dedza and Mchinji where aflatoxin-laden crops like groundnuts are grown?

Silence before death

While many countries that import or grow groundnuts have put up  measures to reduce consumption of aflatoxin-infested legumes, more  especially groundnuts, Malawi is yet to say something, not even a  proposition on aflatoxin control.  

But even if we pay a blind-eye to aflatoxin research, the chilling fact is that our  trade partners are getting stricter on aflatoxin control and may eventually hit us in the long run. This may result in dwindling marketing opportunities for groundnuts as the importing countries will only import carefully-tested groundnuts.

Groundnut market

The issue of aflatoxin in the Malawi nut has already hit the groundnut market. Malawi used to send thousands of tonnes into the European market per year but the market collapsed due unacceptable levels of aflatoxin in the Malawi nut.

In 1997, the European Union set a uniform standard for aflatoxin at the minimum acceptable level of 10 ppb (parts per billion – the measurement of toxic content in nuts or grains) in groundnuts subject to further processing and at 4 ppb in groundnuts for direct human consumption.

It is, therefore, clear that - apart from the heath risk - lack of adequate investment in aflatoxin research may in the short- medium- and
long-term affect the country economically as our produce ends up
having higher levels of aflatoxin due to poor produce management.


Taking control

However, all these may be averted by simply putting up proper  guidelines on aflatoxin control and management. Higher knowledge  levels on aflatoxin control may improve the quality and marketability  of our legumes. 

And, from the look of things, government seems to be aware of the issue. Principal Secretary in the Ministry of Industry and Trade Alex  Gomani says issues to do with aflatoxin are handled by the Ministry  of Agriculture. And Agriculture Principal Secretary Geoffrey Luhanga says the ministry has a technical committee that deals with the issue. 

Among other efforts at international level, the US-based International Food Policy Research Institute has been urging countries to promote a sector-wide approach in addressing the issue of aflatoxin control, calling for agricultural, health, nutritional and value-chain experts’ need to work together to raise awareness of the public health impacts of consuming unsafe food. 

The institute has also been imploring governments to improve drying,  sorting and storage both on-farm and throughout the value chain;  provide training and access to equipment to change inappropriate  practices such as by facilitating access to mechanical shellers to  stop hand-shelling, among others. 

But the jury is still out on whether these efforts are enough to stem death arising from aflatoxin exposure.


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