Mohd Nasir Hassan

Review of air pollution and health impacts in Malaysia

In the early days of abundant resources and minimal development pressures, little attention was paid to growing environmental concerns in Malaysia. The haze episodes in Southeast Asia in 1983, 1984, 1991, 1994, and 1997 imposed threats to the environmental management of Malaysia and increased awareness of the environment. As a consequence, the government established Malaysian Air Quality Guidelines, the Air Pollution Index, and the Haze Action Plan to improve air quality. Air quality monitoring is part of the initial strategy in the pollution prevention program in Malaysia. Review of air pollution in Malaysia is based on the reports of the air quality monitoring in several large cities in Malaysia, which cover air pollutants such as Carbon monoxide (CO), Sulphur Dioxide (SO2), Nitrogen Dioxide (NO2), Ozone (O3), and Suspended Particulate Matter (SPM). The results of the monitoring indicate that Suspended Particulate Matter (SPM) and Nitrogen Dioxide (NO2) are the predominant pollutants. Other pollutants such as CO, O(x), SO2, and Pb are also observed in several big cities in Malaysia. The air pollution comes mainly from land transportation, industrial emissions, and open burning sources. Among them, land transportation contributes the most to air pollution. This paper reviews the results of the ambient air quality monitoring and studies related to air pollution and health impacts.

Air quality in Malaysia: impacts, management issues and future challenges.

Observations have been made on the long‐term trends of major air pollutants in Malaysia including nitrogen dioxide, carbon monoxide, the ozone and total suspended particulate matter (particularly PM10), and sulfur dioxide, emitted from industrial and urban areas from early 1970s until late 1998.

The application of an life cycle inventory (LCI) model for solid waste disposal systems in malaysia

This paper discusses the application of an LCt model for solid waste management systems in Malaysia. The model was used to analyze the environmental and economic impacts of municipal waste management systems in Malaysia. In the first part of the study, the LCI model was adapted to analyze waste management systems of four selected cities: Kuala Lumpur and Penang to represent urban areas; Seremban to represent moderately urban areas and Muar to represent rural areas. The results have shown that Kuala Lumpur and Penang had greater Global Warming Potential (GWP) and the costs spent on the solid waste management were also higher as compared to that in suburban areas. In the second part of the study, a detailed evaluation was carried out by analyzing the implication of introducing incineration and composting into the solid waste management system, and the results were compared with the current system, i.e. 100 % landfilled. The relative GWP was lower for incineration, but the cost was extremely high. The results also showed that the final solid waste to be disposed to landfills and the impact due to water emissions could be reduced significantly when incineration and composting were introduced.

Challenges of global environmental issues on ecosystem management in Malaysia

Environmental problems and their management, particularly when related to urban ecosystems, are becoming increasingly challenging. The end-of-pipe method which has been practiced in the past, and is manifested in our laws and regulations, has gradually changed towards a more pro-active approach. Industries now recognize that environmental management and pollution control are no longer liabilities, but rather opportunities to increase their competitiveness. The general public is increasingly aware of the fact that they have to pay more for management of the environment that is based on the end-of-pipe approach. International agencies and industries world-wide are responding positively with a new paradigm shift towards proactive environmental management through voluntary initiatives. The most challenging task in Malaysia however, is to convince the small and medium scale enterprises to shift from the old to the new management system. While local government agencies remain the key players in the management of urban ecosystems, they still lack human resources and the capacity to handle new challenges. This paper discusses new initiatives towards achieving sustainable urban ecosystem management. It highlights the tools and approaches that are being used as alternatives to the existing end-of-pipe approaches. These tools include, eco-management, wastes minimization, ISO 14000 standardization, design for environment, eco-labeling, life cycle assessment and industrial ecology.

Benefits of air quality improvement in Klang Valley Malaysia

The study evaluated the comparative reliability of different question formats of contingent valuation method by resurvey of the same households nine months after their original survey. The test-retest correlations are statistically significant at 1% level. Comparative reliability of different question formats has been tested comparing the test-retest correlations of these methods. This test has revealed that there is no significant difference in the test-retest correlations between the different question formats for either level A (reduction of the concentration of PM10 by 10%) or level B (reduction of the concentration of PM10 by 20%) air quality improvement.

Current status and needs for life cycle assessment development in Asian/Pacific Regions

ConclusionIn conclusion, LCA that is conducted and used appropriately is an indispensable tool to assist decision-makers in making an informed decision about the environmental impacts of their activities, products or services. A global effort towards LCA use should be encouraged and countries in the Asian/Pacific Regions should not be left out. LCA-related activities reported in the symposium were described

Advantage of the modified Lunn-Mcneil technique over Kalbfleisch-Prentice technique in competing risks

Survival analysis algorithm is often applied in the data mining process. Cox regression is one of the survival analysis tools that has been used in many areas, and it can be used to analyze the failure times of aircraft crashed. Another survival analysis tool is the competing risks where we have more than one cause of failure acting simultaneously. Lunn-McNeil analyzed the competing risks in the survival model using Cox regression with censored data. The modified Lunn-McNeil technique is a simplify of the Lunn-McNeil technique. The Kalbfleisch-Prentice technique is involving fitting models separately from each type of failure, treating other failure types as censored. To compare the two techniques, (the modified Lunn-McNeil and Kalbfleisch-Prentice) a simulation study was performed. Samples with various sizes and censoring percentages were generated and fitted using both techniques. The study was conducted by comparing the inference of models, using Root Mean Square Error (RMSE), the power tests, and the Schoenfeld residual analysis. The power tests in this study were likelihood ratio test, Rao-score test, and Wald statistics. The Schoenfeld residual analysis was conducted to check the proportionality of the model through its covariates. The estimated parameters were computed for the cause-specific hazard situation. Results showed that the modified Lunn-McNeil technique was better than the Kalbfleisch-Prentice technique based on the RMSE measurement and Schoenfeld residual analysis. However, the Kalbfleisch-Prentice technique was better than the modified Lunn-McNeil technique based on power tests measurement.