Genotoxic Effects of Exposure to Urban Traffic Related Air Pollutants on Children in Klang Valley, Malaysia

Abstract

Traffic-related air pollutants (TRAPs) are currently increasing due to the increment of vehicle numbers in Malaysia. The emission of pollutants from these vehicles have genotoxic properties that can potentially induce genetic damage in human. In this study, micronuclei assay is used to determine the potential genotoxic exposure by assessing the presence of micronuclei frequency (MN) in buccal cells. The specific objective of this study is to determine the association between TRAPs and frequency of MN among school children in Klang Valley. A comparative crosssectional study was conducted among primary school children (9-11 years old) in high-density traffic area (n=94, Kuala Lumpur) and low-density traffic area (n=94, Hulu Langat). A questionnaire was distributed to the parents to obtain respiratory symptoms information. Buccal cells were analyzed to determine the frequency of micronuclei. Air quality assessment was carried out in a total of 6 schools (consisted of exposed and comparative groups) by using TSI DustTrak DRX Aerosol Monitor 8534 for measurement of PM2.5 and PM10, LaMotte's Model BD Air Sampling Pump for measurement of Nitrogen dioxide (NO2) and Sulphur dioxide (SO2), ppbRAE 3000 for total Volatile Organic Compound (TVOC) and TSI Q-TRAK 7565 for measurement of Carbon dioxide (CO2) and Carbon monoxide (CO). The concentrations of PM10, PM2.5, NO2, SO2, TVOC and CO at exposed schools were significantly higher (p<0.005). compared to those in comparative schools. All pollutants were significantly associated (p<0.001) with respiratory symptom phlegm and MN frequency. Additionally, the MN frequency in the exposed group was significantly higher (p<0.001) than in the comparative group. All in all, this study demonstrated that air pollutants, especially NO2 and CO, have significantly influenced the MN frequency among children in primary schools. This study suggested that exposure to TRAPs among Malaysian school children has increased the risk for respiratory complications with the formation of MN.

Is micronucleus assay in oral exfoliated cells a suitable tool for biomonitoring children exposed to environmental pollutants? A systematic review

“…The year 2021 was the most recent publication year found and 2012 the oldest. The order of countries that appeared with the most publications on the subject was Italy (Ceretti et al 2014(Ceretti et al , 2020De Donno et al 2016;Idolo et al 2018;Marcon et al 014;Panico et al 2020;Villarini et al 2018), Brazil (Alpire et al 2021;Cavalcante et al 2017;Fleck et al 2014;Silva et al 2015;Sisenando et al 2012), Malaysia (Chokeli et al 2019;Hisamuddin et al 2020;How et al 2014), Mexico (Anguiano-Vega et al 2020Gomez-Arroyo et al, 2013;López Guzmán et al 2017), Argentina (Bernardi et al 2015), and Iraq (Sabah 2021). The results of the characteristics of the included studies are shown in Table 1.…”

“…Of the 20 studies, 12 related to children exposed to air pollution (Cavalcante et al, 2017;Ceretti et al 2014Ceretti et al , 2020De Donno et al 2016;Fleck et al 2014;Hisamuddin et al 2020;Idolo et al 2018;Marcon et al 2014;Panico et al 2020;Sabah, 2021;Silva et al 2015;Sisenando et al, 2012); four reported exposures to pesticides (Anguiano-Vega et al 2020;Bernardi et al 2015;Gomez-Arroyo et al 2013;How et al 2014); two about lifestyle (Alpire et al 2021;Villarini et al 2018); and finally, one article researched exposure to arsenic (López Guzmán et al, 2017) and another to a mobile base station (Chokeli et al 2019). The youngest age found in the articles was 7 months while the oldest was 16 years.…”

The Influence of Traffic-Related Air Pollution (TRAP) in Primary Schools and Residential Proximity to Traffic Sources on Histone H3 Level in Selected Malaysian Children

“…SO 2 has been associated with eye irritation, breathing problems, chest pains, heart disease, and respiratory mortality [48]. Inhalation of highly soluble SO 2 will be metabolized into sulfites, which can interrupt DNA synthesis and activate chromosomal abnormality [3].…”

“…HT schools recorded higher average concentrations of air pollutants than LT schools because, in general, air pollutants were significantly higher at the HT schools than the LT schools, due to the high contribution of heavy traffic density. High-traffic density in Klang Valley is partly attributed to developments of housing complexes, underpasses, and flyovers [3]. School children in their indoor and outdoor environments can be the causes of air emissions in the classroom; for example, the movement of children inside and outside of the classroom contributes to the accumulation of PM in the classroom.…”

“…Previous studies have proven that TRAP is associated with respiratory toxicity in different approaches, such as in vitro [1], in vivo [2], and epidemiology [3]. Generation of the reactive oxygen species (ROS) and oxidative metabolites, that trigger the oxidative stress in the cells located at the lung airways, are the main effects of the TRAP that leads to numerous respiratory health effects [4].…”