Transboundary smoke haze pollution in Malaysia: Inpatient health impacts and economic valuation
Introduction
Open biomass burning from Indonesia which produces transboundary smoke haze is an annual phenomenon that causes deterioration in the local air quality in Malaysia (Mahmud, 2013). Severe smoke haze episodes were recorded in April 1983, August 1990, June 1991, October 1991, and August 1994. However, the worst episode occurred in 1997 when nearly the entire country was engulfed by thick smog for almost six months. Air pollution index (API) readings for some areas went beyond the hazardous range. The Malaysian API ranges from good (0–50), moderate (51–100), unhealthy (101–200), very unhealthy (201–300) and hazardous (greater than 300). Severe smoke haze episodes also occurred in 2005 and 2006, both in the month of August.
Haze is characterized by smog-like tiny suspended solid or liquid particles (Cheng et al., 2013). Haze can emanate from domestic or transboundary sources. However, in Malaysia, the haze has been attributed to forest and peat fires in Indonesia, hence the term smoke haze. Burned biomass contributes to increased aerosol loadings or smoke in the atmosphere (Reid et al., 2013). The burned biomass contains concentrated particulate matter (organic matter, graphitic carbon, toxic metals and acidic species) that is hazardous to health, especially to the lung, heart, and circulatory systems, and cause eye-associated illnesses among susceptible population groups. The health effects range from health symptoms that lead to treatment-seeking behavior, outpatient and emergency department visits, and hospitalization for moderate and severe cases and mortality for the worst-case scenarios.
Many studies have established the health effects of general air pollution (Anderson, 2009, Kwon et al., 2002, Chen et al., 2004). Other studies also showed that air pollution affects the respiratory and circulatory systems (Wan Mahiyuddin et al., 2013, Linaker et al., 2000, Lee et al., 2002). Air pollution may induce alveolar inflammation, which aggravates preexisting lung disease and is associated with an increased risk of cardiovascular events (Brook et al., 2004).
Studies on the health impacts of extreme air pollution events such as haze and Asian dust storms (ASDs) are limited. In Indonesia during the 1997 haze episode, Seema (2008) reported that the phenomenon caused more than 15,600 “missing children” (1.2 percent of the affected birth cohorts) across Indonesia throughout the five-month period of high exposure. Kwon et al. (2002) findings on ASD events in Seoul showed that there are strong associations between ASD events and cardiovascular and respiratory mortality. Sahani et al. (2001) examined the links between hospital-based mortality data and air pollution due to the 1997 haze in Malaysia. They observed no significant association between particulate matter less than 10 μm (PM10) and non-trauma, respiratory, or cardiovascular mortality. Betha et al. (2013) estimated that about 0.5% of people that were exposed to smoke haze from peat fires in Kalimantan can be affected by cancer after an extended exposure to high concentrations of carcinogenic metals in the particulates.
An investigation of specific haze-related illness during the 1997 smoke haze period at many hospitals in Kuala Lumpur revealed sharp increases in asthma, an acute respiratory infection (Brauer and Jamal, 1998). Outpatient attendance in Kuching, Sarawak and Kuala Lumpur increased between 100 and 200 percent during the peak haze period (World Health Organization, 1998). A similar study in Singapore also showed that there was a substantial increase of 30 percent in outpatient cases including accident and emergency attendances for haze-related conditions. However, there was no evidence of significant rise in inpatient cases (Emmanuel, 2000).
The few local studies on the health effects of air pollution in Malaysia have focused on air pollution sciences. Far fewer studies have assessed the economic effect of the health impact due to haze. Othman and Shahwahid (1999) attempted to value the cost of the 1997 haze impact on health along with other economy-wide impacts using the cost of illness (COI) approach. The link between API and related outpatients (inpatients for the most affected state – Sarawak) was estimated using a dose–response function based on a panel data regression. The effects of the socio-demographic characteristics such as age group and spatial factors (rural–urban) were not investigated due to data limitations. A recent study by Pek and Othman (2011) used a choice experiment model to estimate the economic value of air and water quality degradation due to poor solid waste disposal technologies in the Semenyih area in the state of Selangor, Malaysia.
In this study, we examined the economic effect of the impact of smoke haze on associated inpatient cases at selected hospitals in the Kuala Lumpur Federal Territory and the Selangor state in Peninsular Malaysia for four selected years (2005, 2006, 2008, 2009). The impact of spatial factors (rural, semi-urban, urban) and demographic variables (age) of respondents on inpatient cases was also examined. Economic valuation of health impacts is important to better appreciate the scale of the transboundary haze hazard in relation to other domestic health, social, or environmental problems.
Section snippets
Data needs and sources
The Ministry of Health (MOH) Malaysia via the Health Informatics Center (HIC) compiles and manages the national database on visitation rates, health treatment (in- and outpatients), and illness types at public hospitals and clinics throughout the country. This center functions as the repository (known as the Health Information Management System, HIMS) for integrated health information for the country. Socioeconomic information such as age and residential area is also provided. Information on
Profile of inpatient rates across air pollution levels
Table 1 provides the average daily statistics for total inpatient cases per 10,000 persons for all hospitals for each ordinal category of API and PM10 concentrations. Note that we further classified the API Moderate category into two – Upper Moderate category (API between 51 and 75) and Lower Moderate category (API between 76 and 100). The Malaysian government routinely starts alerting the public about any haze-looming effects once the API reading reaches the Lower Moderate category.
The
Implications and concluding remarks
Over the study period (2005, 2006, 2008 and 2009), there were on average 19 days of transboundary smoke haze episodes during which the API ≥ 76 (within Lower Moderate to Hazardous categories). Each haze episode on average resulted in an increase of 2.4 inpatient cases per 10,000 persons each year. The marginal impact of smoke haze on inpatient rates was highest for children, followed by young adults, senior citizens, and infants.
The annual cost to the Malaysian economy due to the incremental
Acknowledgments
Our gratitude goes to the Economy and Environment Program for South East Asia (EEPSEA), who provided the financial support for this study in 2011. The same appreciation to the Ministry of Health, Malaysia for their cooperation in allowing us to access the pertinent database, without which this study would not be realized.
References (24)
Air pollution and mortality: a history
Atmos. Environ.
(2009)- et al.
Chemical speciation of trace metals emitted from Indonesian peat fires for health risk assessment
Atmos. Res.
(2013) - et al.
Effect of Asian dust storm events on daily mortality in Taipei, Taiwan
Environ. Res.
(2004) - et al.
Long-term trend of haze pollution and impact of particulate matter in the Yangtze River Delta
China. Environ. Pollut.
(2013) - et al.
Effects of the Asian dust events on daily mortality in Seoul, Korea
Environ. Res.
(2002) Assessment of atmospheric impacts of biomass open burning in Kalimantan, Borneo during 2004
Atmos. Environ.
(2013)- et al.
A choice experiment analysis for solid waste disposal option: a case study in Malaysia
J. Environ. Manag.
(2011) - et al.
Observing and understanding the Southeast Asian aerosol system by remote sensing: an initial review and analysis for the Seven Southeast Asian Studies (7SEAS) program. 2013
Atmos. Res.
(2013) - et al.
Short-term effects of daily air pollution on mortality
Atmos. Environ.
(2013) - et al.
Cost-of-Illness and willingness-to-pay estimates of the benefits of improved air quality: evidence from Taiwan
Land Econ.
(2000)