Human Feces use in food agriculture no worse than animal feces – or, just as bad!

by Dr. Robert D. Lucas

Special to Barbados Free Press

In the 5th.of June Edition of the ‘Nation” newspaper, there was an article by Mr. Matthew Farley entitled: “Spain blamed.” Farley seemed to be concerned about the use of human feces in the growth of agricultural produce by the Chinese, while conceding the fact that, animal manures are used locally in agricultural production.

Nowhere in his article is it stated whether or not human feces were used in the cultivation of vegetables for salads in the current outbreak of food-borne illnesses in Europe. In the final paragraph of his article Farley urges Caribbean peoples to be cautious when growing vegetables using non-traditional methods. I have some comments to make on the above, but before I do so, I will review some aspects of food microbiology and food safety.

According to the Institute of Food Technologists’ Scientific Status Summary: Food Borne Disease Significance of Escherichia coli O157:H7 and other Enterohemorrhagic E. coli. 1997.51[10]:69-76 : “E.coli has been used since 1890 as a non-pathogenic indicator of enteric pathogens such as Salmonella”.

Most E. coli bacteria are harmless

While most E. coli bacteria are harmless, the enterohemorrhagic E.coli (EHEC) group can produce toxins. Since the 1980’s, strains of E.coli which have acquired virulence characteristics have been isolated; the most common one implicated in food-borne illnesses being E.coli O157:H7 (designated by its somatic or cell wall, O, and flagellar, H antigens). Other E.coli which are pathogenic to humans and animals are referred to as non-O157:H7 stx E.coli. where stx refers to shiga toxins one or two.

It should be pointed out here, that all enterohemorrhagic E.coli (EHEC) produces shiga toxins, also referred to as verocytoxins. Bacteria can acquire virulence traits either by the transfer of genetic material within species and between species ( plasmids or bacteriophages as well as by sexual means). In the case of O157:H7, the shiga toxin was acquired from Shigella spp. via a bacteriophage. The present causative agent of the outbreak in Europe is designated O104:H4. Previously, the serotype O104 was of minor importance to food microbiologists.

From a food safety aspect, it is obvious that, the hazard analysis critical control point (HACCP) program in Germany at the point of concern has malfunctioned. With vegetables which are normally consumed raw, it is necessary that good agricultural and manufacturing practices (GAP and GMP) be observed. HACCP guidelines must be observed from the field to the table. Critical control points in this process are as follows; the quality of the irrigation and rinse water used; manure whether human or animal should be properly treated.

“Animal manure and human fecal matter represent a significant source of human pathogens. A particularly dangerous pathogen, Escherichia coli O157:H7, is known to originate primarily from ruminants such as cattle, sheep and deer, which shed it through their feces. In addition, animal and human fecal matter is known to harbor Salmonella, Cryptosporidium, and other pathogens. Therefore, the use of biosolids and manures, including solid manure, manure slurries, and manure, must be closely managed to limit the potential for pathogen contamination.”

… 1998. Guide to Minimize Microbial Food Safety Hazards for Fresh Fruits and Vegetables. Food and Drug Administration.

Wash those hands!

Additionally, hand-washing after the use of toilets must be enforced. At one of these critical control points, corrective action was not taken, resulting in the outbreak of food borne illness. The ability to pin-point the food which actually caused the problem is not going to be easy, since the contaminated food may have already been discarded. One point, which I find interesting, is the fact that Spanish cucumbers were blame initially. It appears that, the DNA profile of E.coli found on Spanish cucumbers was not compared with the DNA profile of E.coli isolated from the sick people initially. I would hope that, the scientists on the scene did not give into political pressure, to come with the initial finding. In any event, confusion seems to be the order of the day.

As can be seem, Farley need not be unduly worried by the use of human manure in the production of agricultural produce. The Chinese have been using it and their civilization extends back over five thousand years and China has a population of over 1.3 billion. Other countries use the sludge from sewer treatment plants. What I do find amusing, is what Farley means by cautious and non-traditional methods. You cannot get more traditional when manure, either human or animal is used.


Robert D. Lucas, PH.D.
Food biotechnologist.


Filed under Agriculture, Barbados, Health

9 responses to “Human Feces use in food agriculture no worse than animal feces – or, just as bad!

  1. Pingback: Human Feces use in food agriculture no worse than animal feces – or, just as bad! «

  2. Colin L Beadon

    I really like that Doc Lucas article and have known for many years that the Chinese use human manure extensively. But you won’t get Barbadians doing that, just as you won’t get Barbadians or Trinidadians drinking rainwater. If you look up ‘Rainwater’ on Google, it will tell you it is the purest water there is. I myself have always drunk filtered rainwater, and used it in car batteries that have lasted four years or more, as well as in car radiators and windscreen washers. All you need do is filter the rain water.
    In Barbados most of out human manure goes down into our water zones and gets into the water we drink. So, take your choice, rainwater or,…… ? And as for human manure usage on crops, 1.3 million Chinese, can’t be wrong !

  3. Colin L Beadon

    Correction. 1.3 Billion Chinese, can’t be wrong !

  4. HM

    The drinking water in Barbados is one of the cleanest in the world. Unlike many countries – neither Barbadians nor visitors to the island need to resort to bottled water for drinking.

    As for the headline about human waste – utterly disgusting. Of course this is a health hazard. This is one of the reasons why people going on holiday to certain countries around the world are warned about eating fresh fruit and vegetables or drinking local water. This is not the case in Barbados.

    Anyone looking at the headline without reading the article could be under the impression that Barbadians ‘go off into the fields’ like poor people in some parts of the world. Why on earth would they when they have plumbed in toilets and running water at home?

    The food and drinking water in Barbados is clean and safe.

    By the way – in mediaeval England, human waste was routinely used on the fields – people made a habit of not drinking water (this is why beer was drunk instead as it was considered safe) and boiled their fruit, cereals, vegetables to a revolting pulp.

  5. Green Monkey

    Recycling animal and human dung is the key to sustainable farming
    by Kris De Decker

    Flushing the water closet is handy, but it wreaks ecological havoc, deprives agricultural soils of essential nutrients and makes food production dependent on fossil fuels.

    For 4,000 years, human excrements and urine were considered extremely valuable trade products in China, Korea and Japan. Human dung was transported over specially designed canal networks by boats.

    Thanks to the application of human “waste” products as fertilizers to agricultural fields, the East managed to feed a large population without polluting their drinking water. Meanwhile, cities in medieval Europe turned into open sewers. The concept was modernized in late 19th century Holland, with Charles Liernur’s sophisticated vacuum sewer system.

    The innocent looking water closet breaks up a natural cycle in our food supply. Basically, it turns extremely valuable resources into waste products. When we grow crops, we withdraw essential nutrients from the soil: potassium, nitrogen and phosphate, to name but the most important. During the greater part of human history, we recycled these nutrients through our bodies and returned them to the soil, via excreta, food trimmings and the burial of dead. Today, we flush them mostly into the sea (see the infographic below, source).


    However, as obvious as it seems to us today, the water closet is not the only possible answer to the problem of sanitation. There are other, much more sustainable methods to separate human waste from drink water supplies. To start with, the grim sanitary conditions of the Middle Ages and the early Industrial Revolution were a purely western phenomenon. At the turn of the twentieth century in the East, the water in Chinese rivers was safe to drink.

    The Chinese were as numerous as the Americans and Europeans at the time, and they had large, densely populated cities, too. The difference was that they maintained an agricultural system that was based on human “waste” as a fertilizer. Stools and urine were collected with care and discipline, and transported over sometimes considerable distances. They were mixed with other organic waste, composted and then spread across the fields (illustration on the right).

    That’s killing two birds with one stone: no pollution of drinking water, and an agricultural system that could have lasted forever. In fact, it did last 4,000 years, which is considerably longer than even our most abundant resource – potassium, with 700 years of reserves – will allow.

  6. Colin L Beadon

    Green Monk.
    Good investigation.
    If HM wants to go on drinking local water out of the tap, let him go ahead.
    Some of us can drink water in almost any country, and not suffer. It depends if your own natural system can deal with it. I myself have been lucky in that respect , but rainwater is still purer how ever you look at it, provided it is collected the right way .
    Filtering the roof rain after dry spells, is the way to go. Many Islanders in the West Indies, live off rainwater collected from the roof.
    The population of Barbados is expanding. There is no way the local clarity and safety of Barbadian ground water can escape more and more contamination, both from human waste of all sorts, and animal and agricultural husbandry and all the chemicals we use to those ends, such as pesticides, and fertilizers.
    The death of our reefs, attest this.

  7. The Watcher

    To all. Go to Yahoo and take a look at the article entitled “Steak Made from Human Excrement: Is It Safe?”
    While this is a slight divergence from the discussion here, I would like readers to be aware that when you think it’s geting bad, its already worst. This debate may really be a distraction away from the true dangers lurking elsewhere in our food suply.
    In the article, these wack-jobs are now synthesizing steak or something like it from proteins found in human waste. Just imagine the food industry’s dirty little secret about being in bed with the sewerage industry where they take our “pup” and feed this “pup” back to us! Some greed-monger will certainly see dollar signs here in abundance and the cost fo real food, grown under the most natural of circumstances will cease to exist except for the “filthy rich”(no pun intended there) or those insulated from the folly of capitalism gone awry.
    It is bad enough that we are exposed to “Edible food-like substances” , daily masquerading as food, but now to take it to this level is demonstrating that Greed and Stupidity, those maternal twins, have no bounds or limits. I wasn’t there, but it is behaviour and actions like these that seemed to have been responsible for setting off the Second World War. So by my calculations, I think that he third is just around the corner as more crap is done!
    Here’s the link for those interested in reaading he full article.;_ylt=AvpmSxlx0BloYMalKEm7fFehOrgF;_ylu=X3oDMTN1M3BlbG1tBGFzc2V0A2xpdmVzY2llbmNlLzIwMTEwNjE3L3N0ZWFrbWFkZWZyb21odW1hbmV4Y3JlbWVudGlzaXRzYWZlBGNjb2RlA29mZmdiNTBrBGNwb3MDNQRwb3MDNQRzZWMDeW5fdG9wX3N0b3JpZXMEc2xrA3N0ZWFrbWFkZWZybw–

  8. i must commend dr lucas for his willingness to educate the barbadian public. his articles always give much food for thought. however i want to support mr beadon’s comment that it is the extensive chemical use that has been responsible for the desruction of our reefs which in turn has been responsible for decimating much of the sea life particularily what we call the sea egg which thrive in the reef environment.

  9. There is a process called composting and with human waste it is exothermic, hot enough to kill all pathogens. Mix human waste mixed with sawdust (as in a sawdust toilet) and straw, pile it up in a compost bin and let it compost for 12 months to get pathogen free humus perfect for use in a veggie garden. Google “humanure” to get more details. Bonus: a toilet system like that is cheap to build and waterless.