Geochemistry of arsenic in paddy soils and its accumulation in rice grains: An updated analysis with human health perspectives
The elevated concentration of arsenic (As) in rice grains poses a major global health concern. This review investigates the geochemical behavior of As in paddy soils and the mechanisms responsible for its accumulation in rice, providing insights into why As concentrations in rice are considerably hi...
Saved in:
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-09-01
|
| Series: | Ecotoxicology and Environmental Safety |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0147651325010127 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | The elevated concentration of arsenic (As) in rice grains poses a major global health concern. This review investigates the geochemical behavior of As in paddy soils and the mechanisms responsible for its accumulation in rice, providing insights into why As concentrations in rice are considerably higher than in other cereals. Our findings highlight that under the strongly reducing and anaerobic conditions typical of flooded paddy soils, the bioavailability of As increases markedly. Multiple As species coexist in these soils, but arsenite (As(III)) predominates due to the low redox potential and absence of oxygen. Arsenite is significantly more mobile and bioavailable than arsenate (As(V)), which dominates under aerobic conditions. In addition, rice roots take up As(III) efficiently through aquaporin channels that also transport silicic acid. These geochemical and physiological factors together result in elevated As accumulation in rice grains. In the second part, we provide a comprehensive overview of As speciation in rice grains and its associated human health risks. Our synthesis highlights substantial variation in exposure levels, carcinogenic risk, and non-carcinogenic hazards across regions, age groups, and dietary habits. Finally, key knowledge gaps are identified to guide future research on As geochemistry, speciation, and risk mitigation strategies in rice systems. |
|---|---|
| ISSN: | 0147-6513 |