Home Physical Sciences Spatial mapping of indoor air quality in a light metro system using the geographic information system method
Article Open Access

Spatial mapping of indoor air quality in a light metro system using the geographic information system method

  • Ahmet Çoşgun ORCID logo EMAIL logo
Published/Copyright: April 1, 2024

Abstract

It is known that one of the greatest problems of developed countries in the twenty-first century is traffic. For this reason, engineers have searched for alternative solutions to the problem of traffic. One such solution is the construction and utilization of rail systems instead of main roads. From an engineering perspective, rail systems can be divided into three groups: metro, light metro, and tram systems. Light metro systems, which are a form of public transportation, are not directly inside the traffic. Their most important advantages include the fact that they do not release combustion products such as CO, and metro and light metro systems may be considered environmentally friendly based solely on their electricity consumption. In this study, measurements of parameters affecting indoor air quality were made inside light metro cars and in and around light metro stations belonging to the light metro system of the Metropolitan Municipality of Antalya, known as the tourism capital of Turkey. In February and March 2021, when the COVID-19 pandemic was first registered in Turkey, particulate matter (PM), temperature, and relative humidity measurements were made for testing indoor and outside air quality. Moreover, as outside air parameters, outside temperature, outside relative humidity, CO, normalized difference vegetation index, and ultraviolet aerosol index data were obtained from the General Directorate of Meteorology of Turkey. The measurement results were analyzed using the inverse distance weighting method in the geographic information system. Based on the results of the analyses, spatial maps were created for indoor and outside air quality parameters in the light metro system. Using these maps, the effects of passenger density and environmental factors both inside the metro cars and at the metro stations on indoor air quality were identified. In addition, the spread of the SARS-CoV-2 virus in the COVID-19 period was analyzed using spatial maps of the PM0.3 and PM0.5 parameters. It is believed that the results of this study will set an example for further indoor air quality studies worldwide, and this study is unique in that it employed a method that is used particularly in survey and geomatics engineering for analyzing indoor air quality in light metro systems.

1 Introduction

Rail systems are among the most preferred land transport vehicles for fast transportation. However, their initial investment costs are high compared to other forms of transportation. In general, they are the most prevalently employed mode of transportation in the capitals and metropolitan cities of countries. Rail systems can be divided into three groups: metro, light metro, and tram systems. Light metro systems are popular due to their speed in transportation and the comfort parameters they provide, including air conditioning parameters (temperature, relative humidity, air velocity, air distribution, and air purity). In contrast with metro systems, light metro systems mostly travel above ground on rails.

In large cities, individuals spend 4–8% of their day (1–2 h) commuting to and from work. As stated in several different studies, during this period, people are exposed to high concentrations of particulate matter (PM) [1].

The properties of a light metro system are presented in Table 1.

Table 1

Properties of a light metro system [9]

Light metro system Value/unit
Platform length ∼100 m
Car width 2,650 mm
Rail type S46 vignole rail
Energy supply Rigid catenary or 3rd rail
Current 750 DC or 1500 DC
Commercial speed 42–45 km/h
Maximum speed 80 km/h
Maximum passenger capacity 35,000/direction
Total car length 20–33 m
Distance between stations 600–1,000 m

1.1 Previous studies on the topic

Several studies on indoor air quality have been carried out in the relevant literature for metro and light metro systems in Asia and Europe. In particular, some studies on PM values are presented in Table 2.

Table 2

PM measurements made in rail systems in Asia and Europe [2]

Ctiy Metro production year Measurement year Polluting Average concentration
ASYA
Hong Kong 1979 1995–96 CO, NOx 1,500, 205 ppb
2014 PM10, PM2.5 120; 10.2 µg/m3
Beijing 1969 2004 TVOC 0.3 ppm
TSP, PM10, PM2.5, PM1 166; 108; 36.9; 14.7
Benzen, Toluen, Xylen µg/m3
2005 Karbonlu Bileşenler 13.7; 12.4; 4.1 µg/m3
2007 Bakteri ve Mantar 98.5 µg/m3
2011 PAHs 12,639; 1,806 CFU/m3
50.3 ng/m3
Shanghai 1993 2008 PM10, PM2.5, PM1 366; 287; 231 µg/m3
2008 Karbonlu Bileşenler 24 µg/m3
2015 Siyah Karbon 9.43 µg/m3
Guangzhou 1997 2002 PM10, PM2.5 55; 44 µg/m3
2000 Volatile organic compounds (VOC) 60.5 µg/m3
Tianjin 1984 2015 PM2.5 151.4 µg/m3
Taipei 1996 2011 PM10, PM2.5 58; 32 µg/m3
Seoul 1971 2007–2008 PM10, PM2.5 150; 118 µg/m3
2005 Fe 70%
2015 Bakteri, Mantar 210; 75 CFU/m3
2006 VOC 146.7 µg/m3
Tokyo 1927 2004 Mantar 342 CFU/m3
1997 TSP 90 µg/m3
Tehran 1986 2011 Mantar 1,210 CFU/m3
2015–2016 [2] PM10, PM2.5 33–102; 40–98 µg/m3
Delhi 2002 2012 PM2.5 78 µg/m3
St.Petersburg 1935 2007 Bakteri ve Mantar 2,236; 205 CFU/m3
AMERİKA
Boston 1897 1990 VOC 12.5 µg/m3
Washington 1976 1999 PM 106 adet/m3
New York 1907 1999 Fe, Cr, Mn 500; 84; 240 ng/m3
2007 PM2.5 30.6 µg/m3
Los Angeles 1990 2012 PM 27,500 adet/m3
2010 PM10, PM2.5 78; 56.7 µg/m3
2011 PAHs 3,693 µg/m3
Mexico City 1969 2002 PM10, PM2.5 126; 78 µg/m3
Benzen 4 ppb
VOC 22.2 µg/m3
2010-2011 Bakteri ve Mantar 415; 284 CFU/m3
Montreal 1966 2003 Mn 32 ng/m3
Buenos Aires 1913 2002-2006 TSP 211 µg/m3
Fe, Zn, Cu 86; 0.08; 0.8 µg/m3
Santiago 1975 2011 PM2.5 16.9 µg/m3
AVRUPA
London 1863 1996 Mantar 284 CFU/m3
PM2.5 892.8 µg/m3
Barcelona 1924 2013 PM10, PM3, PM1 183; 165; 67 µg/m3
Milan 1964 2010 UFP; PM10, PM2.5, PM1 1.3 × 104 adet/cm3; 147.7;
91.1; 36.7 µg/m3
Italya 1964 2006 PM10, PM2.5 217; 53 µg/m3
şehirleri
Lisbon 1959 2014 PM10, PM2.5 40; 13 µg/m3
Berlin 1902 1995 PAHs 19.7 ng/m3
Frankfurt 1902 2013 PM10, PM2.5, PM1 77; 44; 23 µg/m3
Paris 1900 2007 Fe 41.8%
Stockholm 1950 2000 PM10, PM2.5 390; 139 µg/m3
Helsinki 1982 2004 PM2.5 53 µg/m3
Prague 1974 2004 PM10, PM2.5, PM1 164.3; 93.9; 44.8 µg/m3
Budapest 1894 2007 PM10; Fe 155 µg/m3, 40%
Athens 2000 2013 PM10, PM2.5, PM1 400; 100; 40 µg/m3
İstanbul 1910 2007 [2427] PM10, PM2.5 50–200; 49–181 µg/m3
Fe, Cu 10–28 ; 0.13–0.32 µg/m3;

As seen in Table 2, PM values were investigated in metro systems for the first time in 1995. The aforementioned study was carried out in the London Underground, which was established in 1863, and a PM2.5 concentration of 893 µg/m3 was determined [2].

While PM values usually vary between 10 and 200 µg/m3 in Asian countries, the highest PM measurements in Shanghai (respectively, PM10, PM2.5, and PM1) were 366, 287, and 231 µg/m3.

In the metro system of Athens in Greece, PM1, PM2.5, and PM10 measurements were made at fixed positions inside metro cars on the Blue Line in November 2014 and November 2015, and assessments were made according to the Directive 2008/50/EC of the European Parliament on air quality. PM10 measurements were made in two directions of travel on all routes during commuting hours. The PM10 concentration was found as 132.2 ± 34 µg/m3 on the Red Line and 138.0 ± 35.6 µg/m3 on the Blue Line. In Athens, where measurements were made on eight different lines, passenger density was observed to be high in stations located under the streets of the city center with high traffic. To calculate the accumulation and retention dose of aerosols in the respiratory tract (RT) and the gastrointestinal system and their uptake into the bloodstream, an exposure model was applied using the formula E*DoM2. Consequently, while PM values were found lower inside metro cars with open windows, they were high especially when the windows were closed [3].

Previous studies have mostly made comparisons between indoor air quality parameters measured in metro, light metro, tram, and train cars and values in existing standards.

In Turkey, indoor air quality measurements for metro systems were made for the first time in 2007 by the Environmental Engineering Department of Istanbul University. In the study, PM10, PM2.5, Fe, and Cu measurements were analyzed [4].

In a review study in Turkey, studies conducted on indoor air quality on the platforms and in the cars of metro and other rail systems in Turkey and the rest of the world were examined. Indoor air quality measurements in metro and train cars in Turkey were compared to those in other countries by taking into account the properties of metro systems [5].

In a master’s thesis titled “the Effects of Ventilation Systems on Indoor Air Quality in Metro Systems in Istanbul,” PM2.5 measurements were made in metro systems in Istanbul, and the concentrations to which the personnel and passengers were exposed were determined. By making comparisons between indoor and outside air quality measurements, the effects of metro ventilation systems on indoor air quality were examined. It was determined that indoor air quality in metro systems could be significantly improved by supporting metro ventilation systems with platform screen doors and improving outside air quality [4].

In a study conducted to investigate and model the effects of PM on indoor air quality in light metro systems in Antalya, Turkey, PM measurements were made in January, February, and March in 2012, and it was determined that there were differences between the values measured in the metro cars and those measured on the platforms [6].

In a presentation about traffic-related carbon black levels in Istanbul, Turkey, and their relationship to PM2.5 concentrations, both in-vehicle and outside measurements were made in different transportation systems including buses, metrobuses, metros, automobiles, fast ferries, and ferries between June and September 2016. In the comparisons of the outside air quality measurements of three different metrobus stops (Zincirlikuyu, Avcılar, and Söğütlüçeşme), the highest mean black carbon concentrations in June, July, August, and September in Avcılar were 14.1 ± 10.4, 15.5 ± 17.6, 18.4 ± 12.2, and 15.3 ± 11.6 μg/m³, respectively. In measurements made at two bus stops, the highest PM2.5 concentrations in June, July, August, and September in Bakırköy were 4.5 ± 4.0, 8.2 ± 11.7, 9.8 ± 16.2, and 13.3 ± 33.1 μg/m³, respectively [7].

There are also other studies on vehicles other than metro trains in Turkey. In one of such studies, a doctoral thesis on the experimental measurement of changes in thermal parameters and indoor air quality in automobile cabins, experiments were carried out under real climate conditions using different air conditioning and heating parameters. The temperatures of the solid surfaces of the cabin and human skin were measured using an infrared camera with the thermographic method, and real-time temperature distributions were determined during cooling and heating periods. As a result, mathematical models to analyze the fluid dynamics of thermal comfort parameters and the thermophysical interactions between individuals and their surroundings were developed [8].

In previous studies mentioned earlier, it is seen that they have mostly compared measurement results to standard values. However, there is no study on how PM would be distributed in enclosed spaces, especially in metro, light metro, and tram systems during a global health crisis such as COVID-19.

The importance of thermal comfort is shown in studies on the increase in heat stress and changing climate in cities [10], in studies on finding monthly and annual maximum and minimum average temperature values [11], and in geostatistical methods of lead-zinc-silver mineral deposit. In the study of modeling and calculating the underground grade distribution and reserve by applying reserve parameters (density, area, thickness, grade, etc.) [12]. It is especially preferred in air pollution studies. Different approaches are applied in modeling pollution by constructing geostatistical, linear, or nonlinear models in the forward or backward direction. It is important to use emission inventory, meteorological, and topographic conditions together in layers with different methods for the spatial distribution of pollutant concentration. The methods developed in this study are based on obtaining different coefficients on the time and space scale and applying them in different layers [13]. Inverse distance weighting (IDW) was preferred due to the close and distant relationship of air studies with pollutant sources in the main theory of increasing the effect as you get closer and decreasing the effect as you move away. While the pollutant source is dirtier, the pollutant effect decreases at long distances. For this reason, the IDW method is preferred in many international studies to create spatial distribution maps [1418].

2 Parameters affecting indoor air quality in light metro systems

2.1 Temperature (°C) and relative humidity (%)

Thermal comfort and indoor air quality are closely related. Perceived air quality changes depending on variations in the thermal conditions of interior spaces. Temperature and humidity depend on changes in the enthalpy (total energy) of air, and they change how the RT is cooled. The temperature of the respiratory mucosa of humans is between ∼30 and ∼32°C. While cooling the mucosal membrane to the optimum temperature and humidity ranges provides more acceptable breathing and comfort, insufficient cooling results in respiratory problems [1921]. In field studies conducted inside buildings, it has been stated that the effects of normal temperature and humidity are negligible, and air pollutant concentrations are the main parameters at low enthalpy levels, whereas pollutant concentrations are not significantly effective at high enthalpy levels. The main parameters controlling perceived air quality are temperature and relative humidity. For indoor air quality, the optimum ranges of temperature (18–28°C) and humidity (30–70%) are reported in the ASHRAE standards. According to the ASHRAE standard 62-1989 titled “Ventilation for Acceptable Indoor Air Quality,” a clean air feeding rate of 8.0 L/s (28.8 m3/h) is recommended for transportation vehicles, waiting rooms, and platforms [10,22].

2.2 PM

PM is defined as solids, liquids, or a mixture of liquids surrounding solid particles in air. These particles may consist of both organic and inorganic substances such as dust, smoke, soot, liquid droplets, spores, bacteria, metallic compounds, elemental carbon, and inorganic ions. Some particles in the atmosphere are hygroscopic, and they absorb moisture. Organic particles include complexes that can consist of hundreds of organic compounds [23].

Particle size refers to the diameter of a particle. The classification of particles based on their diameters according to the United States Environmental Protection Agency (EPA) is shown in Table 3.

Table 3

EPA classification of particles based on their aerodynamic diameters [30]

EPA particle size definitions:
Highly coarse DPa > 10 μm
Coarse 2.5 μm < DPa ≤ 10 μm
Fine 0.1 μm < DPa ≤ 2.5 μm
Ultrafine DPa ≤ 0.1 μm

Figure 1 shows the PM concentrations reported for underground metro stations in different cities of the world listed according to measurement years.

Figure 1 
                  PM concentration measurements in different cities of the world by years [31].
Figure 1

PM concentration measurements in different cities of the world by years [31].

In all studies in the literature, PM2.5 and PM10 values have been measured.

2.3 Aerosols

Aerosols are found both inside and outside metro cars. In addition to their negative effects on human health, aerosols also have significant direct and indirect effects on the global climate as a parameter of outside air quality. A direct effect of aerosols on the climate depends on how much they reflect or absorb solar radiation. Moreover, aerosol particles can affect the lifespan and size of clouds by acting as cloud condensation nuclei [28]. It is known that desert dust, which constitutes most of the aerosols released into the atmosphere, triggers precipitation in low clouds [29]. For these reasons, in this study, aerosol parameters depending on outside air were examined using spatial data maps.

2.4 Carbon monoxide (CO)

CO is a colorless, odorless, and tasteless gas that is formed by the incomplete combustion of carbon-containing fuels. The main source of CO in outdoor spaces is transportation. More than 70% of the release of CO in the world and 44% of the release of CO in Turkey originates from the transportation sector (IPCC, 2007).

Even at low concentrations, the health effects of CO can be observed. CO enters the body via inhalation, it is not metabolized in the body, and it is removed by exhalation. Exposure to CO at low concentrations leads to fatigue even in healthy individuals, while it can result in chest pain in individuals with cardiovascular problems. Exposure to higher concentrations can reduce the sensation of sight and the ability to communicate and cause headaches, dizziness, imbalance, and nausea. Fatal outcomes can be seen at high concentrations [10,22].

3 Materials and methods

In this study, temperature, humidity, and PM values were measured and automatically recorded on a Fluke 983 device at 16 stations with the highest human traffic in the light metro system of the Antalya Metropolitan Municipality (Figure 2) with a total of 25 stations (Figure 3). Because the number of measurements was too high, only some of the measurements made in the light metro system (ANTRAY) are presented in Table 4.

Figure 2 
               An Antalya ANTRAY light metro train.
Figure 2

An Antalya ANTRAY light metro train.

Figure 3 
               Light metro and tram lines and stops/platforms in Antalya, Turkey.
Figure 3

Light metro and tram lines and stops/platforms in Antalya, Turkey.

Table 4

ANTRAY air quality parameter measurements

Light metro stop name Indoor air particles substance, temperature, and humidity values Outside air particles matter
0.3 µm 0.5 µm 1.0 µm 2.0 µm 5.0 µm 10 µm Sıcaklık (°C) Bağıl Nem (%) PM 10 µm
Ferro krom 198,566 17,311 1,102 400 46 17 25 54 26.90
Kepezaltı 188,568 15,172 768 225 17 6 25 54 21.01
Fatih 186,368 15,225 1,150 508 40 9 25 53 22.10
Vakıf Çitliği 169,479 12,200 634 203 11 4 25 55 29.30
Otogar 166,947 12,197 762 276 25 10 25 55 36.89
Pil fabrikası 160,509 11,005 591 192 14 6 26 53 38.86
Dokuma 155,137 10,294 454 113 5 3 26 53 34.18
Callı 186,077 17,061 2,503 1,304 110 30 30 49 28.48
Emniyet 154,479 10,200 659 235 23 7 23 52 26.29
Sigorta 166,716 13,455 1,177 464 41 8 25 52 25.88
Şarampol 147,721 9,739 502 131 9 3 26 50 26.71
Muratpaşa 158,375 11,034 692 202 10 3 26 49 29.12
İsmetpaşa 154,628 10,377 544 159 6 4 26 49 30.54
Doğu garajı 148,780 9,791 467 89 8 2 26 50 29.29
B.Onat 168,258 12,903 681 192 7 3 27 48 25.55
Meydan 163,719 12,094 570 126 5 2 26 50 21.69
Kışla 215,059 25,395 2,905 1,315 13 26 26 46 22.56
Topcular 204,064 18,290 1,112 280 17 9 26 50 25.59
Demokrasi 229,764 23,193 1,327 325 34 12 26 48 25.47
Cırnık 254,596 30,978 2,321 738 47 8 25 47 27.22
Altınova 233,572 24,077 1,389 374 13 2 25 47 30.82
Yenigöl 234,453 23,726 1,418 370 20 5 27 46 33.62
Sinan 237,791 24,237 1,289 303 12 3 26 45 40.55
Yonca kavşağı 217,924 19,044 694 65 2 1 26 45 50.40
Dış hatlar 205,754 16,951 596 62 0 0 26 45 22.38

The technical properties of the air conditioning setup used in the ANTRAY light metro system are not presented as the setup was not operated during the COVID-19 period.

Measurements were made inside and outside metro cars at 16 stations with the highest human traffic from the Fatih station to the Meydan station. Each station was numbered. For example, the Fatih station was coded S1, while the Meydan station was coded S16. The hand-held Fluke 983 PM measurement device that was used in the study is shown in Figure 4.

Figure 4 
               Fluke 983 PM measurement device.
Figure 4

Fluke 983 PM measurement device.

Some of the temperature, relative humidity, and PM measurement values recorded on 8 February, 22 February, and 8 March 2021, which corresponded to the active phase of the COVID-19 pandemic, are presented in Table 4.

The accuracy and calibration of the measuring devices were made by the relevant companies. In the study, daily measurements were taken three times: in the morning, at noon and in the evening. In each measurement, measurements were taken from close to the ground in the subway, again from 1 m above the ground and from 1.5 m above the ground.

Using the temperature, relative humidity, and PM (0.3, 0.5, 1, 5, and 10 µm) measurement results for indoor (in metro cars) and outside (stations) air quality parameters which are shown in Table 4, as well as aerosol, CO, formaldehyde, normalized difference vegetation index (NDVI), NO2, and SO2 values, spatial maps were created in the geographic information system (GIS) using the IDW method. The maps were produced in the order given below, and each map was examined in the context of the indoor air quality analyses. Since the study was conducted during the Covid-19 pandemic, there is no information on the number of passengers.

In Figure 5, the dark red zones show the very high concentrations of PM0.3 at S1, S2, and S3 among the 16 stations where the measurements were made on 8 February 2021. The lowest PM0.3 concentrations, shown in dark blue, were measured at S7, S11, S13, and S14.

Figure 5 
               Spatial map of PM0.3 based on measurements on 8 February 2021 (indoor).
Figure 5

Spatial map of PM0.3 based on measurements on 8 February 2021 (indoor).

On Figure 6, the dark red zones show the very high concentrations of PM0.3 at S1, S2, S3, S8, and S9 among the 16 stations where the measurements were made on 22 February 2021. The lowest PM0.3 concentrations, shown in dark blue, were measured at S13, S14, S15, and S16.

Figure 6 
               Spatial map of PM0.3 based on measurements on 22 February 2021 (indoor).
Figure 6

Spatial map of PM0.3 based on measurements on 22 February 2021 (indoor).

On Figure 7, the dark red zones show the very high concentrations of PM0.3 at S1, S2, S3, S4, S5, and S6 among the 16 stations where the measurements were made on 8 March 2021. The lowest PM0.3 concentrations, shown in dark blue, were measured at S9, S10, S11, and S12.

Figure 7 
               Spatial map of PM0.3 based on measurements on 8 March 2021 (indoor).
Figure 7

Spatial map of PM0.3 based on measurements on 8 March 2021 (indoor).

According to Maps 1, 2, and 3, S1, S2, and S3 had very high concentrations of PM0.3 on all measurement days. Among these stations, S1 was the station where the light metro line started, and it had a high traffic of people both inside and outside the metro cars. In addition, considering that the area was a crowded area where large numbers of working people would be present, it may have been the first point of the spread of COVID-19 through the light metro system. The lowest PM0.3 concentrations were at S13 and S14 on all measurement days. These were the Doğu Garajı and Burhanettin Onat stations, which were located right after the point where the light metro traffic connected to other lines, meaning that passenger traffic would be less.

According to these results, an infrared thermometer could be used at the entrance of the stations to prevent those with a fever from using the metro.

In Figure 8, the dark red zones show the very high concentrations of PM0.5 at S1, S2, S3, and S8 among the 16 stations where the measurements were made on 8 February 2021. The lowest PM0.5 concentrations, shown in dark blue, were measured at S11, S12, S13, and S14, which included the Doğu Garajı and Burhanettin Onat stations where lower rates of passenger traffic would be found.

Figure 8 
               Spatial map of PM0.5 based on measurements on 8 February 2021 (indoor).
Figure 8

Spatial map of PM0.5 based on measurements on 8 February 2021 (indoor).

In Figure 9, the dark red zones show the very high concentrations of PM0.5 at S1 and S8 among the 16 stations where the measurements were made on 22 February 2021. The lowest PM0.5 concentrations, shown in dark blue, were measured at S13, S14, S15, and S16, which included the Doğu Garajı and Burhanettin Onat stations where lower rates of passenger traffic would be found.

Figure 9 
               Spatial map of PM0.5 based on measurements on 22 February 2021 (indoor).
Figure 9

Spatial map of PM0.5 based on measurements on 22 February 2021 (indoor).

In Figure 10, the dark red zones show the very high concentrations of PM0.5 at S1, S2, S4, S5, and S6 among the 16 stations where the measurements were made on 8 March 2021. The lowest PM0.5 concentrations, shown in dark blue, were measured at S9, S10, S11, and S12.

Figure 10 
               Spatial map of PM0.5 based on measurements on 8 March 2021 (indoor).
Figure 10

Spatial map of PM0.5 based on measurements on 8 March 2021 (indoor).

According to Figures 810, S2 and S8 had very high concentrations of PM0.5 on all measurement days. Among these stations, S1 was the station where the light metro line started, and it had a high traffic of people both inside and outside the metro cars. In addition, considering that the area was a crowded area where large numbers of working people would be present, it may have been the first point of the spread of COVID-19 through the light metro system. The lowest PM0.5 concentrations were at S13 and S14 on all measurement days. These were the Emniyet and Sigorta stations.

According to these results, an infrared thermometer could be used at the entrance of the stations to prevent those with a fever from using the metro.

In Figure 11, the dark red zones show the very high relative humidity values at S6 among the 16 stations where the measurements were made on 8 February 2021. The lowest relative humidity values, shown in dark blue, were measured at S9, which was the Çallı station.

Figure 11 
               Spatial map of relative humidity (%) based on measurements on 8 February 2021 (indoor).
Figure 11

Spatial map of relative humidity (%) based on measurements on 8 February 2021 (indoor).

In Figure 12, the dark red zones show the very high relative humidity values at S15 among the 16 stations where the measurements were made on 22 February 2021. The lowest relative humidity values, shown in dark blue, were measured at S4.

Figure 12 
               Spatial map of relative humidity (%) based on measurements on 22 February 2021 (indoor).
Figure 12

Spatial map of relative humidity (%) based on measurements on 22 February 2021 (indoor).

In Figure 13, the dark red zones show the very high relative humidity values at S9, S10, S11, and S12 among the 16 stations where the measurements were made on 8 March 2021. Relative humidity could be high in these areas due to evaporation as they were close to the underground stream named Kırkgöz, which supplies the drinking water of Antalya, and the hydroelectric power plant, which is fed by Kırkgöz through canals. The lowest relative humidity values, shown in dark blue, were measured at S1, S2, and S3.

Figure 13 
               Spatial map of relative humidity (%) based on measurements on 8 March 2021 (indoor).
Figure 13

Spatial map of relative humidity (%) based on measurements on 8 March 2021 (indoor).

According to Figures 1113, the relative humidity values in the area were not similar on different measurement days.

In Figure 14, the dark red zones show the highest outside temperature values at S8 among the 16 stations where the measurements were made on 8 February 2021. The lowest temperature values, shown in light blue, were measured at S9.

Figure 14 
               Spatial map of outside temperature (°C) based on measurements on 8 February 2021.
Figure 14

Spatial map of outside temperature (°C) based on measurements on 8 February 2021.

In Figure 15, the dark red zones show the highest outside temperature values at S6 and S12 among the 16 stations where the measurements were made on 22 February 2021. The lowest temperature values were measured at S13 and S14.

Figure 15 
               Spatial map of outside temperature (°C) based on measurements on 22 February 2021.
Figure 15

Spatial map of outside temperature (°C) based on measurements on 22 February 2021.

In Figure 16, the dark red zones show the highest outside temperature values at S1 among the 16 stations where the measurements were made on 8 March 2021. The lowest temperature values, shown in blue, were measured at S9.

Figure 16 
               Spatial map of outside temperature (°C) based on measurements on 8 March 2021.
Figure 16

Spatial map of outside temperature (°C) based on measurements on 8 March 2021.

According to Figures 1416, S8, S6, S12, and S1 had the highest outside temperature measurements. No apparent relationship could be found between these temperature values and their spatial distributions. On the other hand, S9, S13, S14, and S9 had the lowest outside temperatures, with the lowest at S9, which was the Çallı station.

As shown in Figure 17, which shows the CO measurements made on 8 February (a), 22 February (b), and 8 March 2021 (c), the CO concentrations between S4 and S16 were very low, while the CO concentrations between S3 and S4 (Fatih and Vakıf Çiftliği stations) were very high. The reason for the high concentrations of CO in this area may be the industrial zone of Antalya and the ferrochromium factory at the location. Other spatial maps also showed that the areas with high CO concentrations also had high PM0.3 and PM0.5 concentrations.

Figure 17 
               Spatial maps of CO on 8 February (a), 22 February (b), and 8 March 2021 (c).
Figure 17

Spatial maps of CO on 8 February (a), 22 February (b), and 8 March 2021 (c).

Figure 18 shows the measurements of aerosols, which considerably affect air quality, made on 8 February (a), 22 February (b), and 8 March 2021 (c). The aerosol concentrations between S7 and S16 were very high. This was attributed to the high traffic of people in these areas due to their proximity to the city center.

Figure 18 
               Spatial maps of aerosols on 8 February (a), 22 February (b), and 8 March 2021 (c).
Figure 18

Spatial maps of aerosols on 8 February (a), 22 February (b), and 8 March 2021 (c).

Figure 19 shows the spatial maps of the NDVI values measured on 8 February (a), 22 February (b), and 8 March (c). It is seen that the area between S7 and S16 had a low amount of vegetation, and this was attributed to the proximity of the area to the city center. On the other hand, in seven areas between S3 and S7, a relatively higher amount of vegetation was observed. This result may be explained by the presence of an olive grove in the area consisting of several olive trees.

Figure 19 
               Spatial maps of NDVI on 8 February (a), 22 February (b), and 8 March 2021 (c).
Figure 19

Spatial maps of NDVI on 8 February (a), 22 February (b), and 8 March 2021 (c).

4 Discussion and conclusion

The following results were obtained based on the measurements that were made with difficulty in Antalya in Turkey on 8 February, 22 February, and 8 March 2021, when mask and social distancing rules were in place due to the COVID-19 pandemic.

  1. PM0.3 analysis results:

    According to Figures 57, S1, S2, and S3 had very high concentrations of PM0.3 on all measurement days. Among these stations, S1 was the station where the light metro line started, and it had a high traffic of people both inside and outside the metro cars. In addition, considering that the area was a crowded area where large numbers of working people would be present, it may have been the first point of the spread of COVID-19 through the light metro system. The lowest PM0.3 concentrations were at S13 and S14 on all measurement days. These were the Doğu Garajı and Burhanettin Onat stations, which were located right after the point where the light metro traffic connected to other lines, meaning that passenger traffic would be less.

  2. PM0.5 analysis results:

    According to Figures 810, S2 and S8 had very high concentrations of PM0.5 on all measurement days. Among these stations, S1 was the station where the light metro line started, and it had a high traffic of people both inside and outside the metro cars. In addition, considering that the area was a crowded area where large numbers of working people would be present, it may have been the first point of the spread of COVID-19 through the light metro system. The lowest PM0.5 concentrations were at S13 and S14 on all measurement days. These were the Emniyet and Sigorta stations.

  3. Outside temperature (°C) analysis results:

    According to Figures 1416, S8, S6, S12, and S1 had the highest outside temperature measurements. No apparent relationship could be found between these temperature values and their spatial distributions. On the other hand, S9, S13, S14, and S9 had the lowest outside temperatures, with the lowest at S9, which was the Çallı station. The spatial maps also did not show a meaningful relationship between outside temperature and PM0.3 or PM0.5 values.

  4. Relative humidity (%) analysis results:

    According to Figures 1113, the relative humidity values in the area were not similar on different measurement days.

  5. CO analysis results:

    As shown in Figure 17(a)–(c), the CO concentrations between S4 and S16 were very low, while the CO concentrations between S3 and S4 (Fatih and Vakıf Çiftliği stations) were very high. The reason for the high concentrations of CO in this area may be the industrial zone of Antalya and the ferrochromium factory at the location. Other spatial maps also showed that the areas with high CO concentrations also had high PM0.3 and PM0.5 concentrations, which could indicate a relationship.

  6. Aerosol analysis results:

    As shown in Figure 18(a)–(c), showing the measurements of aerosols, which considerably affect air quality, the aerosol concentrations between S7 and S16 were very high. This was attributed to the high traffic of people in these areas due to their proximity to the city center. Other spatial maps also showed increased PM0.3 and PM0.5 concentrations at these locations, indicating a relationship between aerosol and PM concentrations.

  7. NDVI analysis results:

    As shown in Figure 19, showing the spatial maps of NDVI values, the area between S7 and S16 had a low amount of vegetation, and this was attributed to the proximity of the area to the city center. On the other hand, in seven areas between S3 and S7, a relatively higher amount of vegetation was observed. This result may be explained by the presence of an olive grove in the area consisting of several olive trees. Moreover, in areas with low CO concentrations, vegetation was scarcer according to the NDVI values, and PM0.3 and PM0.5 concentrations were higher. This suggested a relationship among NDVI, CO, PM0.3, and PM0.5 values. It is seen that without conducting statistical analyses, the relationships among indoor air quality parameters can be observed using spatial maps.

According to the results of this study, it is recommended to use an infrared thermometer at the entrance of metro, tram, and train stations to prevent those with a fever from using these vehicles.

Metro systems are among the areas used by a large proportion of the population, where the comfort and health of passengers are affected by air quality parameters. Studies on air quality allow us to analyze human exposure to pollutants and calculate indoor air quality parameters, which can then be used to identify health risks and take precautions to protect public health. Such studies can be utilized as important tools to develop effective policies for reducing human exposure to aerosols in trams, metro, light rail, and train transportation systems.

The negative effects of PM, which is among indoor quality parameters, can be reduced in metro systems. The main issue here is to determine how to lower the PM concentrations in systems that involve the operation of metal wheels on metal rails. To reduce the concentrations of PM originating from the movement of the vehicle on the rails for older trains and metro systems, modifications such as automated brake systems, rubber tires, and air conditioning systems can be recommended. The usage of automated brake systems and rubber tires will not only reduce the concentrations of PM but also lower the levels of noise and sound that the passengers are exposed to. The implementation of these modifications in older metro systems might not always be economically and technologically viable. Using high-performance air conditioning systems is a highly effective method of eliminating PM accumulation. However, as seen in the example used in this study, in a global public health problem like the COVID-19 pandemic, the air conditioning systems of metro systems may be turned off to minimize the spread of viruses. Because these systems not only lower the PM concentrations inside metro cars but also provide the passengers with thermal comfort by providing optimal temperature and humidity conditions, it is recommended to use HEPA filters in air conditioning equipment used for metro systems. These filters can also be used in older transportation systems by modifying or replacing their existing air conditioning equipment. The greatest disadvantage of these systems is that they consume a lot of energy. Officials are recommended to ensure that the areas where dust can accumulate at locations where trains are maintained and repaired are cleaned regularly, the cleaning of trains, stations, and platforms, in general, is not overlooked, and PM concentrations at certain locations are regularly measured using appropriate devices.

It is recommended that field studies be carried out to investigate the effects of thermal parameters on perceived indoor air quality in terms of the exposure of passengers to various air pollutants in metro and tram cars, as well as underground stations and platforms. In addition, in underground stations, more attention should be paid to mechanical ventilation systems, including air filtering systems, by using an integrated building management system. These measures can improve the general indoor air quality in metro systems.

Previous studies on indoor air quality in metro systems have mostly compared field measurements to standard values. However, there is no study on how PM would be distributed in enclosed spaces, especially in metro, light metro, and tram systems during a global health crisis such as COVID-19. This is why it is believed that this study is unique. Furthermore, by taking the results of this study as a reference, it will be possible to create spatial maps of various indoor air quality parameters such as temperature, humidity, PM, and VOC for other areas where air quality is important, including residential buildings, hospitals, and shopping malls.

Considering that PM1 (1 μm) and smaller particles are small enough to enter the bloodstream of humans through the alveoli in their lungs, this study was planned to measure the concentrations of PM0.3 (0.3 µm) and PM0.5 (0.5 µm), which are smaller than PM1, as a pioneering study to investigate their effects on human health.

  1. Funding information: The author states no funding.

  2. Author contributions: The author confirms sole responsibility for the following: study conception and design, data collection, analysis and interpretation of results, and manuscript preparation.

  3. Conflict of interest: The authors declare no conflict of interest.

  4. Ethical approval: The conducted research is not related to either human or animal use.

  5. Data availability statement: The data used to support the findings of this study are available from the corresponding author upon request.

References

[1] Nieuwenhuijsen M, Gómez-Perales J, Colvile R. Levels of particulate air pollution, its elemental composition, determinants and health effects in metro systems. Atmos Environ. 2007;41:7995–8006. 10.1016/j.atmosenv.2007.08.002.Search in Google Scholar

[2] Xu B, Hao J. Air quality inside subway metro indoor environment worldwide: A review. Environ Int. 2017;107:33–46.10.1016/j.envint.2017.06.016Search in Google Scholar PubMed

[3] Mammi-Galani E, Eleftheriadis K, Mendes L, Lazaridis M. Exposure and dose to particulate matter inside the subway system of Athens, Greece. Air Qual Atmos Health. 2017;10(10):1015–28. 10.1007/s11869-017-0490-z.Search in Google Scholar

[4] Abanoz MS. İstanbul’da metrolarda iç hava kalitesine havalandırma sistemine etkisi. İstanbul Üniversitesi Cerrahpaşa Lisansüstü Eğitim Enstitüsü Çevre Mühendisliği anabilimdalı. İstanbul, TürkiyeHaziran: 2019.Search in Google Scholar

[5] Onat B. Metro istasyonları ile metro ve şehirlerarası tren vagonlarında iç hava kalitesi. Teskon 2015 İç Hava Kalitesi Semineri. İzmir, Türkiye; 2015.Search in Google Scholar

[6] Çoşgun A, Okuyan C. Antalya ilinde hafif raylı metro sisteminde partiküller maddelerin iç hava kalitesine etkisinin araştırılması ve modellenmesi. 1. Ulusal İklimlendirme Soğutma Eğitimi Sempozyumu. Balıkesir, Türkiye: 2012.Search in Google Scholar

[7] Onat B, Uzun B, Akın Ö, Şahin AÜ. Ulaşım araçları içinde ve dış ortamda siyah karbon ve partikül madde maruziyeti. Teskon 2017/İç Hava Kalitesi Sempozyumu. İzmir, Türkiye; 2017.Search in Google Scholar

[8] Korukcu MÖ. Otomobil kabininde termal parametrelerin ve iç hava kalitesinin değişiminin deneysel ölçümlerle incelenmesi. Doktora tezi, Uludağ Üniversitesi Fen Bilimleri Enstitüsü. Bursa, Türkiye: 2020.Search in Google Scholar

[9] MHSTŞ. Metro Havalandırma Sistemleri Teknik Şartname. İstanbul, Türkiye: 2018.Search in Google Scholar

[10] Tağıl Ş, Ersayın K. Balıkesir ilinde dış ortam termal konfor değerlendirmesi. J Int Soc Res. 2015;8(41):747–55.10.17719/jisr.20154115054Search in Google Scholar

[11] Tuncer K, Yılmaz E. Muğla ilinin aylık ortalama maksimum ve minimum hava sıcaklığı dağılışının ıdw yöntemiyle coğrafi bilgi sistemleri (cbs) ortamında haritalanması ve analizi. Akademi Sosyal Bilimler Dergisi. 2023;10(28):29–51.10.34189/asbd.10.28.003Search in Google Scholar

[12] Günaydın O. Balıkesir/Balya Hastanetepe bölgesi kurşun-çinko-gümüş yeraltı ocağı rezervinin jeoistatistik yöntemlerle değerlendirilmesi. Konya Teknik Üniversitesi, Yüksek Lisans Tezi; 2019.Search in Google Scholar

[13] Toros H, Bağış S, Gemici Z. Ankara’da hava kirliliği mekânsal dağılımının modellenmesi. Ulusal Çevre Bilimleri Araştırma Dergisi. 2018;1(1):20–53.10.21605/cukurovaummfd.357001Search in Google Scholar

[14] Rahman MH, Agarwal S, Sharma S, Suresh R, Kundu S, Vranckx S, et al. High-resolution mapping of air pollution in delhi using Detrended Kriging Model. Environ Model Assess. 2023;28(1):39–54.10.1007/s10666-022-09842-5Search in Google Scholar

[15] Gogeri I, Gouda KC, Aruna ST. Spatio-temporal analysis of air pollution dynamics over Bangalore city during the second wave of COVID-19. Nat Hazards Res. 2023;1–65.10.1016/j.nhres.2023.10.002Search in Google Scholar

[16] Nasehi S, Yavari A, Salehi E. Investigating the spatial distribution of land surface temperature as related to air pollution level in Tehran metropolis. Pollution. 2023;9(1):1–14.Search in Google Scholar

[17] Tang T, Fan H, Sun Q, Zhao W. Spatial and temporal analysis of daily measurements of PM2.5 Air Pollution in Beijing, China. J Geogr. 2023;11(1):1–42.Search in Google Scholar

[18] Račić N, Malvić T. Relation between air and soil pollution based on statistical analysis and interpolation of Nickel (Ni) and Lead (Pb): Case study of Zagreb, Croatia. Min Miner Depos. 2023;17(2):112–20.10.33271/mining17.02.112Search in Google Scholar

[19] Fadden MER. Respiratory heat and water exchange: physiological and clinical implications. J Appl Physiol Respir Env Exerc Physiol. 1983;54(2):331–6.10.1152/jappl.1983.54.2.331Search in Google Scholar PubMed

[20] Fang L, Clausen G, Fanger PO. Impact of temperature and humidity on perception. Indoor Air. 1998;8:80–90. 10.1111/j.1600-0668.1998.t01-2-00003.Search in Google Scholar

[21] IPCC Türkiye Raporu. National Inventory Report (NIS) - TURKEY Greenhouse Gas Inventory, 1990 to 2005. Ankara, Türkiye: 2007.Search in Google Scholar

[22] Haksevenler T. İstanbul’da farklı iç ortamlarda hava kalitesinin belirlenmesi. İstanbul Üniversitesi Fen Bilimleri Enstitüsü, Yüksek Lisans Tezi. İstanbul, Türkiye; 2010.Search in Google Scholar

[23] Wilson WE, Chow JC, Claiborn C, Fusheng W, Engelbrecht J, Warson JG. Monitoring of particulate matter outdoors. Chemosphere. 2002;49:1009–43.10.1016/S0045-6535(02)00270-9Search in Google Scholar PubMed

[24] Onat B, Stakeeva B. Assessment of fine particulate matters in the subway system of Istanbul. Indoor Built Env. 2014;23:574–83.10.1177/1420326X12464507Search in Google Scholar

[25] Onat B, Stakeeva B. Personal exposure of commuters in public transport to PM2. 5 and fine particle counts. Atmos Pollut Res. 2013;4(3):329–35.63.10.5094/APR.2013.037Search in Google Scholar

[26] Onat B, Şahin ÜA, Sivri N. The relationship between particle and culturable airborne bacteria concentrations in public transportation. Indoor Built Environ. 2017;26(10):1420–8.10.1177/1420326X16643373Search in Google Scholar

[27] Onat B, Şahin ÜA, Uzun B, Akın Ö, Özkaya F, Ayvaz C. Determinants of exposure to ultrafine particulate matter, black carbon, and PM2.5 in common travel modes in Istanbul. Atmos Environ. 2019;206:258–70.10.1016/j.atmosenv.2019.02.015Search in Google Scholar

[28] Lohmann U, Feichter J. Global indirect aerosol effects: A review. Atmos Chem Phys. 2005;5(3):715–37.10.5194/acp-5-715-2005Search in Google Scholar

[29] Kahraman O, Dündar C. Toz taşınımı olayının uzaktan algılama ve sayısal tahmin modeli ile analizi. Ege Coğrafya Dergisi. 2014;23(2):53–64. İzmir, Türkiye.Search in Google Scholar

[30] USEPA (2008). Characteristics of particles–Particle Size Categories. EPA.gov (Erişim Tarihi: 14.12.2023).Search in Google Scholar

[31] Passi A, Nagendra SMS, Maiya MP. Characteristics of indoor air quality in underground metro stations: A critical review. Build Environ. 2021;198:107907. 10.1016/j.buildenv.2021.107907.Search in Google Scholar

Received: 2023-12-26
Revised: 2024-01-24
Accepted: 2024-02-09
Published Online: 2024-04-01

© 2024 the author(s), published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

Articles in the same Issue

  1. Regular Articles
  2. Porous silicon nanostructures: Synthesis, characterization, and their antifungal activity
  3. Biochar from de-oiled Chlorella vulgaris and its adsorption on antibiotics
  4. Phytochemicals profiling, in vitro and in vivo antidiabetic activity, and in silico studies on Ajuga iva (L.) Schreb.: A comprehensive approach
  5. Synthesis, characterization, in silico and in vitro studies of novel glycoconjugates as potential antibacterial, antifungal, and antileishmanial agents
  6. Sonochemical synthesis of gold nanoparticles mediated by potato starch: Its performance in the treatment of esophageal cancer
  7. Computational study of ADME-Tox prediction of selected phytochemicals from Punica granatum peels
  8. Phytochemical analysis, in vitro antioxidant and antifungal activities of extracts and essential oil derived from Artemisia herba-alba Asso
  9. Two triazole-based coordination polymers: Synthesis and crystal structure characterization
  10. Phytochemical and physicochemical studies of different apple varieties grown in Morocco
  11. Synthesis of multi-template molecularly imprinted polymers (MT-MIPs) for isolating ethyl para-methoxycinnamate and ethyl cinnamate from Kaempferia galanga L., extract with methacrylic acid as functional monomer
  12. Nutraceutical potential of Mesembryanthemum forsskaolii Hochst. ex Bioss.: Insights into its nutritional composition, phytochemical contents, and antioxidant activity
  13. Evaluation of influence of Butea monosperma floral extract on inflammatory biomarkers
  14. Cannabis sativa L. essential oil: Chemical composition, anti-oxidant, anti-microbial properties, and acute toxicity: In vitro, in vivo, and in silico study
  15. The effect of gamma radiation on 5-hydroxymethylfurfural conversion in water and dimethyl sulfoxide
  16. Hollow mushroom nanomaterials for potentiometric sensing of Pb2+ ions in water via the intercalation of iodide ions into the polypyrrole matrix
  17. Determination of essential oil and chemical composition of St. John’s Wort
  18. Computational design and in vitro assay of lantadene-based novel inhibitors of NS3 protease of dengue virus
  19. Anti-parasitic activity and computational studies on a novel labdane diterpene from the roots of Vachellia nilotica
  20. Microbial dynamics and dehydrogenase activity in tomato (Lycopersicon esculentum Mill.) rhizospheres: Impacts on growth and soil health across different soil types
  21. Correlation between in vitro anti-urease activity and in silico molecular modeling approach of novel imidazopyridine–oxadiazole hybrids derivatives
  22. Spatial mapping of indoor air quality in a light metro system using the geographic information system method
  23. Iron indices and hemogram in renal anemia and the improvement with Tribulus terrestris green-formulated silver nanoparticles applied on rat model
  24. Integrated track of nano-informatics coupling with the enrichment concept in developing a novel nanoparticle targeting ERK protein in Naegleria fowleri
  25. Cytotoxic and phytochemical screening of Solanum lycopersicum–Daucus carota hydro-ethanolic extract and in silico evaluation of its lycopene content as anticancer agent
  26. Protective activities of silver nanoparticles containing Panax japonicus on apoptotic, inflammatory, and oxidative alterations in isoproterenol-induced cardiotoxicity
  27. pH-based colorimetric detection of monofunctional aldehydes in liquid and gas phases
  28. Investigating the effect of resveratrol on apoptosis and regulation of gene expression of Caco-2 cells: Unravelling potential implications for colorectal cancer treatment
  29. Metformin inhibits knee osteoarthritis induced by type 2 diabetes mellitus in rats: S100A8/9 and S100A12 as players and therapeutic targets
  30. Effect of silver nanoparticles formulated by Silybum marianum on menopausal urinary incontinence in ovariectomized rats
  31. Synthesis of new analogs of N-substituted(benzoylamino)-1,2,3,6-tetrahydropyridines
  32. Response of yield and quality of Japonica rice to different gradients of moisture deficit at grain-filling stage in cold regions
  33. Preparation of an inclusion complex of nickel-based β-cyclodextrin: Characterization and accelerating the osteoarthritis articular cartilage repair
  34. Empagliflozin-loaded nanomicelles responsive to reactive oxygen species for renal ischemia/reperfusion injury protection
  35. Preparation and pharmacodynamic evaluation of sodium aescinate solid lipid nanoparticles
  36. Assessment of potentially toxic elements and health risks of agricultural soil in Southwest Riyadh, Saudi Arabia
  37. Theoretical investigation of hydrogen-rich fuel production through ammonia decomposition
  38. Biosynthesis and screening of cobalt nanoparticles using citrus species for antimicrobial activity
  39. Investigating the interplay of genetic variations, MCP-1 polymorphism, and docking with phytochemical inhibitors for combatting dengue virus pathogenicity through in silico analysis
  40. Ultrasound induced biosynthesis of silver nanoparticles embedded into chitosan polymers: Investigation of its anti-cutaneous squamous cell carcinoma effects
  41. Copper oxide nanoparticles-mediated Heliotropium bacciferum leaf extract: Antifungal activity and molecular docking assays against strawberry pathogens
  42. Sprouted wheat flour for improving physical, chemical, rheological, microbial load, and quality properties of fino bread
  43. Comparative toxicity assessment of fisetin-aided artificial intelligence-assisted drug design targeting epibulbar dermoid through phytochemicals
  44. Acute toxicity and anti-inflammatory activity of bis-thiourea derivatives
  45. Anti-diabetic activity-guided isolation of α-amylase and α-glucosidase inhibitory terpenes from Capsella bursa-pastoris Linn.
  46. GC–MS analysis of Lactobacillus plantarum YW11 metabolites and its computational analysis on familial pulmonary fibrosis hub genes
  47. Green formulation of copper nanoparticles by Pistacia khinjuk leaf aqueous extract: Introducing a novel chemotherapeutic drug for the treatment of prostate cancer
  48. Improved photocatalytic properties of WO3 nanoparticles for Malachite green dye degradation under visible light irradiation: An effect of La doping
  49. One-pot synthesis of a network of Mn2O3–MnO2–poly(m-methylaniline) composite nanorods on a polypyrrole film presents a promising and efficient optoelectronic and solar cell device
  50. Groundwater quality and health risk assessment of nitrate and fluoride in Al Qaseem area, Saudi Arabia
  51. A comparative study of the antifungal efficacy and phytochemical composition of date palm leaflet extracts
  52. Processing of alcohol pomelo beverage (Citrus grandis (L.) Osbeck) using saccharomyces yeast: Optimization, physicochemical quality, and sensory characteristics
  53. Specialized compounds of four Cameroonian spices: Isolation, characterization, and in silico evaluation as prospective SARS-CoV-2 inhibitors
  54. Identification of a novel drug target in Porphyromonas gingivalis by a computational genome analysis approach
  55. Physico-chemical properties and durability of a fly-ash-based geopolymer
  56. FMS-like tyrosine kinase 3 inhibitory potentials of some phytochemicals from anti-leukemic plants using computational chemical methodologies
  57. Wild Thymus zygis L. ssp. gracilis and Eucalyptus camaldulensis Dehnh.: Chemical composition, antioxidant and antibacterial activities of essential oils
  58. 3D-QSAR, molecular docking, ADMET, simulation dynamic, and retrosynthesis studies on new styrylquinolines derivatives against breast cancer
  59. Deciphering the influenza neuraminidase inhibitory potential of naturally occurring biflavonoids: An in silico approach
  60. Determination of heavy elements in agricultural regions, Saudi Arabia
  61. Synthesis and characterization of antioxidant-enriched Moringa oil-based edible oleogel
  62. Ameliorative effects of thistle and thyme honeys on cyclophosphamide-induced toxicity in mice
  63. Study of phytochemical compound and antipyretic activity of Chenopodium ambrosioides L. fractions
  64. Investigating the adsorption mechanism of zinc chloride-modified porous carbon for sulfadiazine removal from water
  65. Performance repair of building materials using alumina and silica composite nanomaterials with electrodynamic properties
  66. Effects of nanoparticles on the activity and resistance genes of anaerobic digestion enzymes in livestock and poultry manure containing the antibiotic tetracycline
  67. Effect of copper nanoparticles green-synthesized using Ocimum basilicum against Pseudomonas aeruginosa in mice lung infection model
  68. Cardioprotective effects of nanoparticles green formulated by Spinacia oleracea extract on isoproterenol-induced myocardial infarction in mice by the determination of PPAR-γ/NF-κB pathway
  69. Anti-OTC antibody-conjugated fluorescent magnetic/silica and fluorescent hybrid silica nanoparticles for oxytetracycline detection
  70. Curcumin conjugated zinc nanoparticles for the treatment of myocardial infarction
  71. Identification and in silico screening of natural phloroglucinols as potential PI3Kα inhibitors: A computational approach for drug discovery
  72. Exploring the phytochemical profile and antioxidant evaluation: Molecular docking and ADMET analysis of main compounds from three Solanum species in Saudi Arabia
  73. Unveiling the molecular composition and biological properties of essential oil derived from the leaves of wild Mentha aquatica L.: A comprehensive in vitro and in silico exploration
  74. Analysis of bioactive compounds present in Boerhavia elegans seeds by GC-MS
  75. Homology modeling and molecular docking study of corticotrophin-releasing hormone: An approach to treat stress-related diseases
  76. LncRNA MIR17HG alleviates heart failure via targeting MIR17HG/miR-153-3p/SIRT1 axis in in vitro model
  77. Development and validation of a stability indicating UPLC-DAD method coupled with MS-TQD for ramipril and thymoquinone in bioactive SNEDDS with in silico toxicity analysis of ramipril degradation products
  78. Biosynthesis of Ag/Cu nanocomposite mediated by Curcuma longa: Evaluation of its antibacterial properties against oral pathogens
  79. Development of AMBER-compliant transferable force field parameters for polytetrafluoroethylene
  80. Treatment of gestational diabetes by Acroptilon repens leaf aqueous extract green-formulated iron nanoparticles in rats
  81. Development and characterization of new ecological adsorbents based on cardoon wastes: Application to brilliant green adsorption
  82. A fast, sensitive, greener, and stability-indicating HPLC method for the standardization and quantitative determination of chlorhexidine acetate in commercial products
  83. Assessment of Se, As, Cd, Cr, Hg, and Pb content status in Ankang tea plantations of China
  84. Effect of transition metal chloride (ZnCl2) on low-temperature pyrolysis of high ash bituminous coal
  85. Evaluating polyphenol and ascorbic acid contents, tannin removal ability, and physical properties during hydrolysis and convective hot-air drying of cashew apple powder
  86. Development and characterization of functional low-fat frozen dairy dessert enhanced with dried lemongrass powder
  87. Scrutinizing the effect of additive and synergistic antibiotics against carbapenem-resistant Pseudomonas aeruginosa
  88. Preparation, characterization, and determination of the therapeutic effects of copper nanoparticles green-formulated by Pistacia atlantica in diabetes-induced cardiac dysfunction in rat
  89. Antioxidant and antidiabetic potentials of methoxy-substituted Schiff bases using in vitro, in vivo, and molecular simulation approaches
  90. Anti-melanoma cancer activity and chemical profile of the essential oil of Seseli yunnanense Franch
  91. Molecular docking analysis of subtilisin-like alkaline serine protease (SLASP) and laccase with natural biopolymers
  92. Overcoming methicillin resistance by methicillin-resistant Staphylococcus aureus: Computational evaluation of napthyridine and oxadiazoles compounds for potential dual inhibition of PBP-2a and FemA proteins
  93. Exploring novel antitubercular agents: Innovative design of 2,3-diaryl-quinoxalines targeting DprE1 for effective tuberculosis treatment
  94. Drimia maritima flowers as a source of biologically potent components: Optimization of bioactive compound extractions, isolation, UPLC–ESI–MS/MS, and pharmacological properties
  95. Estimating molecular properties, drug-likeness, cardiotoxic risk, liability profile, and molecular docking study to characterize binding process of key phyto-compounds against serotonin 5-HT2A receptor
  96. Fabrication of β-cyclodextrin-based microgels for enhancing solubility of Terbinafine: An in-vitro and in-vivo toxicological evaluation
  97. Phyto-mediated synthesis of ZnO nanoparticles and their sunlight-driven photocatalytic degradation of cationic and anionic dyes
  98. Monosodium glutamate induces hypothalamic–pituitary–adrenal axis hyperactivation, glucocorticoid receptors down-regulation, and systemic inflammatory response in young male rats: Impact on miR-155 and miR-218
  99. Quality control analyses of selected honey samples from Serbia based on their mineral and flavonoid profiles, and the invertase activity
  100. Eco-friendly synthesis of silver nanoparticles using Phyllanthus niruri leaf extract: Assessment of antimicrobial activity, effectiveness on tropical neglected mosquito vector control, and biocompatibility using a fibroblast cell line model
  101. Green synthesis of silver nanoparticles containing Cichorium intybus to treat the sepsis-induced DNA damage in the liver of Wistar albino rats
  102. Quality changes of durian pulp (Durio ziberhinus Murr.) in cold storage
  103. Study on recrystallization process of nitroguanidine by directly adding cold water to control temperature
  104. Determination of heavy metals and health risk assessment in drinking water in Bukayriyah City, Saudi Arabia
  105. Larvicidal properties of essential oils of three Artemisia species against the chemically insecticide-resistant Nile fever vector Culex pipiens (L.) (Diptera: Culicidae): In vitro and in silico studies
  106. Design, synthesis, characterization, and theoretical calculations, along with in silico and in vitro antimicrobial proprieties of new isoxazole-amide conjugates
  107. The impact of drying and extraction methods on total lipid, fatty acid profile, and cytotoxicity of Tenebrio molitor larvae
  108. A zinc oxide–tin oxide–nerolidol hybrid nanomaterial: Efficacy against esophageal squamous cell carcinoma
  109. Research on technological process for production of muskmelon juice (Cucumis melo L.)
  110. Physicochemical components, antioxidant activity, and predictive models for quality of soursop tea (Annona muricata L.) during heat pump drying
  111. Characterization and application of Fe1−xCoxFe2O4 nanoparticles in Direct Red 79 adsorption
  112. Torilis arvensis ethanolic extract: Phytochemical analysis, antifungal efficacy, and cytotoxicity properties
  113. Magnetite–poly-1H pyrrole dendritic nanocomposite seeded on poly-1H pyrrole: A promising photocathode for green hydrogen generation from sanitation water without using external sacrificing agent
  114. HPLC and GC–MS analyses of phytochemical compounds in Haloxylon salicornicum extract: Antibacterial and antifungal activity assessment of phytopathogens
  115. Efficient and stable to coking catalysts of ethanol steam reforming comprised of Ni + Ru loaded on MgAl2O4 + LnFe0.7Ni0.3O3 (Ln = La, Pr) nanocomposites prepared via cost-effective procedure with Pluronic P123 copolymer
  116. Nitrogen and boron co-doped carbon dots probe for selectively detecting Hg2+ in water samples and the detection mechanism
  117. Heavy metals in road dust from typical old industrial areas of Wuhan: Seasonal distribution and bioaccessibility-based health risk assessment
  118. Phytochemical profiling and bioactivity evaluation of CBD- and THC-enriched Cannabis sativa extracts: In vitro and in silico investigation of antioxidant and anti-inflammatory effects
  119. Investigating dye adsorption: The role of surface-modified montmorillonite nanoclay in kinetics, isotherms, and thermodynamics
  120. Antimicrobial activity, induction of ROS generation in HepG2 liver cancer cells, and chemical composition of Pterospermum heterophyllum
  121. Study on the performance of nanoparticle-modified PVDF membrane in delaying membrane aging
  122. Impact of cholesterol in encapsulated vitamin E acetate within cocoliposomes
  123. Review Articles
  124. Structural aspects of Pt(η3-X1N1X2)(PL) (X1,2 = O, C, or Se) and Pt(η3-N1N2X1)(PL) (X1 = C, S, or Se) derivatives
  125. Biosurfactants in biocorrosion and corrosion mitigation of metals: An overview
  126. Stimulus-responsive MOF–hydrogel composites: Classification, preparation, characterization, and their advancement in medical treatments
  127. Electrochemical dissolution of titanium under alternating current polarization to obtain its dioxide
  128. Special Issue on Recent Trends in Green Chemistry
  129. Phytochemical screening and antioxidant activity of Vitex agnus-castus L.
  130. Phytochemical study, antioxidant activity, and dermoprotective activity of Chenopodium ambrosioides (L.)
  131. Exploitation of mangliculous marine fungi, Amarenographium solium, for the green synthesis of silver nanoparticles and their activity against multiple drug-resistant bacteria
  132. Study of the phytotoxicity of margines on Pistia stratiotes L.
  133. Special Issue on Advanced Nanomaterials for Energy, Environmental and Biological Applications - Part III
  134. Impact of biogenic zinc oxide nanoparticles on growth, development, and antioxidant system of high protein content crop (Lablab purpureus L.) sweet
  135. Green synthesis, characterization, and application of iron and molybdenum nanoparticles and their composites for enhancing the growth of Solanum lycopersicum
  136. Green synthesis of silver nanoparticles from Olea europaea L. extracted polysaccharides, characterization, and its assessment as an antimicrobial agent against multiple pathogenic microbes
  137. Photocatalytic treatment of organic dyes using metal oxides and nanocomposites: A quantitative study
  138. Antifungal, antioxidant, and photocatalytic activities of greenly synthesized iron oxide nanoparticles
  139. Special Issue on Phytochemical and Pharmacological Scrutinization of Medicinal Plants
  140. Hepatoprotective effects of safranal on acetaminophen-induced hepatotoxicity in rats
  141. Chemical composition and biological properties of Thymus capitatus plants from Algerian high plains: A comparative and analytical study
  142. Chemical composition and bioactivities of the methanol root extracts of Saussurea costus
  143. In vivo protective effects of vitamin C against cyto-genotoxicity induced by Dysphania ambrosioides aqueous extract
  144. Insights about the deleterious impact of a carbamate pesticide on some metabolic immune and antioxidant functions and a focus on the protective ability of a Saharan shrub and its anti-edematous property
  145. A comprehensive review uncovering the anticancerous potential of genkwanin (plant-derived compound) in several human carcinomas
  146. A study to investigate the anticancer potential of carvacrol via targeting Notch signaling in breast cancer
  147. Assessment of anti-diabetic properties of Ziziphus oenopolia (L.) wild edible fruit extract: In vitro and in silico investigations through molecular docking analysis
  148. Optimization of polyphenol extraction, phenolic profile by LC-ESI-MS/MS, antioxidant, anti-enzymatic, and cytotoxic activities of Physalis acutifolia
  149. Phytochemical screening, antioxidant properties, and photo-protective activities of Salvia balansae de Noé ex Coss
  150. Antihyperglycemic, antiglycation, anti-hypercholesteremic, and toxicity evaluation with gas chromatography mass spectrometry profiling for Aloe armatissima leaves
  151. Phyto-fabrication and characterization of gold nanoparticles by using Timur (Zanthoxylum armatum DC) and their effect on wound healing
  152. Does Erodium trifolium (Cav.) Guitt exhibit medicinal properties? Response elements from phytochemical profiling, enzyme-inhibiting, and antioxidant and antimicrobial activities
  153. Integrative in silico evaluation of the antiviral potential of terpenoids and its metal complexes derived from Homalomena aromatica based on main protease of SARS-CoV-2
  154. 6-Methoxyflavone improves anxiety, depression, and memory by increasing monoamines in mice brain: HPLC analysis and in silico studies
  155. Simultaneous extraction and quantification of hydrophilic and lipophilic antioxidants in Solanum lycopersicum L. varieties marketed in Saudi Arabia
  156. Biological evaluation of CH3OH and C2H5OH of Berberis vulgaris for in vivo antileishmanial potential against Leishmania tropica in murine models
Downloaded on 6.12.2025 from https://www.degruyterbrill.com/document/doi/10.1515/chem-2023-0208/html
Scroll to top button