Qualité de l’air à Meycauayan

What is the level of air pollution in Meycauayan now?

Meycauayan, also known as the City of Meycauayan is in the province of Bulacan, Philippines. According to a census which was conducted in 2015 it had an estimated population of approximately 210,000 people. It is one of the oldest towns in the province. It can be found 19 kilometres north of the capital city, Manila.

Towards the middle of 2021, Meycauayan was experiencing a period of air quality classified as being “Unhealthy for sensitive groups” with a US AQI reading of 135. This United States Air Quality Index number is an internationally used set of metrics supported by the World Health Organisation (WHO) and is used to compare air quality in different cities throughout the world using comparable standards. It is calculated by using the levels of the six most commonly found pollutants. If figures are not all available, the figure is calculated using what information is available. In this instance, only PM2.5 was measured with a recorded figure of 49.2 µg/m³.

This is currently over four times the recommended limit by the World Health Organisation (WHO).

With air pollution at this level, the advice is to close doors and windows to prevent the ingress of more polluted air. Those of a sensitive disposition are advised to remain indoors or if travel outside is unavoidable, then a good quality mask is recommended. Most people would be advised from exercising outside until the quality improves. The use of an air purifier would be beneficial if one is available. The table published at the top of this page will help you decide when it is safe to venture outside again.

At what time of year is air quality at its best in Meycauayan?

The quality of air is affected by many variables such as the seasons of the year, the wind speed and direction and the strength of sunlight and the hours of sunlight.

Looking back at the figures for 2020 published by the Swiss air monitoring company, IQAir.com it can be seen that Meycauayan experienced “Moderate” quality air for the whole twelve months. Recorded figures were between 12.1 and 35.4 µg/m³. This is quite unusual as there is nearly always a seasonal variation due to air temperature.

Looking back at historic figures from 2019, it can be seen that in that year the quality of air was recorded as being “Moderate” with a reading of 35.3 µg/m³ with a slight improvement in 2020 when the figure was just 27.4 µg/m³. These figures are quoted in micrograms/microns per cubic metre. The figure could be artificially lower than usual because of the restrictions brought into force due to the COVID-19 pandemic when the use of private vehicles was mainly prohibited due to the drivers being furloughed and many manufacturing plants were told to cease production until further notice.

What are the sources of all this polluted air in Meycauayan?

Being located on the fringes of Metro Manila, the municipalities of Marilao and Meycauayan are hosts to a multitude of industries and urban-related activities. Of particular interest are the lead recycling facilities, the tanneries, open dumpsites, electroplating industries, piggeries and a host of other industries, from the formal and informal sector. Like many of the industrialising municipalities in the Philippines, there is no well-planned development of the area where human settlement, fish culture, agriculture and industrial development are located in the same geographical area.

Most of these pollutants result from burning biomass (biological material usually from plants) or fossil fuels (coal and gasoline) – the same pollutants that serve as Southeast Asia’s emission sources including vehicle exhaust. Fact is, pollution sources can travel around the world! Regionally, South Asia, Southeast Asia, and Western Asia carry the highest burden of fine particulate matter (PM2.5) pollution overall.

According to figures from 2016, 80 per cent of the country’s air pollution comes from motor vehicle exhausts whilst the remaining 20 per cent comes from factories and the open burning of organic matter in the surrounding rural areas.

Can anything be done to lower pollution levels in Meycauayan?

Vehicle emissions are one of the major sources of air pollution. In order to reduce pollution think of ways to get things done that don’t require a car, such as bicycles and transit systems.

The lowering of the sulphur content of industrial and automotive diesel, respectively, from 0.5% to 0.3% and from 0.2% to 0.05%, is to be introduced as well as the lowering of aromatics in unleaded gasoline from 45% maximum to 35% maximum; and the lowering of benzene in unleaded gasoline from 4% maximum to 2% maximum.

In-use motor vehicles will only be allowed renewal of their registration upon proof of compliance with emission standards through actual testing by the Motor Vehicle Inspection System (MVIS) of the DOTC/LTO, and authorized private emission testing centres.

Industries will be subjected to more stringent requirements and will be tested periodically to ensure they comply.

How does this poor air quality in Meycauayan affect human health?

According to a recent estimate, "air pollution" kills nine million people worldwide each year. The main causes of which are heart attack, severe brain diseases, lung diseases and cancer. Air pollution is caused by harmful chemicals (natural and man-made), biological and some particulate matter, which harms humans and other organisms, as well as the natural environment of the atmosphere. While some sources of air pollution are natural such as volcanic eruptions, wildfires, fires, most are man-made. Consumption of combustible fossil fuels has increased significantly with modernisation, apart from man-made sources of air pollution such as deforestation, animal husbandry and agriculture.

When the particulate matter enters the nose or mouth through the breath, the fate of each particle depends on its size - the smaller the particles, the deeper they go inside our body.

PM with diameter less than 10 micrometres are included in the 'fully suspended substances'.

They are so small that the hairs in the nose fail to stop them and they go inside. They pass through the respiratory tract into the lungs where the metal elements present on the surface of the particles oxidise the lung cells, damage their DNA and increase the risk of causing cancer.

Particle contact with the lung cells causes swelling, irritation, disturbance, and obstruction of airflow causing lung breathing difficulties such as COPD (Chronic Obstructive Pulmonary Disorder), Cystic Lung Disease, and bronchitis. The risk of diseases increases accordingly.