This cross-sectional comparative study investigates the association between particulate matters (PM; PM 10 , PM 2.5 and ultrafine particle (UFP) and concentration of biomarkers; Interleukin-6 (IL-6) and Tumor Necrosis Factor-Alpha (TNF-α) using 62 bus drivers as exposed group and 62 administrative staff as comparative group in Klang Valley, Malaysia. T-test results showed that the mean exposure level of PM 10 (t = 8.14, p<0.01), PM 2.5 (t = 9.95, p<0.01) and UFP (t = 19.61, p<0.01) were significantly higher among the bus drivers compared to comparative group. Mann-Whitney U test of IL-6 (z =-2.43, p<0.05) and TNF-α (z =-5.88, p<0.01) were also found to be significantly higher in the bus drivers. Positive correlations were found between the exposure level of PM and concentration of biomarkers. In conclusion, the bus drivers showed higher concentration of IL-6 and TNF- and were at a higher risk of getting respiratory illnesses compared to comparative group. Thus, more attention should be given on the control of high level of exposure to PM in order to minimize the adverse health effects among the groups at risk.

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.

The high loading of air pollutants in heavy traffic area has urged researcher to pay greater attention as it frequently associated with significant health impact particularly among children. This study aims to determine the association between traffic-related air pollutants and respiratory health among Malay primary school children in heavy traffic area and low traffic area. A cross-sectional comparative study was carried out among Malay children in heavy traffic area (N=69, Kajang) and low traffic area (N=69, Hulu Langat) areas. Air quality monitoring was conducted in 6 primary schools which include parameters of PM10, PM2.5, ultrafine particles (UFP), nitrogen dioxide (NO2), sulphur dioxide (SO2), carbon monoxide (CO) and carbon dioxide (CO2). A set of standardized questionnaire was distributed to obtain respondents’ background information, exposure history and respiratory health symptoms. Spirometry test was carried out to determine the lung function of the respondents. Traffic count survey was conducted at two time intervals per day (7.00-7.30 am and 1.00-1.30 pm). The result showed that there is a significant difference between concentration of PM10 [t=22.37; p≤0.001], PM2.5 [t=9.73; p≤0.001], UFP [Z= -3.36; p=0.001], NO2 [t=5.73; p=0.001], SO2 [t=6.88; p≤0.001] and CO2 [t=15.67; p≤0.001] in school in exposed and comparative area. Lung function abnormalities found in children in exposed area was 3 times higher than comparative area. All respiratory symptoms show significant difference between both exposed and comparative groups. All pollutants show a significant association with lung function abnormality among the respondents. The finding indicated that higher PM10 and PM2.5 will increase the FVC abnormality by 4 and 6 times of getting FVC abnormality and increase the FVC abnormality by 2 and 3 times of getting FEV1 abnormality. The finding concluded that exposures to traffic-related air pollutants, especially PM10, PM2.5 increase the risk of getting lung function abnormality and respiratory health symptoms among respondents.

This article reviewed the published studies on the environmental exposure to polycyclic aromatic hydrocarbons (PAHs) among children and assessed the urinary 1-hydroxypyrene (1-OHP) level as a biomarker of exposure to PAHs. The current knowledge of the potential health effects of increased 1-OHP in children was reviewed. Additionally, the influence of genetic polymorphism on the urinary 1-OHP level was discussed in this review. The assembled data showed that children who are attending schools or living close to industrial and polluted urban areas might have greater exposure to higher concentrations of PAHs with a higher level of urinary 1-OHP when compared to those children living in rural areas. Urinary 1-OHP may be a reliable biomarker for determining the genotoxic effects, oxidative stress and inflammation caused by exposure to PAHs. Strong research evidence indicated that the total body burden of PAHs should be evaluated by biomonitoring of 1-OHP in line with other urinary PAHs metabolites (with 2–3 rings) to evaluate recent total exposure to PAHs. Overall, the study suggests implementing a mitigation plan to combat air pollution to provide a cleaner environment for children.

This study aimed to investigate the association between particulate PAHs exposure and DNA damage in Malaysian schoolchildren in heavy traffic (HT) and low traffic (LT) areas. PAH samples at eight schools were collected using a low volume sampler for 24 h and quantified using Gas Chromatography-Mass Spectrometry. Two hundred and twenty-eight buccal cells of children were assessed for DNA damage using Comet Assay. Monte-Carlo simulation was performed to determine incremental lifetime cancer risk (ILCR) and to check the uncertainty and sensitivity of the estimated risk. Total PAH concentrations in the schools in HT area were higher than LT area ranging from 4.4 to 5.76 ng m−3 and 1.36 to 3.79 ng m−3, respectively. The source diagnostic ratio showed that PAHs in the HT area is pyrogenic, mainly from diesel emission. The 95th percentile of the ILCR for children in HT and LT area were 2.80 × 10−7 and 1.43 × 10−7, respectively. The degree of DNA damage was significantly more severe in children in the HT group compared to LT group. This study shows that total indoor PAH exposure was the most significant factor that influenced the DNA damage among children. Further investigation of the relationship between PAH exposure and genomic integrity in children is required to shed additional light on potential health risks.