דו״ח מאומת

Brown rice is often considered a healthy alternative to white rice due to the additional nutrients contained within the rice bran. However, the proposition of improved health outcomes by replacing white rice with brown rice in diets ignores a potential food safety concern: arsenic exposure. In this manuscript, we seek to critically compare potential arsenic exposure and the associated risks between brown and white rice for US populations. Rice bran and brown rice are shown to have a higher arsenic content and inorganic arsenic concentration than the grain endosperm or white rice. Americans who regularly consume brown rice versus white rice were found to have higher estimated arsenic exposures. Because young children consume considerably more food relative to their bodyweights than adults, brown rice consumption in young children was found to more substantially increase foodborne arsenic exposures. However, there are no acute public health risks indicated for the general American population from rice-related arsenic exposures. Risk-benefit analyses are needed to assess relative risks of arsenic exposure in brown rice compared with the nutritional benefits, in comparison to white rice.…

PMID: 40018851

Heavy metal pollution in rice fields is a major concern; however, little research has addressed its exposure and risk to waterbirds inhabiting rice fields. We investigated the accumulation of heavy metals (Cd, Pb, As, Cr, Cu, and Zn) in sediment, water, food, feces, feathers, and eggshell samples collected from different nesting sites (Chongwei Village and Wuji Village) of little egrets (<i>Egretta garzetta</i>) on Hainan Island, China, and compared the differences in their breeding parameters and eggshell quality. Higher levels of heavy metals were observed in all samples except feces from Wuji Village compared to those from Chongwei Village. As, Cd, and Pb exhibited little bioaccumulation in all feather and eggshell samples, whereas Cr concentrations in feather samples from both heronries and eggshell samples in Wuji Village exceeded the toxicity threshold in birds, indicating that the high maternal Cr was transferred to eggs in Wuji Village. Significantly lower hatching and breeding success rates were observed in Wuji Village than in Chongwei Village, which may be closely related to Cr contamination. This study revealed that waterbirds breeding in rice fields are under threat from heavy metal contamination and highlighted the suitability of bird feathers and eggshells as biomonitors of the environment.…

PMID: 40863952

Arsenic is a human carcinogen present in drinking water and food, especially rice, rice products and seafood. It can be found in both organic and inorganic forms, the latter being the most toxic. In addition to the carcinogenic effect, exposure to inorganic arsenic can cause numerous disorders in different organs/systems of the human body, such as the skin, cardiovascular, neurological, endocrine, immune, and reproductive systems. The risk assessment associated with dietary arsenic is mainly based on the margin of exposure, i.e., the ratio between the dose at which a small but measurable adverse effect may occur and the estimated daily intake of the target substance. It is mainly influenced by arsenic concentrations and consumption data of average or 95th percentile consumers. This review focuses on the toxicity of arsenic, its sources and routes of human exposure, with particular attention to the ingestion of contaminated water and food, considering the differences between age groups and dietary habits.…

PMID: 40646981

Lead (Pb) and arsenic (As) exist in soil with different ionic forms, and it is difficult to immobilize simultaneously Pb and As in soil. The objective of this study is to determine the effects of water management including flooding (FL), alternate wetting and drying (AWD) and dry farming (DF) combined with addition of phosphate (P) on the accumulation of Pb and As in rice. Our results showed that Pb accumulated in root during vegetative stage, and most of As in root was transported to the above ground parts during the reproductive stage. Pb was evenly distributed in grains, and As was mostly accumulated in bran and aleurone layer. Water management had a reverse effect on the accumulation of Pb and As in rice. However, the effects of P on arid soil environment and Pb, As accumulation in rice were stronger than that in flooded soil. Application of P under AWD treatment could maintain a similar quantity of Fe plaque with flooding, decrease the availability of Pb in rhizosphere soil, reduce Pb and As accumulation in root, and result in the reduction of Pb and As accumulation in grains by 86% and 66% respectively. Besides, our study also found that flooding or AWD during vegetative stage facilitated the formation of iron plaque. In conclusion, AWD combined with P application could maintain a relatively lower concentrations of Pb and As in grains.…

PMID: 34146868

Cereal aleurone cells are differentiated from triploid endosperm cells and exhibit distinct cytological, physiological, and biochemical characteristics that distinguish them from the starchy endosperm cells of cereals. Aleurone cells maintain viability throughout seed development, whereas starchy endosperm cells undergo programmed cell death during maturation. Despite variations in aleurone-related traits among cereal species, the aleurone layer plays a crucial role in regulating many aspects of seed development, including the accumulation of storage reserves, the acquisition of dormancy, and germination. Given that many nutrients-such as lipids, dietary fibers, vitamins, and minerals like iron and zinc-are predominantly accumulated in the aleurone cells of cereal grains, this layer has attracted considerable attention aimed at improving the nutritional value of cereals. This review provides a comprehensive overview of the developmental, genetic, and molecular basis of aleurone cell differentiation and proliferation. It focuses on the improvement of aleurone-related traits informed by knowledge of the molecular networks governing aleurone development and presents a detailed discussion on the challenges and potential solutions associated with cereal improvement through the manipulation of aleurone-related traits.…

PMID: 39949062

In this study, the effect of washing, soaking (1, 5 and 12 h), and cooking rice methods including Rinsed (boiling in excess water) and Kateh (conventional) cooking on the reduction of the arsenic (As), lead (Pb), and cadmium (Cd) were evaluated. The results showed that the rinsed cooking has higher efficiency for removal of toxic metals (As = 42.3%, Pb = 42.9% and = 27.6%) than Kateh method (As = 26.9%, Pb = 26.9% and = 20.9%). Additionally, by increasing of rice soaking time from 1 to 12 h, the toxic metals removal was increased up to 37.1%, 42.6% and 16.6% for As, Pb and Cd, respectively. Although the toxic metals reduction was such that the non-carcinogenic risk was regarded as acceptable level after all processes, for arsenic, these reductions did not lower the carcinogenic risk to an acceptable level. Finally, it is suggested that Tehran households, after washing and soaking to 5 h, then cook it by rinse method.…

PMID: 30642500

Rice (Oryza sativa L.) is particularly susceptible to arsenic (As) accumulation. Currently, to decrease the level of As accumulated in rice, various post-harvest methods, i.e., polishing, parboiling, pH-dependent soaking, washing, and cooking at different rice-to-water ratios (r/w), are being focused, because it removes significant amount of As from rice grain. Depending upon the rice variety and type, i.e., rough (with husk), husked (without husk/brown), or polished rice, these methods can remove 39-54% As by parboiling, 38-55% by polishing, 37-63% by soaking, and 6-80% by washing and cooking. Infants are highly vulnerable to As exposure; thus, these methods can be helpful for the production of rice-based infant foods. Although concern arises during the use of these methods that apart from decreasing the level of As in rice grain, they also lead to a significant loss of nutrients, such as macro- and micro-elements present in rice. Among these discussed methods, parboiling curtails 5-59%, polishing curtails 6-96%, soaking curtails 33-83%, and washing and cooking in different r/w reduce 8-81% of essential nutrients resulting in 2-90% reduction in contribution to the RDI of these nutrients through rice-based diet. Thus, these post-harvest arsenic removal methods, although reduce arsenic induced health hazard, but may also lead to malnutrition and compromised health in the population based on rice diet. There is a need to explore another way to reduce As from rice without compromising the nutrient availability or to supplement these nutrients through grain enrichment or by introducing additional dietary sources by changing eating habits; however, this may impose an extra economic burden on people.…

PMID: 37615784