巴基斯坦的空气质量

How bad are pollution levels in Pakistan?

Pakistan is a country located in south Asia, bordering on other highly prominent countries such as India, China, Iran and Afghanistan, all of which have sizeable pollution problems of their own. The economic giants that are India and China have many of their cities taking the top spots for some of the most polluted in the world, and Pakistan does not find much exception from this. Pakistan is an ancient region that has seen many cultures and kingdoms come and go, but now finds itself as an Islamic republic, with a massive population of some 212.2 million inhabitants, making it the 5^th most populous country in the entire world.

In terms of its pollution levels, Pakistan has shown numbers that have come in very poorly in the past, with many of its megacities creating vast amounts of smoke, haze and deadly smog that permeates the air, causing a multitude of issues for its inhabitants.

In 2019, Pakistan came in with a PM2.5 reading of 65.81 μg/m³, not only putting it into the ‘unhealthy’ ratings category, which requires a reading of anywhere between 55.5 to 150.4 μg/m³ to be classed as such, but also into the 2^nd place position out of most polluted countries in the world. PM2.5 refers to particulate matter that is 2.5 micrometers or less in diameter, roughly 3% the size of an average human hair.

It has a slightly larger cousin known as PM10 (10 micrometers or less) which has a number of ill effects on people’s health, but far less prominently than that of PM2.5. Due to its incredibly small size, it has some very serious health implications on those who respire it, and as such it is used as a major component in the calculation of overall air quality ratings.

With yearly average readings of numbers such as 65.81 μg/m³, Pakistan has a long way to go in order to remove itself from the top spot of most polluted countries worldwide, coming in with a reading that was nearly double that of China’s in 2019 (39.12 μg/m³). Two of its major cities, Gujranwala and Faisalabad, both came in the top 5 most polluted cities spot, taking 3^rd and 4^th place, with PM2.5 readings of 105.3 μg/m³ and 104.6 μg/m³ respectively, numbers that place them into the higher end of the unhealthy bracket, making the air quality not only detrimental but outright severe for all members of the population.

With numbers such as these, a plethora of unwanted health issues would arise, many of which will be discussed in detail. So, as it stands, Pakistan is indeed a polluted country, with some of the worst levels of pollution found in the world as of 2019.

What are the main causes of pollution in Pakistan?

There are numerous causes of pollution across the major cities of Pakistan, with some of them being more of a year-round constant, such as the pollution put out by vehicles and factories, and others being seasonal such as the stubble burning taking place in the winter months, compounded by the cold air being trapped on ground level unable to disperse. Cities such as Lahore, once known as the city of gardens, suffers terribly from pollution caused by vehicles, and in the year 2020 with the covid-19 induced lockdowns, it became apparent how much of an effect this vehicular pollution has on the overall air quality. With mass lockdowns in effect after March, pollution levels began to gradually clear, but as soon as they were lifted, the smog quickly crept back to permeate the atmosphere and affect the citizens.

This is just an example of how badly vehicles can alter the level of pollution, with a great increase in air quality during lockdown quickly returning to its awful pre-lockdown levels, being indicative of how badly Pakistan is affected by its numerous cars, motorbikes, trucks and buses on the road. Many of them would also be utilizing heavily outdated and unsafe engines, running on lower quality fuel, which when compounded together the end result is pollution spewing monsters that are unfortunately seen on many roads across Asia.

So, vehicles, in particular poor-quality ones running on fossil fuels are a large contributor to pollution. Other sources would include the infamous brick kilns seen countrywide, a phenomenon also seen in Bangladesh, with many large-scale operations as well as small family run businesses churning out bricks in the millions.

Other operations that emit large volumes of pollution would be the countries steel mills, which once again rely on fossil fuels such as coal to provide energy. The burning of fossil fuel leads to large amount of highly dangerous pollutants, which will be discussed in short. The emissions from these factories are often unregulated as well, leading to companies and manufacturing plants running their operations with no regards to the environment, which can have catastrophic effects to not only air pollution, but also to the surrounding wildlife and water areas, with large amounts of industrial effluence making their way into bodies of water and damaging ecosystems, killing off vast swathes of vegetation and thus wreaking havoc on the environment.

Lastly, the open burning of fires on streets can add an additional level of toxic pollution, with a number of materials such as wood, garbage, synthetic and man-made materials such as plastic all being burnt and releasing a myriad of their own poisonous fumes. In closing, the main sources, starting with the most prominent, are vehicular pollution and factory emissions, followed by open burning sources, and other miscellaneous additions to PM2.5 and PM10 levels such as poorly maintained construction sites, which can give off large amounts of finely ground rock, gravel and silica, adding to the levels of fine particulate matter in the air.

What types of pollutants are found in the air in Pakistan?

With the majority of its smoke, haze and pollution coming from vehicles, naturally a large amount of the gases, compounds and fine particulate matter would arise from the burning of fuels taking place inside car engines. Fine particulate matter such as black carbon is released in high quantities, its creation taking place as a result of the incomplete combustion of fossil fuels or organic matter. As such it can also be found coming from the burning of wood or coal, but most prominently from vehicle fumes.

Black carbon is a major component of soot, and can often be found coating areas that see high volumes of traffic, with motorways, underpasses and roadsides in busy city centers having thick layers of black dust on them, full of black carbon that is highly dangerous for a number of reasons. With its extremely small size, it can make its way deep into lung tissues where it can cause scarring or a reduction in full lung function, as well as having carcinogenic properties, leading to increased instances of cancer of the lungs, throat and stomach.

Before moving on to other pollutants, it is worth acknowledging the terrible effect that black carbon can have on the environment. It has the ability to absorb solar radiation and give it off directly as heat, causing cities to see large increases in temperature that can have knock on effects to both the climate as well as human health and wellbeing.

Other materials found in the air in Pakistan would include nitrogen dioxide (N0₂) and sulfur dioxide (SO₂), both of which are also released from vehicles, with nitrogen dioxide being particularly prominent in areas of high traffic. Other chemicals include volatile organic compounds (VOC’s) such as benzene, labelled as ‘volatile’ due to their nature of becoming gases at very low temperatures, thus having the added danger of being easier to respire once in the air.

Fumes from burnt plastics would include chemicals such as dioxins, furans, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, as well as dangerous metals such as lead, mercury and cadmium. Others would include carbon monoxide (CO), stemming from the burning of wood as well as combustion units such as boilers, which is well known for being a very dangerous household contaminant, which if not ventilated thoroughly enough can lead to deaths occurring very quickly, due to its odorless and colorless nature.

These are to name but a few of the main chemicals found in the air of highly polluted areas, with a vast array of ill health effects that come with them, a display of the terrible consequences that unchecked industry and pollution can have on the environment and human health.

Is the air quality in Pakistan getting better?

Observing the data taken over the last few years, it appears that the levels of air pollution in Pakistan have improved overall, with some exceptions such as Karachi actually showing worse numbers in more recent times than in years past. To give an example of the numbers, Karachi came in with a PM2.5 reading of 38.5 μg/m³ in 2017, putting it into the unhealthy for sensitive groups bracket. In 2018 it came in with a reading of 33.7 μg/m³, a marked improvement from the year prior. However, in 2019 the reading came in at 40.2 μg/m³, showing that the levels of pollution had indeed gotten worse since 2017.

Looking at Pakistan as a whole, in 2018 the country came in with a PM2.5 reading of 74.27 μg/m³. in 2019 its yearly average was 65.81 μg/m³, a considerable improvement however still not enough to take its world ranking down, coming in at 2^nd most polluted country in the world and still in the unhealthy group bracket.

Whilst the air quality levels are still indeed a massive danger to its population, the numbers are showing their slight improvements, with cities such as Faisalabad showing a large improvement from the years prior to 2019 (130.4 μg/m³ in 2018 going to 104.6 μg/m³ in 2019), and with the city of Lahore making some of the most prominent improvements, going from 133.2 μg/m³ in 2017, to 114.9 μg/m³ in 2018, and finally going down to 89.5 μg/m³ in 2019.

Whilst this is still very much a dangerous reading, it made an improvement of 43.7 μg/m³ over the course of two years, a number that even on its own would be an elevated level of pollution for a city. So as mentioned, all cities apart from Karachi made an improvement, but Pakistan still has a long way ahead of it if it is to move itself out of its dire pollution situation.

What are some health issues from breathing polluted air in Pakistan?

Health issues that arise from breathing polluted air are numerous, with a correlation of elevated pollution levels matching an increased rate of illness and disease, as well as mortality rate. Health issues would include ones such as all manner of respiratory ailments, with chronic obstructive pulmonary disease (COPD) very likely to develop, which contains within it a number of respiratory ailments such as pneumonia, bronchitis, emphysema and aggravated asthma attacks.

In regards to asthma, not only is the air in Pakistan verging on being lethal for sufferers of it, but it may outright cause it to occur in people with no prior signs of asthma, with young children being the most vulnerable, as well as the sick and immunocompromised also being at risk.

Other issues would include the ability of PM2.5 to penetrate deep into the lung tissue, as touched on briefly before. From here it can cause scarring to the lungs and a reduced ability to take in oxygen, which in younger children could stunt growth and even cause cognitive defects, opening up the possibility for further health issues down the line.

Another worrying aspect of PM2.5 is its ability to enter into the bloodstream via the alveoli in the lungs, the small air sacs that are responsible for allowing oxygen to enter the blood. PM2.5 can enter into these sacs, either accumulating and causing damage or reduced lung capacity, or passing into the circulatory system via the blood barrier, where they can cause a number of equally destructive issues such as ischemic heart disease, which arises when the heart does not receive enough blood to keep the tissues function at full capacity.

Other cardiac issues include increased risk of stroke, heart attacks, arrythmias, as well as damage to the blood vessels and filtration organs such as the liver and kidneys due to this dangerous particulate matter actually being in the blood. These are but a few of the side effects of being exposed to high levels of pollution, and with such information in mind, it should be of utmost importance for people to not only keep themselves safe and reduce exposure, but to take steps towards reducing their own pollutive output and taking part in initiatives to keep their countries air as clean as possible, lest their younger generation suffer greatly as a result.