Air pollution is a major challenge for public health in Asia, especially in China and India. It is particularly serious in winter when the need or demand for energy supplies increases because many people rely on fossil fuels (coal, oil, and natural gas) or biomass burning to keep warming.
Numerous reports have documented various air pollution episodes in different Asian countries. Recently, I have reviewed seasonal air pollution in winter in the enclosed posts. To fully understand the dynamics of air pollution in Asia, it may be interesting and necessary to overview the air pollution in the continent of Asia in spring.
The starting date of spring varies in different Asian countries because of the heterogeneity of local climates, cultures, and customs. In some countries (e.g., India, Turkey), spring months generally include March, April, and May, while in some other countries (e.g., China), spring begins in early February and continues until early May.
Thus, this post aimed to conduct a brief overview of air pollution across Asia in March and April 2018 since it is springtime shared by almost all Asian countries. The Real-Time Map of Air Pollution displayed at the US-based non-profit Berkeley Earth website was used to demonstrate air pollution patterns and trends. Such an effort may also help people decide when and where to have their spring visits in the next few years.
Overall, as shown on the Real-Time Map of Air Pollution, different levels of air pollution were persistently evident across inland countries in the continent of Asia (such as China, Mongolia, India, and Iran) and frequently presented in island countries in Asia, including Malaysia, Indonesia, Philippines, and Japan, during March and April 2018. With the available data, air quality was worse in China, followed by Mongolia, India, Turkey, Iran, Thailand, and Vietnam. In late April, air quality was improved in most areas of the continent of Asia.
Specifically, toxic air pollution was persistently evident across China in March 2018. This month, an orange smog alert – the second-highest in a four-level system after red – was declared twice in more than 30 cities in northern China (from March 12 to 14 and March 25 to 27, respectively). On March 27, many areas in northern China were hit by the year’s first severe sand storm attributable to land deterioration and desertification coupled with climate change. It can be noted on the Real-Time Map of Air Pollution that dust and sand covered an area of around 1.5 million square kilometers in northern China and lasted for days.
In April 2018, sandstorms continued to smother northern China and the Chinese Capital in the dust. The sandstorm episodes were particularly severe on April 4 and April 9. Air pollution levels in Beijing and some other areas were so high they went off the Air Quality Index system scale. It was reported that many areas recorded a PM10 density higher than 2,000 micrograms per cubic meter of air. In total, hazardous air pollution attributable to the sandstorms persisted for more than 20 days in northern China, from March 27 to April 19. The heavy air pollutants were also floated to southeast China. Since April 21, air quality has much improved across China, possibly due to seasonal winds, temperature increases, and decreased demands for coal-powered energy. In many areas, PM2.5 density became lower than 100 ug/m3.
The severity levels of air pollution in Mongolia were always consistent with those in Northern China during the period.
It was surprisingly noted that air pollution data from Kazakhstan have been added to the Real-Time Map of Air Pollution since March 11, 2018, which will be useful and help advance our understanding of air pollution in Central Asia. Over the past two months, mild to moderate levels of air pollution have been persistently evident across Kazakhstan. Very often, air quality in Eastern Kazakhstan worsened because of cross-border air pollutants from Western China.
For Iran, the data on air pollution over the whole country have also been added to the Real-Time Map of Air Pollution since March 11, 2018. Over the past two months, harmful air pollution patterns were persistently or frequently visible in many areas across Iran. The severity levels of air pollution seemed comparable to those in Turkey, where PM2.5 concentrations persistently fluctuated around 100 ug/m3 but were lower than those in India.
In India, air pollution seemed to improve slightly in northern areas in spring compared to last winter. Harmful air pollution patterns were still persistently visible in early spring in most areas, especially in northern India. In late April, air pollution in India improved further, but not as significantly as in China. As shown on the Real-Time Map of Air Pollution, PM2.5 concentrations in India became higher than in most areas of China for the first time in the year.
In Thailand, Vietnam, and Korea, mild to moderate levels of air pollution were also frequently evident in spring, possibly due to mixed air pollutant emissions generated locally and regionally.
For island countries in Asia, including Malaysia, Indonesia, Philippines, and Japan, air pollution patterns varied from time to time in spring, depending on seasonal winds and the amount of air pollutants floated from the continent of Asia. As I have addressed in a previous post, the real-time air pollution index is not a sensitive indicator of air pollutant emissions in these countries.
In summary, air pollution is still a major concern across the Asian continent in early and middle spring and does not improve until late April.
Related Posts:
Seasonally Persistent and Hazardous Air Pollution in Asia
Bi-weekly Review of Air Pollution in Asia
