Unsafe food, containing bacteria, viruses, parasites or harmful chemicals, causes 1.5 million deaths worldwide each year, particularly affecting children under five, the WHO warned on Thursday.

"Food security is not an abstract issue: it concerns every meal, every family, every day," said World Health Organization Director-General Tedros Adhanom Ghebreyesus in a statement released ahead of World Food Safety Day on June 7.

According to this analysis by the WHO, which assessed 42 foodborne risks in 194 countries between 2000 and 2021, each year 866 million people contract an illness related to the consumption of unsafe food and 1.5 million die from it.

Young children under five are particularly vulnerable. Their risk of contracting a foodborne illness is almost three times higher than that of older children and adults.

Although the overall burden of foodborne illness has declined since 2000, significant regional disparities persist, with Africa and Southeast Asia being the most affected regions. These regions account for nearly three-quarters of all foodborne illness cases and 60% of deaths worldwide.

Exposure to biological hazards, including foodborne bacteria and viruses and parasitic infections, caused the majority of foodborne illnesses (around 860 million in 2021), while exposure to chemicals was responsible for a disproportionate share of deaths.

Inorganic arsenic (42%) and lead (31%) were thus responsible in 2021 for the majority of deaths related to chemical substances, largely because exposure to these agents increases the risk of cardiovascular diseases and cancers.

"The data shows that foodborne illnesses are not only persistent, but are exacerbated by climate change, which increases the risk of contamination, and by antimicrobial resistance, which makes infections more difficult to treat," explained Yuki Minato, WHO technical lead for food safety.

Beyond the health effects, the study estimates that in 2021 foodborne illnesses resulted in $647 billion in lost productivity.

"Unsafe food has always been a major public health problem, but until now we did not have a comprehensive view of its colossal human and economic cost. These new estimates change the game," noted the head of the WHO.