Ambient concentrations of PM2.5 remain above the WHO guideline in several places

2021 ◽  
Keyword(s):  
Ambient Concentrations ◽  
Who Guideline

Atmospheric transport and deposition of trace elements to lake erie from Urban areas

1996 ◽  
Vol 33 (4-5) ◽  
pp. 259-265
Author(s):  
Gerald J. Keeler ◽  
Nicola Pirrone
Keyword(s):  
Trace Elements ◽  
Urban Areas ◽  
Lake Erie ◽  
Atmospheric Transport ◽  
Spatial And Temporal Variation ◽  
Deposition Flux ◽  
Emission Sources ◽  
Dry Deposition Flux ◽  
Ambient Concentration ◽  
Ambient Concentrations

A hybrid receptor-deposition (HRD) modeling approach was used to determine the spatial and temporal variation in the ambient concentration and dry deposition flux of trace elements on fine (< 2.5 mm) and coarse (> 2.5 mm) particulate matter over Lake Erie. Upper-air observations from the National Weather Service (NWS) and ambient concentrations measured at two sampling sites downwind of major emission sources in the Lake Erie basin were input to the model. An evaluation of the deposition flux of size-segregated trace elements to the lake during the over-water transport was performed. The average total (fine + coarse) deposition flux was 9.6 ng/m2-h for V, 70 ng/m2-h for Mn, 3.2 ng/m2-h for As, 4.2 ng/m2-h for Se, 10 ng/m2-h for Cd, and 43.3 ng/m2-h for Pb.

scholarly journals Pathways of China's PM2.5 air quality 2015–2060 in the context of carbon neutrality

2021 ◽  
Author(s):  
Jing Cheng ◽  
Dan Tong ◽  
Qiang Zhang ◽  
Yang Liu ◽  
Yu Lei ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Critical Role ◽  
Climate Mitigation ◽  
Air Pollution Control ◽  
Carbon Neutrality ◽  
Climate Action ◽  
Clean Air ◽  
Near Term ◽  
Who Guideline

ABSTRACT Clean air policies in China have substantially reduced PM2.5 air pollution in recent years, primarily by curbing end-of-pipe emissions. However, further reaching the WHO guideline may instead depend upon the air quality co-benefits of ambitious climate action. Here, we assess pathways of Chinese PM2.5 air quality from 2015 to 2060 under a combination of scenarios which link Global and China's climate mitigation pathways (i.e. global 2°C- and 1.5°C-pathways, NDC pledges, and carbon neutrality goals) to local clean air policies. We find that China can achieve both its near-term climate goals (peak emissions) and PM2.5 air quality annual standard (35 μg/m3) by 2030 by fulfilling its NDC pledges and continuing air pollution control policies. However, the benefits of end-of-pipe control reductions are mostly exhausted by 2030, and reducing PM2.5 exposure of the majority of the Chinese population to below 10 μg/m3 by 2060 will likely require more ambitious climate mitigation efforts such as China's carbon neutrality goals and global 1.5°C-pathways. Our results thus highlight that China's carbon neutrality goals will play a critical role in reducing air pollution exposure to the WHO guideline and protecting public health.

Using ambient concentrations as proxy for methane flux measurements from rice fields

Chemosphere ◽  
1998 ◽  
Vol 37 (6) ◽  
pp. 1197-1205 ◽  
Author(s):  
M.A.K. Khalil ◽  
R.A. Rasmussen
Keyword(s):  
Methane Flux ◽  
Rice Fields ◽  
Flux Measurements ◽  
Ambient Concentrations

The response of planktonic phosphate uptake and turnover to ultraviolet radiation in Lake Erie

2002 ◽  
Vol 59 (5) ◽  
pp. 778-786 ◽  
Author(s):  
C D Allen ◽  
R E.H Smith
Keyword(s):  
Ultraviolet Radiation ◽  
Lake Erie ◽  
Radiation Treatment ◽  
Phosphate Uptake ◽  
Ultraviolet B ◽  
Phosphate Limitation ◽  
Bacterial Cells ◽  
Near Surface ◽  
Ambient Concentrations ◽  
Uptake Activity

The hypothesis that ambient ultraviolet radiation (UVR), at near-surface intensities, may diminish phosphorus availability to phytoplankton was tested in Lake Erie in July and August of 1998 and 1999. Relative to samples exposed to photosynthetically active radiation (PAR, 400–700 nm) only, those exposed to ultraviolet-B (UVB, 280–320) and (or) ultraviolet-A (UVA, 320–400 nm) in natural sunlight, or kept in darkness, had diminished phosphate uptake rates at elevated (1 µM P) dissolved phosphate concentrations. By contrast, the specific uptake rate of dissolved phosphate at ambient concentrations (turnover rate) was not significantly affected by UVR or darkness. Turnover was usually dominated by particles smaller than 0.8 µm, whereas uptake from elevated concentrations was dominated by larger particles. The size distribution of turnover and uptake activity was not affected by radiation treatment. Chlorophyll a concentrations were decreased by sufficient exposure to UVB and (or) UVA and increased by deprivation of PAR (dark controls), but the concentration of bacterial cells was unaffected. The results showed that UVR inhibited the phosphate uptake potential of larger, probably algal, plankton but did not change the apparent severity of phosphate limitation at ambient concentrations.

scholarly journals 915 Furazolidone as an Antibiotic for Childhood Gastroenteritis and its Comparison with Who Guideline: Is it Used Still?

2012 ◽  
Vol 97 (Suppl 2) ◽  
pp. A262-A262
Author(s):  
F. F. Jahani ◽  
E. Ahmadnezhad ◽  
M. Karramyyar
Keyword(s):  
Who Guideline

New WHO Guideline for Treating Chronic Pain in Children

JAMA ◽  
2021 ◽  
Vol 325 (11) ◽  
pp. 1031
Author(s):  
Bridget M. Kuehn
Keyword(s):  
Chronic Pain ◽  
Who Guideline

Pharmacognostical Investigation of Trapa natans L Leaves

2021 ◽  
pp. 4680-4684
Author(s):  
Chandana Majee ◽  
Rupa Mazumder ◽  
Alka N. Choudhary
Keyword(s):  
Aquatic Plant ◽  
Single Layer ◽  
Total Phenolic ◽  
Phytochemical Analysis ◽  
Trapa Natans ◽  
Microscopic Evaluation ◽  
Anomocytic Stomata ◽  
Physicochemical Evaluation ◽  
The Right ◽  
Who Guideline

Background: Trapa natans L., is annual aquatic plant generally kwon as Water caltrp, Water chest nut belonging to the Trapaceae or Lytraceae family. Trapa natans L is use for the treatment of wide no of diseases without proper standardization. Objective: To give the right pharmacognostical and photochemical information of the Trapanatan L leaves. In this study pharmacognostical investigation of the fresh leaves and powder drug were done to determine the macroscopical, microscopical, quantitative physicochemical and phytochemical property of the drugs. Method: Macroscopical, quantitative and qualitative microscopy, physicochemical evaluation, extractive value, florescence analysis and phytochemical analysis were done according to the WHO guideline. Result: Macroscopical analysis showed that, leaves are greenish to purplish color, rhomboidal shape; alternate, acute, margin is dentate, pinnate venation. Microscopic evaluation showed that leaf is dorsi ventral in nature, upper layer epidermis cells were covered with cuticle layer. Single layer of barrel shape cell were present bellow the upper epidermis layer. Trichomes are generally multicellular. Anomocytic stomata were observed in upper epidermis. From the experiment it was found that methanolic extract give the highest extractive value. Phytochemical analysis gives the evidence for the presence of carbohydrate, alkaloids, glycoside, steroids, flavonoids, tannin, and triterpenoids. Qualitative phytochemical analysis give the evidence for presence of high amount total phenolic content. Conclusion: Different pharmacognostical parameters assessed in this examination help to detection and standardization of Trapa natans L., leaves.

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