Malaysian Ambient Air Quality Guidelines Research Articles

Variability of PM10 level with gaseous pollutants and meteorological parameters during episodic haze event in Malaysia: Domestic or solely transboundary factor?

Haze has become a seasonal phenomenon affecting Southeast Asia, including Malaysia, and has occurred almost every year within the last few decades. Air pollutants, specifically particulate matter, have drawn a lot of attention due to their adverse impact on human health. In this study, the spatial and temporal variability of the PM10 concentration at Kelang, Melaka, Pasir Gudang, and Petaling Jaya during historic haze events were analysed. An hourly dataset consisting of PM10, gaseous pollutants and weather parameters were obtained from Department of Environment Malaysia. The mean PM10 concentrations exceeded the stipulated Recommended Malaysia Ambient Air Quality Guideline for the yearly average of 150 μg/m3 except for Pasir Gudang in 1997 and 2005, and Petaling Jaya in 2013. The PM10 concentrations exhibit greater variability in the southwest monsoon and inter-monsoon periods at the studied year. The air masses are found to be originating from the region of Sumatra during the haze episodes. Strong to moderate correlation of PM10 concentrations was found between CO during the years that recorded episodic haze, meanwhile, the relationship of PM10 level with SO2 was found to be significant in 2013 with significant negatively correlated relative humidity. Weak correlation of PM10-NOx was measured in all study areas probably due to less contribution of domestic anthropogenic sources towards haze events in Malaysia.

Evaluating the Performance of Random Forest and Multiple Linear Regression for Higher Observed PM10 Concentrations

Background: Air pollution is notable for its direct impact on human health. Hence, the ability to accurately predict air pollution concentrations is vital to raising public awareness of this issue and for better understanding of air quality management. Aim: Therefore, the aim of this research is to predict PM10 concentrations in Malaysia, specifically on Langkawi Island using random forest and multiple linear regression. Method: The predictive analytics were based on air pollution hourly data from 2003 until 2017. The eight parameters chosen in this study were PM10, NO2, O3, CO, SO2, Relative Humidity (RH), Temperature (T), and Wind Speed (WS). The findings revealed that PM10, SO2, NO2, CO, and O3 hourly trends at Langkawi Island were below the recommended Malaysian Ambient Air Quality Guidelines (MAAQG) standard. Multiple linear regression (MLR) and random forest (RF) were used for modelling and compared based on their prediction accuracy. Result: The values of RMSE, NAE, IA, PA and R2 for MLR were 8.0698, 0.1368, 0.8584, 0.7737 and 0.5984 respectively while the values of RMSE, NAE, IA, PA and R2 for RF were 6.674038, 0.107664, 0.911974, 0.852570 and 0.726681 correspondingly. From the results, the RF method was chosen as a better model than MLR since both; the error measures and the accuracy measures results are close to 1. Nevertheless, the PM10 models (RF and MLR) are unable to take into account the higher observed concentrations.

CLASSIFICATION OF HIGH AND LOW LEVEL OF PM10 CONCENTRATIONS IN KLANG AND SHAH ALAM, MALAYSIA

Particulate matter (PM) comprises of a complex mixture of small solid or liquid particles of organic and inorganic elements that floats freely in air. PM10 is defined as a particulate matter with an aerodynamic diameter of 10 m or less. The main objective of this paper is to classify the level of PM10 in selected locations in Peninsular Malaysia using discriminant analysis. Two important components considered in this study, namely; the meteorological factors and pollutant factors. The meteorological factors comprise of wind speed, wind direction, humidity and temperature while pollutant factors consist of Carbon Monoxide (CO), Sulphur Dioxide (SO2), Nitrogen Dioxide (NO2) and Ozone (O3). The classification of high or low level of PM10 concentrations was based on the Malaysia Ambient Air Quality Guideline (MAAQG). The findings indicated that the classification equation differs from location to location due to different levels of PM10 concentrations, location of monitoring stations and factors affecting air pollution in that location. The simulation data also verified that the classification of PM10 concentration was almost similar to the real condition that occurred in Klang in October 2015.

Particulate matter study at residential and educational areas in Shah Alam, Malaysia

Air pollution has become a crucial problem nowadays, especially on particulate matter. Major sources of particulate matter came from transportation, while wind speed, temperature and other factors can contribute to this problem. This research focuses on the determination of levels of particulate matter at residential and educational areas in Shah Alam. Two (2) sites were chosen, namely Flat Nilam Sari that represented the residential areas while University of Selangor represented the educational areas. Four (4) sets of levels of particulate matter and other parameters (traffic volume, temperature and wind speed) were obtained by using Dylos DC1700 Laser Particle Counters and Mini Thermo-Anemometer respectively. The results obtained showed that the particulate matters (PM2.5 and PM10) at both study areas are below permissible limits required by Malaysian Ambient Air Quality Guidelines (MAAQS). However, the Air Quality Indexes of PM2.5 at both study areas shows that the AQI readings are categorized as unhealthy. The highest AQI reading was 159, which was recorded at residential area. In most cases, the results revealed that particulate matter produced by traffic vehicles has significant correlation with the increase of travelled particles. From the correlation analysis, both study areas have significant correlation of PM2.5 with medium vehicles while the educational area has correlation with all types of heavy, medium and small vehicles.

Study of Dispersion of HCL from Waste-to-energy Plant at Different Receptor and Chimney Height at Taman Beringin, Kuala Lumpur

Combustion of solid waste from waste-to-energy (WtE) plant emits a variety of air pollutants that may be hazardous to the environment and health. In order to control these hazardous air pollutants, regulation and emission limits has been established. The emission of these air pollutants can be control but not eliminated by implementing air pollution control (APC) devices. The emitted air pollutants will then be dispersed base on local weather. In Malaysia, the Malaysia Ambient Air Quality Guideline (MAAQG) is referred to ensure that the concentration of pollutants does not exceeds limit. For parameters that are not included in the MAAQS, other standard from other nation such as the Alberta’s Ambient Air Quality Objectives and Guidelines (AAQOG) is referred. Ground level concentrations (GLC) are commonly reported. In a developing city where new high-rise building may be constructed in the future, it is important that the concentration of pollutants at the higher height to be reported as well. In this study, Taman Beringin, Kuala Lumpur, Malaysia is taken as a case study for studying the air pollutants concentration at different height for a 1,200 t capacity WtE plant. This study is performed using an air dispersion software preferred by the United State (US) Environmental Protection Agency (EPA) known as AERMOD atmospheric dispersion modelling system. Based on the local weather pattern of Taman Beringin and a chimney stack height of 60 m, the maximum height of a building at the location of N 3° 13’ 31.61” E 101° 39’ 36.59” is about 80 m.

Variations of Ground-level Ozone Concentration in Malaysia: A Case Study in West Coast of Peninsular Malaysia

Hourly ground ozone concentration, measured from the monitoring stations in the West Coast of Peninsular Malaysia for the period of 10 years (2003-2012) were used to analyse the ozone characteristic in Nilai, Melaka and Petaling Jaya. The prediction of tropospheric ozone concentrations is very important due to the negative impacts of ozone on human health, climate and vegetation. The mean concentration of ozone at the studied areas had not exceeded the recommended value of Malaysia Ambient Air Quality Guideline (MAAQG) for 8-hour average (0.06 ppm), however some of the measurements exceeded the hourly permitted concentration by MAAQG that is 0.1 ppm. Higher concentration of ozone can be observed during the daytime since ozone needs sunlight for the photochemical reactions. The diurnal cycle of ozone concentration has a mid-day peak (14:00-15:00) and lower night-time concentrations. The ozone concentration slowly rises after the sun rises (08:00), reaching a maximum during daytime and then decreases until the next morning.

HEALTH RISK ASSESSMENT DUE TO EMISSIONS FROM MEDICAL WASTE INCINERATOR IN MALAYSIA

In this research, health risk assessment due to the emission of pollutants from a medical waste incinerator located within industrial estate in the northern part of Malaysia was presented. The influence of pollutants emission in the vicinity of the incineration plant was the main concern in this research. The measured emissions of pollutants from the stacks of the studied plant that may pose risk to human health and the environment are compared against the acceptable limit as in the Environmental Quality (Clean Air) Regulation 2014. Next, the levels of pollutants in ambient air are assessed in comparison with the guideline established by the Malaysia Ambient Air Quality Guideline (MAAQG). The health risk assessment was then conducted by calculating the quantitative risk for non-carcinogenic and carcinogenic pollutants. The study reveals that the total cancer risk due to emission of carcinogenic pollutants from the incinerator is 1.84 x 10-5, which indicates risky circumstances as the calculated risk is higher than the benchmark of acceptable risk of 1 x10-6. Meanwhile the health risk calculated due to emission of non-carcinogenic pollutants ranges between 0.000286 and 0.1, indicating acceptable risk. The result shows that the non-carcinogenic pollutants emitted from the studied medical waste incinerator are within the acceptable exposure limits. However, for carcinogens, the released amounts may cause human health risk, and therefore demands for further attention to reduce the concentrations as low as reasonably practicable, at least in compliance with the established guidelines.

Particulate Matter Levels in Ambient Air Adjacent to Industrial Area

Air quality in the residential areas adjacent to the industrial regions is of great concern due to the association with human health risks. In this work, the concentrations of particulate matter (PM10) in the ambient air of UTHM campus was investigated tostudy the air qualityand their compliance to the Malaysian Ambient Air Quality Guidelines (AAQG). The PM10 samples were taken over 24 hours from the most significant area at UTHM including Stadium, KolejKediamanTunDr. Ismail (KKTDI) and MakmalBahan. The meteorological parameters; temperature, relative humidity, wind speed and wind direction as well as particulate matterwere estimated by using E-Sampler Particulate Matter (PM10) Collector. The highest concentrations of PM10 (55.56 µg/m3) was recorded at MakmalBahan during the working and weekend days. However, these concentrations are less than 150 pg/m3. It can be concluded that although UTHM is surrounded by the industrial area, the air quality in the campus still within the standards limits.

PREDICTION OF PM10 EXTREME CONCENTRATIONS IN URBAN MONITORING STATIONS IN SELANGOR, MALAYSIA USING THREE PARAMETERS EXTREME VALUE DISTRIBUTIONS (EVD)

Objective: The purpose of the study was to determine the best distribution to predict the extreme concentrations of PM10 using the three parameters Weibull, Generalized Extreme Value (GEV) and Generalized Pareto Distribution (GPD). Methodology: The study used maximum concentration of daily PM10 data recorded in the period of 2000-2012 in Klang and Shah Alam, Selangor. The parameters of all distributions were estimated using the method of Maximum Likelihood Estimator (MLE). The goodness of fit of the distribution was determined using performance indicators namely; the accuracy measures and error measures. The best distribution was selected based on the highest accuracy measures and the smallest error measures. Results: The findings showed that the three parameters GEV was the best fit for daily maximum concentration for PM10 in these two stations. The result also demonstrated that the predicted number of days in which the concentration of PM10 exceeded the Malaysia Ambient Air Quality Guideline (MAAQG) for daily concentrations of 150µg/m3 were more than 85% in compliance of the actual number of days. Hence, the GEV can be used for the prediction of the PM10 extreme concentrations.

Diurnal variations of ground-level ozone in three port cities in Malaysia

The diurnal variations of ground-level ozone (O3) concentrations along a gradient of three major port cities (Klang, Perai, and Pasir Gudang) in Malaysia were evaluated. Annual monitoring records (2009) of O3, nitrogen dioxide (NO2), nitric oxide (NO), carbon monoxide (CO), sulfur dioxide (SO2), and particulate matter (PM10) were obtained. Weather-influencing parameters such as incoming solar radiation, temperature, relative humidity, and wind speed were also analyzed. Although an overwhelming majority (99.9 %) of the recorded data are below the prescribed levels in the Malaysian Ambient Air Quality Guidelines (MAAQG), a number of exceedances (0.1 %) (>100 ppb) have been recorded in Klang and Pasir Gudang. The annual hourly average concentrations of O3 were 20.3 ± 18.2, 15.4 ± 15.8, and 14.4 ± 13.1 ppb for Klang, Perai, and Pasir Gudang, respectively. The diurnal cycles of ground-level O3 concentrations and cluster analysis suggest that a unimodal peak occurs between 1 p.m. and 3 p.m., and the highest O3 concentrations were observed during the first quarter of 2009 as a result of the higher rate of local photochemical production. Results of principal component analysis showed that the contributions to O3 level variation by meteorological variables (UVB, temperature, relative humidity, and wind speed) are higher at 47.7, 39.5, and 18.2 % than those of primary air pollutants (NOx, CO, SO2, PM10) at 28.9, 32.6, and 45 % for Perai, Pasir Gudang, and Klang, respectively. The exposure of the population in the three port cities to the elevated levels of ozone during January–May months validated the increasing threat and risks that ozone presents to humans. Result indicated that the concentration of O3 in the three ports was still below the maximum permissible values prescribed by the MAAQG, and expansion in shipping industries is possible in exaggerating O3 problems especially in Klang.

English

One of the concerns of the air pollution studies is to compute the concentrations of one or more pollutants’ species in space and time in relation to the independent variables, for instance emissions into the atmosphere, meteorological factors and parameters. One of the most significant statistical disciplines developed for the applied sciences and many other disciplines for the last few decades is the extreme value theory (EVT). This study assesses the use of extreme value distributions of the two-parameter Gumbel, two and three-parameter Weibull, Generalized Extreme Value (GEV) and two and three-parameter Generalized Pareto Distribution (GPD) on the maximum concentration of daily PM10 data recorded in the year 2010 - 2012 in Pasir Gudang, Johor; Bukit Rambai, Melaka; and Nilai, Negeri Sembilan. Parameters for all distributions are estimated using the Method of Moments (MOM) and Maximum Likelihood Estimator (MLE). Six performance indicators namely; the accuracy measures which include predictive accuracy (PA), coefficient of determination (R2), Index of Agreement (IA) and error measures that consist of Root Mean Square Error (RMSE), Mean Absolute Error (MAE) and Normalized Absolute Error (NAE) are used to find the goodness-of-fit of the distribution. The best distribution is selected based on the highest accuracy measures and the smallest error measures. The results showed that the GEV is the best fit for daily maximum concentration for PM10 for all monitoring stations. The analysis also demonstrates that the estimated numbers of days in which the concentration of PM10 exceeded the Malaysian Ambient Air Quality Guidelines (MAAQG) of 150 mg/m3 are between ½ and 1½ days.

Performance of Home-Scale Incinerator in Releasing NO<sub>x </sub>and Hydrocarbon Gaseous

Treatment of municipal solid waste has been performed by home-scale incinerator (HSI) to identify the gas emission formation and to evaluate the safety level of gases from home scale incinerator (HSI). Incineration of kitchen waste, disposable diapers and yard waste were performed with 1.5 kg for different time of combustion and observed every 5 minutes. These three wastes emitted at different value of NOx due to the composition of waste. The highest value of NOx obtained from kitchen waste was 23 ppm after 25 minutes, disposable diapers was 40 ppm after 20 minutes and yard waste was 56 ppm after 15 minutes. According to Malaysian Ambient Air Quality Guidelines, the emitted NOx gas from HSI meet the requirement while HC did not meet the requirement.

The exposure assessment of airborne particulates matter (PM10 & PM2.5) towards building occupants: A case study at KL Sentral, Kuala Lumpur, Malaysia

Airborne particulates have been recognized as a crucial pollutant of indoor air. These pollutants can contribute towards poor indoor air quality (IAQ), which may affect human health in immediate or long term. This study aims to determine the level of IAQ and the effects of particulate towards occupants of office buildings (the office buildings selected for the case study are SSM, KTMB and MRCB at KL Sentral). The objectives of study are (i) to measure the level of airborne particulates that contribute to the IAQ during working hours, (ii) to compare the level of airborne particulates with the existing guidelines and standards of IAQ in Malaysia and other Asian countries and (iii) to assess the symptoms associated with airborne particulates among the building occupants, which were achieved through primary data collection (case study or site survey, structured interview and questionnaire survey) and supported by literature reviews. The results showed that the mass concentration level of airborne particulates within the areas has exceeded the allowable limit of 0.15mg/m3 by IAQ Code of Practice, 2005 of the Department of Safety and Health (DOSH), Malaysia and 0.05mg/m3 by the Department of Environmental (DOE) (outdoor) of 8 hours continuous sampling. Based on the findings, the highest mass concentration values measured is 2.581 mg/m3 at lobby of SSM building which is the highest recorded 17 times higher from the maximum limit recommended by DOSH than the others. This is due to the nearby construction works and the high numbers of particulates are generated from various types of vehicles for transportation surrounding KL Sentral. Therefore, the development of Malaysian Ambient Air Quality Guidelines on PM2.5 as one of the crucial parameters is highly recommended.

Statistical analysis of PM10 concentrations at different locations in Malaysia

Malaysia has experienced several haze events since the 1980s as a consequence of the transboundary movement of air pollutants emitted from forest fires and open burning activities. Hazy episodes can result from local activities and be categorized as "localized haze". General probability distributions (i.e., gamma and log-normal) were chosen to analyze the PM(10) concentrations data at two different types of locations in Malaysia: industrial (Johor Bahru and Nilai) and residential (Kota Kinabalu and Kuantan). These areas were chosen based on their frequently high PM(10) concentration readings. The best models representing the areas were chosen based on their performance indicator values. The best distributions provided the probability of exceedances and the return period between the actual and predicted concentrations based on the threshold limit given by the Malaysian Ambient Air Quality Guidelines (24-h average of 150 μg/m(3)) for PM(10) concentrations. The short-term prediction for PM(10) exceedances in 14 days was obtained using the autoregressive model.

Carbon monoxide levels along roadway

This paper predicts and compares the carbon monoxide (CO) concentration levels along Sembulan Road for years 2004 and 2014 using CAL3QHC air dispersion model at two major locations, i.e., at Sembulan Roundabout and Sutera Harbour Intersection, Kota Kinabalu, Sabah, Malaysia. The CO concentration “hot-spots” were also identified at Sutera Harbour Intersection, and the highest maximum 1-hr average ground level concentrations of CO modeled for Kpg. Air Sembulan located in the northeast of idling road was 9.33 ppm for year 2004. This study showed that there would be no extreme changes in CO concentration trends for year 2014 although a substantial increase in the number of vehicles is assumed to affect the level of CO concentrations. It was also found that the CO levels would be well below the Malaysian Ambient Air Quality Guidelines of 30 ppm for 1-hour Time-Weighted Average (TWA). Comparisons between the modeled and observed outputs using quantitative data analysis technique and statistical methods indicated that the CAL3QHC predicted results correlated well with measured data. It was predicted that receptors located near to the major intersection, in the long-term would be potentially exposed to relatively higher CO levels.