Evaluation of Pollutants Along the National Road N2 in Togo using the AERMOD Dispersion Model

Abstract

Background. Air pollution has become a major problem around the world and is increasingly an issue in Togo due to increased vehicular traffic. Gaseous pollutants are released by engines and are very harmful to human health and the environment. The fuels used on the major road in Togo, the N2, are adulterated with unknown contents and are of poor quality. Many of the vehicles come from neighboring countries, such as Benin, Ghana and Nigeria. Objectives. The present study aims to evaluate the pollution rate in Togo through the estimation of the concentrations of sulfur dioxide (SO2), nitrogen oxides (NOx), and particular matter (PM) on the international road, the National Road N2, in Lomé, compared to the World Health Organization's (WHO) standard limit. Methods. The simulations of pollutant concentration were performed using the Industrial Source Complex Short Term Version 3 model, which is included in the United States Environmental Protection Agency Regulatory Model (USEPA) AERMOD View software. The meteorological averages data were obtained from the local station near the National Road N2 in Togo in 2018. Hourly averages were calculated according to the European Monitoring Evaluation Programme/European Environmental Agency air pollutant emission inventory guidebook 2016 and were processed using AERMET View and a terrain pre-processor, AERMAP. For the model, the sources of pollution were the vehicles traveling on the road segment. The source was a line volume with 20 m of width and 2 m of height. The estimation methodology covered exhaust emissions of NOx, SO2 and PM contained in the fuel. Results. The simulations provided average hourly, daily and annual concentrations of the different pollutants: 71.91 μg/m3, 42.41 μg/m3,11.23 μg/m3 for SO2; 16.78 μg/m3, 9.89 μg/m3, 2.46 μg/m3 for NOx and below the detection limit, 0.62 μg/m3, 0.15 μg/m3 for PM, respectively. These results indicate that on the National Road N2 in Togo, the concentrations of SO2 were high compared to those of NOx and PM. The daily average concentration of SO2 was twice the permissible limits set by the WHO. Conclusions. Emissions obtained from the AERMOD for NOx and PM were less than the permissible limits set by the WHO, while the rate of SO2 was twice the permissible limit. The fuels used on this road were very rich in sulfur. The sulfur level in fuels must be monitored by stakeholders in Togo. Competing Interests. The authors declare no competing financial interests.

A Network of Field-Calibrated Low-Cost Sensor Measurements of PM2.5 in Lomé, Togo, Over One to Two Years

“…To our knowledge, there are no published ambient PM 2.5 measurement data in the country of Togo. Amouzouvi et al 19 simulated PM, SO 2 , and NO 2 in Lomé using the USEPA AERMOD dispersion model, but no ground-based observational data were included in the study. Diallo et al 20 measured personal exposure to PM 2.5 in Lomé indoor environments using simple devices.…”

Modelling of Pollutants Dispersion from Open Burning of Solid Waste Using AERMOD

“…Air pollutants are usually defined as substances in the atmosphere arising from anthropogenic activities or from natural processes, to the detriment of humans, plants, or animal lives. A lot of studies have shown a significant relationship between the degeneration of the environment and human health and the presence of pollutants in the atmosphere [3]. The main air pollutants in the atmosphere are: carbon monoxide (CO), oxides of nitrogen (NOx), particulate matter (PM), oxides of sulphur (SOx) and volatile organic compounds (VOCs) [4].…”

“…AERMOD and CALPUFF model were used to evaluate the concentration of NOX, SOx and PM emitted in Ghana. The result showed that the daily concentrations were greater during the rainy season than the dry season [3]. The ground level concentration of PM, SO2 and NOx in an industrial area were determined using AERMOD model in Bangalore (India).…”

“…The ground level concentration of PM, SO2 and NOx in an industrial area were determined using AERMOD model in Bangalore (India). NOx had the highest concentration of 24 μg/m 3 , SO2 with 1.2 μg/m 3 and PM with 0.0028 μg/m 3 [3]. The objective of air quality dispersion models is to relate mathematically the effects of source on ground level concentrations, and to establish that permissible levels are, or are not, being exceeded [9].…”

Documenting Environmental Contamination in Vulnerable Populations

“…We are proud to have published articles from countries very underrepresented in the scientific literature, including Algeria, 7 Armenia, 8 Belize, 9 Botswana, 10 Jamaica, 11 – 14 Liberia, 15 Mongolia, 16 Myanmar/Burma, 17 , 18 Nepal, 19 , 20 Sri Lanka, 21 Sudan, 22 , 23 Tajikistan, 24 Tanzania, 25 – 27 Togo, 28 , 29 Uganda 30 – 33 and Zimbabwe. 34 …”