Burning mosquito coils indoors generates smoke that can control mosquitoes effectively. This practice is currently used in numerous households in Asia, Africa, and South America. However, the smoke may contain pollutants of health concern. We conducted the present study to characterize the emissions from four common brands of mosquito coils from China and two common brands from Malaysia. We used mass balance equations to determine emission rates of fine particles (particulate matter < 2.5 microm in diameter; PM(2.5)), polycyclic aromatic hydrocarbons (PAHs), aldehydes, and ketones. Having applied these measured emission rates to predict indoor concentrations under realistic room conditions, we found that pollutant concentrations resulting from burning mosquito coils could substantially exceed health-based air quality standards or guidelines. Under the same combustion conditions, the tested Malaysian mosquito coils generated more measured pollutants than did the tested Chinese mosquito coils. We also identified a large suite of volatile organic compounds, including carcinogens and suspected carcinogens, in the coil smoke. In a set of experiments conducted in a room, we examined the size distribution of particulate matter contained in the coil smoke and found that the particles were ultrafine and fine. The findings from the present study suggest that exposure to the smoke of mosquito coils similar to the tested ones can pose significant acute and chronic health risks. For example, burning one mosquito coil would release the same amount of PM(2.5) mass as burning 75-137 cigarettes. The emission of formaldehyde from burning one coil can be as high as that released from burning 51 cigarettes.

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Air pollution is the culprit to yearly millions of deaths worldwide, deteriorating human health. What is not yet clear is the impact of environmental factors on susceptibility to getting infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The study aimed to determine associations between air quality, meteorological factors, and COVID-19 cases in Kuala Lumpur, Malaysia. Air pollutants and meteorological data in 2018-2020 were obtained from the Department of Environment Malaysia, while daily new COVID-19 cases in 2020 were obtained from the Ministry of Health Malaysia. Data collected were statistically analyzed using the Statistical Package for Social Sciences (SPSS). There were significant differences between PM 10 , PM 2.5 , SO 2 , NO 2 , CO, O 3, and solar radiation in 2019 and 2020 since movement control order (MCO) was implemented on 18 March 2020. Spearman's correlation test showed that COVID-19 cases were positively correlated with PM 10 (r = 0.131, p < 0.001), PM 2.5 (r = 0.151, p < 0.001), SO 2 (r = 0.091, p = 0.003), NO 2 (r = 0.228, p < 0.001), CO (r = 0.269, p = 0.001), and relative humidity (RH) (r = 0.106, p = 0.001), whereas ambient temperature (AT) was negatively correlated with COVID-19 cases (r =-0.118, p < 0.001). Further, multiple linear regression suggested that NO 2 and AT (R 2 = 0.071, p < 0.001, f 2 = 0.08) were the most significant air pollutant and meteorological factors with weak contribution that influenced the incidence of COVID-19 cases in Kuala Lumpur. In general, better air quality, lower RH, higher AT, along with the targeted approach implemented thus far, have proven to curb the spread of this virus infection in Malaysia. This study supports future research in studies documented to understand the potential of transmission, survival, and infection of SARS-CoV-2.

This study was done to investigate the relationship between Indoor Air Quality (IAQ) and prevalence of Sick Building Syndrome (SBS) in two different offices (old and new) in Selangor. Hundred and seventy workers were selected consist of 85 office workers for each building. Questionnaire based on Indoor Air Quality and Work Symptoms Survey, NIOSH, Indoor Environmental Quality Survey, 1991 was used to record prevalence of SBS. Measurement of indoor air quality was performed using instruments recommended by IAQ Code of Practice, Department of Occupational Safety and Health, Malaysia. IAQ supplied air was significantly higher in new building with the median 22.49 cfm/person while 15.79 cfm/person in old building (z = -6.23, p<0.001). The prevalence of SBS in old building was significantly higher compared to the new building (χ 2 = 30.6, p<0.001). Levels of indoor air pollutants in old building were significantly higher compared to new building for: CO 2 (z = -4.62, p<0.001); TVOC (z = -2.71, p<0.05); PM 10 (z = -2.11, p<0.05); PM 2.5 (z = -2.35, p<0.05), meanwhile for UFP (z = 4.72, p<0.001) and THI value (z = -4.57, p<0.001), new building was significantly higher compared to old building. There was significant association between the prevalence of SBS and the indoor air pollutants in the old building namely CO 2 (OR = 3.56, 95% CI = 1.327-9.548); CO (OR = 4.95, 95% CI = 1.740-14.127); TVOC (OR = 4.71, 95% CI = 1.571-14.151); PM 10 (OR = 6.23, 95% CI = 2.278-17.065) and PM 2.5 (OR = 4.18, 95% CI = 1.564-11.199), while in the new building, the prevalence of SBS showed significant association with an indoor air pollutant namely UFP (OR = 6.53, 95% CI = 1.757-24.327). After controlling the cofounders; age, medical condition, smoking and having pet at home, the results showed that CO 2 , CO, TVOC, PM 10 , PM 2.5 influenced SBS in old building while UFP influenced SBS in the new building. This study suggested that when there was an increase in the ventilation rates per person in office building, it would significantly reduced prevalence of SBS, even though both buildings meet the existing ASHRAE ventilation standards for office building. Reduction in prevalence of SBS would depend on the increase in ventilation rates, ventilation effectiveness and reduction in indoor air pollutants that can cause SBS.

Some of the environmental toxicants from air pollution include particulate matter (PM10), fine particulate matter (PM2.5), and ultrafine particles (UFP). Both short- and long-term exposure could result in various degrees of respiratory health outcomes among exposed persons, which rely on the individuals' health status. Methods. In this paper, we highlight a review of the studies that have used biomarkers to understand the association between air particles exposure and the development of respiratory problems resulting from the damage in the respiratory system. Data from previous epidemiological studies relevant to the application of biomarkers in respiratory system damage reported from exposure to air particles are also summarized. Results. Based on these analyses, the findings agree with the hypothesis that biomarkers are relevant in linking harmful air particles concentrations to increased respiratory health effects. Biomarkers are used in epidemiological studies to provide an understanding of the mechanisms that follow airborne particles exposure in the airway. However, application of biomarkers in epidemiological studies of health effects caused by air particles in both environmental and occupational health is inchoate. Conclusion. Biomarkers unravel the complexity of the connection between exposure to air particles and respiratory health.

This study was carried out to determine the level of exposure to PM10 and NO2 and its relation to respiratory health among primary school children living near petrochemical industry area at Kertih, Terengganu. This cross sectional comparative study was conducted among 60 children from studied group and 60 children from comparative group. The respondents were selected based on inclusive criteria's for this study. Level of exposure of PM10 was measured using DustTrak Aerosol Monitor while level of exposure of NO2 was measured using LaMotte Air Sampling Pump. Questionnaire was used to collect information on respondent's socio-demography background and respiratory symptoms. Lung function test was performed using Spirometer. Results showed that the mean concentration of PM10 (79 μg/m3) and NO2 (3.73 ppm) for studied group was higher compared to comparative group, PM10 (49 μg/m3) and NO2 (0.14 ppm). As overall, reported respiratory symptoms were significantly higher among studied group compare to comparative group. Significant reduction value of FEV1/FVC% showed that there was airways obstruction for studied group. Findings from this study indicated that exposure to indoor PM10 and NO2 concentrations may increase risk of getting respiratory symptoms and reduction of lung function among primary school children living near petrochemical industry area.

In the last few years, air within homes have been indicates by various and emerging body as more serious polluted than those outdoor. Prevalence of respiratory inflammation among school children aged 8 and 10 years old attending national primary schools in urban and rural area were conducted in Klang Valley. Two population studies drawn from the questionnaires were used to investigate the association between indoor particulate matter (PM2.5 & PM10) in a home environment and respiratory implication through the understanding of biological responses. Approximately 430 healthy school children of Standard 2 and Standard 5 were selected. Indication of respiratory symptoms using adaptation questionnaire from American Thoracic Society (1978). Sputum sample collection taken for biological analysis. IL-6 then was analyse by using ELISA techniques. Indoor PM2.5 and PM10 were measured using Dust Trak Aerosol Monitor. The mean concentration of PM2.5 (45.38 µg/m3) and PM10 (80.07 µg/m3) in urban home environment is significantly higher compared to those in rural residential area (p=0.001). Similar trend also shows by the prevalence of respiratory symptom. Association were found with PM2.5 and PM10 with the level of IL-6 among school children. A greater exposure to PM2.5 and PM10 are associated with higher expression of IL-6 level suggesting that the concentration of indoor particulate in urban density area significantly influence the health of children.

Studies have found a high seroprevalence of T. gondii in schizophrenia patients than controls. This casecontrol study was done to determine the serprevalence of Toxoplasma gondii and to identify its risk factors among schizophrenia patients at Hospital Kajang. Eighty-eight (88) schizophrenia patients and 88 nonpsychiatric controls were examined for the presence of anti-Toxoplasma IgG and IgM antibodies by Enzyme Linked Immunosorbent Assay (ELISA). Questionnaires were used to collect socio-demographic and behavioral data among the respondents. From the results, the seroprevalence of anti-T. gondii IgG antibodies was significantly higher (51.0%) in schizophrenia patients than in controls (30.7%); (OR = 2.01; 95% CI: 2.16-3.01; p = 0.023. There was no significant association between the socio-demographic factors and toxoplasmosis. Beef consumption (p = 0.004, OR = 3.852, CI: 1.550-9.569), pork consumption (p<0.001, OR = 13.089, 95%CI: 4.730-36.219) and risky cat contact (p = 0.047, OR = 4.061, 95% CI: 1.985-16.745), were found to be significantly associated with T. gondii infection. Our results show that there is a relationship between toxoplasmosis and schizophrenia.