# Exposure to NO\({}_{2}\) and PM\({}_{2.5}\) While Commuting: Utility of Low-Cost Sensor
## 4 Discussion
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Mode of** **Transport**} & \multirow{2}{*}{**Person**} & \multirow{2}{*}{**Location**} & \multicolumn{2}{c}{**Mean (Min–Max) Concentration**} & \multirow{2}{*}{**Mean (Min–Max) Dose, \(\mu\)g/km**} & \multirow{2}{*}{**References**} \\ \cline{4-4}  & & & **Per Trip, \(\mu\)g/m\({}^{3}\)** & & & \\ \hline \multirow{4}{*}{Adults} & \multirow{4}{*}{Gliwice} & \multirow{4}{*}{Gliwice} & **PM2.5** & **NO2** & **PM2.5** & **NO2** \\ \cline{4-5}  & & & Heating: & & Male: & Male: \\  & & \(55\pm 6.0\) & \(347\pm 30.2\) & 3.3 & 8.1 & \\  & & (20-24.4) & (0.3-109.6) & (0.07-38.2) & (0.05-83.7) & \\  & & Non-heating: & Non-heating: & Female: & Female: & Female: \\  & & \(10.6\pm 23.2\) & \(24.8\pm 21.6\) & 0.6 & 2.4 & \\  & & (20-117.9) & (1.0-97.4) & (0.02-5.0) & (0.01-20.0) & \\ \hline \multirow{4}{*}{Adults} & \multirow{4}{*}{Barcelona, Spain} & Bus: \(25\pm 1.4\) & \multicolumn{2}{c}{Bus: \(18.0\) *} & \\  & & \(20.0\) per 1 h & & & \\  & & \(20.0\) per 1 h & & & \\  & & \(21.2\) per 1 h & & & \\ \hline Adults & Thessaloniki, Greece & Bus: 84.6 & \multicolumn{2}{c}{Bus: \(6.9\)} & \multicolumn{2}{c}{} \\  & & & Car: \(17\)-\(3.1\) & & [38] \\ \hline \multirow{4}{*}{Adults} & Montreal, Canada & \multicolumn{2}{c}{Bus: \(87.62\)} & \multicolumn{2}{c}{} \\  & & & (24.49-161.90) & \multicolumn{2}{c}{5.52 car} & \\  & & Canada & Car: \(114.87\) & \multicolumn{2}{c}{6.78 bus} & \\  & & \(45.04-177.45\) & \multicolumn{2}{c}{} \\ \hline \multirow{4}{*}{Adults} & Lisbon, Portugal & Bus: \(28.4\pm 5.3\) & \multicolumn{2}{c}{} \\  & & (20.7-61.6) & \multicolumn{2}{c}{Bus: \(25\)} & \multicolumn{2}{c}{[41]} \\  & & \(23.37\pm 8.6\) & \multicolumn{2}{c}{Car: \(13\)} & \\  & & \(20.7-61.6\) & \multicolumn{2}{c}{} \\ \hline \multirow{4}{*}{Adults} & Bus: \(8\) & Bus: & & \\  & & \(8\) h: \(56\pm 55\) & \multicolumn{2}{c}{8 h: \(4.89\)} & \\  & & \(11\) h: \(30\pm 18\) & \multicolumn{2}{c}{11 h: \(2.36\)} & \\  & & \(14\) h: \(52\pm 27\) & \multicolumn{2}{c}{14 h: \(4.40\)} & \\  & & \(17\):\(30\pm 50\pm 23\) & \multicolumn{2}{c}{17;\(30\pm 3.15\)} & \\  & & \(21\) h: \(40\pm 16\) & \multicolumn{2}{c}{21 h: \(2.42\)} & \\  & & \(8\) h: \(61\pm 12\) & \multicolumn{2}{c}{8 h: \(2.16\)} & \\  & & \(11\) h: \(55\pm 13\) & \multicolumn{2}{c}{11 h: \(1.82\)} & \\  & & \(14\) h: \(52\pm 10\) & \multicolumn{2}{c}{14 h: \(1.99\)} & \\  & & \(1730\pm 14\pm 7.0\) & \multicolumn{2}{c}{17;\(30\pm 1.83\)} & \\  & & \(21\) h: \(35\pm 6.7\) & \multicolumn{2}{c}{21 h: \(1.08\)} & \\ \hline \multirow{4}{*}{Adults} & \multirow{4}{*}{Milan, Italy} & Car: & Car: & & \\  & & Winter: \(8.0\) & Winter: \(5.9\) & \(1.6\) * & \(2.5\) * & [43] \\  & & Summer: \(5.3\) & Summer: \(17.0\) & \multicolumn{2}{c}{} \\ \hline \multirow{4}{*}{Adults} & \multirow{4}{*}{Milan, Italy} & \multirow{4}{*}{N/A} & \multicolumn{2}{c}{Car} & \multicolumn{2}{c}{} \\  & & & Female: & & \\  & & & Winter: & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\ \hline \multirow{4}{*}{Adults} & Salt Lake City, USA & Bus: \(13.03\) & Bus: \(0.2\) & \multicolumn{2}{c}{[45]} \\  & Car WO: \(15.21\) & Car WO: \(0.46\) & \multicolumn{2}{c}{[45]} \\  & & Car WC: \(5.31\) & Car WC: \(0.12\)} & \\ \hline \multirow{4}{*}{Adults} & Mexico City & Bus: \(38\) & Bus: \(5.77\) & \multicolumn{2}{c}{[46]} \\  & & Car: \(32\) & Car: \(3.09\) & \multicolumn{2}{c}{[46]} \\  & & Carsharing: \(29.5\) & \multicolumn{2}{c}{Carsharing: \(2.77\)} & \\ \hline \multirow{4}{*}{Adults} & \multirow{4}{*}{Vellore, India} & Bus: morning \(118\) & \multicolumn{2}{c}{} \\  & & \((96\)-150) & \multicolumn{2}{c}{Bus: \(3\)–\(4\)} & \multicolumn{2}{c}{[47]} \\  & & afternoon \(11\) & \multicolumn{2}{c}{Car: \(2\)–\(6\)} & \\  & & \((89\)-138) & \multicolumn{2}{c}{Car: \(174\) (150–202)} & \\ \hline \multirow{4}{*}{Adults} & Bogota, Colombia & \multicolumn{2}{c}{130.0–176.3} & Bus: \(460.8\) ug/day & \multicolumn{2}{c}{[48]} \\  & & Colombia & \multicolumn{2}{c}{} \\ \hline \multirow{4}{*}{Adults} & Singapore & Bus: \(28\pm 6\) & \multicolumn{2}{c}{Bus: \(3.0\) *} & \multicolumn{2}{c}{[49]} \\  & & Taxi: \(2.4\) * & \multicolumn{2}{c}{} \\ \hline \multirow{4}{*}{Walking} & \multirow{4}{*}{Children} & Heating: & Male: & & \\  & & \(7.3\pm 10.0\) & \(33.0\pm 23.4\) & \(30.7\) & \(141.3\) \\  & & \((20\)-\(44.7)\) & \((0.7-78.6)\) & \((29.-159.1)\) & \((44.4-428.9)\) & \\  & & Non-heating: & Female: & Female: & Female: \\  & & \(7.3\pm 17.0\) & \(21.4\pm 15.4\) & \(31.6\) & \(77.9\) & \\  & & \((20.-95.4)\) & \((0.6-99.5)\) & \((0.8-838.7)\) & \((0.6-401.4)\) & \\ \hline \multirow{2}{*}{Adults} & Barcelona, Spain & \multicolumn{2}{c}{} & \(35.1\) * & \multicolumn{2}{c}{} \\  & & Spain & \(21\pm 1.3\) & \multicolumn{2}{c}{} \\  & & & \(36.1\) per 1 h & \multicolumn{2}{c}{} \\ \hline \multirow{4}{*}{Children} & Children & Hamilton, Canada & \(15.7\)-\(19.3\) & \multicolumn{2}{c}{} \\  & & (10.4-32.3) & \multicolumn{2}{