Qualité de l’air à Howrah

Is Howrah a city with bad pollution levels?

Howrah is a city located in western Bengal, in close proximity to the Hooghly river and its twin city Kolkata. It also finds itself being part of the Kolkata metropolitan area, one of the third most heavily populated metropolitan areas in India after Delhi and Mumbai. The city of Howrah is home to over 1.07 million inhabitants, a sizeable population, as well as having a significant economy and industry based around engineering, with a history of this dating back hundreds of years. Nowadays, Howrah sees itself subject to some major pollutive issues from sources that afflict many cities throughout India, with rapid growth, urbanization and development all being compounding factors, as well as the layout of the city contributing to the issue due to its many areas of congested traffic.

In 2019, Howrah came in with a PM2.5 reading of 55.9 μg/m³ as its yearly average, a considerably high number that placed it within the ‘unhealthy’ ratings bracket, which requires a PM2.5 reading of anywhere between 55.5 to 150.4 μg/m³ to be classified as such. This is a worrying level of pollution, so much so that it placed the city of Howrah in 91^st place out of all cities ranked worldwide, an extremely high ranking that presents a plethora of health issues to its citizens as well as to the environment. This reading also placed it in 38^th place out of all cities ranked in India, indicating that Howrah has a long way to go to get its air quality to more appreciable and safe levels.

Why is Howrah so polluted?

Howrah is a city that sees many different sources of pollution occurring throughout the year, with these different sources coming together to compound the already hazardous situation of polluting agents and fine particulate matter in the air. Coupled with this, meteorological conditions can sometimes work against the appreciation of air quality levels, with lack of rain or winds allowing higher amounts of PM2.5, PM10 and other chemicals to accumulate within the city’s limits.

Some of main causes include ones such as the ever present automobile industry, with countless cars, motorbikes and tuk tuks inhabiting the roads, moving across the city as well as in and out, taking people on their daily commute. These vehicles can put out large quantities of chemicals and particulate matter, all contained within the exhaust smoke they put out. As well as this, as with many cities in India, the condition of a large amount of these vehicles can be particularly poor, with many aged motors still being used way past their best days, which can contribute to excessive leakage of oil vapors as well as greater pollutive output than a newer or cleaner counterpart would put out.

Other sources include ones such as widespread burning of garbage and refuse, something which has come to many people’s attention as one of the most problematic sources in the city, with large amounts of organic refuse and synthetic materials releasing highly poisonous chemicals into the air upon combustion. Further causes include construction sites, road repairs, factory emissions as well as power sites and other similar industrial areas.

When are the pollution levels at their highest in Howrah?

Going off of the data collected over the course of 2019, Howrah showed some exceptionally high periods of pollution, which found themselves cornered into certain months of the year. Observing the data on record, it can be seen that in the months of September through to October is when the pollution levels started to take a turn for the worst. September came in with a PM2.5 reading of 26.4 μg/m³, which was followed by a rapid jump up to 69.9 μg/m³ in October. These numbers continued to go up to 98.9 μg/m³, and then even further to 118.3 μg/m³ in December.

This continued on until the early months of the following year, as was shown in 2019’s early months as well. January came in with the highest reading of the year at a massive 130.7 μg/m³, a time period when the air would be at its most polluted and the air full of smog, haze and choking clouds of smoke. February showed a considerable drop in its PM2.5 reading, but jumped back up again for the next two months. In closing, the months of October through to April of the following year were when the pollution levels where at their worst, with January having the highest reading of pollution out of the entire year.

What are some types of air pollutants found in Howrah?

Whilst there would be an extremely large amount of different chemicals and material pollutants found in the air over Howrah, when observing the smaller details such as synthetic materials being burnt and what different chemical compounds they release, one could get caught up in an excessive amount of different pollutants, so in following, the main and most prominent ones will only be discussed.

These include ones such as nitrogen dioxide (NO₂), sulfur dioxide (SO₂), carbon monoxide (CO) as well as ozone (O₃). There are many different primary and secondary pollutants that top these lists, with primary ones being pollutants that are formed from a singular source such as a fire or vehicle engine, whilst others form afterwards in the atmosphere as a result of different chemicals bonding and undergoing structural changes, which can oftentimes make them more destructive to the environment and human health.

Other ones of note would be black carbon, the main component of soot, as well as volatile organic compounds (VOC's) that include chemicals such as benzene, toluene, xylene and methylene chloride. Construction sites and other similar areas can also leak vast amounts of finely ground gravel and silica dust, as well as heavy metals such as mercury or lead (also released from garbage burning sites and certain industrial processes).

Who is most at risk to air pollution in Howrah?

Whilst all members of the population would suffer some adverse effects from the air quality in Howrah, there are some that are even more at risk due to a number of different factors. These groups would be young children, the elderly, those who are sick or have compromised immune systems as well as preexisting conditions. Lastly, pregnant mothers have many risks to contend with, with babies exposed to pollution via their mother whilst in the womb being susceptible to cases of miscarriage, being born prematurely or with a low birth weight, as well as having the chance of developing cognitive or physical defects early on in life.