Pourquoi ?
Parce que l'élévation de température et de la teneur en CO₂ provoque la prolifération de certaines bactéries dans les rizières ; bactéries qui provoquent le passage de l'arsenic du sol vers la plante. La teneur en arsenic va donc augmenter dans le riz, consommé en grande quantité en Asie. Ce qui va entraîner l'augmentation de certaines pathologies associées.
Dongming Wang et al., « Impact of climate change on arsenic concentrations in paddy rice and the associated dietary health risks in Asia: an experimental and modelling study », The Lancet, 16 avril 2025
https://www.thelancet.com/action/showPd ... 7Lw8W3YDgw
We aimed to assess the impact of increases in CO₂ and temperature (individually and in combination) on arsenic concentrations in rice, characterise soil properties that might influence arsenic uptake, and model the associated risks of cancer and other health outcomes due to increased arsenic exposure.
[...]
We modelled dietary inorganic arsenic exposure and the associated risks of cancer and non-cancer health outcomes via rice consumption for seven of the leading rice-consuming countries in east and southeast Asia.
Findings: Concomitant increases in CO₂ and temperature resulted in a synergistic increase of inorganic arsenic in rice
grain. The observed increase is likely to be related to changes in soil biogeochemistry that favoured reduced arsenic
species. Modelled consumption of rice under these conditions resulted in projected increases in inorganic arsenic
exposure and lifetime cancer and health risks for multiple Asian countries by 2050
[...]
Our study showed that elevated CO₂ and temperature could increase bacterial growth and differentially affect the abundance of reducing versus oxidative arsenic genes.