Outdoor air pollution in India
Air pollution is a serious environmental and health problem worldwide. The most affected regions are the fast-developing cities in low-, middle-, and high-income countries. Air pollution causes approximately 7 million deaths per year. This makes it one of the highest risk factors for death globally. However, the number of deaths from air pollution is slowly starting to decline, mainly due to tackling indoor pollution. Air pollution can be divided in outdoor air pollution and indoor air pollution (household). This blog post mainly focuses on outdoor pollution, particularly in India. The indoor pollution will be discussed in the blog post of next week. The major drivers for air pollution are: rapid population growth, economic development, energy consumption, urbanization and transportation.
Picture 1: Smog in India
Outdoor air pollution is worse in newly industrialized countries as they transition from low- to middle-income countries. Outdoor air pollution causes circa 4.2 million deaths per year due to lung cancer, heart disease, stroke, acute and chronic respiratory diseases. In 2012, 25% of the lung cancer deaths, 17% of the respiratory infection deaths and 8% of the chronic obstructive pulmonary disease (COPD) deaths were due to outdoor air pollution. Outdoor pollution thus has an adverse effect on respiratory health. About 91% of the global population lives in areas where levels of air quality exceed the WHO’s threshold. The WHO measures the air quality usually with the PM10 standard. The PM10 standard is particles with a diameter of 10 μm and less. These particles are the reason for adverse health effects because they can reach the lower respiratory tract. The WHO’s threshold for PM10 is 20 μg/m3. In New Delhi the PM10 rate was 139 μg/m3 in 2020, this exceeds the WHO’s threshold extremely. South Asia and Western Pacific regions experiencing the highest burden, due to the high population densities and high pollution levels.
One of the countries in South Asia with severe air pollution is India, with a death rate of 8% in 2017 (fig.1). New Delhi was even ranked first place for most polluted city amongst the 1600 cities worldwide according to the WHO in 2014. The air quality causes 1,2 million deaths every year in India, of which 35000 in New Delhi alone. Factors for outdoor air pollution in India are: industry emissions, road dust, waste burning, diesel generators, coal burning for thermal power production, brick kilns and construction activity, commercial and residential biomass burning and agriculture stubble burning. This in combination with indoor pollution adverse local weather conditions and causes a cloud of trapped pollutants also called smog.
Fig.1: Deaths from outdoor air pollution in India, 2017
Outdoor air pollution causes many diseases, mostly associated with non-communicable diseases (NCDs), which mostly occurs in elderly. Outdoor air pollution frequently accelerates or exacerbates the extent of NCDs, resulting in premature death. Therefore, the burden of air pollution is higher in the elderly. People aged 70 and older are at most risk of premature death resulting from long-term exposure during their life. Figure 2 shows that the number of deaths from outdoor air pollution is highest in the 70+ years old group in India in 2017, with a death rate of 805,1 per 100000 individuals.
Fig.2: Premature death rates by age due to air pollution in India, 2017
As can be seen in fig.1 & 2, outdoor air pollution has many negative health effects and is a great burden in India. In New Delhi, concerned office bearers and stakeholders implemented remedial measures to put the situation under control, such as discouraging morning walks, rising parking costs and reduction in metro train fares. However, these measures are not efficient, since they do not address the problem from a long-term, larger perspective. The government needs a good solution to limit outdoor air pollution as much as possible. These could be integrating air quality monitoring, management, improving public transport systems to reduce vehicles on the road or a waste management system. Implementing these measures could improve the situation of outdoor air pollution and, thus, improve health among India’s population.
This blog post was written by Charmain Kemper
