What has global climate change to do with food safety you ask? Well quite a lot is the unfortunate answer. In a previous blog we have already described the increased risk of finding toxic levels of arsenic in rice due to global warming. Not convinced yet? Maybe the following quotes from a range of official global organisations can provide some compelling information for you to change your mind.
Opinions expressed by some official agencies
Climate change is likely to have considerable impacts on food safety, both direct and indirect, placing public health at risk. With changing rainfall patterns and increases in extreme weather events and the annual average temperature we will begin to face the impacts of climate change. These impacts will affect the persistence and occurrence of bacteria, viruses, parasites, harmful algae, fungi and their vectors, and the patterns of their corresponding foodborne diseases and risk of toxic contamination. Alongside these impacts, chemical residues of pesticides and veterinary medicines in plant and animal products will be affected by changes in pest pressure. The risk of food contamination with heavy metals and persistent organic pollutants following changes in crop varieties cultivated, cultivation methods, soils, redistribution of sediments and long-range atmospheric transport, is increased because of climate changes.
Climate change poses significant challenges to global food safety. Long-term changes in temperature, humidity, rainfall patterns and the frequency of extreme weather events are already affecting farming practices, crop production and the nutritional quality of food crops. The sensitivity of germs, potentially toxin-producing microorganisms and other pests to climate factors suggests that climate change has the potential of affecting the occurrence and intensity of some foodborne diseases. Also, changing conditions may favour the establishment of invasive alien species harmful to plant and animal health. Surface seawater warming and increased nutrients input leads to the profusion of toxin-producing algae causing outbreaks of seafood contamination.
The transmission of infections or diseases between animals and humans (“zoonotic diseases”) is a major source of food safety risks. Environmental factors such as temperature, rainfall, humidity levels and soil can help to explain the distribution and survival of bacteria.
There is a growing consensus that human activities may be changing our planet’s climate. These changes in climate have a number of possible implications for human health and welfare, one of which could be the safety of food.
It is impossible to accurately assess the full impact of climate change on food safety. However, it is likely that some effect on microbiological and chemical hazards will be seen. The extent of the risk posed by these hazards will depend on the type of hazard and the local conditions and practices.
Climate change does not only imply increased average global temperature. Other effects of climate change include trends towards stronger storm systems, increased frequency of heavy precipitation events and extended dry periods. The contraction of the Greenland ice sheet will lead to rising sea-levels.
These changes have implications for food production, food security and food safety. It is widely understood that the risks of global climate change occurring as a consequence of human behaviour are inequitably distributed, since most of the actions causing climate change originate from the developed world, but the less developed world is likely to bear the brunt of the public health burden.
There is reason to believe that climate change can affect infection of crops with toxigenic fungi, the growth of these fungi and the production of mycotoxins. Given the great importance of this hazard, it is necessary that we understand what changes we might expect in order to better prepare ourselves to deal with this critically important issue.
Changes in climate may be creating a marine environment particularly suited to the growth of toxic-forming species of algae. Toxin-producing algal species are particularly dangerous to humans. A number of human illnesses are caused by ingesting seafood (primarily shellfish) contaminated with natural toxins produced algae; these include amnesic shellfish poisoning (ASP), diarrheic shellfish poisoning (DSP), neurotoxic shellfish poisoning (NSP), azaspiracid shellfish poisoning (AZP), paralytic shellfish poisoning (PSP), and ciguatera fish poisoning. These toxins may cause respiratory and digestive problems, memory loss, seizures, lesions and skin irritation, or even fatalities in fish, birds, and mammals (including humans).
Like EFSA, FAO also comments on zoonotic diseases such a hot topic with COVID-19 a prescient example:
Climate change is one of several ‘global change’ factors driving the emergence and spread of diseases in livestock and the transfer of pathogens from animals to humans.
Climate change will have a variety of impacts that may increase the risk of exposure to chemical contaminants in food. For example, higher sea surface temperatures will lead to higher mercury concentrations in seafood, and increases in extreme weather events will introduce contaminants into the food chain through stormwater runoff.
The assessment finds that climate change is likely to diminish continued progress on global food security through production disruptions leading to local availability limitations and price increases, interrupted transport conduits, and diminished food safety, among other causes. The risks are greatest for the global poor and in tropical regions. In the near term, some high-latitude production export regions may benefit from changes in climate.
A bleak future
As you can see a fairly bleak uniform view from many official agencies. Global efforts to reduce greenhouse emissions and regional measures to adapt to changing climatic conditions will be important to mitigate the impact on food and feed safety in relation to human health and nutrition, animal and plant health, and the environment.
The previous blog on arsenic was used as an example of a an increasing human health problem of a contaminant due to climate change. In some future blogs we will cover the the increased prevalence of algal and fungal toxins due to global warming.