[Effects of Ozone Pollution on Growth, Yields, and Mineral Metallic Element Contents of Paddy Rice].

ABSTRACT

The increase in the surface ozone (O3) concentration causes air pollution, which has become a significant environmental issue that is of increasing concern. Ozone pollution not only directly harms human health, but also influences the agricultural ecosystem by impacting crop growth, which may then indirectly affect human health through food quality and the safety of agricultural products. The effects of O3 pollution on rice growth, yields, and mineral metal contents in grains were investigated through field experiments with increased O3 concentration treatment (remaining at 100 nL·L-1) in open top chambers (OTC). The crop growth and metal contents of two rice varieties were analyzed and compared. The results showed that the higher O3 concentration inhibited the photosynthesis of Nanjing 5055 and Yangdao 6 rice leaves, reduced the chlorophyll content and leaf area index, and subsequently led to a decline in the rice yield of 45.5% and 28.6%, respectively. However, compared with the natural control, the contents of most mineral metallic elements in the brown rice and glume of the harvested grains increased by 3.6%-19.8% and 3.9%-36.0%, respectively, thus resulting in a lack of essential trace elements or pollution of heavy metals; hence, the impact of O3 on rice food quality and safety requires a comprehensive evaluation.