Environment Quiz: Environment Pollution & Issues |26 Apr, 2021

Long-term exposure to outdoor and household air pollution contributed to over 1.67 million annual deaths from stroke, heart attack, diabetes, lung cancer, chronic lung diseases and neonatal diseases in India in 2019, according to the State of Global Air 2020 by the U.S.-based Health Effects Institute.

Overall, air pollution was now the largest risk factor for death among all health risks, the report noted.

Source: https://www.thehindu.com/news/cities/Delhi/air-pollution-now-biggest-health-risk-in-india-says-report/article32912916.ece

New Delhi was the world’s most polluted capital for the third straight year in 2020, according to IQAir, a Swiss group that measures air quality levels based on the concentration of lung-damaging airborne particles known as PM2.5.

• India was home to 35 of the world’s 50 most polluted cities, according to IQAir’s 2020 World Air Quality Report, which gathered data for 106 countries.
• The findings were based on the country’s annual average of particulate matter PM2.5, airborne particles with less than 2.5 microns in diameter.
• Prolonged exposure to PM2.5 can lead to deadly diseases, including cancer and cardiac problems.

Source: https://indianexpress.com/article/india/new-delhi-is-worlds-most-polluted-capital-for-third-straight-year-iqair-study-7230892/

PM2.5 and PM10 are mixture of solid and liquid particles generally having diameters of or less than 2.5 and 10 micrometers— smaller than the diameter of a single strand of average human hair, which is about 70 micrometers.

• The 24-hour exposure limit of PM2.5 in India is 60 micrograms per cubic meter air (ug/m3), while that of PM10 is 100 ug/m3.

• At the three highly polluted areas in Delhi between 12PM Thursday and Friday, the levels of PM2.5 and PM10 had reached 500 ug/m3 or close to it.
• These particulates are emitted from various sources and can be inhaled, causing serious health problems.
• Their physical and chemical characteristics vary by location, and common chemical composition includes nitrates, sulfates, ammonium, and also metals and biological components.

Source: https://indianexpress.com/article/explained/explained-as-pollution-peaks-in-delhi-a-look-at-pollutants-you-should-be-worried-of-6853273/

Combustion of diesel and petrol in engines, combustion of solid fuel for energy production, construction and industrial activities, and erosion of pavement by road traffic are some of the primary sources of PM, but they are also formed in the atmosphere through chemical reaction of gaseous pollutants.

Source: https://indianexpress.com/article/explained/explained-as-pollution-peaks-in-delhi-a-look-at-pollutants-you-should-be-worried-of-6853273/

Ammonia (NH3) is another gaseous pollutant that is monitored, whose 24-hour exposure limit is 400 ug/m3.

• The average 24-hour range of NH3 as of 1pm on Friday at the three highly polluted areas in Delhi was between 9 and 28 ug/m3, as per CPCB data.
• The EPA states that ammonia occurs naturally in air, soil and water, and is used as an agricultural fertilizer and in cleaning products.
• Short-term inhalation of high levels of ammonia can cause irritation and serious burns in the mouth, lungs and eyes.
• Chronic exposure to airborne ammonia can increase the risk of respiratory problems, including impaired lung function.

Source: https://indianexpress.com/article/explained/explained-as-pollution-peaks-in-delhi-a-look-at-pollutants-you-should-be-worried-of-6853273/

Sulphur dioxide (SO2) and particulate matter emitted from combustion of fossil fuels have, historically, been the main components of air pollution in many parts of the world.

• A Greenpeace report from 2019 had found that India was the largest emitter of SO2 in the world due to burning of coal.
• The EPA states that largest source of SO2 in atmosphere is burning of fossil fuels by power plants and other industrial facilities.
• Short-term exposure to SO2 can harm respiratory system, making breathing more difficult.
• SO2 emissions in the air can also lead to formation of other sulphur oxides (SOx), which can react with other compounds in the atmosphere and form particulate matter.

Source: https://indianexpress.com/article/explained/explained-as-pollution-peaks-in-delhi-a-look-at-pollutants-you-should-be-worried-of-6853273/

Cement can be replaced by fly ash up to 35%, thus reducing the cost of construction, making roads, etc.

• Fly ash bricks are light in weight and offer high strength and durability.
• Fly ash is a better fill material for road embankments and in concrete roads.
• Fly ash can be used in reclamation of wastelands.

• Abandoned mines can be filled up with fly ash.
• Fly ash can increase the crop yield and it also enhances water holding capacity of the land.

Source: Shankar page no: 58

National Air Quality Index was launched by the Prime Minister in April, 2015 starting with 14 cities to disseminate air quality information.

• The AQI has six categories of air quality, viz Good, Satisfactory, Moderately Polluted, Poor, Very Poor and Severe with distinct colour scheme.
• Each of these categories is associated with likely health impacts.

• AQI considers eight pollutants (PM10, PM 2.5, NO2, SO2, CO, O3, NH3 and Pb) for which (up to 24-hourly averaging period) National Ambient Air Quality Standards are prescribed.

Source: Shankar page no: 61

The higher amounts of waste increase the rates of decomposition and O2 consumption, thereby decreases the DO content of water.

• The demand for O2 is directly related to increasing input of organic wastes and is empresses as biological oxygen demand (BOD) of water.

• Water pollution by organic wastes is measured in terms of Biochemical Oxygen Demand (BOD).
• BOD is the amount of dissolved oxygen needed by bacteria in decomposing the organic wastes present in water. It is expressed in milligrams of oxygen per litre of water.
• The higher value of BOD indicates low DO content of water. Since BOD is limited to biodegradable materials only. Therefore, it is not a reliable method of measuring pollution load in water.
• Chemical oxygen demand (COD) is a slightly better mode used to measure pollution load in water.
• It is the measure of oxygen equivalent of the requirement of oxidation of total organic matter (i.e. biodegradable and non-biodegradable) present in water.

Source: Shankar page no: 63

Excess nitrate in drinking water reacts with hemoglobin to form non-functional methaemoglobin, and impairs oxygen transport. This condition is called methaemoglobinemia or blue baby syndrome.

Source: Shankar page no: 64