Food contaminated with harmful bacteria, viruses, parasites or chemicals kills 1.5 million people worldwide each year, with young children worst hit, the World Health Organization warned on Thursday.

After analysing 194 countries between 2000 and 2021, the United Nations health agency found that 886 million people contract an illness linked to the consumption of unsafe food a year, with under-fives nearly three times more likely to be at risk.

"Food safety is not an abstract issue -- it touches every meal, every family, every day," said WHO chief Tedros Adhanom Ghebreyesus.

Although illnesses from ingesting dangerous food have declined overall since 2000, massive regional inequalities remain.

Africa and southeast Asia alone account for nearly three-quarters of all cases of food-related ailments and 60 percent of deaths worldwide.

At some 860 million cases in 2021, biological hazards such as bacteria and viruses caused the overwhelming majority of food-borne illnesses.

But ingesting chemicals was responsible for a disproportionate share of the deaths, with arsenic and lead poisoning the prime non-biological culprits.

"The data show that food-borne diseases are not only persistent but are being made worse by climate change, which increases contamination risks, and by antimicrobial resistance, which makes infections harder to treat," said Yuki Minato, WHO technical officer for food safety.

Besides the health effects, the study estimates that food-borne diseases cost the world economy $647 billion in lost productivity in 2021.