1,2,3-trichloropropane (TCP) is an industrially synthesized aliphatic chlorinated hydrocarbon and an intermediate product in the industrial production of epichlorohydrin, which can be used as a precursor for the manufacture of soil fumigant and organic solvents. Due to its biological toxicity, environmental persistence and strong environmental migration ability, 1,2,3-TCP is listed as an emerging organochlorine pollutant in the environment and regulated by many international organizations. Currently, the degradation of 1,2,3-TCP and the remediation of 1,2,3-TCP-contaminated sites receive great attention, but the degradation mechanism of 1,2,3-TCP has not been summarized in depth. This article discussed the origin of 1,2,3-TCP, its environmental impact and ecological effects, and the physical and chemical degradation techniques. This was followed by summarizing the degradation mechanisms of 1,2,3-TCP (e.g., aerobic co-biodegradation, anaerobic biodegradation). Specially, the pathways and mechanisms of microbial biodegradation and transformation of 1,2,3-TCP in anoxic environments (e.g., groundwater) were thoroughly reviewed. The feasibility of using 1,2,3-TCP as an electron acceptor by organohalide-respiring bacteria under anoxic conditions was predicted based on thermodynamic analysis. Last but not least, in situ bioremediation of 1,2,3-TCP contaminated sites was summarized, and prospects for future research were discussed.
Biodegradation, Environmental ; Environmental Restoration and Remediation ; Hydrocarbons, Chlorinated ; Propane/analogs & derivatives* ; Technology

OBJECTIVEThis paper aims to elucidate the combined toxicity of magnetite nanoparticles/Chromium [MNPs/Cr(VI)] adducts.

METHODSThe HEK293 cell was exposed to either Cr(VI) or MNPs, or their adducts MNPs/Cr(VI). The cytotoxicity was evaluated by assessing the cell viability, apoptosis, oxidative stress induction, and cellular uptake.

RESULTSThe toxicity of formed adducts is significantly reduced when compared to Cr(VI) anions. We found that the cellular uptake of MNPs/Cr(VI) adduct was rare, only few particles were endocytosed from the extracellular fluid and not accumulated in the cell nucleus. On the other hand, the Cr(VI) anions entered cells, generated oxidative stress, induced cell apoptosis, and caused cytotoxicity.

CONCLUSIONThe results showed minor effects of the nanoadducts on the tested cells and supported that magnetite nanoparticles could be implemented in the wastewater treatment process in which advantageous properties outweigh the risks.

Chromium ; chemistry ; toxicity ; Environmental Restoration and Remediation ; methods ; Ferrosoferric Oxide ; chemistry ; toxicity ; HEK293 Cells ; Humans ; Metal Nanoparticles ; chemistry ; toxicity

OBJECTIVETo evaluate the effect of schistosomiasis control by forbidding livestock denaturing on marshland with Oncomelania snails and to analyse its influencing factors.

METHODSThe village of Aiguo, Xinhe, Huangjia, Fanrong, Fengfu and Caomen and its respective nearby marshland, i.e., Aiguoniu, Liulingwei, Huangjianiu, Da, Goulian, and Litouzui, in Jinxian county, Jiangxi province were selected as the pilot areas for implementing the measures of forbidding livestock denaturing on the marshlands with Oncomelania snails during the period of the year 2005 to 2007. A total of 300 residents in each village were randomly chosen for stool examination with the Kato-Katz technique every year. The snail survey was carried out in spring and autumn every year on the marshlands close to the villages with systemic sampling method. The marshlands with a height 16.5 m above the sea level in Futian was selected for snail survey and planting with sesame. The residents aged 20 - 50 years old in Fengfu and Aiguo villages were studied by using questionnaire on the compliance of forbidding livestock pasturing on marshlands with Oncomelania snails.

RESULTSBefore implementation of the measures, human infection rate with Schistosoma japonicum was 11.35% (90/793) in Aiguo, 4.00% (12/300) in Xinhe, 4.00% (6/150) in Huangjia, 8.00% (12/150) in Fanrong, 3.17% (4/126) in Fengfu and 6.64% (14/211) in Caomen. After implementation in 2008, human schistsome infection rate in the aforementioned 6 villages was declined to 0.18% (1/551), 0.00% (0/348), 0.00% (0/316), 2.27% (7/308), 1.17% (5/428) and 1.16% (5/430), respectively. Only in Fengfu village the decline of the human prevalence was not significant (χ(2) = 2.4, P = 0.12), while in the other 5 villages, human prevalence rate had been declined significantly (χ(2) = 126.77, P < 0.01; χ(2) = 16.31, P < 0.01; χ(2) = 18.79, P < 0.01; χ(2) = 10.39, P < 0.01; χ(2) = 14.17, P < 0.01, respectively). Infected snails were not found in 5 out of the 6 marshlands close to the villages. Three infected snails were founded in Da marshland because of poor environmental isolation. Before planting, the living snail density was 0.063/0.11 m(2) (34/540), and after planting, the living snail density was 0.0074/0.11 m(2) (4/538), a 88.25% reduction (Z = 12.47, P < 0.01) was recorded through economy crop planting at Futiandaan marshland in 2008. A total of 986 pieces of questionnaire were provided, and 968 valid ones were collected. The results of questionnaire indicate that compliance of forbidding livestock denaturing on marshland with Oncomelania snails in Aiguo and Fengfu villages was 84.38% (216/256) and 75.42% (537/712), respectively. Using logistic regression model, knowledge level on harmfulness of livestock denaturing on marshland with Oncomelania snails, willingness of culture with machine to substitute traditional cattle culture, and willingness of investment to marshland culture development are 3 varieties that affect residents' implementation of forbidding livestock denaturing on marshland with Oncomelania snails.

CONCLUSIONThe infected snail density and human schistosome infection rate were reduced on the marshlands of well environmental isolation after 2 - 3 years implementation of forbidding livestock denaturing on marshlands with Oncomelania snails. The key influencing factors of forbidding livestock denaturing on marshland with Oncomelania snails are knowledge level on harmfulness of livestock denaturing on the snail infested marshlands, the willingness of machine culture to substitute cattle culture, and the willingness of investment to marshland culture development.

Adult ; Animal Husbandry ; methods ; Animals ; Cattle ; Environmental Restoration and Remediation ; Humans ; Logistic Models ; Middle Aged ; Risk Factors ; Schistosomiasis ; prevention & control ; Young Adult

OBJECTIVETo characterize the heterotrophic nitrifying bacteria.

METHODSThe bacteria were isolated from membrane bioreactor for treating synthetic wastewater using the method newly introduced in this study. Fluorescence in situ hybridization (FISH) was used to validate the nonexistence of autotrophic ammonia oxidizers and nitrite oxidizers. Batch tests were carried out to investigate the capability of heterotrophic nitrification by the pure culture. Phylogenetic analysis of the pure culture was performed.

RESULTSA heterotrophic nitrifier, named Bacillus sp. LY, was newly isolated from the membrane bioreactor system in which the efficiency of TN removal was up to 80%. After 24-day, incubation, the removal efficiency of COD by Bacillus sp. LY was 71.7%. The ammonium nitrogen removal rate after assimilation nearly ceased by Bacillus sp. LY was 74.7%. The phylogenetic tree of Bacillus sp. LY and the neighbouring nitrifiers were given.

CONCLUSIONSThe batch test results indicate that Bacillus sp. LY can utilize the organic carbon as the source of assimilation when it grows on glucose and ammonium chloride medium accompanying the formation of oxidized-nitrogen. It also can denitrify nitrate while nitrifying. Bacillus sp. LY may become a new bacterial resource for heterotrophic nitrification and play a bioremediation role in nutrient removal.

Bacillus ; classification ; genetics ; isolation & purification ; metabolism ; Base Sequence ; DNA Primers ; DNA, Ribosomal ; genetics ; Environmental Restoration and Remediation ; methods ; Nitrates ; metabolism ; Phylogeny ; RNA, Ribosomal, 16S ; genetics

Direct observation of a wide range of natural microorganisms has revealed the fact that the majority of microbes persist as surface-attached communities surrounded by matrix materials, called biofilms. Biofilms can be formed by a single bacterial strain. However, most natural biofilms are actually formed by multiple bacterial species. Conventional methods for bacterial cleaning, such as applications of antibiotics and/or disinfectants are often ineffective for biofilm populations due to their special physiology and physical matrix barrier. It has been estimated that billions of dollars are spent every year worldwide to deal with damage to equipment, contaminations of products, energy losses, and infections in human beings resulted from microbial biofilms. Microorganisms compete, cooperate, and communicate with each other in multi-species biofilms. Understanding the mechanisms of multi-species biofilm formation will facilitate the development of methods for combating bacterial biofilms in clinical, environmental, industrial, and agricultural areas. The most recent advances in the understanding of multi-species biofilms are summarized and discussed in the review.
Animals ; Bacterial Adhesion ; physiology ; Bacterial Typing Techniques ; Biofilms ; growth & development ; Environmental Restoration and Remediation ; Equipment Contamination ; Humans ; Microbial Consortia ; genetics ; physiology ; Microbial Interactions ; physiology ; Microscopy, Confocal ; Models, Biological ; Nucleic Acid Hybridization ; Polymerase Chain Reaction ; Polysaccharides, Bacterial ; chemistry

BACKGROUND: The purpose of the study was to estimate the mental health problems and other related factors in residents that experienced the Samsung-Hebei spirits oil spill by surveying PTSD symptoms. METHOD: Trained interviewers performed direct interviews of the residents approximately 70 days after the oil spill. We investigated PTSD symptoms through PTSD Symptom Scale Interview Version (PSS-I). To determine those factors related to PTSD symptoms, the following factors were determined as part of the survey: gender, age, occupation, duration of cleanup activity, monthly income and amount of debt. Logistic regression analysis was used to analyze all factors. RESULTS: Of the 318 residents investigated, 56.6% of the subjects had PTSD symptoms related to the spirits oil spill (about 70 days post spill). With regard to occupation, those subjects answering fishery (POR:3.05) and commerce (POR:4.24) as their occupations experienced higher PTSD symptoms than residents answering farming as their occupation. Residents who answered that they had debt over 10 million KRW (POR:2.61) were more vulnerable to PTSD symptoms compared to residents without debt; residents with acute physical symptoms were vulnerable (POR:5.11) to PTSD symptom compared to residents without acute physical symptoms. The results of multiple logistic analysis, including the cleanup activity, age, gender, occupation, acute physical symptoms and amount of debt in the model suggest that only cleanup activity increased PTSD symptoms. The subjects who had engaged in cleanup activities for longer periods of time had more PTSD symptoms and an additional dose-response relationship. CONCLUSION: Many residents in Samsung-Hebei spirits oil spill area had PTSD symptoms. This suggests that there were serious mental health problems among the residents, who might require specific social supports and psychiatric interventions as a result of the oil spill.
Commerce ; Environmental Remediation ; Fisheries ; Logistic Models ; Mental Health ; Occupations ; Petroleum ; Petroleum Pollution ; Stress Disorders, Post-Traumatic

Mercury is emitted to the atmosphere from various natural and anthropogenic sources, and degrades with difficulty in the environment. Mercury exists as various species, mainly elemental (Hg0) and divalent (Hg2+) mercury depending on its oxidation states in air and water. Mercury emitted to the atmosphere can be deposited into aqueous environments by wet and dry depositions, and some can be re-emitted into the atmosphere. The deposited mercury species, mainly Hg2+, can react with various organic compounds in water and sediment by biotic reactions mediated by sulfur-reducing bacteria, and abiotic reactions mediated by sunlight photolysis, resulting in conversion into organic mercury such as methylmercury (MeHg). MeHg can be bioaccumulated through the food web in the ecosystem, finally exposing humans who consume fish. For a better understanding of how humans are exposed to mercury in the environment, this review paper summarizes the mechanisms of emission, fate and transport, speciation chemistry, bioaccumulation, levels of contamination in environmental media, and finally exposure assessment of humans.
Air Pollutants/chemistry/metabolism ; *Environmental Exposure ; Environmental Remediation ; Food Chain ; Humans ; Mercury/chemistry/*metabolism ; Methylmercury Compounds/chemistry/metabolism ; Photolysis ; Sulfur-Reducing Bacteria/metabolism ; Water Pollutants, Chemical/metabolism

With the continuously increasing demands of plastic products in the current society, the challenge of disposing plastic waste is constantly increasing, leading to the urgent need of mitigating plastic pollution. As a consequence, much attention has been paid to biodegradable plastics due to their degradability in a bio-active environment under certain conditions. Biodegradable plastics herald vast development potentials and considerable market prospects. The degradation of numerous types of biodegradable plastics will be affected by many factors. A thorough understanding of degradation mechanisms as well as functional microbial strains and enzymes is the key to comprehensive utilization and efficient treatment and disposal of biodegradable plastics. The article summarized the types, properties, advantages and disadvantages, and main applications of common biodegradable plastics. The degradation mechanisms, functional microbial strains and enzymes, as well as the degradation degree and duration under different environmental conditions, were also summarized. This review may help better understand the degradation of biodegradable plastics wastes.
Biodegradable Plastics ; Biodegradation, Environmental

The course Bioremediation of Environmental Pollution, which plays a vital role in the professional training system, is a professional elective course for college students majored in environmental science, environmental engineering and agricultural resources and environment. In view of the problems identified in previous teaching experiences, the teachers carried out teaching reform to meet the demand for high-quality personnel training. The teaching reform included optimization of course objectives, reconstruction of course content and knowledge integration, reform and innovation of teaching methods. The practices indicate that a reformed curriculum teaching significantly improves the achievement of the teaching objectives. Moreover, it effectively enhances the students' independent learning, thinking and comprehensive knowledge application ability, achieving sound teaching effects.
Humans ; Biodegradation, Environmental ; Curriculum ; Students

Humanity shares the common interest to protect the environment and to maintain a healthy global ecosystem. International collaboration is key in this context, to advance the necessary science and technology. The National Science Foundation of China (NSFC) and European Commission (EC) have agreed to collaborate in innovative knowledge and technology in the field of bioremediation of polluted environments and biodegradation of plastics. In this context, projects on bioremediation of soils, wastewater and sediment matrices and on microbial degradation of plastics were supported. This special issue aimed to introduce these projects and their progresses in the related fields. In total, 23 papers have been collected in this issue, covering both fundamental and applied researches.
Biodegradation, Environmental ; China ; Ecosystem ; Plastics