Controlling factors of iron plaque formation and its adsorption of cadmium and arsenic throughout the entire life cycle of rice plants.

Iron (Fe) plaque, which forms on the surface of rice roots, plays a crucial role in immobilizing heavy metal(loids), thus reducing their accumulation in rice plants. However, the principal factors influencing Fe plaque formation and its adsorption capacity for heavy metal(loid)s throughout the rice plant's lifecycle remain poorly understood. Thus, this study investigated the dynamics of Fe plaque formation and its ability to adsorb cadmium (Cd) and arsenic (As) across different growth stages, aiming to identify the key drivers behind these processes.

Controlling factors of heavy metal(loid) accumulation in rice: Main and interactive effects.

Identifying the key determinants of heavy metal(loid) accumulation in rice and quantifying their contributions are critical for precise prediction of heavy metal(loid) concentrations in rice and the formulation of effective pollution control strategies. The accumulation of heavy metal(loid)s in rice can be influenced by both natural and anthropogenic factors, which may interact with each other. However, distinguishing the independent roles (main effects) from interactive effects and quantifying their impacts separately pose challenges.

Bioavailability of antimony and arsenic in a flowering cabbage-soil system: Controlling factors and interactive effect.

Soil contamination with antimony (Sb) and arsenic (As) has become a well-recognized environmental and human health issue. Consumption of vegetables, especially leafy vegetables, is one of the most important sources of Sb and As exposure in humans. Accordingly, it is necessary to understand the behaviors of Sb and As in the vegetable-soil system.

Genotype-Phenotype Analysis and Mutation Spectrum in a Cohort of Chinese Patients With Congenital Nystagmus.

Congenital nystagmus (CN) is a genetically and clinically heterogeneous ocular disorder that manifests as involuntary, periodic oscillations of the eyes. To date, only and have been reported to be responsible for causing CN. Here, we aimed to identify the disease-causing mutations and describe the clinical features in the affected members in our study.

Enhanced immobilization of arsenic and cadmium in a paddy soil by combined applications of woody peat and Fe(NO): Possible mechanisms and environmental implications.

Organic matter (OM) plays an important role in the mobility of heavy metal(loid)s. Peat containing abundant OM can be used as an organic fertilizer improving physical and chemical properties of soil. Previous studies indicated that the immobilization of heavy metal(loid)s by peat is affected by the presence of metal oxides and/or hydroxides and that Fe-enriched peat is very effective in immobilizing metal(loid)s.

Thallium in flowering cabbage and lettuce: Potential health risks for local residents of the Pearl River Delta, South China.

Thallium (Tl), a rare metal, is universally present in the environment with high toxicity and accumulation. Thallium's behavior and fate require further study, especially in the Pearl River Delta (PRD), where severe Tl pollution incidents have occurred. One hundred two pairs of soil and flowering cabbage samples and 91 pairs of soil and lettuce samples were collected from typical farmland protection areas and vegetable bases across the PRD, South China.

Mutation of IPO13 causes recessive ocular coloboma, microphthalmia, and cataract.

Ocular coloboma is a developmental structural defect of the eye that often occurs as complex ocular anomalies. However, its genetic etiology remains largely unexplored. Here we report the identification of mutation (c.

Arsenic mobility and bioavailability in paddy soil under iron compound amendments at different growth stages of rice.

Iron (Fe)-based solids can reduce arsenic (As) mobility and bioavailability in soils, which has been well recognized. However, to our knowledge, there are few studies on As uptake at different growth stages of rice under Fe compound amendments. In addition, the formation of Fe plaques at different growth stages of rice has also been rarely reported.

The availabilities of arsenic and cadmium in rice paddy fields from a mining area: The role of soil extractable and plant silicon.

Adequate silicon (Si) can greatly boost rice yield and improve grain quality through alleviating stresses associated with heavy metals and metalloids such as arsenic (As) and cadmium (Cd). The soil plant-available Si is relatively low in South China due to severe desilicification and allitization of the soils in this region. Conversely, pollution of heavy metals and metalloids in the soils of this region occurs widely, especially As and Cd pollution in paddy soil.

Cadmium availability in rice paddy fields from a mining area: The effects of soil properties highlighting iron fractions and pH value.

Cadmium (Cd) availability can be significantly affected by soil properties. The effect of pH value on Cd availability has been confirmed. Paddy soils in South China generally contain high contents of iron (Fe).

Arsenic availability in rice from a mining area: is amorphous iron oxide-bound arsenic a source or sink?

The effect of iron (Fe) redox cycling on the mobility and bioavailability of arsenic (As) in paddy soils has attracted increasing concerns, especially in Asia, where the paddy soil is characteristic of Fe with high abundance and activity. However, whether amorphous Fe oxide-bound As acts as a source or a sink of As in natural field conditions needs to be clarified further. In this study, 73 pairs of soil and rice were collected from paddy fields contaminated by As-containing acid mining drainage.

The effect of ammonium chloride and urea application on soil bacterial communities closely related to the reductive transformation of pentachlorophenol.

Pentachlorophenol (PCP) is widely distributed in the soil, and nitrogen fertilizer is extensively used in agricultural production. However, studies on the fate of organic contaminants as affected by nitrogen fertilizer application have been rare and superficial. The present study aimed to examine the effect of ammonium chloride (NH4Cl) and urea (CO(NH2)2) application on the reductive transformation of PCP in a paddy soil.

Effect of nitrate addition on reductive transformation of pentachlorophenol in paddy soil in relation to iron(III) reduction.

Reductive dechlorination is a crucial pathway for anaerobic biodegradation of highly chlorinated organic contaminants. Under an anoxic environment, reductive dechlorination of organic contaminants can be affected by many redox processes such as nitrate reduction and iron reduction. In the present study, batch incubation experiments were conducted to investigate the effect of nitrate addition on reductive dechlorination of PCP in paddy soil with consideration of iron transformation.

Assessment of organochlorine pesticide contamination in relation to soil properties in the Pearl River Delta, China.

High levels of organochlorine pesticides (OCPs) such as hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) have been found in soil of the Pearl River Delta (PRD), attributable to high pesticide application in this area. Consequently, the occurrence and environmental effect of HCHs and DDTs in the PRD have attracted considerable attention. However, study focusing on the influence of potential factors such as soil property on the environmental fate of HCHs and DDTs in the PRD has been rare.

Enhanced biotransformation of DDTs by an iron- and humic-reducing bacteria Aeromonas hydrophila HS01 upon addition of goethite and anthraquinone-2,6-disulphonic disodium salt (AQDS).

A fermentative facultative anaerobe, strain HS01 isolated from subterranean sediment, was identified as Aeromonas hydrophila by 16S rRNA sequence analysis. The biotransformation of 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (DDT), 1,1-dichloro-2,2-bis(4-chlorophenyl) ethylene (DDD), and 1,1-dichloro-2,2-bis (4-chlorophenyl) ethane (DDE) by HS01 was investigated in the presence of goethite and anthraquinone-2,6-disulphonic disodium salt (AQDS). The results demonstrated that HS01 was capable of reducing DDTs, goethite and AQDS.

Sedimentary loadings and ecological significance of polycyclic aromatic hydrocarbons in a typical mariculture zone of South China.

Two sediment cores were collected from Hailing Bay located in a typical mariculture zone of Guangdong Province, South China, and analyzed for polycyclic aromatic hydrocarbons (PAHs). The concentrations of the sum of 27 PAHs ranged from 62 to 1200 ng g(-1) dry wt, and sediment in the study area was considered to be moderately polluted by PAHs. Source diagnostics based on PAH composition and principal component analysis suggested that PAHs in the study area were mainly derived from petroleum combustion, with discharge of PAHs from fishing boats as an important source.

Inputs of antifouling paint-derived dichlorodiphenyltrichloroethanes (DDTs) to a typical mariculture zone (South China): potential impact on aquafarming environment.

Existing evidence indicated that dichlorodiphenyltrichloroethane (DDT)-containing antifouling paints were an important source of DDT residues to mariculture zones. However, the magnitude of the impact on aquafarming environment has remained largely unknown. In the present study, the concentrations of DDT and its metabolites (designated as DDXs) were determined in harbor sediment and antifouling paint samples collected from a typical mariculture zone in South China.

Field validation of anaerobic degradation pathways for dichlorodiphenyltrichloroethane (DDT) and 13 metabolites in marine sediment cores from China.

Although the production and use of dichlorodiphenyltrichloroethane (DDT), a legacy component of persistent organic pollutants, have been highly restricted worldwide, the environmental fate of DDT has remained a great concern as it is not only ubiquitous and bioaccumulative but can also be degraded to a series of metabolites that may be more hazardous ecologically. The present study, taking advantage of the abundant levels of DDT and its metabolites in a subtropical coastal region of China, investigated into the degradation pathways of DDT in natural coastal sediment. Sediment profiles indicated that degradation of 1,1,1-trichloro-2,2-bis-(p-chlorophenyl)ethane (p,p'-DDT) to 1,1-dichloro-2,2-bis-(p-chlorophenyl)ethane (p,p'-DDD) mainly occurred in sediment of the top 20 cm layer.

Persistent halogenated compounds in aquaculture environments of South China: implications for global consumers' health risk via fish consumption.

This study examined the potential sources of persistent halogenated compounds (PHCs), including organochlorine pesticides, mainly DDXs (sum of o,p'- and p,p'-DDT, -DDD, and -DDE and p,p'-DDMU) and polybrominated diphenyl ethers, to typical aquaculture environments of South China, determined the relative importance of gill diffusion and fish feeding for exposure of fish to these contaminants and assessed potential health risk for global consumers via consumption of fish from South China. Fish feed is generally a direct and important source of PHCs in both freshwater and seawater aquaculture. In addition, gill diffusion is the predominant uptake route for PHCs (except p,p'-DDMU, o,p'-DDD and -DDT) in farmed freshwater fish, whereas accumulation from the diet is the major route for farmed marine fish.

Input pathways of organochlorine pesticides to typical freshwater cultured fish ponds of South China: hints for pollution control.

Air, rain, pond water, bank soil, pond sediment, fish feed, and fish were sampled from four freshwater cultured fish ponds (FWCFPs) in rural areas within the Pearl River Delta (PRD) of South China. Compositional analyses indicated that historical residues were the main sources of DDXs (defined as the sum of dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethane (DDD), and dichlorodiphenyldichloroethylene (DDE) and 1-chloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDMU)), and hexachlorocyclohexanes (HCHs) in the FWCFPs. The input fluxes to the FWCFPs were estimated at 4.

Persistent halogenated compounds in two typical marine aquaculture zones of South China.

Samples of two seawater farmed fish (crimson snapper (Lutjanus erythopterus) and snubnose pompano (Trachinotus blochii)), water, air, sediment, fish feed, macroalgae and phytoplankton were collected from two estuarine bays (Daya Bay and Hailing Bay) in South China. The concentrations of persistent halogenated compounds (PHCs) including polybrominated diphenyl ethers (PBDEs), organochlorine pesticides and polychlorinated biphenyls (PCBs) varied widely with the different sample matrices under investigation. The compositional patterns in fish, fish feed, macroalgae and phytoplankton, as well as the good correlations between the abundances of p,p'-DDT and BDE-209 and their metabolites (i.

Dietary intake of persistent organic pollutants and potential health risks via consumption of global aquatic products.

The concentration levels of typical persistent organic pollutants such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) including dioxin-like PCBs (DL-PCBs) and non-dioxin-like PCBs, organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs) in global aquatic products from major producing countries were summarized. Daily intakes of these compounds via consumption of various aquatic products for global consumers were also estimated based on available literature data. Risk assessment based upon existing criteria for OCPs and PBDEs shows that there is minimal risk to global consumers from consumption of aquatic products, with the exception of products from specific regions located around known heavy-point sources.

Occurrence and fate of 1-chloro-2,2-bis(4-chlorophenyl)ethene in the environment of the Pearl River Delta, South China.

1-Chloro-2,2-bis(4-chlorophenyl)ethene (p,p'-DDMU), a metabolite of either 1,1-dichloro-22-bis(4-chlorophenyl)ethane (p,p'-DDD) or 1,1-dichloro-2,2-bis(4-chlorophenyl)ethene (p,p'-DDE), which is degraded from 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDT), was detected in a variety of environmental matrices of the Pearl River Delta (PRD), South China, including fish, fish feeds, semidigested fish stomach contents, marine surface sediment, surface soil, atmospheric gaseous phase, and particulates, rainwater, and coastal rainwater. Forfish species,the concentrations of p,p'-DDMU were significantly higher in farmed fish than in marine wild fish, with the highest value obtained in seawater farmed fish species (mear/median values of 262/173 ng/g lipid). The relative abundance of p,p'-DDMU to total DDTs (sum of o,p'- and p,p'-DDT, DDD, and DDE) was higher in samples of marine origin (approximately 5%) than in those of terrestrial origin (approximately 2%).

Persistent halogenated hydrocarbons in fish feeds manufactured in South China.

Persistent halogenated hydrocarbons (PHHs), including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs), in fish feeds (including trash fish and compound feed) manufactured in South China, were analyzed. PHHs were ubiquitous in fish feeds, with the concentrations of OCPs, PBDEs, and PCBs at the upper, mid, and lower levels of the global range. Trash fish generally contained higher concentrations of DDXs (sum of o,p'- and p,p'-DDT, -DDD, and -DDE and p,p'-DDMU), especially p,p'-DDT and low-brominated PBDEs, while compound feeds had higher concentrations of highly brominated BDEs, e.

Occurrence, source diagnosis, and biological effect assessment of DDT and its metabolites in various environmental compartments of the Pearl River Delta, South China: a review.

This review summarizes and analyzes available data in the literature (mostly after 2000) on the occurrence of dichlorodiphenyltrichloroethane (DDT) and its main metabolites, dichlorodiphenyldichloroethane (DDD) and chlorodiphenyldichloroethylene (DDE), in the environment of the Pearl River Delta (PRD), South China. Generally, the concentration levels of the sum of DDT, DDD, and DDE, designated as DDTs thereafter, have not significantly declined since 1983. However, the composition of DDTs residues has changed with time.