Predicting Within-City Spatial Variations in Outdoor Ultrafine Particle and Black Carbon Concentrations in Bucaramanga, Colombia: A Hybrid Approach Using Open-Source Geographic Data and Digital Images

2021 ◽  
Vol 55 (18) ◽  
pp. 12483-12492
Author(s):  
Marshall Lloyd ◽  
Ellison Carter ◽  
Florencio Guzman Diaz ◽  
Kento Taro Magara-Gomez ◽  
Kris Y. Hong ◽  
...  
2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Marshall Lloyd ◽  
Ellison Carter ◽  
Florencio Guzman Diaz ◽  
Kento Taro Magara Gomez ◽  
Kris Y. Hong ◽  
...  

2014 ◽  
Vol 2014 (1) ◽  
pp. 1462
Author(s):  
Scott Weichenthal* ◽  
William Farrell ◽  
Mark Goldberg ◽  
Lawrence Joseph ◽  
Marianne Hatzopoulou

2014 ◽  
Vol 132 ◽  
pp. 305-310 ◽  
Author(s):  
Scott Weichenthal ◽  
William Farrell ◽  
Mark Goldberg ◽  
Lawrence Joseph ◽  
Marianne Hatzopoulou

2013 ◽  
Vol 2013 (1) ◽  
pp. 3938
Author(s):  
Moniek Zuurbier ◽  
Bernard Groot ◽  
Anouk Besselink ◽  
Lex Groenewold ◽  
Manon Vaal ◽  
...  

Author(s):  
Borut Jereb ◽  
Brigita Gajšek ◽  
Gregor Šipek ◽  
Špela Kovše ◽  
Matevz Obrecht

Black carbon is one of the riskiest particle matter pollutants that is harmful to human health. Although it has been increasingly investigated, factors that depend on black carbon distribution and concentration are still insufficiently researched. Variables, such as traffic density, wind speeds, and ground levels can lead to substantial variations of black carbon concentrations and potential exposure, which is even riskier for people living in less-airy sites. Therefore, this paper “fills the gaps” by studying black carbon distribution variations, concentrations, and oscillations, with special emphasis on traffic density and road segments, at multiple locations, in a small city located in a basin, with frequent temperature inversions and infrequent low wind speeds. As wind speed has a significant impact on black carbon concentration trends, it is critical to present how low wind speeds influence black carbon dispersion in a basin city, and how black carbon is dependent on traffic density. Our results revealed that when the wind reached speeds of 1 ms−1, black carbon concentrations actually increased. In lengthy wind periods, when wind speeds reached 2 or 3 ms−1, black carbon concentrations decreased during rush hour and in the time of severe winter biomass burning. By observing the results, it could be concluded that black carbon persists longer in higher altitudes than near ground level. Black carbon concentration oscillations were also seen as more pronounced on main roads with higher traffic density. The more the traffic decreases and becomes steady, the more black carbon concentrations oscillate.


Hypertension ◽  
2021 ◽  
Vol 77 (3) ◽  
pp. 823-832
Author(s):  
Neelakshi Hudda ◽  
Misha Eliasziw ◽  
Scott O. Hersey ◽  
Ellin Reisner ◽  
Robert D. Brook ◽  
...  

Exposure to traffic-related air pollution (TRAP) may contribute to increased prevalence of hypertension and elevated blood pressure (BP) for residents of near-highway neighborhoods. Relatively few studies have investigated the effects of reducing TRAP exposure on short-term changes in BP. We assessed whether reducing indoor TRAP concentrations by using stand-alone high-efficiency particulate arrestance (HEPA) filters and limiting infiltration through doors and windows effectively prevented acute (ie, over a span of hours) increases in BP. Using a 3-period crossover design, 77 participants were randomized to attend three 2-hour-long exposure sessions separated by 1-week washout periods. Each participant was exposed to high, medium, and low TRAP concentrations in a room near an interstate highway. Particle number concentrations, black carbon concentrations, and temperature were monitored continuously. Systolic BP (SBP), diastolic BP, and heart rate were measured every 10 minutes. Outcomes were analyzed with a linear mixed model. The primary outcome was the change in SBP from 20 minutes from the start of exposure. SBP increased with exposure duration, and the amount of increase was related to the magnitude of exposure. The mean change in SBP was 0.6 mm Hg for low exposure (mean particle number and black carbon concentrations, 2500 particles/cm 3 and 149 ng/m 3 ), 1.3 mm Hg for medium exposure (mean particle number and black carbon concentrations, 11 000 particles/cm 3 and 409 ng/m 3 ), and 2.8 mm Hg for high exposure (mean particle number and black carbon concentrations, 30 000 particles/cm 3 and 826 ng/m 3 ; linear trend P =0.019). There were no statistically significant differences in the secondary outcomes, diastolic BP, or heart rate. In conclusion, reducing indoor concentrations of TRAP was effective in preventing acute increases in SBP.


2018 ◽  
Vol 7 (2.4) ◽  
pp. 147
Author(s):  
Swati Hira ◽  
Samir Ajani ◽  
Pratibha Kokardikar ◽  
Shubhangi Neware

The proposed email setup consist of multiple mail servers distributed at two levels to achieve desirable email access performance. It is a well-established fact that 99% of the emails received over internet are either spam or contained viruses and such emails can be dropped at the first entry point of the Network. Thus, the first level in the proposed architecture has been taken as an email gateway which is equipped with antivirus and anti-spam software. Spam assassion is an open source freeware software for filtering of the spam emails. Perl based spamassassion id to CPU and Memory hungry for heavily loaded server thus this new arrangement would then overcome the Problem of slow Email access for users by detaching spamassassion from email repository servers. The second level of the servers with email repositories for users all the email servers used in this implementation would be Linux X86 servers. Virtualization technique presents a software interface to virtual machines that is similar but not identical to that of the underlying hardware. First level is implemented in Virtual machine. So as to provide scalability, portability, migration and vendor independent. 


Sign in / Sign up

Export Citation Format

Share Document