Food safety and climate change

How climate change is affecting the safety of our food supply.

A wheat field.
Photo: Pixabay.

The impacts of climate change are broad, from affecting obscure animals most of us have barely heard of, like the Hine’s emerald dragonfly, to impacting all of us by changing many aspects of food safety.

According to the Food and Agriculture Organization of the United Nations (FAO), climate change is affecting food safety by influencing foodborne pathogens and parasites, algal blooms, heavy metals, pesticides and mycotoxins. Let's take a more in-depth look into these food safety issues.

  • Foodborne pathogens: When considering foodborne pathogens, germs on and in food that can make us sick, environmental changes caused by climate change can contribute greatly to unsafe food. For example, changes in temperature and precipitation can lead to an increase in infections by many different common pathogens such as E. coli, Campylobacter and Salmonella. It has been documented that Salmonella grows better in warmer environments and some plants, such as leafy greens, increase their uptake of pathogens during times when water is scarce.

  • Algal blooms: Algal blooms are characterized by an overabundance of growth by one type of algae, and they can cause numerous problems for marine and aquatic ecosystems. With regard to food safety, algal blooms are known to create toxins that can accumulate in fish. When people eat contaminated fish or seafood, there is a risk of becoming severely ill. For example, according to the United States Centers for Disease Control and Prevention (CDC), the most widespread illness of this type in the world, Ciguatera fish poisoning, can cause gastrointestinal symptoms such as nausea and vomiting and neurological symptoms such as tingling fingers or toes.

  • Heavy metals: According to the Food and Agriculture Organization of the United Nations (FAO), heavy metals are environmental contaminants that come from many processes including industry. Heavy metals that are of particular concern when considering human health are lead, chromium, cadmium, mercury and arsenic. Even at low levels of exposure, these metals are considered poisonous. Climate change can have an impact on heavy metals and food safety through a number of different pathways. For example, according to the FAO, changes in rainfall intensity will increase the chances of run-off from soils, causing an increase of heavy metals in water systems. Research also indicates that as temperatures increase so does the uptake of heavy metals, such as arsenic, in plants like rice.

  • Pesticides: With regard to food, pesticides are used to control an array of damaging agricultural pests improving the quality and quantity of food harvested. According to the World Health Organization (WHO), pesticides can have many negative health effects including cancer. Pesticides can also affect the reproductive system, immune system and nervous system. The FAO asserts that as climate change continues, “climate change is expected to change the geographic distribution, life cycles, population dynamics and trophic interactions of various agricultural insect pests globally.” This means that as the climate changes, pest populations could increase dramatically and move into new locations. This may necessitate the increased use of pesticides on food crops, possibly increasing human exposure.

  • Mycotoxins: According to the United States Department of Agriculture (USDA), “mycotoxins are toxins produced by molds (fungi) and can accumulate in crops.” Because there are many types of mycotoxins, there are many different ways people can be affected by them. Exposure to mycotoxins has been known to cause many health issues such as nausea, vomiting, diarrhea, fever and even cancer. Climate change-induced increases in temperature, significant droughts, unseasonal rain during harvest and extreme weather events that induce flooding are thought to increase the risk of mycotoxin exposure.

These are all big issues, so what can the individual consumer do? To address the potential increase in foodborne pathogens, keep following the four basic food safety steps recommended by the USDA: clean, separate, cook, and chill. To find out more about potential pesticides or heavy metals in your foods, you can shop local or participate in community supported agriculture (CSA), which can give you a chance to talk to your local farmers and learn about their practices.

The landscape of food safety is always shifting and with climate change accelerating that shift, MSU Extension is here with the most up-to-date food safety information to answer any questions you may have. For answers to your food safety questions, call MSU Extension's Food Safety Hotline at 1-877-643-9882. For more information on food safety, visit MSU Extension's Safe Food & Water website.

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