Qualité de l’air à Navi Mumbai

Does Navi Mumbai have bad air quality?

Navi Mumbai, formerly known as new Bombay, is a planned city located on the western coast of the Indian subcontinent. It is the largest planned city in the world, conceived by a group of civil engineers who were dissatisfied with the massive overcrowding occurring in Mumbai (then known as Bombay) and its inability to cope with the massive influx of people and lack of infrastructure. So, Navi Mumbai was thus conceived, and today it is a well-developed city with many attractive and modernized features being part of its character.

Whilst it has many interesting characteristics as a city that make it unique, including its history and conception, it unfortunately suffers from some very bad pollution levels that place it quite high up amongst many of the cities in India.

In 2019, Navi Mumbai came in with a PM2.5 yearly average of 61.6 μg/m³, a reading that was high enough to place it into 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.

Whilst it is on the lower end of this bracket, it still nevertheless meets the criteria to be named as such, and as its name would imply, the air quality would be very poor and somewhat hazardous to large portions of the population.

What are the main causes of pollution in Navi Mumbai?

As with many cities in India, Navi Mumbai sees its pollution readings being elevated from a number of different sources, with some more being significantly more prominent than others, depending on the region as well as meteorological conditions or urban geography.

In cities such as Delhi, the urban geography coupled with the surrounding landscape can create a ‘pollution sink’ whereby large accumulations of smoke and particulate matter can accumulate within an area and fail to disperse due to low elevations, tall buildings and a lack of wind.

Back to Navi Mumbai, one of the most salient causes of pollution would be that of vehicle emissions, with a portion of it coming from personal vehicles such as cars and motorbikes (often running on low quality or diesel fuels), but the main majority of vehicular fumes coming from heavy duty ones, which include trucks, lorries and any industrial vehicle above a certain size or weight.

Environmentalists in Navi Mumbai have noticed a spike in heavy duty vehicle numbers over the last few years, along with the cities increased industrial activity. Of note is that these larger vehicles are not subject to many regulations regarding the condition of their engines as well as the fuels used, and as such, when coupled with industrial and factory emissions, can cause the exaggerated leaps in PM2.5 that the city sees.

Other sources of pollution would include the incorrect disposal of waste, with much of it being burnt in landfills or other similar sites. Construction sites and road repairs are another source as well, particularly when it comes to releasing finely ground particulate matter and, in some cases, dangerous metals such as mercury and lead, as well as micro plastics and silica particles.

When is pollution in Navi Mumbai at its worst?

Observing the data taken over 2019 as the most valuable source (due to 2020 having mass lockdowns occurring, thus reducing the pollution levels in certain areas massively. Whilst this was great for air quality, it does not give a clear picture of what regular air pollution levels would be like during times of normal activity, hence why 2019 is being used), there emerges a distinct pattern as to when the pollution levels are at their worst.

This is not something that is just native to Navi Mumbai, but is seen as a theme throughout many cities across India. Simply speaking, the end of the year and the very start of the year is when pollution levels are at their worst, often correlating with India's winter months. It is around October that a significant spike in pollution is seen, with the previous months reading of 12.1 μg/m³ jumping up to 37.9 μg/m³ in October, a threefold increase.

From here the pollution levels just continue to increase, with increments that are so drastic that they are rarely witnessed in many countries round the world. From October to November the PM2.5 reading went up to a massive 80.2 μg/m³, whereby it continues into the early months of the following year (although 2019’s early months are being used as an example here).

The pollution levels continue to rise until they hit their absolute peaks in February and March, with readings of 140.1 μg/m³ and 147.2 μg/m³ respectively. This makes March this most polluted month of the year with some extremely dangerous readings of pollution.

When is Navi Mumbai’s air quality at its cleanest?

In direct contrast to the previous question, despite having some very disastrous levels of PM2.5 in the air, there is a period of the year when the air pollution levels actually drop so significantly that they almost hit the ‘good’ ratings bracket, which requires a fine margin of 10 to 12 μg/m³ for classification. Although they fall just short, the fact that they came close is a good indicator that Navi Mumbai is not subject to really dangerous air pollution all year round.

After the peak in March, the PM2.5 readings start to drop rapidly, and from May to June is when a significant drop is seen, with May coming in at 70.8 μg/m³ and then June coming in at 15.5 μg/m³, a distinctly huge drop.

So, from here on out, from June through to September, is when the pollution levels are at their best in Navi Mumbai, with PM2.5 readings of 15.5 μg/m³, 12.4 μg/m³, 13.2 μg/m³ and 12.1 μg/m³ respectively. This made September the cleanest month of the year, only 0.1 unit away from being moved into the ‘good’ ratings category.

What are some health problems related to breathing polluted air in Navi Mumbai?

With pollution readings as high as the aforementioned 140.1 μg/m³ and 147.2 μg/m³ occurring, during period of time such as this there would be some significant detrimental health effects possible. Among them would be increased rates of throat and lung cancer, as well as irritation to the mucous membranes including the eyes, nose, mouth and ears.

Instances of ischemic heart disease would be on the rise, as well as higher rates of heart attacks and arrythmias. Respiratory ailments such as pneumonia, bronchitis, emphysema and asthma would escalate massively as well, along with damage to multiple organ systems such as the liver, kidneys as well as reproductive health. These are but a few of the ill effects of breathing polluted air in Navi Mumbai.