Development of a Rapid Survey Method of Sampling and Analysis for Asbestos in Ambient Air

1972 ◽  
Vol 30 ◽  
pp. 630-631 ◽  
Author(s):  
R. E. Heffelfinger ◽  
C. W. Melton ◽  
D. L. Kiefer ◽  
W. M. Henry ◽  
R. J. Thompson
Keyword(s):  
Neutron Activation ◽  
Ambient Air ◽  
Survey Method ◽  
Potential Hazard ◽  
Transmission Microscopy ◽  
Comparative Analyses ◽  
Asbestos Fibers ◽  
Controlled Conditions ◽  
Unequivocal Identification ◽  
Identification And Quantification

A methodology has been developed and demonstrated which is capable of determining total amounts of asbestos fibers and fibrils in air ranging from as low as fractional nanograms per cubic meter (ng/m3) of air to several micrograms/m3. The method involves the collection of samples on an absolute filter and provides an unequivocal identification and quantification of the total asbestos contents including fibrils in the collected samples.The developed method depends on the trituration under controlled conditions to reduce the fibers to fibrils, separation of the asbestos fibrils from other collected air particulates (beneficiation), and the use of transmission microscopy for identification and quantification. Its validity has been tested by comparative analyses by neutron activation techniques. It can supply the data needed to set emissions criteria and to serve as a basis for assessing the potential hazard for asbestos pollution to the populace.

Design and testing of twig chambers for ozone fumigation and gas exchange measurements in mature trees

1994 ◽  
Vol 102 ◽  
pp. 541-546 ◽  
Author(s):  
Wilhelm M. Havranek ◽  
Gerhard Wieser
Keyword(s):  
Gas Exchange ◽  
Net Photosynthesis ◽  
Ambient Air ◽  
Field Conditions ◽  
Chamber System ◽  
Mature Trees ◽  
Diurnal Courses ◽  
Controlled Conditions ◽  
Design And Testing

SynopsisA twig chamber system was developed for the exposure of mature trees to ozone (O3) under field conditions. The fumigation system allowed the exact control of O3 concentrations in the chambers, the measurement of O3 uptake as well as gas exchange measurements under ambient and controlled conditions during and after O3 fumigation. Because of differences in individual twigs the system should provide the exposure of replicates to different O3 treatments. Tests showed that temperature, humidity and O3 concentrations inside the chambers were comparable with diurnal courses observed in the field. Comparative gas exchange measurements indicated that there were no differences in net photosynthesis and conductance of twigs outside the chambers and twigs which remained within the chambers for 23 weeks receiving ambient air.

scholarly journals Determination of Airborne Concentration and Type of Asbestos Fibers in High-Traffic Areas of Zahedan City

2019 ◽  
Author(s):  
Ramazan Mirzaei ◽  
Alireza Ansarimoghadam ◽  
Naser Hamidinejad ◽  
Ahmadreza Khazaei ◽  
Jamshid gholampoor ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Ambient Air ◽  
Cross Sectional Study ◽  
Threshold Limit Value ◽  
Hazardous Air Pollutants ◽  
Cross Sectional ◽  
Asbestos Fibers ◽  
Limit Value ◽  
Airborne Concentration ◽  
Asbestos Contamination

Background:Asbestos fibers are one of the hazardous air pollutants in high-traffic areas of cities. This study was conducted during summer 2016 with the aim of determining the concentration and type of asbestos fibers in the air of high-traffic areas of Zahedan, Iran.  Methods: In this descriptive, cross-sectional study, 4 high-traffic and 2 traffic-free areas of Zahedan were chosen. Ambient air samples were collected according to the NIOSH 7400 method, with a flow rate of 2 l/m and 4 hours per day. The asbestos fiber in the samples were analyzed with the use of Phase-Contrast optical Microscopy (PCM) and Scanning Electronic Microscopy (SEM). Results:The mean and standard deviation of asbestos contamination density in high-traffic areas were 0.0012 (0.0004) f/cc and 0.0012, respectively, which were higher than the threshold limit value (TLV). In traffic-free areas with mean and standard deviation of 0.0003 ± 0.0003 f/cc the asbestos concentration was lower than the allowed limits. To check the normality of data Kolmogorov-Smirnov test was used (p< 0.05). The results of Kruskal-Wallis test showed that there is a meaningful difference between the means of the two measured groups (p< 0.001). The types of asbestos fibers based on EDS spectrums and electron microscope images were actinolite, tremolite, and chrysotile. Conclusion: The findings of the present study indicated that the concentration of asbestos fibers in the sampleswas higher than the WHO standards for ambient air (0.00005 PCM f/ml). The use of asbestos fibers in car brake and clutch, as well as in asbestos cement sheet and insulation in buildings are among the most important sources of air pollution in the city.  

scholarly journals Air Pollution with Asbestos Fibers in Some Heavy Traffic Areas of Baghdad

2021 ◽  
pp. 2143-2152
Author(s):  
Nahla Sh. Ajeel ◽  
Nada A. Fleeh ◽  
Matham A. Sultan
Keyword(s):  
Membrane Filter ◽  
Heavy Traffic ◽  
Ambient Air ◽  
Average Concentration ◽  
World Health ◽  
Low Flow ◽  
Cellulose Ester ◽  
Industrial Sites ◽  
Asbestos Fibers ◽  
Health Organization

     This research was conducted to measure the levels of asbestos fibers in the air of some dense sites of Baghdad city, which were monitored in autumn 2019. Samples collection was conducted via directing air flow to a mixed cellulose ester membrane filter mounted on an open‑faced filter holder using sniffer with a low flow sampling pump. Air samples were collected from four studied areas selected in some high traffic areas of Baghdad city, two of them were located in Karkh (Al-Bayaa and Al-Shurta tunnel) and two in Rusafa (Al-Jadriya and Al-Meshin complex), then analyzed to determine concentrations of asbestos. Measuring of levels of asbestos fibers on the filters was carried out via using scanning electron microscope SEM together with  an energy dispersive X‑ray system (EDS). The results showed that the lowest level was recorded in Al-Jadriya intersection (0.0352 fiber/ml), while the maximum concentration was in Al-Bayaa (0.156 f/ml). Asbestos average concentration in the ambient air of the four studied areas was 0.0718 f/ml, which exceeded the standards of world health organization (WHO) for air which is equal to 0.0022 f/ml. This may be due to the presence of crowded traffic and the occurrence of industries near the city. Therefore, plans such as management of traffic, changing locations of industrial sites, and products substitution can be effective in minimizing the concentrations of airborne fibers.

An Overview of FDA Regulatory Requirements for Vascular Devices

2020 ◽  
Vol 07 ◽  
Author(s):  
Monika Targhotra ◽  
Rohan Aggarwal ◽  
Meenakshi K. Chauhan
Keyword(s):  
High Risk ◽  
Drug Administration ◽  
Medical Devices ◽  
Food And Drug Administration ◽  
Survey Method ◽  
Potential Hazard ◽  
Clinical Consideration ◽  
Regulatory Requirements ◽  
Administrative Procedures ◽  
Commercial Center

Background: Likewise with latest medications, the Food and Drug Administration (FDA) endorsement proce-dure is expected to give assurance, when it arrives at the commercial center, a clinical device is efficacious and safe in its planned use. Objective: The objective of the particular review is to give an outline of the FDA survey method for vascular clinical devices. This audit centers principally on the FDA survey route for the high-risk based or type-III class clinical devices that obtain the utmost analysis. Methods: The clinical device guideline is achieved by CDRH. Exacting adjustment to wanted standards is required to get promoting approval. 510 (k), PMA, and HDE are the administrative pathways for acquiring promoting approval by the FDA. The decision of the administrative pathway received by organizations relies basically on the multifaceted nature of the structure, a potential hazard to the strength of client, and safety. Results: Clinical devices are fundamentally imperative to vascular care, and doctors who utilize clinical gadgets ought to be increasingly mindful about the administrative procedures supporting their accessibility. The FDA audits high-risk based devices for safety and adequacy. Conclusion: The rationale for this analysis is to talk about current FDA arrangements identified with the endorsement of medical devices alongside the ramifications of these approaches for clinical consideration, especially with regards to vas-cular care.

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