Question

The pollution in a city like Delhi may be controlled to be a great extent
A. By proper sewage and proper exit of chemicals from factories
B. By wide road and factories away from the city
C. By cleaning the city and scanty use of pesticides
D. All of the above

Answer 1

Pollutants can be natural, such as volcanic ash.
They can also be created by human activity, such as trash or runoff produced by factories.
Pollutants damage the quality of air, water, and land.

Complete answer:
In modern times major types of pollution in urban areas are atmosphere, water, and noise. Atmospheric pollution can be controlled to a large extent by the location of factories and industries away from cities.
1. Widening of roads will lead to less congestion, reduce the idling time of engines of vehicles, and ultimately be helpful in controlling atmospheric pollution due to vehicles.
2. Sewage treatment plants and control of the use of pesticides will reduce the pollution of water bodies and prevent eutrophication of natural ponds and lakes.
3. Clean city surroundings and proper waste disposal will reduce or eliminate breeding grounds of stray animals and disease spreading insect and noninsect vectors.
Maintaining a high-quality environment in Scotland is essential for marketing high-quality agricultural products. Water quality in Scotland is generally good, and adherence to good agricultural practice is on the increase. Nevertheless, there are areas of concern. SEPA considers that diffuse agricultural pollution is now the most significant cause of poor river quality in certain parts of Scotland and that it will continue to be unless appropriate action is taken at individual farm and catchment level to turn the situation around.
4. Losses of nutrients or agrochemicals to land or water represent not only a financial loss to farming but can also damage the environment. The total effect of a number of individually minor sources of contamination can be highly significant over an entire catchment area.
5. If the sources of water for a river are predominately contaminated, then the whole river is likely to be polluted. Small watercourses, with little dilution, are more likely to be adversely affected by diffuse pollution than larger rivers. Over abstraction of irrigation water from watercourses can exacerbate this problem by lessening the potential for dilution.

So, the correct answer is “Option D ”.

Note: Normally, the practices described in this section should be sufficient to prevent or at least minimize the risk of diffuse agricultural pollution. In some cases, however, it may be necessary to consider the installation of some form of treatment system near the source of potential pollution.