New Delhi: Climate change is increasing the risk of foodborne diseases by altering temperatures, rainfall patterns, water quality and agricultural practices. Foodborne diseases occur when people consume food contaminated by bacteria, viruses, parasites or harmful substances such as mycotoxins, pesticide residues and heavy metals. The World Health Organization estimates that foodborne diseases cause around 866 million cases and 1.52 million deaths globally each year.
Rising air and water temperatures can create conditions that allow disease causing organisms to multiply and spread more rapidly. Salmonella, for instance, has been linked to higher temperatures, which can accelerate bacterial growth. Changes in rainfall and farming practices can also affect the movement of pathogens through soil, water, livestock and crops.
Drought can create additional risks as agricultural producers become more dependent on irrigation. Contaminated water used to grow or wash fresh produce can introduce pathogens into the food supply. Poor quality irrigation water has been identified as a potential source in several E. coli outbreaks involving leafy green vegetables in the United States.
Warming oceans are also contributing to the spread of Vibrio bacteria. The bacteria can accumulate in shellfish such as oysters and cause serious illness when contaminated shellfish are consumed raw. Exposure through open wounds in warmer seawater can also result in severe infections.
Extreme weather events pose another threat to food safety. Flooding can contaminate agricultural land and fresh produce with sewage, animal waste and other pollutants. Following flooding associated with Hurricane Irma in 2017, the US Food and Drug Administration warned against eating fresh produce that had come into contact with floodwater.
Climate change may also alter farming practices and extend growing seasons in some regions, potentially increasing opportunities for pathogens such as Salmonella to circulate between livestock, the environment and food systems.
The Wellcome analysis said climate mitigation must be accompanied by adaptation measures to reduce foodborne disease risks. These include stronger disease surveillance, improved food safety education, better food preparation and storage practices, stronger infection control in livestock, safer food transportation and storage systems, and early warning systems that monitor climate-related changes.
The analysis emphasised that protecting food safety in a changing climate will require action across the entire food supply chain, from production and water management to storage, transportation and consumption.