Climate change threatens food security | nourish with science | The USA Print


The profound changes brought about by climate change will not only compromise the survival of plants and insects that we have never heard of, but will also profoundly affect our way of life, even if we have heating and air conditioning. We can see a clear example in food. One of those privileges that we enjoy in our environment is that of having sufficient and stable access to food: to dispose of it we only have to go to a supermarket. In addition, we can consume them without fear that they will poison us or transmit diseases to us, because they are generally safe.

But climate change can also have a significant impact on these two aspects. It directly affects primary production, that is, livestock, agriculture and fishing, threatening the availability of food (what is known as food security or food safety, in English). This impact is well studied and documented, but much less attention has been devoted to the implications of climate change for food safety (also known as food safety in Spanish and as food safety in English). food safety).

Climate change and food safety

Despite the striking food alerts that occur from time to time, it can be said that the level of food safety in Spain and in Europe is high. To achieve this, work is carried out at various levels throughout the entire food chain, from the moment the tomatoes are planted, until the sauce made with them reaches our shopping cart. One of the fundamental aspects of this task is to carry out a risk assessment, which is carried out continuously because the risks can change over time due to different reasons, such as changes in eating habits or the advancement of scientific knowledge. .

For example, it’s only been a couple of decades since we’ve known that when we over-toast bread or over-fry potatoes, a potentially toxic compound called acrylamide is formed. Precisely what is worrying about climate change in this sense is that it is causing new threats to food safety to appear and those that already existed to intensify.

biological threats

One of the most important threats to food safety is the presence of pathogenic bacteria, such as listeria, Campylobacter either Salmonella. The increase in temperatures associated with climate change can favor its development, especially if we do not handle food properly or do not refrigerate it. Data from some European countries show that, for every increase of one degree in the weekly temperaturecases of salmonellosis increased between 5% and 10% (when the ambient temperature is higher than 5ºC).

It is advisable not to fall into alarmism, because in general the controls work. But you also need to be realistic. Controls are not foolproof

In the case of campylobacteriosis the correlation is not as strong, but in general a 3% increase is expected in the coming decades. And the same goes for Vibrio spp., a genus of bacteria that lives in the marine environment. It is transmitted primarily through the consumption of shellfish (primarily contaminated raw oysters) and its development is increasing with the increase in temperature of seas and oceans. It is possible that this warming also explains the greater presence of anisakis in fish (multiplied by 283 between 1978 and 2015), although at the moment it is not entirely clear.

In any case, the increase in temperature is only one of the factors that influence the development of these organisms. There are many others. Heavy rains can multiply by 25 or 30 the levels of bacteria in the crop fields due to the increase in environmental humidity. Floods increase the probability of contamination of water, crops, fish and food animals with pathogenic microorganisms, due to the overflow and runoff of wastewater. The scarcity of water caused by the absence of rain increases the probability that it will be contaminated, with the risk that this implies for food of vegetable and animal origin.

In addition, these are not isolated factors that act independently, but are interrelated and affect the environment together. The increase in the temperature of seas and oceans, changes in the salinity and acidity of the water and the absence of cloudiness, among others, favor the development of marine microalgaesuch as dinoflagellates and diatoms. These organisms are capable of producing different toxins that can cause various adverse health effects (paralysis, diarrhea, amnesia, etc.) when we eat contaminated fish or shellfish. Examples of this are the famous red tides, which from time to time prevent the collection of mussels on the Galician coast, or the development of microalgae of the genus Gambierdiscusproducers of ciguatoxins, which are more and more frequent in areas where they were not present before, like the waters of the Canary Islands.

Precisely this last example shows how some of these threats are not only intensifying, but are also expanding into geographical areas where they were previously unknown. Something similar happens with some fungi such as Aspergillus, fusarium Y Penicillium, capable of producing mycotoxins, which are very toxic chemical compounds (they are genotoxic, carcinogenic and immunotoxic). Of particular concern is aflatoxin B1, produced by Aspergillus flavuswhose development has been favored in corn crops in places where it was not common before, like northern italy. Rising temperatures and changes in precipitation and humidity are expected to also cause an increase in the presence of this toxin in other corn-producing countries, such as France, Hungary and Romania.

chemical threats

Changes in the geographical distribution of agricultural pests (fungi, insects, etc.) are predicted to lead to increased use of plant protection products (pesticides). Furthermore, it is feared that rising temperatures, carbon dioxide levels and exposure to sunlight will cause these substances to volatilize further, so it is likely that it is necessary to apply a greater amount to be effectivewhich implies a greater risk to health and the environment.

Something similar happens in the case of livestock. Animals are expected to be more susceptible to diseases for different reasons: an increase in vectors, such as insects and ticks, which are transmitters of pathogenic microorganisms; increased incidence of mastitis (inflammation of the udder) in dairy animals due to exposure to extreme weather conditions (too cold or hot and too wet or dry), etc. As a consequence, it is predicted that a greater use of drugs, and particularly antibiotics, will be necessary, which may aggravate microbial resistance to these substances, a problem that is already considered to be of great concern today.

What awaits us in the future?

But the thing does not end here. There are many other signs of the implications of this phenomenon. For examplea study conducted in Bangladesh showed that the increase in soil temperature causes a greater accumulation of arsenic in rice grains, a metalloid that is present in the environment, both naturally and by human action, and that consumed in high doses for a long time can cause different types of cancer. And the warming of seas and oceans causes the methylation of mercury that is found polluting their waters, which implies the accumulation of methylmercury in fish, especially in large species (an increase of 3-5% of methylmercury has been found for every 1ºC increase in water temperature). This compound affects the developing central nervous system. That’s why it is recommended that pregnant or lactating women and children under ten years of age avoid the consumption of certain species of fish; specifically bluefin tuna, swordfish, pike and shark.

As we have mentioned, prevention and control measures already exist to avoid all these risks and ensure that food is safe (for example, legislation establishes limits for the presence of pathogens and toxic substances). But in view of the situation and what is to come, it will be necessary to intensify these measures and incorporate new ones, which will have economic and other costs (human resources, time, etc.). It is advisable not to fall into alarmism, because in general the controls work. But you also need to be realistic. The controls are not foolproof. The more numerous and intense the threats, the more compromised food safety and our health will be.

Miguel A. Lurueña (@gominolasdpetro) has a doctorate, a degree in food science and technology, a technical agri-food engineer and scientific communicator (

nourish with science It is a section on food based on scientific evidence and the knowledge contrasted by specialists. Eating is much more than a pleasure and a necessity: diet and eating habits are now the public health factor that can most help us prevent many diseases, from many types of cancer to diabetes. A team of dietitians-nutritionists will help us to better understand the importance of food and, thanks to science, to break down the myths that lead us to eat poorly.

You can follow THE COUNTRY Health and Wellness in Facebook, Twitter and Instagram.

#Climate #change #threatens #food #security #nourish #science


Please enter your comment!
Please enter your name here