Environment & Ecology GK Questions with Answers – Page 32

The Montreal Protocol was adopted in 1987 under the Vienna Convention of 1985 and sets the timetable by which countries must stop producing and using chlorofluorocarbons, halons, carbon tetrachloride, methyl chloroform and methyl bromide.

The Dobson unit, named after the scientist who built the instrument for measuring atmospheric ozone, expresses how thick the ozone column would be if all of it were brought down to the surface at standard temperature and pressure; a hundred Dobson units correspond to a layer one millimetre thick.

About nine tenths of the atmosphere's ozone lies in the stratosphere, roughly fifteen to thirty five kilometres above the surface, where ultraviolet rays split oxygen molecules and the free atoms combine with other oxygen molecules to make ozone.

Nitric oxide and nitrogen dioxide, together written as nitrogen oxides, are air pollutants that come mainly from combustion in vehicles and power stations; they help form smog and acid rain but are not counted among the greenhouse gases of the natural atmosphere.

A primary pollutant is released directly from a source, while a secondary pollutant is formed in the atmosphere when primary pollutants react.

Each of the other three statements is correct on its own, which is exactly why the combined option is the answer.

A small quantity of fluoride in drinking water protects teeth against decay, but when the concentration rises above the permissible limit it causes fluorosis.

Water hyacinth is an aquatic weed introduced into India from South America.

The mission, working under the Ministry of Jal Shakti, is the implementing agency of the Namami Gange Programme launched in 2014, and it works through State Ganga Committees and district committees along the river.

The Ganga Action Plan was launched in 1985 to intercept, divert and treat the sewage of the towns along the river, and it was the first programme of its kind in India.

The Water (Prevention and Control of Pollution) Act of 1974 was India’s first comprehensive law on pollution.

When fertilisers, detergents and sewage add nitrates and phosphates to a lake or a slow-moving river, algae multiply into a bloom that covers the surface.

Nitrate from fertiliser run-off and from sewage seeps into groundwater; in an infant it is converted to nitrite, which binds to haemoglobin and forms methaemoglobin, a compound that cannot carry oxygen.

Biochemical oxygen demand measures the oxygen that micro-organisms need in order to break down the organic matter present in a sample.

Minamata disease takes its name from Minamata Bay in Japan, where a factory discharged mercury compounds that were converted by bacteria into methylmercury, concentrated in fish through biomagnification and then eaten by people.

Itai-Itai disease was first identified in Japan among people who ate rice grown with water polluted by cadmium from mining waste.

Mulching means covering the bare soil between plants with a layer of organic matter such as straw, dry leaves, husk or grass clippings.

Mulching means covering the bare ground between plants with straw, dry leaves or crop waste, so that the soil holds moisture and raindrops cannot beat the topsoil loose.

Ashtamudi is a backwater lake in Kollam district of Kerala and the second largest estuarine system in the state after Vembanad.

A lichen is a partnership of an alga and a fungus and takes its water and nutrients straight from the air, with no protective cuticle and no roots.