The Environment in Numbers

RAPID URBANISATION, economic development, population growth, limited land area and industrial expansion all pose significant environmental challenges for Penang. This includes air and water pollution, landslides, flash floods and solid waste management.

Air Quality

Malaysia uses the Air Pollution Index (API) to assess the ambient air quality based on the health risks of air pollution. The air quality in Penang is monitored at four stations, namely Balik Pulau, Minden, Seberang Jaya and Seberang Perai. The state’s overall air quality worsened in 2019; this is reflected in the decreasing number of days with good API levels and an increase in the number of unhealthy days as compared to 2018 (Table 1). On average, the air quality was measured at Good 12.4% of the time, Moderate at 85.6%, Unhealthy at 1.7%, and Very Unhealthy at 0.5%. The worsening air quality over the years is mainly attributed to industrialisation, a higher number of motor vehicles and seasonal haze in the country.

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Water Quality

The Water Quality Index (WQI) is the most effective method of measuring water quality and the level of pollution. There are seven river basins in Penang, namely Juru, Pinang, Jawi, Kluang, Perai, Kerian, and Bayan Lepas. The state’s overall river basin water quality is moderately polluted. In 2018, of Penang’s river basins, eight (20.5%) rivers were found to be clean, 21 (53.8%) slightly polluted and 10 (25.6%) polluted (Figure 1). The overall WQI increased by about 5.6% in 2018 compared to 2017.

The marine environment is also exposed to pollution from municipal and industrial wastewaters; runoffs from urban, agriculture, land clearing and construction activities; deposition from atmospheric sources; shipping activities; offshore oil and gas exploration; and exploitation activities. The Marine Water Quality Index (MWQI) is used as a method to reflect the marine water quality status.

In 2018 the overall marine water quality in Penang with respect to coastal areas improved compared to the previous year. The monitoring results identified five stations (29%) as Excellent, two stations (12%) as Good and 10 stations (59%) as Moderate. No stations were categorised as Poor (Table 2).

The number of stations in the Excellent and Good categories increased in 2018, from three stations in 2017, to seven. Likewise, areas such as Pantai Sungai Batu Ferringhi and Pantai Miami saw remarkable improvements in MWQI in 2018 compared to 2017.

Waste Management

Over the past five years, the generation, disposal and recycling of municipal solid waste in Penang has changed significantly. Generation of waste increased from less than one million metric tons in 2015 to 1.5 million metric tons in 2019 – an average increase of 11.9% (Table 3). In 2019 the total waste disposed at landfills in Penang was about 2,220 metric tons per day (705 metric tons per day on Penang Island and 1,516 metric tons per day in Seberang Perai) – an increase of nearly 13% compared to 2018. In 2019 the per capita waste generation rate was about 2.3kg per person per day1 in which domestic waste is the primary source. The rise in the standard of living and changes in household consumption patterns have greatly accelerated the rate and amount of domestic waste generation.

Climate Change

For the past two decades, the average temperature in Penang has been increasing by 0.13˚C per year. The historical temperature data in Penang indicates that 2019 was the warmest year since 1997. This is parallel to the global mean temperature changes – 2019 was recorded as the second hottest year since 1880. In 2019 the average temperature in Penang increased to 28.5˚C from 28.1˚C in 20182– an increase of 0.4˚C (Figure 2).

As temperature increases, more moisture evaporates from land and water into the atmosphere and affects overall rainfall patterns. Figure 3 indicates an increase in the variability of rainfall, as well as the number and size of extreme wet and dry spells in various parts of Penang. In 2019 the average rainfall and the number of rainy days in Penang decreased by about 14% and 17.8% respectively compared to 2018.

Environmental Protection and Management

In 2018 Penang spent about RM219.7mil on environmental protection; it contributed about 8.2% of the country’s total environmental protection expenditure, though the sum was a 22.2% decrease from 2017.

As illustrated in Figure 4, expenditure for waste management was the largest contributor at RM116mil (52.8%), followed by pollution management at RM99.3mil (45.2%). Penang recorded the sixth highest environmental protection expenditure in the country after Selangor, Johor, KL, Negeri Sembilan and Terengganu (Figure 5).

1 Including domestic and industrial waste disposed at landfills and recycling items.
2 NOAA. (2020, January 15). 2019 was the second hottest year on record for Earth say NOAA, NASA. Retrieved from:

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