This article was originally published on Ensia.
For many of us, March 2020 marked a turning point in our lives when the World Health Organization declared COVID-19 a global pandemic. Since then, we have heard the term “wet market” thrown around in science and in the news, as a wet market in Wuhan, China, is the site of the first cluster of cases of COVID-19.
In the wake of the pandemic’s emergence, some public health officials, lawmakers, celebrities and average citizens called for a general closure of wet markets. However, a recent study published by researchers at Princeton University suggests that a general ban on wet markets would do more harm than good. Many people rely on wet markets, which are often similar to the farmers’ markets in Europe and the United States, for important goods and services. Banning them altogether, the study claims, would trigger pushback from suppliers and customers and likely push wildlife trade further into the ground.
Another problem is that not all wet markets are the same: “Wet markets are often incorrectly mixed with live or wildlife markets,” the researchers write. In fact, sellers in many wet markets simply sell fresh fruits, vegetables, fish and meat, with only meat from dead, domesticated animals. The study notes that imprecise language – statements that mix a type of traditional, harmless market commonly found in countries like China, with different kinds of markets – can incite xenophobia against people from East and Southeast Asia, regions where wet markets are most important, or only food source for many people.
As an alternative to comprehensive generalizations and complete closures, the researchers offer what they call a “wet market taxonomy,” risk classification based on whether the markets contain live or dead animals and whether the animals sold were domesticated or wild. More targeted regulatory approaches, they conclude, may be a more sustainable way of protecting human health.
Most wet markets are likely to pose a relatively small risk to human health or biodiversity, but a few pose a disproportionate risk.
One way in which some markets may pose a threat to human health is by potentially promoting new infectious diseases (EIDs). “In general, the building blocks of an EID event (the emergence of a new infectious disease in humans) consist of interspecific zoonotic transmission, viral amplification, and viral modification,” the researchers write.
The study identified key risk factors for diseases that make the leap from animals to humans in markets: the presence of high disease risk taxi and live animals, hygiene conditions, market size, density of animals, mix between species and the length and breadth of animals. supply chains.
Potential hazards are also not only limited to human health, as some markets also pose risks to biodiversity. Currently, the study notes, wet markets only assess biodiversity risks based on the types of animals sold, rather than the condition in which the animals are sold. Certain markets have become a channel for the sale of endangered or declining animal species, an illegal practice, and these markets , the researchers write, pose the greatest threat to biodiversity.
To guide effective regulation, researchers have divided wet markets into four categories. The first includes wet markets that do not sell live animals except seafood, which historically have less risk of pathogens jumping to humans. The second classification covers markets that sell live domestic animals, while the third covers markets that also sell dead wild animals. The final classification includes all of the above – plus markets that sell live wildlife. The risk to human health and biodiversity increases with the third and fourth classifications.
Based on these classifications, the researchers suggest that politicians should prioritize regulating markets that pose the greatest risk – those in the fourth category, the sale of live wildlife – to allow for the least possible disturbance in wetland-dependent communities. food. “Most wet markets are likely to pose a relatively small risk to human health or biodiversity, but a few pose a disproportionate risk,” the researchers write. Targeting such harmful wet markets, they argue, can help mitigate the threat of future pandemics and reduce risks to biodiversity.