菲律宾的空气质量

What is the air quality forecast for Philippines?

The Philippines is an archipelagic state in Southeast Asia. It consists of over 7,500 islands which can be regarded as being in three separate areas, Luzon, Visayas and Mindanao. The capital city is Manila which is located in the northern area of Luzon. A survey conducted in 2020 estimated the population to be in excess of 109 million people. In December 2020 the air quality index AQI for Manila recorded levels of 91 US AQI which classifies it as “Moderate” according to the World Health Organisation’s (WHO) recommendations. The main pollutant being PM2.5 with a concentration of 31.2 µg/m³.

In 2019 Philippines was ranked as being 57 out of 98 countries, with an average US AQI reading of 63 and an average PM2.5 reading of 17.6 µg/m³.

How bad is the air pollution in Philippines?

The population of Manila has grown at an alarming rate since 1970, faster than any other city. It is estimated that the density of people is roughly 12,600 per square kilometre. Thousands live in poor quality housing in the shadow of industrial plants or power stations. Smog is almost constantly hanging over the city, exacerbated by the 2.2 million vehicles that clog the streets on a daily basis. According to reports published by the World Health Organisation (WHO), levels of airborne particles of lead (Pb) are three times than the acceptable figure. Concentrations of PM2.5 have also found to be unacceptably high, too.

Before the COVID 19 pandemic, there were some rainy days in Manila when a thick haze would envelop the city totally obscuring the city skyline. Because this was so commonplace, many Philippinos accepted it as the norm. At the start of lockdown, due to the reduction in traffic and industries working, the air quality began to improve due to the lack of emissions. Many residents were reminded just how close the city is to the majestic Sierra Madre range of mountains which was now visible from the city centre due to the lack of haze hanging over the city.

Residents took to social media to spread photographs of sunsets over the city using the Sierra Madre as a dramatic backdrop. By following the lead set by other countries in trying to contain the spread of COVID 19, the Philippine government inadvertently improved the air quality in Metro Manila within a fortnight.

Following the publication of a report conducted by the University of the Philippines’ Institute of Environmental Science and Meteorology (IESM), it was seen that the levels of fine particulate matter or PM2.5 decreased by 40 per cent when compared to levels recorded in January before the enhanced community quarantine, or ECQ commenced in March. These figures were taken from instruments at the ground-level monitoring station in Quezon City, in the northern part of Metro Manila.

Data showed PM2.5 levels had fallen to 7.1 µg/m³ during the first week of the lockdown, much lower than the 20 µg/m³ recorded two weeks earlier and below the World Health Organisation’s recommended safety guideline of 10 µg/m³.

Similar findings were reported by other monitoring organisations, too. For example, Clean Air Asia, which started monitoring air pollution in the capital earlier this year, recorded a 51% to 71% decrease in PM2.5 levels in three areas of Manila for the last week of April when compared to the period before the lockdown.

What are the main causes of air pollution in Philippines?

According to figures from 2016, 80 per cent of the country’s air pollution comes from motor vehicles whilst the remaining 20 per cent comes from stationary sources, such as factories and the open burning of organic matter. Another contributory factor is the weather.

Satellite data showed a significant drop in the pollution levels both in Metro Manila and its neighbouring province of Bulacan for the second half of March. Which coincided with the start of the ECQ (enhanced community quarantine) in Luzon city. These figures were compared to the comparable timescale from previous years. However, some areas reported an increase in levels due to burning organic waste.

A notable scientist who measures air pollution using the aerosol optical depth (AOD), reports that whilst these pieces of apparatus are very good at measuring particle such as dust, smoke and pollution in the air, they are only able to do so at a relatively “local” level, whereas satellite data can record the quality of air over the entire Philippine archipelago.

It was noted that the improvement in air quality was evident when comparing satellite AOD information with figures measured over the same period of time in previous years. Because the seasons affect the air quality it was noted that summer started toward the end of March which corresponded to the start of lockdown. The first half of April was affected by a haze which was drifting over from Indonesia where they were burning biomass.

What can be done to improve the air quality in Philippines?

Proposals have been put forward to phase out the use of leaded gasoline, reduce industrial emissions through filtration, encourage recycling and outlaw vehicles older than 15 years and ban bonfires where garbage is incinerated. With an average speed of just 7 kilometres per hour, the rush-hour traffic in Metro Manila moves more slowly than anywhere else in Southeast Asia. There is currently an overhead rail system but presently only covers a 30-kilometre track. Investing in the expansion of this system would help reduce the number of vehicle on the roads.

It was stated that residents should not rejoice about the better quality air over the lockdown period as it increases again as soon as it came to an end. They were also reminded that once carbon dioxide (CO₂) is released, it has the ability to remain for the next century. So a few relatively “clean” months will have no effect in the long run.

Air pollution can be defined as the alteration of air quality that can be characterised by measurements of physical or biological elements in the air. The undesirable presence of these particles can fall into 2 categories, visible and invisible. Air pollution use usually attributed to human activity, but it can be caused naturally on some occasions, such as wildfires, volcanic eruption and dust storms.

Which city in Philippines had the highest levels of air pollution?

Air pollution has long been seen as a problem in the Philippines. In 2018, a study by the World Health Organisation reported that there were 45.3 air pollution-related deaths for every 100,000 people in the Philippines. This was the third-highest in the world, after China’s 81.5 pollution-related deaths and Mongolia’s 48.8 deaths per 100,000 people.

The two areas recording the highest levels of pollution in the Philippines are Meycauayan, in Central Luzon with a recorded figure of 100 US AQI and Bulacan, again in Central Luzon with a figure of 138 US AQI.

What does the future hold with regards to air quality in Philippines?

The Special Report on Managing Air Quality Beyond COVID-19 revealed that pollution levels in Metro Manila have been steadily increasing since the lockdown finished in May 2020. Industries restarted producing goods again and motorists began commuting again. The report went on to study the two main airborne pollutants found in Manila’s air, namely nitrogen dioxide (NO₂) and PM 2.5 particulate matter, both of which are produced from the emissions given off by the burning fossil fuels. The lockdown in Manila started on the 15^th March and ended on the 15^th May 2020. A study of these two pollutants between these dates showed a dramatic drop in their levels at the start of lockdown. As is to be expected, once lockdown was relaxed and Manila entered a state of general community quarantine (GCQ) on 1^st June, the smog began to return to the skies above Manila.

This post-lockdown report closely examined the air quality in seven major areas within the Metro Manila metropolis. This was done to prove that the reduction in pollutants was not localised and dramatically fell throughout the whole of Metro Manila. Although the overall quality of Manila’s air is better than it was two decades ago, it underlines the reliance the city has on fossil fuels across the entire spectrum.

A post-COCID 19 report recommends recovery options that give priority to clean, sustainable fuels and green transportation systems. To enhance micro-mobility around local areas and to keep air pollution at manageable levels, where possible.

A little-known fact is that air pollution can have a direct effect on a country’s GDP. A figure of between 0.8-1.9 per cent is lost due to air pollution. This is because when people get sick because of the poor quality air, they do not go to work.

It has been recognised by the Department of Environment and Natural Resources (DENR) that air pollution levels have become higher when compared to acceptable levels recommended by the WHO. This presents a problem to the millions of Philippinos who regularly commute on a daily basis. Every day they are exposed to the noxious range of chemicals produced by the range of automobiles encountered throughout the city. Most of the vehicles here are older ones which often have not been fitted with devices that can help reduce the harmful emissions. A major contributor to Manila’s air pollution, are the dark-coloured fumes that are emitted from jeepneys. (A Jeepney is the Philippines’ most popular mean of public transport, extremely cheap and used by most of the locals). Most jeepneys use diesel as a fuel which can be a great source of pollution if not correctly maintained and serviced regularly. It is notorious for producing carcinogens, black carbon (BC) and nitrogen oxide (NO_x). It has also been recognized from a worldwide perspective that 2 million cars in the Philippines cause over 80% of the air pollution.

What effects does poor air quality in Philippines have on health?

A paediatrician from the medical centre in Makati said that 90 per cent of his patients suffer from some sort of respiratory illness and some babies at a mere 2 months old are seen to be suffering from asthma. A recent survey undertaken by the Philippine Paediatric Society asked doctors what the most common disease their patients were suffering from was. The unanimous answer was: diseases of the upper respiratory tract.

Urine samples were taken from children who live and beg on Manila’s congested streets, and they were found to have very high levels of lead in their bloodstream. Due mainly to their close proximity to vehicle exhaust fumes.

Many middle-class citizens who are aware of this problem choose to keep their children indoors and try to clean the air using filtered air conditioners and ionisers, but this resulted in other problems due to the total lack of exercise.

Following the release of a WHO report on Urban Air Pollution in Megacities throughout the world, they stated that over the next decade the concentration levels of air pollution would rise between 75 and 100 per cent to the figures currently recorded.

Nitrogen dioxide (NO₂) and PM2.5 are linked to severe respiratory and cardiovascular health diseases and exposure to high levels of these pollutants affects the body’s natural defences against airborne viruses and increases vulnerability to COVID-19. Other pollutants such as black carbon (BC) and methane (CH₄) accelerate glacial melt due to global warming. Air pollution poses a threat to water and food systems by reducing sunlight reaching the leaves and thus preventing photosynthesis. They can also change the intensity and trajectory of storms such as monsoons which can have a large impact on food producers.

PM2.5 and PM10 refer to particulate matter that has a diameter of less than 2.5 micrometres and 10 micrometres, respectively. These are two types of pollutants that are measured by air monitoring stations located around the cities. Both are detrimental to health, but PM2.5 is more dangerous, according to statistics, because its small size allows it to reach deep inside the lungs. PM2.5 has been linked to cardiovascular and respiratory diseases and can easily trigger an asthma attack in those affected by poor quality air.