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<front>
<journal-meta>
<journal-id journal-id-type="publisher-id">Front. Environ. Sci.</journal-id>
<journal-title>Frontiers in Environmental Science</journal-title>
<abbrev-journal-title abbrev-type="pubmed">Front. Environ. Sci.</abbrev-journal-title>
<issn pub-type="epub">2296-665X</issn>
<publisher>
<publisher-name>Frontiers Media S.A.</publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="publisher-id">768358</article-id>
<article-id pub-id-type="doi">10.3389/fenvs.2021.768358</article-id>
<article-categories>
<subj-group subj-group-type="heading">
<subject>Environmental Science</subject>
<subj-group>
<subject>Original Research</subject>
</subj-group>
</subj-group>
</article-categories>
<title-group>
<article-title>Estimation of Onsite Factors on Polycyclic Aromatic Hydrocarbon Particulate Buildup in Urban Road Networks</article-title>
<alt-title alt-title-type="left-running-head">Adak and Elumalai</alt-title>
<alt-title alt-title-type="right-running-head">Vehicle-Induced PAH Particulate Buildup</alt-title>
</title-group>
<contrib-group>
<contrib contrib-type="author" corresp="yes">
<name>
<surname>Adak</surname>
<given-names>Prasenjit</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
<xref ref-type="corresp" rid="c001">&#x2a;</xref>
<uri xlink:href="https://loop.frontiersin.org/people/1069569/overview"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname>Elumalai</surname>
<given-names>Suresh Pandian</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
</contrib-group>
<aff id="aff1">
<label>
<sup>1</sup>
</label>School of Chemical Engineering and Physical Sciences, Lovely Professional University, <addr-line>Jalandhar</addr-line>, <country>India</country>
</aff>
<aff id="aff2">
<label>
<sup>2</sup>
</label>Indian Institute of Technology (Indian School of Mines), <addr-line>Dhanbad</addr-line>, <country>India</country>
</aff>
<author-notes>
<fn fn-type="edited-by">
<p>
<bold>Edited by:</bold> <ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/1069007/overview">Abhrajyoti Tarafdar</ext-link>, Korea University, South Korea</p>
</fn>
<fn fn-type="edited-by">
<p>
<bold>Reviewed by:</bold> <ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/1464885/overview">Azadeh Tavakoli</ext-link>, University of Zanjan,&#x20;Iran</p>
<p>
<ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/1481857/overview">Sagnik Chakraborty</ext-link>, Jiangsu University, China</p>
</fn>
<corresp id="c001">&#x2a;Correspondence: Prasenjit Adak, <email>prasenjit.23966@lpu.co.in</email>
</corresp>
<fn fn-type="other">
<p>This article was submitted to Toxicology, Pollution and the Environment, a section of the journal Frontiers in Environmental Science</p>
</fn>
</author-notes>
<pub-date pub-type="epub">
<day>03</day>
<month>11</month>
<year>2021</year>
</pub-date>
<pub-date pub-type="collection">
<year>2021</year>
</pub-date>
<volume>9</volume>
<elocation-id>768358</elocation-id>
<history>
<date date-type="received">
<day>31</day>
<month>08</month>
<year>2021</year>
</date>
<date date-type="accepted">
<day>11</day>
<month>10</month>
<year>2021</year>
</date>
</history>
<permissions>
<copyright-statement>Copyright &#xa9; 2021 Adak and Elumalai.</copyright-statement>
<copyright-year>2021</copyright-year>
<copyright-holder>Adak and Elumalai</copyright-holder>
<license xlink:href="http://creativecommons.org/licenses/by/4.0/">
<p>This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these&#x20;terms.</p>
</license>
</permissions>
<abstract>
<p>Soil samples from the urban road and roadside often exhibit a high concentration of polycyclic aromatic hydrocarbons (PAHs). This contamination is attributed to vehicular exhaust emissions. After their release into the atmosphere, the PAH particulate matter eventually is deposited on the surface of the road and its surrounding areas. In order to develop a theoretical approach to quantify and predict the transport of PAH particulates from the atmosphere to the roadside soil, the estimation of particulate buildup in the atmosphere is a prerequisite. In the present study, empirical and temporal expressions of particulate buildup in the atmosphere have been developed. The developed site-specific expressions, coupled with other non&#x2013;site-specific expressions can be used for indirect estimation of PAH particulate load in the soil of urban road networks.</p>
</abstract>
<kwd-group>
<kwd>vehicular exhaust</kwd>
<kwd>transport of PAHs</kwd>
<kwd>soil contamination</kwd>
<kwd>wet deposition</kwd>
<kwd>dispersion model</kwd>
</kwd-group>
</article-meta>
</front>
<body>
<sec id="s1">
<title>1 Introduction</title>
<p>Polycyclic aromatic hydrocarbons (PAHs) are considered significant contributors to cancer and tumors in human beings (<xref ref-type="bibr" rid="B6">IARC, 2010</xref>). It has been reported that dermal contact with PAH-contaminated soil can be potentially hazardous for human health, as it is one of the major exposure pathways of PAHs to the human body (<xref ref-type="bibr" rid="B27">Tarafdar and Sinha, 2017a</xref>). It was observed that soil samples collected from busy traffic sites contain a significant amount of PAHs (<xref ref-type="bibr" rid="B28">Tarafdar and Sinha, 2017b</xref>). It has also been revealed that vehicular emission is one of the most important sources of PAHs in roadside soil (<xref ref-type="bibr" rid="B26">Suman et&#x20;al., 2016</xref>). The suspended particulate matter (SPM) containing PAHs gets released from the tailpipes of the automobiles and eventually gets deposited into the soil. Another major cause of PAH contamination in the soil is wet deposition of SPM in the atmosphere. Therefore, proper quantification of SPM buildup in the atmosphere can provide crucial insights into the transport of PAHs from the atmosphere to the&#x20;soil.</p>
<p>Several studies have revealed that residing near highways and major urban roadways results in adverse impacts on human health, including respiratory problems (<xref ref-type="bibr" rid="B13">McCreanor et&#x20;al., 2007</xref>), birth defects and developmental issues (<xref ref-type="bibr" rid="B31">Wilhelm and Ritz, 2003</xref>), untimely death (<xref ref-type="bibr" rid="B8">Krewski et&#x20;al., 2009</xref>), cardiovascular issues (<xref ref-type="bibr" rid="B19">Peters et&#x20;al., 2004</xref>; <xref ref-type="bibr" rid="B21">Riediker et&#x20;al., 2004</xref>), and cancer (<xref ref-type="bibr" rid="B5">Harrison et&#x20;al., 1999</xref>; <xref ref-type="bibr" rid="B18">Pearson et&#x20;al., 2000</xref>). These traffic-induced health risks can be the results of both short-term and long-term exposure to PM (<xref ref-type="bibr" rid="B8">Krewski et&#x20;al., 2009</xref>; <xref ref-type="bibr" rid="B13">McCreanor et&#x20;al., 2007</xref>).</p>
<p>It was reported that the traffic parameters and the traffic facilities have a significant influence on vehicular emission (<xref ref-type="bibr" rid="B4">Gokhale and Pandian 2007</xref>; <xref ref-type="bibr" rid="B16">Pandian et&#x20;al., 2009</xref>). Concentrations of traffic-related air pollutants show strong spatial patterns (<xref ref-type="bibr" rid="B22">Roorda-Knape et&#x20;al., 1998</xref>; <xref ref-type="bibr" rid="B2">Funasaka et&#x20;al., 2000</xref>; <xref ref-type="bibr" rid="B7">Kingham et&#x20;al., 2000</xref>; <xref ref-type="bibr" rid="B34">Zhu et&#x20;al., 2002</xref>). A review by the World Health Organization (<xref ref-type="bibr" rid="B32">WHO, 2005</xref>) concluded that concentrations of oxides of nitrogen (NO<sub>x</sub>), black smoke, and particles less than 10&#xa0;&#x3bc;m (PM10) within 200&#x2013;500&#xa0;m of roadways far exceeded the urban background; particles less than 2.5&#xa0;&#x3bc;m (PM2.5) and PM10 had somewhat higher concentrations than the urban background. However, vehicular emission is not the sole determining factor of ambient air quality. Air quality (more specifically the ambient concentration of pollutants) of any road network is a function of onsite and non&#x2013;traffic-related meteorological parameters which have significant temporal variability.</p>
<p>Generally, the prime focus of the line source dispersion model is to explore the spatial dispersion of the vehicle-induced pollutants. The temporal distribution of the pollutants, especially, in context of dry and wet deposition, is often not integrated into the line source models. Therefore, the gradual buildup of pollutant concentrations in the atmosphere after natural removal of the pollutants is often not recognized by the models. Temporal patterns can be dramatic since traffic quantities (and congestion), as well as meteorological factors affecting the dispersion of pollutants, are substantially related to the time of the day, day of the week, and/or season (<xref ref-type="bibr" rid="B23">Roosli et&#x20;al., 2001</xref>; <xref ref-type="bibr" rid="B12">Martuzevicius et&#x20;al., 2004</xref>).</p>
<p>Dispersion models can capture the variability of the pollutant concentration as the effect of mobile sources in the urban road networks and roadside environment. Near-surface dispersion models are widely used for dispersion studies at on road and roadside areas. Two classic examples of near-road dispersion models are the general finite line source model (GFLSM) (<xref ref-type="bibr" rid="B9">Luhar and Patil, 1989</xref>) and R-Line model (<xref ref-type="bibr" rid="B25">Snyder et&#x20;al., 2013</xref>). Both the models are based on a steady-state Gaussian formulation and are designed to simulate the ambient pollutant concentration using line-type source emissions. However, the GFLSM does not account for dynamic change in the pollutant concentration in ambient air and particulate buildup. In order to eliminate this limitation, site-specific, time-dependent, and non&#x2013;traffic-related variables are required to incorporate into the model. The GFLSM was modified to incorporate a temporal term to address the particulate buildup in ambient air of the vehicle-dominated&#x20;sites.</p>
<p>In the present study, a site-specific and temporal expression of the particulate buildup in the atmosphere of the urban road network has been studied which, coupled with wet deposition, can serve as an indirect measure to quantify the PAH particulate concentration in the soil of the roadside and the area in close vicinity.</p>
</sec>
<sec id="s2">
<title>2 Materials and Methods</title>
<sec id="s2-1">
<title>2.1 Study Area</title>
<p>Dhanbad was designated by the Central Pollution Control Board (CPCB, 2009) as one of the 24 critically polluted areas in India. Being designated as the &#x201c;coal capital of India,&#x201d; Dhanbad experiences a huge flow of daily traffic and, hence, an increased level of pollutant load, especially in occupational areas. Most of these occupational sites are located beside (mostly at intersections) National Highway 32 or NH-32 (presently National Highway 18), as it is the most important roadway of Dhanbad. Part of NH-32 located in Dhanbad experiences a dual mode of traffic activities. A portion of the road falls into a dense commercial area, and another portion is in a less dense area and in close vicinity of another national highway, namely, NH-2 (presently National Highway&#x20;19).</p>
<p>NH-32, which traverses through the study area, connects it with Bokaro Steel City and Chas on one side and with NH-2 on the northeastern side. This city is connected to other major cities such as Patna via NH-2, Ranchi via NH-32, and Jamshedpur via SH-12. Barwadda road is another important road that provides connectivity to NH-2. Jharia road, also known as SH-12, runs toward the south connecting the study area with Purulia and&#x20;Chas.</p>
<p>NH-32 connects Govindpur in Dhanbad districts with Jamshedpur in the East Singhbhum district in Jharkhand. The total length of NH-32 is 179&#xa0;km. It originates from the intersection of NH-2 at Govindpur. A 13-km long road segment up to Bank More covering a large and populated part of Dhanbad city is selected for the present study (<xref ref-type="fig" rid="F1">Figure&#x20;1</xref>). A total of 10 monitoring points on the study road segment were selected to record the traffic activities (<xref ref-type="fig" rid="F1">Figure&#x20;1</xref>) and (<xref ref-type="sec" rid="s9">Supplementary Table S1</xref>). The reason for selecting the monitoring stations is their importance as commercial sites. Some onsite observations at the monitoring sites and notable traffic activities have been tabulated in <xref ref-type="sec" rid="s9">Supplementary Table S3</xref>. Large crowds are often observed at the selected sites. The presence of PAH particulates in the soil and atmosphere of these locations may lead to significant exposure of PAH to the public.</p>
<fig id="F1" position="float">
<label>FIGURE 1</label>
<caption>
<p>Road map of the study route and location of the monitoring points (base map source: <ext-link ext-link-type="uri" xlink:href="https://www.openstreetmap.org">https://www.openstreetmap.org</ext-link>).</p>
</caption>
<graphic xlink:href="fenvs-09-768358-g001.tif"/>
</fig>
</sec>
<sec id="s2-2">
<title>2.2 Methodology</title>
<sec id="s2-2-1">
<title>2.2.1 Data Collection</title>
<p>To study the near-road dispersion and the role of local source contribution, particulate matter (PM) was selected as the key pollutant. Additionally, carbon monoxide (CO) has been used as a reference gas for comparing the performances of the dispersion models in order to support the decision of model selection. The source of CO in near-road ambient air is mainly vehicular emission. As a result, the outcome of the dispersion study is more prone to yield accurate results than the pollutants (such as PM) with additional non&#x2013;traffic-related sources. The measurement of CO and PM concentrations was carried out at the predefined monitoring locations (<xref ref-type="sec" rid="s9">Supplementary Table S1</xref>) on NH-32. To study the pollutant buildup in the atmosphere, winter rainfall was considered to be a suitable monitoring time. Monitoring was carried out during winter before the first winter rainfall, immediately after the last rainfall, and at specified intervals afterward (1, 2, 7, 15, and 30&#xa0;days after rainfall). The measurement of CO was performed using a CO meter (make: KIMO, model: AQ 200), and the measurement of PM was carried out using an aerosol spectrophotometer (make: GRIMM, model: 1.109). The duration of data collection was 1&#xa0;h for both pollutants. The data collection was performed at the highest possible data collection frequency of the instruments (1 data point per 6&#xa0;s in case of CO, and 1 data point per second in case of PM). The ERs of CO were obtained using a flue gas analyzer (HORIBA, CVS-51S). The emission rate (ER) of PM10, PM2.5, and PM1 was obtained using the <xref ref-type="bibr" rid="B17">PART5 (1995)</xref> emission&#x20;model.</p>
</sec>
<sec id="s2-2-2">
<title>2.2.2 Dispersion Models</title>
<p>The concentration of gaseous matter and PM was estimated for all the sites considered in the present study with the help of the GFLSM and R-Line dispersion model. Both the models are based on a steady-state Gaussian formulation and are designed to simulate the ambient pollutant concentration using line-type source emissions. The GFLSM was developed by <xref ref-type="bibr" rid="B9">Luhar and Patil (1989)</xref>. This model is based on Gaussian diffusion equations and modified to take the diversity of wind direction into account. Unlike the GM, this model does not consider an infinite length of the roadway. The GFLSM was extensively used by many researchers (<xref ref-type="bibr" rid="B1">Banerjee et&#x20;al., 2011</xref>; <xref ref-type="bibr" rid="B3">Ganguly and Broderick 2008</xref>; <xref ref-type="bibr" rid="B30">Wang et&#x20;al., 2006</xref>; <xref ref-type="bibr" rid="B14">Mishra et&#x20;al., 2016</xref>; <xref ref-type="bibr" rid="B20">Rajput et&#x20;al., 2019</xref>; <xref ref-type="bibr" rid="B10">Madhavan and Geetha, 2021</xref>; <xref ref-type="bibr" rid="B24">Sangeetha and Amudha, 2021</xref>). It was reported that the GFLSM performs better than the GM, CALINE3, and Highway-2 due to the finite length consideration. Moreover, due to the simplicity and flexibility of this model, it is appropriate to be integrated with other models, such as traffic flow simulation models (<xref ref-type="bibr" rid="B35">Drag and Wojciech, 2009</xref>). The Research LINE-source (R-LINE) (v1.2) model was developed by the U.S. EPA in the 2010s which is a steady-state dispersion model for line sources (<xref ref-type="bibr" rid="B25">Synder et&#x20;al., 2013</xref>). It was developed for predicting mobile source air quality impacts near roadways. It is frequently used in simulating dispersion processes, but only in the simulation of the physical processes and not chemical processes. Clearly, it accounts only for primary and chemically inert pollutants. The R-LINE model takes meteorologic parameters as inputs, such as wind speed, wind direction, Monin&#x2013;Obukhov length for turbulence, and surface friction velocity. However, it does not consider the impact of wet deposition (e.g., due to precipitation) or non-linear chemical transformation (<xref ref-type="bibr" rid="B29">Venkatram et&#x20;al., 2013</xref>). The concentration from a finite line source in the R-LINE model is estimated by approximating the line as a series of point sources. The number of points needed for convergence to the proper solution is determined by the model and, in particular, is a function of the distance from the source line to the receptor. Each point source is simulated using a Gaussian plume formulation. The GFLSM was executed for each of the sites using a site-specific ER of gaseous pollutants and particulates separately. The meteorological parameters (wind speed and wind direction) were collected from the Meteorological and Oceanographic Satellite Data Archival Center (MOSDAC) meteorological data repository. The dispersion coefficients (&#x3c3;y and &#x3c3;z) were calculated using Martin&#x2019;s equations (<xref ref-type="disp-formula" rid="e1">Eq. 1</xref> and <xref ref-type="disp-formula" rid="e2">Eq. 2</xref>) (<xref ref-type="bibr" rid="B11">Martin, 1976</xref>).<disp-formula id="e1">
<mml:math id="m1">
<mml:mrow>
<mml:msub>
<mml:mi>&#x3c3;</mml:mi>
<mml:mi>y</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>a</mml:mi>
<mml:msup>
<mml:mi>x</mml:mi>
<mml:mi>b</mml:mi>
</mml:msup>
<mml:mo>,</mml:mo>
</mml:mrow>
</mml:math>
<label>(1)</label>
</disp-formula>
<disp-formula id="e2">
<mml:math id="m2">
<mml:mrow>
<mml:msub>
<mml:mi>&#x3c3;</mml:mi>
<mml:mi>y</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>c</mml:mi>
<mml:msup>
<mml:mi>x</mml:mi>
<mml:mi>d</mml:mi>
</mml:msup>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>f</mml:mi>
<mml:mo>,</mml:mo>
</mml:mrow>
</mml:math>
<label>(2)</label>
</disp-formula>where <italic>a</italic>, <italic>b</italic>, <italic>c</italic>, <italic>d</italic>, and <italic>f</italic> are stability-dependent constants. The values of <italic>a, b, c, d,</italic> and <italic>f</italic> are tabulated in <xref ref-type="table" rid="T1">Table&#x20;1</xref>.</p>
<table-wrap id="T1" position="float">
<label>TABLE 1</label>
<caption>
<p>Values of <italic>a, b, c, d,</italic> and <italic>f</italic> for <italic>&#x3c3;</italic>
<sub>
<italic>y</italic>
</sub> and <italic>&#x3c3;</italic>
<sub>
<italic>z</italic>
</sub> for different stability conditions (<xref ref-type="bibr" rid="B11">Martin, 1976</xref>).</p>
</caption>
<table>
<thead valign="top">
<tr>
<th align="left">Stability class</th>
<th align="center">a</th>
<th align="center">b</th>
<th align="center">c</th>
<th align="center">d</th>
<th align="center">f</th>
</tr>
</thead>
<tbody valign="top">
<tr>
<td align="left">A</td>
<td align="char" char=".">213</td>
<td align="char" char=".">0.894</td>
<td align="char" char=".">440.8</td>
<td align="char" char=".">1.041</td>
<td align="char" char=".">9.27</td>
</tr>
<tr>
<td align="left">B</td>
<td align="char" char=".">156</td>
<td align="char" char=".">0.894</td>
<td align="char" char=".">106.6</td>
<td align="char" char=".">1.149</td>
<td align="char" char=".">3.3</td>
</tr>
<tr>
<td align="left">C</td>
<td align="char" char=".">104</td>
<td align="char" char=".">0.894</td>
<td align="char" char=".">61</td>
<td align="char" char=".">0.911</td>
<td align="char" char=".">0</td>
</tr>
<tr>
<td align="left">D</td>
<td align="char" char=".">68</td>
<td align="char" char=".">0.894</td>
<td align="char" char=".">33.2</td>
<td align="char" char=".">0.725</td>
<td align="char" char=".">-1.7</td>
</tr>
<tr>
<td align="left">E</td>
<td align="char" char=".">50.5</td>
<td align="char" char=".">0.894</td>
<td align="char" char=".">22.8</td>
<td align="char" char=".">0.678</td>
<td align="char" char=".">-1.3</td>
</tr>
<tr>
<td align="left">F</td>
<td align="char" char=".">34</td>
<td align="char" char=".">0.894</td>
<td align="char" char=".">14.35</td>
<td align="char" char=".">0.74</td>
<td align="char" char=".">-0.35</td>
</tr>
</tbody>
</table>
</table-wrap>
<p>The R-Line model uses the pre-processed surface meteorological data files generated by AERMET (a meteorological pre-processor of AERMOD). The raw meteorological files (in SCRAM format) were used as the input of AERMET. The raw meteorological data were obtained from the MOSDAC meteorological data repository. The dispersion study for PM was carried out using the site-specific ER-derived emission model Part-5. The derived concentration data for CO and particulates were then compared with the observed concentration of CO and particulates.</p>
<p>In order to study the particulate buildup in the atmosphere, the dispersion study was carried out in regular intervals after rainfall. The ERs of PM10, PM2.5, and PM1 from the traffic sources were assumed to be constant over time. The dispersion model GFLSM was used to estimate the pollutant concentration. The relationship between the particulate concentration and the time elapsed after rainfall was established.</p>
</sec>
<sec id="s2-2-3">
<title>2.2.3 Modification in the General Finite Line Source Model</title>
<p>The dispersion model GFLSM was modified to address the particulate buildup in the atmosphere by incorporating a temporal term in the governing equation (<xref ref-type="disp-formula" rid="e3">Eq. 3</xref>) (<xref ref-type="bibr" rid="B9">Luhar and Patil, 1989</xref>). The derived relationship between the particulate concentration in ambient air and the time elapsed after rainfall was primarily observed to be logarithmic. Again, the ER was considered uniform over time, and on the other hand, the GFLSM is a steady-state dispersion model; the concentration value directly derived from the GFLSM was considered the non-incremental term of the observed relationship (<xref ref-type="disp-formula" rid="e4">Eq. 4</xref>). The incremental term was considered to be attributed to the background level of particulates in ambient air. In order to quantify the particulate buildup in ambient air of road networks in Dhanbad, the coefficients of the incremental term were defined to be site-specific and non&#x2013;traffic-associated parameters.<disp-formula id="e3">
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<mml:mtable groupalign="decimalpoint">
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<mml:mi>C</mml:mi>
<mml:mrow>
<mml:mi>G</mml:mi>
<mml:mi>F</mml:mi>
<mml:mi>L</mml:mi>
<mml:mi>S</mml:mi>
<mml:mi>M</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mi>Q</mml:mi>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:msqrt>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:mi>&#x3c0;</mml:mi>
</mml:mrow>
</mml:msqrt>
<mml:msub>
<mml:mi>&#x3c3;</mml:mi>
<mml:mi>z</mml:mi>
</mml:msub>
<mml:msub>
<mml:mrow>
<mml:mover accent="true">
<mml:mi>u</mml:mi>
<mml:mo>&#xaf;</mml:mo>
</mml:mover>
</mml:mrow>
<mml:mi>e</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfrac>
<mml:mrow>
<mml:mo>[</mml:mo>
<mml:mrow>
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</disp-formula>where <italic>C</italic>
<sub>
<italic>GFLSM</italic>
</sub> is the concentration of pollutants in ambient air (estimated with the GFLSM); <italic>Q</italic> is the vehicular ER; <italic>u</italic>
<sub>
<italic>e</italic>
</sub> is the wind speed; <italic>z</italic> is the receptor height; <italic>h</italic>
<sub>
<italic>0</italic>
</sub> is the plume rise; &#x3b8; is the wind direction; <italic>L</italic> is the length of the road segment; <italic>y</italic> is the receptor distance from the roadway center line along the line source; <italic>x</italic> is the downwind distance; <italic>C</italic>
<sub>
<italic>MGFLSM</italic>
</sub> is the concentration of pollutants in ambient air (after the modification in the GFLSM); <italic>a</italic> is the site-specific non&#x2013;traffic-associated parameter; and <italic>t</italic>
<sub>
<italic>rain</italic>
</sub> is the time elapsed after rainfall in&#x20;days.</p>
</sec>
</sec>
</sec>
<sec sec-type="results|discussion" id="s3">
<title>3 Results and Discussion</title>
<p>The results of the dispersion study are displayed and discussed in this section. First, the inter-comparison between the performance of the GFLSM and R-Line model is presented. The observed concentration and temporal variability of PM10, PM2.5, and PM1 are displayed.</p>
<p>The estimated and observed values of CO concentration in ambient air at different sites of Dhanbad road networks are depicted in <xref ref-type="fig" rid="F2">Figure&#x20;2</xref>. It can be observed that the highest concentration of CO was at SC for both observed data and estimated data (GFLSM and R-Line). The lowest observed concentration of CO was at ISM and BB, and on the other hand, the lowest value of CO concentration estimated with the GFLSM and R-Line was found at BB and GP, respectively. The R-Line model overestimated the CO concentration at most of the sites (except CC). The concentration of CO was underestimated by the GFLSM at BM, SC, STN, CC, and RVC, but the same was overestimated at HP, ISM, SG, BB, and GP. The observed concentration of CO was found to be above the national ambient air quality standards (NAAQS, 2009) at BM, SC, and CC. The CO concentration estimated with the GFLSM followed the same trend in this aspect, but in the case of the R-Line model, BM, SC, STN, and CC were above the NAAQS limit of&#x20;CO.</p>
<fig id="F2" position="float">
<label>FIGURE 2</label>
<caption>
<p>Estimated and observed values of CO concentration in ambient air at different sites of Dhanbad road networks.</p>
</caption>
<graphic xlink:href="fenvs-09-768358-g002.tif"/>
</fig>
<p>The comparison between the performance of the GFLSM and R-Line model is depicted in <xref ref-type="fig" rid="F3">Figure&#x20;3</xref>. It can be observed that the general tendency of the GFLSM was to underestimate the ambient concentration of CO, whereas the tendency of the R-Line model was to overestimate it. It can also be observed that the GFLSM produces better estimates of CO concentration than the R-Line&#x20;model.</p>
<fig id="F3" position="float">
<label>FIGURE 3</label>
<caption>
<p>Comparison between the performance of the GFLSM and R-Line&#x20;model.</p>
</caption>
<graphic xlink:href="fenvs-09-768358-g003.tif"/>
</fig>
<sec id="s3-1">
<title>3.1 Particulate Buildup in the Atmosphere</title>
<p>
<xref ref-type="fig" rid="F4">Figures 4A&#x2013;J</xref> depicts the concentration of PM10, PM2.5, and PM1 at different sites in Dhanbad road networks at specified time intervals after rainfall. It can be observed that in all sites, the concentration of ambient PM increased significantly. A similar trend was observed by <xref ref-type="bibr" rid="B33">Yoo et&#x20;al. (2020)</xref>. The researchers investigated the impacts of the meteorological conditions on the concentration of PM10 and PM2.5. Although the researchers of the aforementioned study observed the increment of PM concentration within the days after rainfall, any well-defined relationship was not established. Another study by <xref ref-type="bibr" rid="B15">Olszowski (2016)</xref> demonstrated the gradual increment of PM10 concentration with time elapsed after rainfall. However, the temporal resolution of the present study is different from that of the aforementioned study. In the present study, a logarithmic relationship between the PM concentrations and the days after rainfall was observed. The coefficients of the logarithmic term and the intercept of the site-specific relationship between particulate concentration in ambient air and time elapsed after rainfall are tabulated in <xref ref-type="table" rid="T2">Table&#x20;2</xref>. The increments were likely to be attributed to the local non&#x2013;traffic-related sources and local meteorological parameters that cause the buildup of PM in ambient air. The buildup tendency was observed to be the highest in the case of PM10 at all sites followed by PM2.5 and PM10. At most of the sites, the difference between the particulate concentration in ambient air before rainfall and after 30&#x20;days from rainfall was observed to be negligible (<xref ref-type="fig" rid="F5">Figure&#x20;5</xref>; <xref ref-type="sec" rid="s9">Supplementary Table&#x20;S2</xref>).</p>
<fig id="F4" position="float">
<label>FIGURE 4</label>
<caption>
<p>Concentration buildup of PM10, PM2.5, and PM1 after rainfall at different sites in Dhanbad road networks [<bold>(A)</bold> BM, <bold>(B)</bold> SC, <bold>(C)</bold> STN, <bold>(D)</bold> CC, <bold>(E)</bold> RVC, <bold>(F)</bold> HP, <bold>(G)</bold> ISM, <bold>(H)</bold> SG, <bold>(I)</bold> BB, and <bold>(J)</bold> GP].</p>
</caption>
<graphic xlink:href="fenvs-09-768358-g004.tif"/>
</fig>
<table-wrap id="T2" position="float">
<label>TABLE 2</label>
<caption>
<p>Coefficients of the logarithmic term and the intercept of the site-specific relationship between particulate concentration in ambient air and time elapsed after rainfall.</p>
</caption>
<table>
<thead valign="top">
<tr>
<th rowspan="2" align="left"/>
<th colspan="2" align="center">PM10</th>
<th colspan="2" align="center">PM2.5</th>
<th colspan="2" align="center">PM1</th>
</tr>
<tr>
<th align="center">a<sub>(MGFLSM)</sub>
</th>
<th align="center">c</th>
<th align="center">a</th>
<th align="center">c</th>
<th align="center">a</th>
<th align="center">c</th>
</tr>
</thead>
<tbody valign="top">
<tr>
<td align="left">BM</td>
<td align="char" char=".">175</td>
<td align="char" char=".">104.7</td>
<td align="char" char=".">56.39</td>
<td align="char" char=".">78.87</td>
<td align="char" char=".">31.5</td>
<td align="char" char=".">74.84</td>
</tr>
<tr>
<td align="left">SC</td>
<td align="char" char=".">181.61</td>
<td align="char" char=".">79.5</td>
<td align="char" char=".">82</td>
<td align="char" char=".">62.34</td>
<td align="char" char=".">60.92</td>
<td align="char" char=".">62.56</td>
</tr>
<tr>
<td align="left">STN</td>
<td align="char" char=".">204.2</td>
<td align="char" char=".">154.7</td>
<td align="char" char=".">47.57</td>
<td align="char" char=".">79.47</td>
<td align="char" char=".">24.94</td>
<td align="char" char=".">66.56</td>
</tr>
<tr>
<td align="left">CC</td>
<td align="char" char=".">131.31</td>
<td align="char" char=".">119</td>
<td align="char" char=".">37.4</td>
<td align="char" char=".">83.12</td>
<td align="char" char=".">22.48</td>
<td align="char" char=".">74.91</td>
</tr>
<tr>
<td align="left">RVC</td>
<td align="char" char=".">138.8</td>
<td align="char" char=".">96.21</td>
<td align="char" char=".">68.04</td>
<td align="char" char=".">69.54</td>
<td align="char" char=".">55.32</td>
<td align="char" char=".">63.56</td>
</tr>
<tr>
<td align="left">HP</td>
<td align="char" char=".">154.5</td>
<td align="char" char=".">159.5</td>
<td align="char" char=".">50.54</td>
<td align="char" char=".">82.56</td>
<td align="char" char=".">26.24</td>
<td align="char" char=".">68.06</td>
</tr>
<tr>
<td align="left">ISM</td>
<td align="char" char=".">92.53</td>
<td align="char" char=".">101</td>
<td align="char" char=".">36.21</td>
<td align="char" char=".">75.66</td>
<td align="char" char=".">24.36</td>
<td align="char" char=".">70.52</td>
</tr>
<tr>
<td align="left">SG</td>
<td align="char" char=".">193.8</td>
<td align="char" char=".">157.6</td>
<td align="char" char=".">47.18</td>
<td align="char" char=".">78.18</td>
<td align="char" char=".">20.81</td>
<td align="char" char=".">61.02</td>
</tr>
<tr>
<td align="left">BB</td>
<td align="char" char=".">95.84</td>
<td align="char" char=".">105.2</td>
<td align="char" char=".">37.51</td>
<td align="char" char=".">77.58</td>
<td align="char" char=".">24.43</td>
<td align="char" char=".">74.57</td>
</tr>
<tr>
<td align="left">GP</td>
<td align="char" char=".">163.5</td>
<td align="char" char=".">135.4</td>
<td align="char" char=".">61.59</td>
<td align="char" char=".">80.8</td>
<td align="char" char=".">34.09</td>
<td align="char" char=".">83.54</td>
</tr>
<tr>
<td align="left">Average</td>
<td align="char" char=".">153.109</td>
<td align="char" char=".">121.281</td>
<td align="char" char=".">52.443</td>
<td align="char" char=".">76.812</td>
<td align="char" char=".">32.509</td>
<td align="char" char=".">70.014</td>
</tr>
</tbody>
</table>
</table-wrap>
<fig id="F5" position="float">
<label>FIGURE 5</label>
<caption>
<p>Difference between the particulate concentration in ambient air before rainfall and after 30&#xa0;days from rainfall.</p>
</caption>
<graphic xlink:href="fenvs-09-768358-g005.tif"/>
</fig>
<p>It was observed that the GFLSM operates with relatively high performance immediately after rainfall than before rainfall. The detailed result of the performance evaluation study is tabulated in <xref ref-type="table" rid="T3">Table&#x20;3</xref>. It can be noticed that the difference in the fractional bias (FB) was significantly high. The FB of the after-rainfall particulate concentration was within the acceptable limit (&#x2212;0.5 to 0.5). The index of agreement (IOA) was found to be higher in the case of after-rainfall particulate concentration.</p>
<table-wrap id="T3" position="float">
<label>TABLE 3</label>
<caption>
<p>Performance of the GFLSM for estimating particulate concentration before and after rainfall.</p>
</caption>
<table>
<thead valign="top">
<tr>
<th align="left">Performance measurers</th>
<th align="center">Before rainfall</th>
<th align="center">After rainfall</th>
</tr>
</thead>
<tbody valign="top">
<tr>
<td align="left">Correlation coefficient (r)</td>
<td align="char" char=".">&#x2212;0.15</td>
<td align="char" char=".">0.85</td>
</tr>
<tr>
<td align="left">Mean bias (MB)</td>
<td align="char" char=".">&#x2212;479.81</td>
<td align="char" char=".">52.62</td>
</tr>
<tr>
<td align="left">Mean absolute gross error (MAGE)</td>
<td align="char" char=".">479.81</td>
<td align="char" char=".">52.62</td>
</tr>
<tr>
<td align="left">Root mean square error (RMSE)</td>
<td align="char" char=".">507.24</td>
<td align="char" char=".">55.90</td>
</tr>
<tr>
<td align="left">Mean Normalized Bias (MNB)</td>
<td align="char" char=".">&#x2212;0.74</td>
<td align="char" char=".">0.55</td>
</tr>
<tr>
<td align="left">Mean Normalized Gross Error (MNGE)</td>
<td align="char" char=".">0.74</td>
<td align="char" char=".">0.55</td>
</tr>
<tr>
<td align="left">Normalized mean bias (NMB)</td>
<td align="char" char=".">&#x2212;0.76</td>
<td align="char" char=".">0.56</td>
</tr>
<tr>
<td align="left">Normalized mean error (NME)</td>
<td align="char" char=".">0.76</td>
<td align="char" char=".">0.56</td>
</tr>
<tr>
<td align="left">Fractional bias (FB)</td>
<td align="char" char=".">&#x2212;1.22</td>
<td align="char" char=".">0.43</td>
</tr>
<tr>
<td align="left">Fractional gross error (FGE)</td>
<td align="char" char=".">1.22</td>
<td align="char" char=".">0.43</td>
</tr>
<tr>
<td align="left">Mean normalized factor bias (MNFB)</td>
<td align="char" char=".">&#x2212;7.43</td>
<td align="char" char=".">1.55</td>
</tr>
<tr>
<td align="left">Mean normalized gross factor error (MNGFE)</td>
<td align="char" char=".">&#x2212;7.43</td>
<td align="char" char=".">0.55</td>
</tr>
<tr>
<td align="left">Normalized mean bias factor (NMBF)</td>
<td align="char" char=".">0.76</td>
<td align="char" char=".">0.56</td>
</tr>
<tr>
<td align="left">Normalized mean error factor (NMEF)</td>
<td align="char" char=".">3.16</td>
<td align="char" char=".">0.56</td>
</tr>
<tr>
<td align="left">Index of agreement (IOA)</td>
<td align="char" char=".">0.30</td>
<td align="char" char=".">0.33</td>
</tr>
</tbody>
</table>
</table-wrap>
</sec>
</sec>
<sec id="s4">
<title>4 Conclusion</title>
<p>The performance of the GFLSM was observed to be better than that of the R-Line model in the study area. Another notable observation was that the GFLSM underestimated the concentration of the pollutants whereas R-Line overestimated the same. The ambient concentration of PM10, PM2.5, and PM1was observed to increase logarithmically over time after the rainfall event. This relationship was used for the modification of the GFLSM to quantify the pollutant buildup in the atmosphere over time. It was observed that it took approximately 30&#xa0;days for the atmosphere of the Dhanbad road network to regain the concentration of the particulate pollutants similar to that before the scavenging of PM due to rainfall. This information may help in the estimation of PM scavenging due to the next instances of wet deposition within the aforementioned temporal range. The subsequent result can be helpful in estimating the transport of PAH particulates into the roadside soil. Although the study provides an estimation of PAH particulate transport into the soil, the derived coefficients are site-specific. Therefore, initial information of onsite meteorology is required for the estimation of subsequent temporal variation in the PAH concentration. This limitation may be removed if the derived trends of particulate buildup in the atmosphere are integrated in a micro- or meso-scale dispersion model for theoretical estimation of the coefficients. Elaborate information on dispersion and deposition of PM (especially of PM2.5) into the roadside soil can offer a huge scope of exposure study and health risk assessment of&#x20;PAHs.</p>
</sec>
</body>
<back>
<sec id="s5">
<title>Data Availability Statement</title>
<p>The original contributions presented in the study are included in the article/<xref ref-type="sec" rid="s9">Supplementary Material</xref>; further inquiries can be directed to the corresponding author.</p>
</sec>
<sec id="s6">
<title>Author Contributions</title>
<p>Site selection, data collection, and analysis were performed by PA. The study was supervised and guided by&#x20;SE.</p>
</sec>
<sec sec-type="COI-statement" id="s7">
<title>Conflict of Interest</title>
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<ref-list>
<title>References</title>
<ref id="B1">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Banerjee</surname>
<given-names>T.</given-names>
</name>
<name>
<surname>Barman</surname>
<given-names>S. C.</given-names>
</name>
<name>
<surname>Srivastava</surname>
<given-names>R. K.</given-names>
</name>
</person-group> (<year>2011</year>). <article-title>Application of Air Pollution Dispersion Modeling for Source-Contribution Assessment and Model Performance Evaluation at Integrated Industrial Estate-Pantnagar</article-title>. <source>Environ. Pollut.</source> <volume>159</volume> (<issue>4</issue>), <fpage>865</fpage>&#x2013;<lpage>875</lpage>. <pub-id pub-id-type="doi">10.1016/j.envpol.2010.12.026</pub-id> </citation>
</ref>
<ref id="B35">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Drag</surname>
<given-names>&#x141;.</given-names>
</name>
<name>
<surname>Wojciech</surname>
<given-names>S.</given-names>
</name>
</person-group> (<year>2009</year>). &#x201c;<article-title>The Integrated Computer System For Modelling of Air Pollution Based on The Digital Data</article-title>,&#x201d; in <source>2009 IEEE International Workshop on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications</source> (<publisher-name>IEEE</publisher-name>), <fpage>478</fpage>&#x2013;<lpage>483</lpage>. </citation>
</ref>
<ref id="B2">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Funasaka</surname>
<given-names>K.</given-names>
</name>
<name>
<surname>Miyazaki</surname>
<given-names>T.</given-names>
</name>
<name>
<surname>Tsuruho</surname>
<given-names>K.</given-names>
</name>
<name>
<surname>Tamura</surname>
<given-names>K.</given-names>
</name>
<name>
<surname>Mizuno</surname>
<given-names>T.</given-names>
</name>
<name>
<surname>Kuroda</surname>
<given-names>K.</given-names>
</name>
</person-group> (<year>2000</year>). <article-title>Relationship between Indoor and Outdoor Carbonaceous Particulates in Roadside Households</article-title>. <source>Environ. Pollut.</source> <volume>110</volume> (<issue>1</issue>), <fpage>127</fpage>&#x2013;<lpage>134</lpage>. <pub-id pub-id-type="doi">10.1016/s0269-7491(99)00281-x</pub-id> </citation>
</ref>
<ref id="B3">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Ganguly</surname>
<given-names>R.</given-names>
</name>
<name>
<surname>Broderick</surname>
<given-names>B. M.</given-names>
</name>
</person-group> (<year>2008</year>). <article-title>Performance Evaluation and Sensitivity Analysis of the General Finite Line Source Model for CO Concentrations Adjacent to Motorways: A Note</article-title>. <source>Transportation Res. D: Transport Environ.</source> <volume>13</volume> (<issue>3</issue>), <fpage>198</fpage>&#x2013;<lpage>205</lpage>. <pub-id pub-id-type="doi">10.1016/j.trd.2008.01.006</pub-id> </citation>
</ref>
<ref id="B4">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Gokhale</surname>
<given-names>S.</given-names>
</name>
<name>
<surname>Pandian</surname>
<given-names>S.</given-names>
</name>
</person-group> (<year>2007</year>). <article-title>A Semi-empirical Box Modeling Approach for Predicting the Carbon Monoxide Concentrations at an Urban Traffic Intersection</article-title>. <source>Atmos. Environ.</source> <volume>41</volume> (<issue>36</issue>), <fpage>7940</fpage>&#x2013;<lpage>7950</lpage>. <pub-id pub-id-type="doi">10.1016/j.atmosenv.2007.06.065</pub-id> </citation>
</ref>
<ref id="B5">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Harrison</surname>
<given-names>R. M.</given-names>
</name>
<name>
<surname>Leung</surname>
<given-names>P. L.</given-names>
</name>
<name>
<surname>Somervaille</surname>
<given-names>L.</given-names>
</name>
<name>
<surname>Smith</surname>
<given-names>R.</given-names>
</name>
<name>
<surname>Gilman</surname>
<given-names>E.</given-names>
</name>
</person-group> (<year>1999</year>). <article-title>Analysis of Incidence of Childhood Cancer in the West Midlands of the United&#x20;Kingdom in Relation to Proximity to Main Roads and Petrol Stations</article-title>. <source>Occup. Environ. Med.</source> <volume>56</volume> (<issue>11</issue>), <fpage>774</fpage>&#x2013;<lpage>780</lpage>. <pub-id pub-id-type="doi">10.1136/oem.56.11.774</pub-id> </citation>
</ref>
<ref id="B6">
<citation citation-type="journal">
<collab>IARC</collab> (<year>2010</year>). <article-title>Some Non-heterocyclic Polycyclic Aromatic Hydrocarbons and Some Related Exposures</article-title>. <source>IARC Monogr. Eval. Carcinog Risks Hum.</source> <volume>92</volume>, <fpage>1</fpage>&#x2013;<lpage>853</lpage>. </citation>
</ref>
<ref id="B7">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Kingham</surname>
<given-names>S.</given-names>
</name>
<name>
<surname>Briggs</surname>
<given-names>D.</given-names>
</name>
<name>
<surname>Elliott</surname>
<given-names>P.</given-names>
</name>
<name>
<surname>Fischer</surname>
<given-names>P.</given-names>
</name>
<name>
<surname>Erik Lebret</surname>
<given-names>E.</given-names>
</name>
</person-group> (<year>2000</year>). <article-title>Spatial Variations in the Concentrations of Traffic-Related Pollutants in Indoor and Outdoor Air in Huddersfield, England</article-title>. <source>Atmos. Environ.</source> <volume>34</volume> (<issue>6</issue>), <fpage>905</fpage>&#x2013;<lpage>916</lpage>. <pub-id pub-id-type="doi">10.1016/s1352-2310(99)00321-0</pub-id> </citation>
</ref>
<ref id="B8">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Krewski</surname>
<given-names>D.</given-names>
</name>
<name>
<surname>Jerrett</surname>
<given-names>M.</given-names>
</name>
<name>
<surname>Burnett</surname>
<given-names>R. T.</given-names>
</name>
<name>
<surname>Ma</surname>
<given-names>R.</given-names>
</name>
<name>
<surname>Hughes</surname>
<given-names>E.</given-names>
</name>
<name>
<surname>Shi</surname>
<given-names>Y.</given-names>
</name>
<etal/>
</person-group> (<year>2009</year>). <article-title>Extended Follow-Up and Spatial Analysis of the American Cancer Society Study Linking Particulate Air Pollution and Mortality</article-title>. <source>Res. Rep. Health Eff. Inst.</source> <volume>140</volume> (<issue>5</issue>), <fpage>5</fpage>&#x2013;<lpage>36</lpage>. </citation>
</ref>
<ref id="B9">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Luhar</surname>
<given-names>A. K.</given-names>
</name>
<name>
<surname>Patil</surname>
<given-names>R. S.</given-names>
</name>
</person-group> (<year>1989</year>). <article-title>A General Finite Line Source Model for Vehicular Pollution Prediction</article-title>. <source>Atmos. Environ. (1967)</source> <volume>23</volume> (<issue>3</issue>), <fpage>555</fpage>&#x2013;<lpage>562</lpage>. <pub-id pub-id-type="doi">10.1016/0004-6981(89)90004-8</pub-id> </citation>
</ref>
<ref id="B10">
<citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname>Madhavan</surname>
<given-names>S.</given-names>
</name>
<name>
<surname>Geetha</surname>
<given-names>S.</given-names>
</name>
</person-group> (<year>2021</year>). &#x201c;<article-title>Predicting Particulate Air Pollution Using Line Source Models</article-title>,&#x201d; in <source>Urban Air Quality Monitoring, Modelling and Human Exposure Assessment</source> (<publisher-loc>Singapore</publisher-loc>: <publisher-name>Springer</publisher-name>), <fpage>137</fpage>&#x2013;<lpage>153</lpage>. <pub-id pub-id-type="doi">10.1007/978-981-15-5511-4_10</pub-id> </citation>
</ref>
<ref id="B11">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Martin</surname>
<given-names>D. O.</given-names>
</name>
</person-group> (<year>1976</year>). <article-title>Comment On"The Change of Concentration Standard Deviations with Distance"</article-title>. <source>J.&#x20;Air Pollut. Control Assoc.</source> <volume>26</volume> (<issue>2</issue>), <fpage>145</fpage>&#x2013;<lpage>147</lpage>. <pub-id pub-id-type="doi">10.1080/00022470.1976.10470238</pub-id> </citation>
</ref>
<ref id="B12">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Martuzevicius</surname>
<given-names>D.</given-names>
</name>
<name>
<surname>Grinshpun</surname>
<given-names>S. A.</given-names>
</name>
<name>
<surname>Reponen</surname>
<given-names>T.</given-names>
</name>
<name>
<surname>G&#xf3;rny</surname>
<given-names>R. L.</given-names>
</name>
<name>
<surname>Shukla</surname>
<given-names>R.</given-names>
</name>
<name>
<surname>Lockey</surname>
<given-names>J.</given-names>
</name>
<etal/>
</person-group> (<year>2004</year>). <article-title>Spatial and Temporal Variations of PM2.5 Concentration and Composition throughout an Urban Area with High Freeway Density-The Greater Cincinnati Study</article-title>. <source>Atmos. Environ.</source> <volume>38</volume> (<issue>8</issue>), <fpage>1091</fpage>&#x2013;<lpage>1105</lpage>. <pub-id pub-id-type="doi">10.1016/j.atmosenv.2003.11.015</pub-id> </citation>
</ref>
<ref id="B13">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>McCreanor</surname>
<given-names>J.</given-names>
</name>
<name>
<surname>Cullinan</surname>
<given-names>P.</given-names>
</name>
<name>
<surname>Nieuwenhuijsen</surname>
<given-names>M. J.</given-names>
</name>
<name>
<surname>Stewart-Evans</surname>
<given-names>J.</given-names>
</name>
<name>
<surname>Malliarou</surname>
<given-names>E.</given-names>
</name>
<name>
<surname>Jarup</surname>
<given-names>L.</given-names>
</name>
<etal/>
</person-group> (<year>2007</year>). <article-title>Respiratory Effects of Exposure to Diesel Traffic in Persons with Asthma</article-title>. <source>N. Engl. J.&#x20;Med.</source> <volume>357</volume> (<issue>23</issue>), <fpage>2348</fpage>&#x2013;<lpage>2358</lpage>. <pub-id pub-id-type="doi">10.1056/nejmoa071535</pub-id> </citation>
</ref>
<ref id="B14">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Mishra</surname>
<given-names>R. K.</given-names>
</name>
<name>
<surname>Shukla</surname>
<given-names>A.</given-names>
</name>
<name>
<surname>Parida</surname>
<given-names>M.</given-names>
</name>
<name>
<surname>Pandey</surname>
<given-names>G.</given-names>
</name>
</person-group> (<year>2016</year>).<article-title>Urban Roadside Monitoring and Prediction of CO, NO2 and SO2 Dispersion from On-Road Vehicles in Megacity Delhi</article-title>. <source>Transportation Res. Part D: Transport Environ.</source> <volume>46</volume>, <fpage>157</fpage>&#x2013;<lpage>165</lpage>. <pub-id pub-id-type="doi">10.1016/j.trd.2016.03.019</pub-id> </citation>
</ref>
<ref id="B15">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Olszowski</surname>
<given-names>T.</given-names>
</name>
</person-group> (<year>2016</year>). <article-title>Changes in PM10 Concentration Due to Large-Scale Rainfall</article-title>. <source>Arab J.&#x20;Geosci.</source> <volume>9</volume> (<issue>2</issue>), <fpage>160</fpage>. <pub-id pub-id-type="doi">10.1007/s12517-015-2163-2</pub-id> </citation>
</ref>
<ref id="B16">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Pandian</surname>
<given-names>S.</given-names>
</name>
<name>
<surname>Gokhale</surname>
<given-names>S.</given-names>
</name>
<name>
<surname>Ghoshal</surname>
<given-names>A. K.</given-names>
</name>
</person-group> (<year>2009</year>). <article-title>Evaluating Effects of Traffic and Vehicle Characteristics on Vehicular Emissions Near Traffic Intersections</article-title>. <source>Transportation Res. Part D: Transport Environ.</source> <volume>14</volume> (<issue>3</issue>), <fpage>180</fpage>&#x2013;<lpage>196</lpage>. <pub-id pub-id-type="doi">10.1016/j.trd.2008.12.001</pub-id> </citation>
</ref>
<ref id="B17">
<citation citation-type="book">
<collab>PART5</collab> (<year>1995</year>). <source>A Program for Calculating Particle Emission from Motor Vehicles</source>. <publisher-loc>Michigan</publisher-loc>: <publisher-name>Office of Mobile Sources, National Motor Vehicle and Fuels Emission Laboratory, US Environmental Protection Agency</publisher-name>. </citation>
</ref>
<ref id="B18">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Pearson</surname>
<given-names>R. L.</given-names>
</name>
<name>
<surname>Wachtel</surname>
<given-names>H.</given-names>
</name>
<name>
<surname>Ebi</surname>
<given-names>K. L.</given-names>
</name>
</person-group> (<year>2000</year>). <article-title>Distance-weighted Traffic Density in Proximity to a home Is a Risk Factor for Leukemia and Other Childhood Cancers</article-title>. <source>J.&#x20;Air Waste Manag. Assoc.</source> <volume>50</volume> (<issue>2</issue>), <fpage>175</fpage>&#x2013;<lpage>180</lpage>. <pub-id pub-id-type="doi">10.1080/10473289.2000.10463998</pub-id> </citation>
</ref>
<ref id="B19">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Peters</surname>
<given-names>M. J.</given-names>
</name>
<name>
<surname>van der Horst-Bruinsma</surname>
<given-names>I. E.</given-names>
</name>
<name>
<surname>Dijkmans</surname>
<given-names>B. A.</given-names>
</name>
<name>
<surname>Nurmohamed</surname>
<given-names>M. T.</given-names>
</name>
</person-group> (<year>2004</year>).<article-title>Cardiovascular Risk Profile of Patients with Spondylarthropathies, Particularly Ankylosing Spondylitis and Psoriatic Arthritis</article-title>. <source>Semin. Arthritis Rheum.</source> <volume>34</volume>, <fpage>585</fpage>&#x2013;<lpage>592</lpage>. <pub-id pub-id-type="doi">10.1016/j.semarthrit.2004.07.010</pub-id> </citation>
</ref>
<ref id="B20">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Rajput</surname>
<given-names>J.&#x20;S.</given-names>
</name>
<name>
<surname>Saxena</surname>
<given-names>A. K.</given-names>
</name>
<name>
<surname>Singh</surname>
<given-names>U. P.</given-names>
</name>
</person-group> (<year>2019</year>). <article-title>Application of Mathematical Modeling for the Prediction of NOx Concentration Due to Vehicular Emission and Model Performance in Gwalior City,(MP)</article-title>. <source>Int. J.&#x20;Innovative Sci. Res. Techn.</source> <volume>4</volume> (<issue>01</issue>), <fpage>29</fpage>&#x2013;<lpage>36</lpage>. <pub-id pub-id-type="doi">10.13140/RG.2.2.17274.13768</pub-id> </citation>
</ref>
<ref id="B21">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Riediker</surname>
<given-names>M.</given-names>
</name>
<name>
<surname>Cascio</surname>
<given-names>W. E.</given-names>
</name>
<name>
<surname>Griggs</surname>
<given-names>T. R.</given-names>
</name>
<name>
<surname>Herbst</surname>
<given-names>M. C.</given-names>
</name>
<name>
<surname>Bromberg</surname>
<given-names>P. A.</given-names>
</name>
<name>
<surname>Neas</surname>
<given-names>L.</given-names>
</name>
<etal/>
</person-group> (<year>2004</year>). <article-title>Particulate Matter Exposure in Cars Is Associated with Cardiovascular Effects in Healthy Young Men</article-title>. <source>Am. J.&#x20;Respir. Crit. Care Med.</source> <volume>169</volume> (<issue>8</issue>), <fpage>934</fpage>&#x2013;<lpage>940</lpage>. <pub-id pub-id-type="doi">10.1164/rccm.200310-1463oc</pub-id> </citation>
</ref>
<ref id="B22">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Roorda-Knape</surname>
<given-names>M. C.</given-names>
</name>
<name>
<surname>Janssen</surname>
<given-names>N. A. H.</given-names>
</name>
<name>
<surname>De Hartog</surname>
<given-names>J.&#x20;J.</given-names>
</name>
<name>
<surname>Van Vliet</surname>
<given-names>P. H. N.</given-names>
</name>
<name>
<surname>Harssema</surname>
<given-names>H.</given-names>
</name>
<name>
<surname>Brunekreef</surname>
<given-names>B.</given-names>
</name>
</person-group> (<year>1998</year>). <article-title>Air Pollution from Traffic in City Districts Near Major Motorways</article-title>. <source>Atmos. Environ.</source> <volume>32</volume> (<issue>11</issue>), <fpage>1921</fpage>&#x2013;<lpage>1930</lpage>. <pub-id pub-id-type="doi">10.1016/s1352-2310(97)00496-2</pub-id> </citation>
</ref>
<ref id="B23">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>R&#xf6;&#xf6;sli</surname>
<given-names>M.</given-names>
</name>
<name>
<surname>Theis</surname>
<given-names>G.</given-names>
</name>
<name>
<surname>K&#xfc;nzli</surname>
<given-names>N.</given-names>
</name>
<name>
<surname>Staehelin</surname>
<given-names>J.</given-names>
</name>
<name>
<surname>Mathys</surname>
<given-names>P.</given-names>
</name>
<name>
<surname>Oglesby</surname>
<given-names>L.</given-names>
</name>
<etal/>
</person-group> (<year>2001</year>). <article-title>Temporal and Spatial Variation of the Chemical Composition of PM10 at Urban and Rural Sites in the Basel Area, Switzerland</article-title>. <source>Atmos. Environ.</source> <volume>35</volume> (<issue>21</issue>), <fpage>3701</fpage>&#x2013;<lpage>3713</lpage>. <pub-id pub-id-type="doi">10.1016/s1352-2310(00)00511-2</pub-id> </citation>
</ref>
<ref id="B24">
<citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname>Sangeetha</surname>
<given-names>A.</given-names>
</name>
<name>
<surname>Amudha</surname>
<given-names>T.</given-names>
</name>
</person-group> (<year>2021</year>). <article-title>A Particle Swarm Optimization Methodology to Design an Effective Air Quality Monitoring Network</article-title>. <source>Environment, Development and Sustainability</source> <volume>23</volume>, <fpage>15739</fpage>&#x2013;<lpage>15763</lpage>. </citation>
</ref>
<ref id="B25">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Snyder</surname>
<given-names>M. G.</given-names>
</name>
<name>
<surname>Venkatram</surname>
<given-names>A.</given-names>
</name>
<name>
<surname>Heist</surname>
<given-names>D. K.</given-names>
</name>
<name>
<surname>Perry</surname>
<given-names>S. G.</given-names>
</name>
<name>
<surname>Petersen</surname>
<given-names>W. B.</given-names>
</name>
<name>
<surname>Isakov</surname>
<given-names>V.</given-names>
</name>
</person-group> (<year>2013</year>). <article-title>RLINE: A Line Source Dispersion Model for Near-Surface Releases</article-title>. <source>Atmos. Environ.</source> <volume>77</volume>, <fpage>748</fpage>&#x2013;<lpage>756</lpage>. <pub-id pub-id-type="doi">10.1016/j.atmosenv.2013.05.074</pub-id> </citation>
</ref>
<ref id="B26">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Suman</surname>
<given-names>S.</given-names>
</name>
<name>
<surname>Sinha</surname>
<given-names>A.</given-names>
</name>
<name>
<surname>Tarafdar</surname>
<given-names>A.</given-names>
</name>
</person-group> (<year>2016</year>). <article-title>Polycyclic Aromatic Hydrocarbons (PAHs) Concentration Levels, Pattern, Source Identification and Soil Toxicity Assessment in Urban Traffic Soil of Dhanbad, India</article-title>. <source>Sci. Total Environ.</source> <volume>545-546</volume>, <fpage>353</fpage>&#x2013;<lpage>360</lpage>. <pub-id pub-id-type="doi">10.1016/j.scitotenv.2015.12.061</pub-id> </citation>
</ref>
<ref id="B27">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Tarafdar</surname>
<given-names>A.</given-names>
</name>
<name>
<surname>Sinha</surname>
<given-names>A.</given-names>
</name>
</person-group> (<year>2017a</year>). <article-title>Cancer Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Soils and Sediments of India: a Meta-Analysis</article-title>. <source>Environ. Manag.</source> <volume>60</volume> (<issue>4</issue>), <fpage>784</fpage>&#x2013;<lpage>795</lpage>. <pub-id pub-id-type="doi">10.1007/s00267-017-0920-6</pub-id> </citation>
</ref>
<ref id="B28">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Tarafdar</surname>
<given-names>A.</given-names>
</name>
<name>
<surname>Sinha</surname>
<given-names>A.</given-names>
</name>
</person-group> (<year>2017b</year>). <article-title>Estimation of Decrease in Cancer Risk by Biodegradation of PAHs Content from an Urban Traffic Soil</article-title>. <source>Environ. Sci. Pollut. Res.</source> <volume>24</volume> (<issue>11</issue>), <fpage>10373</fpage>&#x2013;<lpage>10380</lpage>. <pub-id pub-id-type="doi">10.1007/s11356-017-8676-3</pub-id> </citation>
</ref>
<ref id="B29">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Venkatram</surname>
<given-names>A.</given-names>
</name>
<name>
<surname>Snyder</surname>
<given-names>M. G.</given-names>
</name>
<name>
<surname>Heist</surname>
<given-names>D. K.</given-names>
</name>
<name>
<surname>Perry</surname>
<given-names>S. G.</given-names>
</name>
<name>
<surname>Petersen</surname>
<given-names>W. B.</given-names>
</name>
<name>
<surname>Isakov</surname>
<given-names>V.</given-names>
</name>
</person-group> (<year>2013</year>). <article-title>Re-formulation of Plume Spread for Near-Surface Dispersion</article-title>. <source>Atmos. Environ.</source> <volume>77</volume>, <fpage>846</fpage>&#x2013;<lpage>855</lpage>. <pub-id pub-id-type="doi">10.1016/j.atmosenv.2013.05.073</pub-id> </citation>
</ref>
<ref id="B30">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Wang</surname>
<given-names>J.&#x20;S.</given-names>
</name>
<name>
<surname>Chan</surname>
<given-names>T. L.</given-names>
</name>
<name>
<surname>Ning</surname>
<given-names>Z.</given-names>
</name>
<name>
<surname>Leung</surname>
<given-names>C. W.</given-names>
</name>
<name>
<surname>Cheung</surname>
<given-names>C. S.</given-names>
</name>
<name>
<surname>Hung</surname>
<given-names>W. T.</given-names>
</name>
</person-group> (<year>2006</year>). <article-title>Roadside Measurement and Prediction of CO and PM2.5 Dispersion from On-Road Vehicles in Hong Kong</article-title>. <source>Transportation Res. Part D: Transport Environ.</source> <volume>11</volume> (<issue>4</issue>), <fpage>242</fpage>&#x2013;<lpage>249</lpage>. <pub-id pub-id-type="doi">10.1016/j.trd.2006.04.002</pub-id> </citation>
</ref>
<ref id="B31">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Wilhelm</surname>
<given-names>M.</given-names>
</name>
<name>
<surname>Ritz</surname>
<given-names>B.</given-names>
</name>
</person-group> (<year>2003</year>). <article-title>Residential Proximity to Traffic and Adverse Birth Outcomes in Los Angeles County, California, 1994-1996</article-title>. <source>Environ. Health Perspect.</source> <volume>111</volume> (<issue>2</issue>), <fpage>207</fpage>&#x2013;<lpage>216</lpage>. <pub-id pub-id-type="doi">10.1289/ehp.5688</pub-id> </citation>
</ref>
<ref id="B32">
<citation citation-type="book">
<collab>World Health Organization</collab> (<year>2005</year>). <source>Health Effects of Transport-Related Air Pollution</source>. <publisher-loc>Copenhagen</publisher-loc>: <publisher-name>WHO Regional Office for Europe</publisher-name>, <fpage>125</fpage>&#x2013;<lpage>165</lpage>. </citation>
</ref>
<ref id="B33">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Yoo</surname>
<given-names>H-G.</given-names>
</name>
<name>
<surname>Hong</surname>
<given-names>J-W.</given-names>
</name>
<name>
<surname>Jinkyu</surname>
<given-names>H.</given-names>
</name>
<name>
<surname>Sunyong</surname>
<given-names>S.</given-names>
</name>
<name>
<surname>Yoon</surname>
<given-names>E. J.</given-names>
</name>
<name>
<surname>Park</surname>
<given-names>J-H.</given-names>
</name>
<etal/>
</person-group> (<year>2020</year>). <article-title>Impact of Meteorological Conditions on the PM2.5 and PM10 Concentrations in Seoul</article-title>. <source>J.&#x20;Clim.</source> <volume>11</volume> (<issue>5-2</issue>), <fpage>521</fpage>&#x2013;<lpage>528</lpage>. <pub-id pub-id-type="doi">10.15531/ksccr.2020.11.5.521</pub-id> </citation>
</ref>
<ref id="B34">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Zhu</surname>
<given-names>Y.</given-names>
</name>
<name>
<surname>Hinds</surname>
<given-names>W. C.</given-names>
</name>
<name>
<surname>Kim</surname>
<given-names>S.</given-names>
</name>
<name>
<surname>Shen</surname>
<given-names>S.</given-names>
</name>
<name>
<surname>Sioutas</surname>
<given-names>C.</given-names>
</name>
</person-group> (<year>2002</year>). <article-title>Study of Ultrafine Particles Near a Major Highway with Heavy-Duty Diesel Traffic</article-title>. <source>Atmos. Environ.</source> <volume>36</volume> (<issue>27</issue>), <fpage>4323</fpage>&#x2013;<lpage>4335</lpage>. <pub-id pub-id-type="doi">10.1016/s1352-2310(02)00354-0</pub-id> </citation>
</ref>
</ref-list>
</back>
</article>