Food risks and hazards: the great confusion

In light of recent media reports (fire at the Lubrizol company, death of a little boy in the Oise region affected by Escherichia coli bacteria, sick pupils after a school cross-country race), I propose to explain as simply as possible in this article the difference between a risk and a danger in the food sector, which are often confused and confuse consumers' understanding of the information disseminated by social networks and the media.

Didier Montet, University of Montpellier

The definition of danger is relatively simple. Risk, on the other hand, is more difficult to define, as it is the probability of encountering a hazard. If the hazard is not present, the risk is zero, and if it is very present, the risk is proportional to the quantity of the hazard.

When it comes to food, you're going to be confronted with chemical hazards (pesticides, certain additives, toxins, hormones...), biological hazards (pathogenic bacteria, toxigenic molds, viruses, prions...), heavy metals (mercury, lead, cadmium, copper, sulfur...). These foreign bodies present a risk to consumers, and will become a danger as soon as they are present in sufficient quantities to cause either an acute violent attack (toxin, metals, virus), as in the case of botulinum toxin poisoning, or a chronic cancer-type attack.

Where are the toxic molecules?

These toxins are often present in very small quantities in foodstuffs, and are governed by strict, globally-accepted standards set by the Codex Alimentarius experts. The Codex Alimentarius is a joint program of the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) to produce a compendium of standards, guidelines and recommendations relating to food production and processing, with the aim of ensuring food safety. Experts consider that the standard ensures a high level of safety for the consumer. Health standard values for food toxins hover around the microgram (µg) per kilo of food. This quantity is extremely small (1 millionth of a gram), but analytical equipment makes it possible to quantify them. For educational purposes, I have calculated what one µg/kilo represents in time for a conference with legal friends. A µg/kilo represents one second in time over 32 years. It's rare in everyday life to be so precise in one's activities.

On October 10, the newspaper 20 minutes reported that levels of dioxins (banned for consumption) in soil in Rouen exceeded the standard by a factor of 4. The World Health Organization recommends a maximum permissible dose of 10 pg/day/kg body weight (i.e. one millionth of a millionth of a gram/day/kg) as a precautionary threshold for daily exposure over a lifetime. That's not much, and neither is four times as much! At these doses, it is extremely difficult to estimate the real danger.

What's the difference between risks and hazards?

Let me give you a few examples to help you understand the terms risk and danger. In Europe, health agencies work on calculating risk, i.e. on the presence of a possible hazard, whereas in Africa, where I often work, food hazards are very present. When a European consumer hears talk of risk, he understands danger, whereas the danger may not actually be there.

Pesticides include herbicides such as the famous Rondup (Monsato, now Bayer Europeen), fungicides (anti-mould) and insecticides. This represents some 500 molecules authorized by Europe, some of which are hazardous to health, particularly for farmers who handle them in large quantities.

For the consumer, the quantities found on foodstuffs in Europe are very low, generally below 5 µg/kg for 95.9% of foodstuffs in conventional and organic farming.

The report shows that 96.2% of the 84,657 samples analyzed complied with legal limits. 50.7% were free of quantifiable residues, while 45.5% of the samples analyzed contained quantified residues not exceeding the maximum residue levels (MRLs). The acute and chronic dietary risk assessment showed that the likelihood of European citizens being exposed to pesticide residue concentrations that could cause adverse health effects was therefore low.

This risk is difficult to estimate, as it involves the toxicology of molecular traces, whose toxicity on humans is almost impossible to calculate using current methods. In the least vigilant countries, banned pesticides are still in circulation. Other pesticides are used on unintended targets.

Faced with a sharp rise in anti-biotic resistance, particularly in certain pathogenic bacteria, the EU banned the use of antibiotics in animal feed in 2005, while these antibiotics are still authorized in most other countries around the world, some of which have trade agreements with Europe (South-East Asia, USA, Mercosur). In Europe, antibiotics are still authorized to treat both conventional and organic animal diseases. The danger is that antibiotic resistance can develop in pathogenic bacteria. The risk is very poorly controlled, as there are currently no health standards on antibiotic resistance, and control is based solely on antibiotic content.

Mycotoxins are toxins produced by certain molds, some of which are carcinogenic. They are very present in humid, warm environments, where they can reach extremely high levels. In Europe, some toxigenic molds are present, but the quantities of mycotoxins measured are generally below the thresholds that experts consider dangerous to health. The danger is therefore identified in Europe, but the risk is hard to calculate and can be considered low. It will depend on the use of chemical fungicides, including copper sulfate, which is well known in organic farming. The general public is not yet aware of this danger, which can kill entire families acutely in Africa, and more insidiously through cancer.

Pathogenic bacteria, which can be fatal, are naturally occurring and can be found everywhere, particularly in soil, but also in animal intestines. No one can escape this danger, and quantifying their presence in fresh food before it is put on the market is virtually impossible, given the speed at which food flows around the world. Only strict hygiene measures and controlled processes can prevent their presence.

The danger therefore depends not only on the initial bacterial load, but also on the process (sterilization, cold chain), the marketing and, above all, consumer behavior. Some accidents are still due to poor consumer training.

Certain mineral elements (lead, arsenic, mercury, copper) may occur naturally in food or come from the manufacturing process. They are toxic and represent a danger that must absolutely be avoided in the diet. Some older fish contain high levels of heavy metals, as they accumulate them in their viscera. The risk is not easy to estimate, as it will depend on the content of the feed and the quantity consumed.

Consuming large quantities of sugar increases the risk of obesity, and therefore of mortality from metabolic diseases. Here we have an example of low danger and high risk.

It's interesting to note that in our countries, people are more afraid of risk than danger, because risk is often poorly understood and explained, whereas danger is mastered by professionals.

In Europe, experts meet every month or so to assess the risk of certain products, such as GMOs, novel foods and additives, which can only be marketed after a positive opinion from the agencies.

Didier Montet, Expert researcher in food safety, University of Montpellier

This article is republished from The Conversation under a Creative Commons license. Read theoriginal article.