Smog Over Pakistan – Causes, Effects and Threats

Published in Blog


Written By: Aimon Tanvir Malghani

Recently, there has been great concern about the rising level of smog prevailing over large areas of the Punjab. Before going into the details of the issue, we need to understand what smog is and what causes it. Generally, smog is a type of air pollution that is caused when smoke combines with fog. The condition is common in urban centers during the winter season, especially in the month of December. Classic smog results from the burning of coal and mixing of sulfur dioxide and smoke. In urban areas, burning of fossil fuels in the engines of vehicles as well as the combustion in industrial zones releases a large amount of pollutant gases in the atmosphere that, under favourable conditions of temperature and humidity, get mixed with the fog to form smog. Hence, basically, smog results from the intervention of human activities and anthropogenic emissions with the natural ecosystems. The phenomenon can be attributed to modernization and industrialization of the human communities and it tends to occur almost every year during a specific time period.

Like every other phenomenon in nature, the conditions for the formation of smog also follow proper clock or timing. It usually does not occur at the start of the season when the temperature has not lowered enough. Plus, the problem of smog was reported earlier in the urban centers only but this time several suburbs and small cities that do not have large industrial settlements, have also encountered the same problem and the problem is no longer at small scale but on a bigger one when people need to wear masks to avoid the contaminated air getting into their lungs. Owing to these extended implications the research institutions, the academia, the government, NGOs and the international organizations have raised concerns over the issue, and have started smog monitoring campaigns in an attempt to identify the causes of this disaster. Although, smog occurs every year, the problem has worsened over the past five years owing to the expansion of cities, overpopulation and increased usage of fossil fuels.


smogoverpak1.jpgComing to the recent episode of smog, the cause cannot be attributed to a single action; rather there are multiple factors involved. Expectedly, and most agreeably, agricultural fires in the state of Punjab (India) are one of the reasons behind the prevailing issue. On October 23, 2016, NASA published an image from Soumi NPP Satellite. The image was taken from the VIRS instrument on the satellite and it showed huge agricultural fires in India and some scattered fires were also shown in Pakistan. The Punjab state grows about one-fifth of India’s wheat. Setting fire to the previous crop’s residue has the benefit of clearing out some pests that may eat the crop, turning the residue to into fertilizing ash. Almost 16% of the crop residue was burnt on the farms in India in 2009 (Jain et Al., 2013). The proportion must have increased manifold by now. The same authors report that agricultural crop residue burning contributes towards the emission of greenhouse gases namely, carbon dioxide, di-nitrogen oxide and methane. Also, many other pollutant gases like carbon monoxide, ammonia, oxides of nitrogen and sulfur, and volatile organic compounds are emitted in the process. Oxides of sulfur play a vital role in the formation of smog.

The red dots showing burning of the crop residue in various areas (Image Source: NASA)
Further evidence suggests that on average, there has been high relative humidity during the month of October which provided favourable conditions for the formation of smog over the region. For Lahore, humidity during the month ranged from 34%-92%, giving an average of 63%.

As the subject environmental problem is of trans-boundary nature, wind speeds and directions may also play a crucial role. Experts say that increase in the levels of construction dust, burning of garbage (open burning of waste), factory emissions and motor vehicle exhausts are all contributing factors in the havoc of smog (The Washington Post, November 5). Meteorologists say that this smog is unusual and loaded with toxic air.

Relative humidity (Lahore), October, 2016 (Source:
Similar problem has been reported in the Indian capital of New Dehli. Dehli is considered to be one of the most polluted city centers of the world and is normally beset by toxic air, but government data shows that the current levels of smog are higher than the last seventeen years recorded (The Washington Post, November 5). Lahore was also listed along with Dehli amongst the top 10 worst cities for smog in 2014.

Serious implications of smog have been observed during the past few years. It causes major health risks including asthma, lung tissue damage, bronchial infections, various forms of allergies and heart problems. There is no other option left for the general public except wearing masks and glasses to avoid the effects of smog. Smog has caused irritation in the eyes of residents and an increase in respiratory related problems has been observed. The condition is particularly more dangerous for the people who already have some sort of respiratory disorders. Meteorology Department of Pakistan has warned people regarding the seriousness of the issue and advised not to go outside unnecessarily. According to monitoring reports from the Environment Protection Department, the levels of carbon dioxide, hydrogen sulphide and sulfur dioxide have risen far above the level of human tolerance and this includes emissions coming from India caused by burning of about 32 million tonnes of crop residue. Smog cover has also contributed in the increase in temperature by acting as a greenhouse and trapping the energy coming from the sun. Fortunately, rains during the second week of November in some areas of Punjab have lowered the severity of the problem to some extent where the smog has been wiped away by rain water.

Air pollution poses serious threats to man and the environment. World Health Organization reports that 92% of the world’s population lives in areas where air quality exceeds the safe levels and poses serious hazards to human health. UNICEF reports say that six million deaths around the globe are caused by exposure to air pollution, whether it is indoor or outdoor. Smog has the capacity to dry out the protective membrane of the nose and throat and hence, can interfere with the human immune system, making it more prone to illness.

Low visibility forces the authorities to close the highways and motorways that connect various parts of the country. Transportation becomes limited and the business sector gets paralyzed. Furthermore, smog may also impact the new crops that are being sown and may cause a delay in their sprouting season which will disturb the overall crop cycle of the region.

The above mentioned threats caused by peaking air pollution demand serious commitment on the behalf of people, institutions and the government to understand the impacts of their footprints on the environment and work towards building a healthier environment for the present as well as for the generations to come.


The writer is a student of MS Environmental Science at NUST.

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