- Extreme events attributed to climate change are becoming more frequent, severe, and unpredictable. Such events not only affect food security by negatively impacting agricultural production and yields and disrupting supply chains, but also affect food safety. Factors such as rising temperatures, alternating periods of severe drought and heavy rainfall, soil degradation, rising sea levels, and ocean acidification are altering the virulence, formation, and distribution of various biological and chemical contaminants in food, leading to serious consequences. This increases our risk of exposure to food-borne hazards. Furthermore, the rapid globalization of food supply chains facilitates the spread of food-borne hazards along the way, creating opportunities for local food-borne incidents to turn into international epidemics.
- Unsafe food is not fit for consumption. With adequate, affordable, nutritious, and safe food being recognized as fundamental components of food security, the effects of climate change on food security will hinder our efforts to ensure food security in the face of a growing global population and increasing food demand. According to estimates, approximately 14% of food produced is lost during the production phase before reaching the retail level or consumers. Part of this enormous loss stems from various food contamination issues (FAO, 2019), and climate change can further exacerbate food loss by creating conditions conducive to the emergence and spread of food-borne hazards.
- Today, an estimated 600 million people (nearly 1 in 10 people worldwide) fall ill after consuming contaminated food, and 420,000 people die each year.
- Climate change has a profound impact on the availability and safety of the food we consume and is expected to lead to a significant increase in public health risks through its effects on bacteria, viruses, parasites, and chemicals and toxins associated with foodborne illnesses. Antimicrobial resistance and zoonotic diseases, both directly linked to food safety, are also expected to be affected by climate change. The various changes caused by climate change affect behaviors that impact food safety.
- Such events are more likely to occur in countries where food monitoring and surveillance systems are less robust and therefore unable to detect environmental and chemical contamination, further increasing public health risks through acute and chronic exposure to contaminants.
- The main effects of climate change: sea level rise, increased global average temperatures, warming oceans, extreme weather events (droughts, heat waves, heavy rainfall, storm surges), and ocean acidification will have a significant impact on these behaviors, with developing countries disproportionately affected.
- Climate change is expected to cause approximately 250,000 additional deaths per year between 2030 and 2050; increases in mortality rates related to food security are expected to contribute to this.
- Climate-sensitive risk factors and diseases, including undernutrition, infectious, non-infectious, and diarrhea and vector-borne diseases, will be among the major contributors to the global burden of disease and mortality.
- Food production itself may be directly affected by climate change through changes in the survival and/or reproduction rates of some foodborne pathogens. For example, the proliferation of Salmonella spp., which contributes significantly to foodborne illnesses and was estimated to cause over 50,000 deaths in 2010, is largely temperature-dependent. Increased temperatures or longer periods of high temperatures in certain geographic regions may provide better conditions for the proliferation of Salmonella spp. in foodstuffs. As stated in the WHO’s 2017 report on protecting health from climate change in Europe, when ambient temperatures are above 5°C, Salmonella cases increase by 5-10% for every 1°C increase in weekly temperature.
- The same report, referring to a study conducted in Kazakhstan, found that a 1°C increase in average monthly temperature resulted in a 5.5% increase in the incidence of salmonellosis.
- The FAO has concluded that a change in climatic conditions could lead to grain being harvested with a moisture content higher than the 12% to 14% required for stable storage, thereby increasing the risk of mycotoxin formation.
- Aflatoxin contamination and related food safety issues are predicted to become more widespread in Europe with a +2°C temperature increase. A one-degree increase in global average temperature is estimated to reduce average global wheat yields by 6%. This reduction in food availability could lead to increased public health risks from mycotoxin poisoning, particularly in (developing) countries where small-scale farmers and families sell locally and consume what they grow, forcing them to sell and consume contaminated products to survive.
- Outbreaks of zoonotic diseases, which can be transmitted from animals to humans, will increase during warmer and drier periods and have a significant impact on public health. Changing weather patterns are expected to alter the survival of pathogens in the environment, changes in migration routes, carriers, and vectors, and changes in natural ecosystems, all of which will contribute to outbreaks and spread of zoonotic diseases.
- Higher humidity and higher temperatures will increase pressure from pests and are expected to lead to a changed weed flora, which will increase the need for pesticides. In response, pesticide usage patterns will likely change. Such changing patterns are predicted to increase the risk of human exposure to pesticides through residues in food.
- Rising ocean temperatures may indirectly affect humans exposed to environmental pollutants such as mercury in some fish and marine mammal oils. Ocean warming facilitates the methylation of mercury, which is subsequently taken up by fish and mammals, and has been found to increase by 3-5% for every 1ºC increase in water temperature.
- The high risk of emerging zoonoses, changes in pathogen survival rates, and changes in vector-borne diseases and parasites in animals may necessitate increased use of veterinary drugs to combat the growing challenges faced by farmers. This could subsequently lead to increased levels of veterinary drug residues in food of animal origin and potentially harmful effects on public health.
- Increased levels of veterinary drug residues in animal-derived foods not only pose acute and chronic risks to human health, but are also directly linked to increased antimicrobial resistance in human and animal pathogens. With the increasing prevalence of antibiotic-resistant diseases and bacteria, humans are becoming more vulnerable, and the effects of climate change and human behavior contribute to this vulnerability.
https://cdn.who.int/media/docs/default-source/food-safety/climate-change.pdf?sfvrsn=59c632e7_2
