A common disease which develops among the coal mine workers is silicosis. Exposure to coal mine dust and crystalline silica results in pneumoconiosis with initiation and progression of pulmonary fibrosis.

The Carnivores is a biotic factor directly operating in an ecosystem. A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging. 

Helium is not a major greenhouse gas. It is a greenhouse gas because it can absorb and re-emit the Sun's energy, but it is not a major greenhouse gas. 

Trapping of sun rays by the atmosphere causes greenhouse effect. A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. 

Many scientists believe that the greenhouse effect is predominantly the result of using large amounts of gasoline, oil and coal in developed nations. The use of these products releases carbon dioxide, which is believed to destroy the ozone layer, which protects Earth from harmful solar radiation. 

One third of land surface is used for agriculture and grazing by the world's 6 billion people. This method of raising livestock is known as intensive rotational grazing or management-intensive grazing. It may be a very non-productive method but it reduces pollution, improves water quality and reduces erosion. 

North America is the largest source of carbon dioxide emissions from the burning of fossil fuels.  North America’s 3,000 fossil fuel-burning power plants continue to produce two-thirds of the region’s electricity and, at the same time, generate the majority of certain harmful air pollutants and emit more greenhouse gases than any other industrial sector. 

The depth at which all the pore spaces are saturated with water only is called water level. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called water level. Groundwater is recharged and eventually flows to the surface naturally. 

One of the best solutions to get rid of non-biodegradable wastes is recycling. Recycling is processing used waste into new products to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy usag, and reduce air pollution and water pollution. One way to prevent the accumulation of non-biodegradable trash is to recycle. 

Global warming has resulted due to increased emissions of CO₂ from automobiles. The main cause of it is greenhouse effect. Naturally occurring amounts of greenhouse gases have a mean warming effect of about 33 °C (59 °F). The major greenhouse gas is carbon dioxide (CO₂) which causes 9-26% of greenhouse effect.

Due to water cycle, the amount of water on Earth remains more or less the same.

Silviculture was initiated for replenishment of forests. Silviculture is used due to the speed of its growth and the value of its timber and is frequently used in replanting and forest control efforts. This field of study is concerned with the regular replenishment of forests, using a variety of tactics like clear-cutting and group selection. 

D.D.T. is an example of non-biodegradable substance. It is a colourless contact insecticide, C₁₄H₉Cl₅, toxic to humans and animals when swallowed or absorbed through the skin. It contains pesticides. Substances that are not broken down by biological processes are called non-biodegradable substances. 

The main cause of mismanagement of natural resources is a large increase in population. As population is increasing day by day, their demand for natural resources is also increasing accordingly which leads to its mismanagement. 

The process in which a harmful chemical enters the food chain and gets concentrated at each level in the food chain is bio-magnification.

Trees give out large amount of water by the process of transpiration. 

Polar ice caps are expected to be very severely affected by global warming. The immediate effect of it could be coastal and island flooding. The main consequence of global warming is the loss of coastal wetlands and barrier islands, and a greater risk of flooding in coastal communities. Low-lying areas, such as the coastal region along the Gulf of Mexico and estuaries like the Chesapeake Bay, are especially vulnerable. 

Common cold is not caused by air pollution. Some of the causes of common cold are transmission of common cold viruses via airborne droplets, i.e. aerosols, direct contact with infected nasal secretions or contaminated objects. 

The gas which leaked from the Union Carbide Plant in Bhopal in 1984 was methyl isocyanate. 

The amount of carbon dioxide in the atmosphere has increased in recent years. Environmentalists suggest this change is a direct result of the overcutting of forests and the increased use of fossil fuels. Deforestation and the use of fossil fuels are both suspected of increasing the amount of carbon dioxide in the atmosphere. This is of worldwide concern because of its potential effects on the environment, such as global warming due to the weakening of the ozone layer which protects the earth from harmful solar radiation.