Mal J Med Health Sci 14(SP2): 56-62, Nov 2018 56 Malaysian Journal of Medicine and Health Sciences (eISSN 2636-9346) ORIGINAL ARTICLE Air Pollutants Exposure and Frequency of Micronuclei (MN) among Primary School Children nearby Industrial Area Siti Aishah Muhamad Daud, Juliana Jalaludin, Nor Ashikin Sopian Department of Environmental and Occupational Health, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia ABSTRACT Introduction: Air pollutants that possessed genotoxic properties have the potential to induce genetic damage. Micro- nuclei (MN) frequency is used as an indicator for identifying potential genotoxic exposures. A comparative cross-sec- tional study was carried out among primary school children in a petrochemical industrial area (N=111, Kemaman) and a rural (N=65, Dungun) area in Terengganu. Methods: Validated questionnaires were distributed to obtain the respondents’ socio-demographic data, previous exposure and reported respiratory illness. The frequency of micronu- clei was assessed in collected buccal mucosa samples of children. The air monitoring was also carried out at 6 select- ed schools. Results: Results from the statistical analysis carried out showed significant differences with p=0.001 for all parameters assessed between areas, which included ultrafine particles, UFP (z = -4.842), PM 2.5 (z = -10.392), PM 10 (z= -11.074) NO 2 (z = -11.868), SO 2 (z = -5.667), relative humidity (z = -5.587). The MN frequency was statistically significant with PM 2.5 (χ 2 = 17.78, p=0.001) and PM 10 (χ 2 = 15.429, p =0.001). The statistical analysis also showed a significant association between UFP and coughing (PR=2.965, 95% CI=1.069-8.225). The multiple logistic regres- sion analysis showed that the main pollutants influencing MN frequencies were UFP and NO 2 with UFP (PR=1.877, 95%CI= 1.174-3.002) and NO 2 (PR=1.008, 95%CI= 1.001-1.015). Conclusion: This study demonstrated that ex- posure to air pollutants may increase the risk of respiratory illness and may induce MN formation among children. Keywords: Air pollutants, Indoor air quality, Respiratory health, Genotoxicity, Micronuclei (MN) Corresponding Author: Juliana Jalaludin, PhD Email: juliana@upm.edu.my Tel: +60389472401 INTRODUCTION The rapid growth of industries has led to environmental health degradation which eventually increases the deterioration of health conditions, both acute and chronic, especially among vulnerable groups such as children, the elderly and the infirmed. It had been postulated that children are more vulnerable than adults to environmental risks due to several factors, such as children breathe in higher volumes of air compared to adults, their body systems are still developing, and they have little control over their environment (1). It is important to know that exposure to toxic air pollutants at early stages of development would lead to irreversible damage to the children. Nowadays, there is a growing concern about the air pollutants that can exhibit genotoxic effects on the receptors, as they are able to induce cancer. Air pollutants like particulate matter, nitrogen dioxide (NO 2 ), and sulfur dioxide (SO 2 ) can cause genotoxic effects to human due to their physical and chemical properties. For instance, inhalation of particulate matter which contains metal, carcinogen organic and inorganic materials can cause DNA damage, inflammation and genomic instability (2). On the other hand, toxicokinetic of NO 2 depends on its behavior as an oxidative agent and free radical properties which can deplete antigen defenses (3). Generally, the chronic exposure to a complex mixture of toxic air pollutants may induce genotoxic damage such as oxidative damage and formation of DNA adducts. These DNA adducts can promote the formation of micronuclei at the cellular level. The micronuclei are derived from acentric chromosome fragments or whole chromosomes which failed to migrate to spindle poles during anaphase. The presence of a small nucleus in the dividing cell is providing a convenient indicator for identifying potential genotoxic exposures and chromosomal instability in humans. A higher number of MN in cells is associated with a higher risk of cancer at the early stage of life (4). This present study intended to quantify the magnitude of air pollutants exposure at school and homes of the