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41.
Louisiana (LA) ranks fifth in the United States in cancer mortality rate. LA's infamous “cancer alley” is a well evidenced region near the southeast part of the Mississippi river surrounding the petrochemical hub of the state. LA has also experienced a high COVID-19 death rate and incidences compared to other states during the recent pandemic. In this study we analyzed publicly available datasets related to health and socio-economic parameters in LA to determine the factors triggering high incidences and deaths caused by COVID-19. Correlation analysis was performed to find the impact of different parameters on the outcome of COVID-19. Our analysis showed higher COVID-19 incidences in the parishes which are in and around the “cancer alley” with a correlation of r = 0.9. Interestingly, results also indicated a strong correlation (r = 0.9) between the death rates caused by asbestos toxicity to COVID-19 caused death rate. Furthermore, we found that office-administration related employment has a positive correlation to COVID-19 incidences in the “cancer alley.” However, we also found both white and black races are equally affected by the COVID-19 pandemic in the “cancer alley” region. In conclusion, our analysis strongly suggests that inhabiting “cancer alley” could significantly enhance the chances of getting affected by SARS-CoV-2 virus compared to other regions in LA.  相似文献   
42.
The need for remediation of poly‐ and perfluoroalkyl substances (PFASs) is growing as a result of more regulatory attention to this new class of contaminants with diminishing water quality standards being promulgated, commonly in the parts per trillion range. PFASs comprise >3,000 individual compounds, but the focus of analyses and regulations has generally been PFASs termed perfluoroalkyl acids (PFAAs), which are all extremely persistent, can be highly mobile, and are increasingly being reported to bioaccumulate, with understanding of their toxicology evolving. However, there are thousands of polyfluorinated “PFAA precursors”, which can transform in the environment and in higher organisms to create PFAAs as persistent daughter products. Some PFASs can travel miles from their point of release, as they are mobile and persistent, potentially creating large plumes. The use of a conceptual site model (CSM) to define risks posed by specific PFASs to potential receptors is considered essential. Granular activated carbon (GAC) is commonly used as part of interim remedial measures to treat PFASs present in water. Many alternative treatment technologies are being adapted for PFASs or ingenious solutions developed. The diversity of PFASs commonly associated with use of multiple PFASs in commercial products is not commonly assessed. Remedial technologies, which are adsorptive or destructive, are considered for both soils and waters with challenges to their commercial application outlined. Biological approaches to treat PFASs report biotransformation which creates persistent PFAAs, no PFASs can biodegrade. Water treatment technologies applied ex situ could be used in a treatment train approach, for example, to concentrate PFASs and then destroy them on‐site. Dynamic groundwater recirculation can greatly enhance contaminant mass removal via groundwater pumping. This review of technologies for remediation of PFASs describes that:
  • GAC may be effective for removal of long‐chain PFAAs, but does not perform well on short‐chain PFAAs and its use for removal of precursors is reported to be less effective;
  • Anion‐exchange resins can remove a wider array of long‐ and short‐chain PFAAs, but struggle to treat the shortest chain PFAAs and removal of most PFAA precursors has not been evaluated;
  • Ozofractionation has been applied for PFASs at full scale and shown to be effective for removal of total PFASs;
  • Chemical oxidation has been demonstrated to be potentially applicable for some PFAAs, but when applied in situ there is concern over the formation of shorter chain PFAAs and ongoing rebound from sorbed precursors;
  • Electrochemical oxidation is evolving as a destructive technology for many PFASs, but can create undesirable by‐products such as perchlorate and bromate;
  • Sonolysis has been demonstrated as a potential destructive technology in the laboratory but there are significant challenges when considering scale up;
  • Soils stabilization approaches are evolving and have been used at full scale but performance need to be assessed using appropriate testing regimes;
  • Thermal technologies to treat PFAS‐impacted soils show promise but elevated temperatures (potentially >500 °C) may be required for treatment.
There are a plethora of technologies evolving to manage PFASs but development is in its early stage, so there are opportunities for much ingenuity.  相似文献   
43.
The rate of degradation of forchlorfenuron, a cytokinin-based plant growth regulator (PGR) was explored in typical grapevine soils of India with simultaneous evaluation of its effect on biochemical attributes of the test soils in terms of the activities of specific soil microbial enzymes. In all the test soils, namely clay, sandy-loam and silty-clay, the dissipation rate was faster at the beginning, which slowed down with time, indicating a non-linear pattern of degradation. Degradation in soils could best be explained by two-compartment 1st + 1st order kinetics with half-life ranging between 4–10 days. The results suggest that organic matter might be playing a major role in influencing the rate of degradation of forchlorfenuron in soil. The rate of degradation in sandy-loam soil was fastest followed by clay and silty-clay soils, respectively. Comparison of the rate of degradation in natural against sterilized soils suggests that microbial degradation might be the major pathway of residue dissipation. Changes in soil enzyme activities as a consequence of forchlorfenuron treatment were studied for extra-cellular enzymes namely acid phosphatase, alkaline phosphatase and β -glucosidase and intracellular enzyme-dehydrogenase. Although small changes in enzyme activities were observed, forchlorfenuron did not have any significant deleterious effect on the enzymatic activity of the test soils. Simple correlation studies between degradation percentage and individual enzyme activities did not establish any significant relationships. The pattern and change of enzyme activity was primarily the effect of the incubation period rather than the effect of forchlorfenuron itself.  相似文献   
44.
As the host city of the 2008 Olympic games, Beijing implemented a series of air pollution control measures before and during the Olympic games. Ambient formaldehyde (HCHO) concentrations were measured using a fluorometric instrument based on a diffusion scrubber and the Hantzsch reaction; hydrocarbons were simultaneously measured using gas chromatography–mass spectrometry (GC–MS). Meteorological parameters, CO, O3, and NO2 concentrations were measured by standard commercial instrumentation. In four separate periods: (a) before the vehicle plate number control (3–19 July); (b) during the Olympic Games (8–24 August); (c) during the Paralympic Games (6–17 September) and (d) after the vehicle control was ceased (21–28 September), the average HCHO mixing ratios were 7.31 ± 2.67 ppbv, 5.54 ± 2.41 ppbv, 8.72 ± 2.48 ppbv, and 6.42 ± 2.79 ppbv, while the total non-methane hydrocarbons (NMHCs) measured were 30.41 ± 18.08 ppbv, 18.12 ± 9.38 ppbv, 30.50 ± 13.37 ppbv, and 33.33 ± 15.85 ppbv, respectively. Both HCHO and NMHC levels were the lowest during the Olympic games, and increased again during the Paralympic games even with the same vehicle control measures operative. Similar diurnal HCHO and O3 patterns indicated that photo-oxidation of NMHCs may be the major source of HCHO. The diurnal profile of total NMHCs was very similar to that of NO2 and CO: morning and evening peaks appeared in rush hours, indicating even after strict vehicle control, automobile emission may still be the dominant source of the HCHO precursors. The contributions of HCHO, alkanes, alkenes, and aromatics to OH loss rates were also calculated. HCHO contributed 22 ± 3% to the total VOCs and 24 ± 1% to the total OH loss rate. HCHO was not only important in term of abundance, but also important in chemical reactivity in the air.  相似文献   
45.

The organic toxicants formed in chlorinated water cause potential harm to human beings, and it is extensively concentrated all over the world. Various disinfection by-products (DBPs) occur in chlorinated water are genotoxic and carcinogenic. The toxicity is major concern for chlorinated DBPs which has been present more in potable water. The purpose of the work was to evaluate genotoxic properties of DBPs in Allium cepa as a plant model system. The chromosomal aberration and DNA laddering assays were performed to examine the genotoxic effect of trichloroacetic acid (TCAA), trichloromethane (TCM), and tribromomethane (TBM) in a plant system with distinct concentrations, using ethyl methanesulfonate (EMS) as positive control and tap water as negative control. In Allium cepa root growth inhibition test, the inhibition was concentration dependent, and EC50 values for trichloroacetic acid (TCAA), trichloromethane (TCM), and tribromomethane (TBM) were 100 mg/L, 160 mg/L, and 120 mg/L respectively. In the chromosome aberration assay, root tip cells were investigated after 120 h exposure. The bridge formation, sticky chromosomes, vagrant chromosomes, fragmented chromosome, c-anaphase, and multipolarity chromosomal aberrations were seen in anaphase–telophase cells. It was noticed that with enhanced concentrations of DBPs, the total chromosomal aberrations were more frequent. The DNA damage was analyzed in roots of Allium cepa exposed with DBPs (TCAA, TCM, TBM) by DNA laddering. The biochemical assays such as lipid peroxidation, H2O2 content, ascorbate peroxidase, guaiacol peroxidase, and catalase were concentration dependent. The DNA interaction studies were performed to examine binding mode of TCAA, TCM, and TBM with DNAs. The DNA interaction was evaluated by spectrophotometric and spectrofluorometric studies which revealed that TCAA, TCM, and TBM might interact with Calf thymus DNA (CT- DNA) by non-traditional intercalation manner.

  相似文献   
46.
This paper investigates the possible impacts of climate change on aquatic salinity and mangrove species in the Bangladesh Sundarbans. The impact analysis combines the salinity tolerance ranges of predominant mangrove species with aquatic salinity measures in 27 scenarios of climate change by 2050. The estimates indicate significant overall losses for Heritiera fomes; substantial gains for Excoecaria agallocha; modest changes for Avicennia alba, A. marina, A. officinalis, Ceriops decandra, and Sonneratia apetala; and mixed results for species combinations. Changes in mangrove stocks are likely to change the prospects for forest-based livelihoods. The implications for neighboring communities are assessed by computing changes in high-value mangrove species for the five sub-districts in the Sundarbans. The results of the impact analysis indicate highly varied patterns of gain and loss across the five sub-districts. Overall, however, the results suggest that salinity-induced mangrove migration will have a strongly regressive impact on the value of timber stocks because of the loss of highest value timber species, Heritiera fomes. In addition, the augmented potential for honey production will likely increase conflicts between humans and wildlife in the region.  相似文献   
47.
In recent years, silver nanoparticles (AgNPs) have attracted considerable interest in the field of food, agriculture and pharmaceuticals mainly due to its antibacterial activity. AgNPs have also been reported to possess toxic behavior. The toxicological behavior of nanomaterials largely depends on its size and shape which ultimately depend on synthetic protocol. A systematic and detailed analysis for size variation of AgNP by thermal co-reduction approach and its efficacy toward microbial and cellular toxicological behavior is presented here. With the focus to explore the size-dependent toxicological variation, two different-sized NPs have been synthesized, i.e., 60 nm (Ag60) and 85 nm (Ag85). A detailed microbial toxicological evaluation has been performed by analyzing minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), diameter of inhibition zone (DIZ), growth kinetics (GrK), and death kinetics (DeK). Comparative cytotoxicological behavior was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. It has been concluded by this study that the size of AgNPs can be varied, by varying the concentration of reactants and temperature called as “thermal co-reduction” approach, which is one of the suitable approaches to meet the same. Also, the smaller AgNP has shown more microbial and cellular toxicity.  相似文献   
48.
This paper seeks to quantify the impact of a 1-m sea-level rise on coastal wetlands in 86 developing countries and territories. It is found that approximately 68 % of coastal wetlands in these countries are at risk. A large percentage of this estimated loss is found in Europe and Central Asia, East Asia, and the Pacific, as well as in the Middle East and North Africa. A small number of countries will be severely affected. China and Vietnam (in East Asia and the Pacific), Libya and Egypt (in the Middle East and North Africa), and Romania and Ukraine (in Europe and Central Asia) will bear most losses. In economic terms, the loss of coastal wetlands is likely to exceed $703 million per year in 2000 US dollars.  相似文献   
49.
Effects of sub-lethal doses of carbaryl (1-Naphthyl-methylcarbamate), chlorpyrifos (O,O-diethyl O-3,5,6-trichloro-2-pyridinyl-phosphorothioate) and endosulfan (6,7,8,9,10,10-Hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin-3-oxide), respectively a carbamate, an organophosphate and an organochlorine insecticide on growth, reproduction and respiration of the tropical earthworm, Perionyx excavatus (Perrier) were investigated under laboratory conditions. The results showed significant reduction in biomass, production and hatching of cocoon and production of juveniles of the worms exposed to 0.75 to 3.03 mg/kg soil of carbaryl, 0.91 to 3.65 mg/kg soil of chlorpyrifos and 3.75 to 15.0 μg/kg soil of endosulfan corresponding to 12.5 to 50 % of LC50 value of the respective insecticide for P. excavatus. Endosulfan was found most dangerous among the three insecticides followed by carbaryl and chlorpyrifos. There was no hatching of the worms at endosulfan treatment 5.0 μg/kg soil (25 % LC50) or above while the highest dose of carbaryl and chlorpyrifos (50 % of LC50) rendered respectively 87.13 and 24.84 % reductions in hatching as compared to control. Chlorpyrifos produced no change in respiration of the worms except at the highest dose, while the worms showed an increase in evolution of CO2 at all doses of carbaryl and endosulfan. Based on the recommended agricultural dose of each insecticide, it was concluded that application of endosulfan and carbaryl was potentially dangerous to earthworms.  相似文献   
50.

From an environmental perspective, the media have raised the level of environmental awareness and, rightly or wrongly, focused the attention of citizens on specific environmental issues. Public reaction to environmental news can filter back into the media and highlight specific policy issues. The importance of the media in this respect has gained strength, particularly in developing countries, where environmental problems have become legitimate concerns, and where access to 'official' information has been historically difficult. In general, newspapers have been found to be one of the most predominant sources of environmental information available to the public, particularly in developing countries. In this paper, we summarise, briefly analyse and compare the newspaper coverage of environmental issues in Argentina, Chile, Mexico and the Philippines. Among numerous other results, it appears that the coverage of environmental issues fell considerably over the period 1990-94 despite an increase in world-wide environmental awareness. Most news reports actions by the environmental agencies (warnings and rewards, etc.). In the Philippines, however, most environmental news reports investments in pollution abatement activities by the private sector. While citizens' complaints represent a small percentage of the coverage of environmental issues, closer examination reveals that such complaints, in the vast majority of cases, trigger governmental actions (warnings) and ultimately an improvement of firms' environmental performance (investment).  相似文献   
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