Environment Quiz: Environmental Pollution and Environmental issues | Nov 30,2020

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

India recorded the highest annual average PM 2.5 concentration exposure in the world last year, according to the State of Global Air 2020 (SOGA 2020) report.
•India was followed by Nepal, Niger, Qatar and Nigeria in high PM 2.5 exposures. This means people in India are exposed to the highest PM 2.5 concentrations globally.
•SOGA, released by US-based Health Effects Institute and Global Burden of Disease (GBD), uses both data from ground monitors and satellite to make their assessments.
•To estimate the annual average PM2.5 exposure, or concentrations, GBD scientists link the concentrations in each block (they divide the globe in blocks or grids) with the number of people living within each block to produce a population weighted annual average concentration.
Source: The Hindu

Shankar page no: 62

The higher amounts of waste increases 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

In India, the Central Pollution Control Board (CPCB) has been executing a nationwide programme of ambient air quality monitoring known as National Air Quality Monitoring Programme (NAMP).
Source: Shankar page no: 60

Soil is a thin layer of organic and inorganic materials that covers the Earth’s rocky surface.
•Soil pollution is defined as the addition of substances to the soil, which adversely affect physical, chemical and biological properties of soil and reduces its productivity.
•A soil pollutant is any factor which deteriorates the quality, texture and mineral content of the soil or which disturbs the biological balance of the organisms in the soil.
Causes of Soil Pollution:
•Indiscriminate use of fertilizers, pesticides, insecticides and herbicides
•Dumping of large quantities of solid waste
•Deforestation and soil erosion.
•Pollution Due to Urbanisation
Source: Shankar page no: 65

Sound is measured in decibels (dB). An increase of about 10 dB is approximately double the increase in loudness.
•A persons hearing can be damaged if exposed to noise levels over 75 dB over a prolonged period of time.
•The World Health Organization recommends that the sound level indoors should be less than 30 dB.
Source: Shankar page no: 66

Each radioactive nuclide has a constant decay rate.
•Half-life is the time needed for half of its atoms to decay.
•Half-life of a radio nuclide refers to its period of radioactivity.
•The half-life may vary from a fraction of a second to thousands of years.
•The radio nuclides with long half-time are the chief source of environmental radioactive pollution.
Source: Shankar page no: 68