Malaysian Journal of Public Health Medicine 2018, Vol. 18 (1): 38-45 ORIGINAL ARTICLE THE MALAYSIA HAZE AND ITS HEALTH ECONOMIC IMPACT: A LITERATURE REVIEW Norfazillah Ab Manan 1 , Mohd Rizal Abdul Manaf 1 and Rozita Hod 1 1 Community Health Department, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, Bandar TunRazak,56000 Cheras, Kuala Lumpur, MALAYSIA. Corresponding author: Norfazillah Ab Manan Email: drfazillah789@gmail.com ABSTRACT Introduction: The transboundary smoke haze has become a major concern as it had a wide ranging impact in Southeast Asia from the aspect of public health to national economics. This review aims to synthesize available literature in epidemiology, economics and haze related studies to provide essential information for the valuation of health costs associated with haze in Malaysia. Methods: Evidence on health economic impact of haze was gathered by conducting a literature review and collecting information on the health effects of haze and the cost of it as well as the hospitalization cost from medical illnesses and hospital admissions due to haze. Articles were taken from those that were published from 1999 to 2016.Results: The 1997 Asian Haze episode has caused increasing trend of prematurity of mortality and respiratory problems and several series of haze later had caused increased number of hospitalization. The cost impact on hospital admission ranges from MYR1.8 million in 2005 to MYR118.9 million in 2013. During the 1997 haze, the incremental cost of illness (COI) was noted to be MYR 21million and it shot up to MYR 410 million during the 2013 haze. Conclusion: The haze gives a serious health effect to our country and our neighbours. These health effect has caused a significant health economy impact which include rise in hospital admission cost and medication, incremental cost of illness and extend to cost of medical-related leaves taken and lead to loss of income opportunities. Keywords: haze, health impact, hospitalization, air pollution and forest fire, particulate matter INTRODUCTION In recent years, the transboundary smoke haze has become a major concern with regards to air pollution as it had a wide ranging impact in Southeast Asia from the view of public health to national economics (1). Haze is a transboundary pollution when its density and extent is so great at the source that it remains at measureable levels after crossing into another country’s airspace (2). Since 1982, these haze pollution has become almost an annual occurrence in Southeast Asia, with the worst episodes being in the period of 1997–1998 and in 2006–2007 (3). However, the haze episode that occurred in 2015 was noted to be the worst after the 1997 Asian Haze (4).The haze affects the health of some 75 million people and the economies of six Southeast Asian nations; Indonesia, Malaysia, Singapore, Thailand, Brunei, and the Philippines (5). In our local setting, the open biomass burning from Indonesia which produces transboundary smoke haze is an annual phenomenon that causes deterioration in the local air quality in Malaysia (6).The influence of wind cause these open biomass burning from our neighbours cross our borders and effect its people.However, there is small contribution of our local source that contribute to the haze condition. These local anthropogenic source came from the few burning hotspots occurred in our local area particularly in the paddy field and palm oil plantation (7). Other than that, domestic factors such as activity in industry, motor vehicle and open burning contributed to the worsening haze (8). Haze is characterized by smog-like tiny suspended solid or liquid particles(9). Haze from biomass smoke contains a large and diverse number of chemical components that many also consider to have some health implications upon the general population. These include the particulate matter (PM), sulphur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), carbon monoxide (CO) and ozone (O 3 )(10). However, recent study showed that CO and O 3 were not listed as the chemical compounds found in haze (11). For most of the studies, PM is the major component of the haze and significantly contribute to it (9, 12). Haze is defined as a pollution phenomenon characterized by deteriorated horizontal visibility of less than 10 km that is caused by fine particles suspended in the atmosphere (13). For Malaysia, the occurrence of haze is based on the level of certain air pollution or based on the Air Pollution Index (API). One of our recent and local study defined haze days as when daily particulate matter with size less than 10 µm(PM 10 ) concentration exceeded 100 μg/m 3 (14). Another local study stated that haze episodes