scholarly journals Box-Jenkins stochastic models for studying air pollutants in a Latin American megacity

2021 ◽  
Vol 2139 (1) ◽  
pp. 012003
Author(s):  
A D Pinzón-Hassan ◽  
V Tique-Ortiz ◽  
C A Zafra-Mejía

Abstract The objective of this paper is to show the development of Box-Jenkins stochastic models to study the behavior of air pollutants concentrations in the megacity of Bogotá, Colombia. Information was collected from 10 stations in the city’s air quality monitoring network over a ten-year period. The temporal relationship between air pollutants, their spatial variation, and the occurrence of extreme pollution episodes was studied using Box-Jenkins models. The results showed that the moving average term of the models developed was the main indicator of spatial distribution for the daily pollutant concentrations. In the case of atmospheric particulate matter < 10 μm, the following spatial distribution was identified in the megacity: northwestern, center-southwest, and southeast. For atmospheric particulate matter < 2.5 μm: north, center, and southwest. For ozone: northwest, center, and south. Maximum hourly particulate matter concentrations were observed between 6-10 a.m., and between 11 a.m. - 4 p.m. for ozone. Monthly, the highest particulate matter concentrations were observed in February (14.1%), January (13.5%), and March (12.2%). In the context of atmospheric physics, this study was relevant for the following findings: The usefulness of Box-Jenkins models in simulating the temporal behavior of air pollutants, and for their adequate performance in detecting urban spatial trends.

2021 ◽  
Vol 3 (9) ◽  
Author(s):  
Katalin Hubai ◽  
Nora Kováts ◽  
Gábor Teke

AbstractAtmospheric particulate matter (PM) is one of the major environmental concerns in Europe. A wide range of studies has proved the ecotoxic potential of atmospheric particles. PM exerts chemical stress on vegetation by its potentially toxic constituents; however, relatively few studies are available on assessing phytotoxic effects under laboratory conditions. In our study, aqueous extract of particulate matter was prepared and used for treatment. Experiment was following the procedure defined by the No. 227 OECD Guideline for the Testing of Chemicals: Terrestrial Plant Test. Tomato (Lycopersicon esculentum Mill.) plants were used; elucidated toxicity was assessed based on morphological and biochemical endpoints such as biomass, chlorophyll-a and chlorophyll-b, carotenoids, and protein content. Biomass reduction and protein content showed a clear dose–effect relationship; the biomass decreased in comparison with the control (100%) in all test groups (TG) at a steady rate (TG1: 87.73%; TG2: 71.77%; TG3: 67.01%; TG4: 63.63%). The tendency in protein concentrations compared to the control was TG1: 113.61%; TG2: 148.21% TG3: 160.52%; TG4: 157.31%. However, pigments showed a ‘Janus-faced’ effect: nutrient content of the sample caused slight increase at lower doses; actual toxicity became apparent only at higher doses (chlorophyll-a concentration decrease was 84.47% in TG4, chlorophyll-b was 77.17%, and finally, carotene showed 83.60% decrease in TG4).


Author(s):  
Jesús Eulises Corona Sánchez ◽  
Ma del Carmen Angeles González Chávez ◽  
Rogelio Carrillo González ◽  
Kirk Scheckel ◽  
Daniel Tapia Maruri ◽  
...  

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