Climate change could be coming for your dinner plate.
Changes to the world’s climate could mean more frequent outbreaks of food-borne illness, according to a recent report from the Public Health Agency of Canada, and Canadians need to be ready to deal with the risks.
The report, published in April, found that food-borne disease “represents a significant climate change-related threat to public health.”
“The things that will really change our food system the most are changes in air temperature, changes in water temperature and changes in rain patterns,” said Sherilee Harper, associate professor in the School of Public Health at the University of Alberta.
Each of these will affect food safety in different ways.
Rising water temperature, for example, has been associated with more shellfish-related illnesses, said Lawrence Goodridge, professor at the Canadian Research Institute for Food Safety at the University of Guelph.
“As the temperature of the ocean rises, it causes a bacteria called vibrio, which is found in seafood, to be able to grow better and in some cases it might even cause it to be able to make us more sick,” he said.
A 2004 outbreak of vibrio on an Alaskan cruise ship was linked to fresh local oysters — unusual because at the time, authorities didn’t think that Alaskan waters were warm enough for that bacteria to grow. But as ocean temperatures rose year after year, it became hot enough in summer for vibrio to infect the oysters, according to a study published in the New England Journal of Medicine.
Warmer air temperatures could mean that we have to pay closer attention to safe food handling, Harper said.
“At the processing plants, warmer temperatures mean that bacteria and pathogens could grow more quickly and in different places, so you need better cleaning protocols and processes and ventilation,” she said.
People will also have to pay closer attention at home, she said. “People handle food differently in warmer weather, and in warmer weather people barbecue more.” When they do that, she said, they’re more lax about food safety.
According to the PHAC report, there is a strong association between air temperature and several common food-borne illnesses, like salmonella and campylobacter. The researchers expect the number of cases to increase due to climate change.
Having more and stronger storms could also have an effect on food-borne illness, Goodridge said. Several recent outbreaks, like E. coli cases tied to romaine lettuce, might have been partially due to animal manure contaminating the water used on the crops. With storm runoff, he said, that could happen more often.
Lagoons filled with hog manure were flooded during Hurricane Florence in 2018, he said, and he thinks the danger remains.
Rain and dust storms also reportedly contributed to a listeria outbreak in cantaloupes that killed seven people in Australia.
A recent Canadian study even suggested that climate change could lead to more houseflies, which could spread food-borne pathogens.
All this means that Canadians will have to be more vigilant with food safety, Harper said. “What climate change does is it exacerbates a lot of those weaknesses that we’re already seeing,” she said.
“I think it comes back to generic food safety practices and being extra vigilant of those.”
The government has a role, too, in monitoring food-borne illness and sharing information, she said.
Goodridge agrees. “I think we have to develop a risk assessment process in which we can determine which foods are most at risk of being contaminated and which pathogens are the ones that would most likely cause increased illness due to climate change,” he said. Then, they could more closely monitor and regulate those foods.
Preventing food-borne illness is important, Harper said.
“People don’t think about food-borne illness as being necessarily a key health consideration, but it is. And we know that it does cost the Canadian economy money. We know that it does cause lots of cases of illness and even death.
“We’re already facing those challenges and grappling with them and climate change will compound those.”