Air Pollution

Acid rain is primarily caused by sulfur oxides (SOx) and nitrogen oxides (NOx), which react with water vapor in the atmosphere to form sulfuric and nitric acids. These come from burning fossil fuels and industrial emissions.

A catalytic converter is an emissions control device that uses catalysts (typically platinum, palladium, and rhodium) to convert harmful pollutants like NOx, CO, and HC into less harmful substances like nitrogen, carbon dioxide, and water vapor. Carburetors mix air and fuel for combustion, 2-stroke is an engine type, and the tailpipe simply expels exhaust.

Acid rain forms when sulfur dioxide and nitrogen oxides from fossil fuel combustion react with water vapor in the atmosphere to create sulfuric and nitric acids. These acidic compounds fall as rain, snow, or dry particles, damaging forest ecosystems, acidifying lakes, and harming wildlife. Smog refers to air pollution, while seasonal and monsoon rains are natural precipitation patterns without chemical contamination.

Lead is a notorious air pollutant in big cities, primarily from vehicle exhaust and industrial emissions. Other metals like copper, chromium, and cadmium can be toxic but are not typically associated with urban air pollution.

Pollution levels are correctly described with 'high' or 'low'. We speak of 'high pollution' or 'low pollution' levels. 'Big', 'large', and 'great' don't collocate properly with 'level of pollution' in standard English.

Yes, it is the correct answer. The smoke released from vehicles makes the air polluted. It is a man made source of air pollution.

Lichens are extremely sensitive to pollutants in the atmosphere and can be used as bioindicators of air quality. They absorb minerals from the air, from rainwater, and directly from their substrate. Lichen growth has been used as an indicator of air pollution, especially sulfur dioxide. Pollutants are absorbed by lichens, causing the destruction of their chlorophyll, which leads to a decrease in the occurrence of photosynthesis and changes in membrane permeability. Pollutants upset the physiological balance between the fungus and the alga or cyanobacterium, and degradation or destruction of the lichens results. Lichens are generally absent in and around cities, even though suitable substrates exist; the reason for this is the polluted exhaust from automobiles and industrial activity. They are beginning to disappear from national parks and other relatively remote areas that are becoming increasingly contaminated by industrial pollution. The return of lichens to an area frequently indicates a reduction in air pollution.

Ammonia is a pungent, hazardous caustic gas. Agriculture, specifically livestock farming and animals waste is the main source of ammonia emissions.

Photochemical smog was reported in Los Angeles. This oxidising type of pollution is characterised by the presence of large concentration of ozone, oxides of nitrogen and various hydrocarbons.

Nitric oxide (NO) is formed by reaction between oxygen and nitrogen.

NO reacts with air forming NO₂.

NO₂ absorbs light and nitric oxide and nascent oxygen [O] are formed.

Nascent oxygen combines with molecular oxygen to form ozone.

Ozone reacts with unburnt hydrocarbons to give aldehydes and ketone.

Nitrogen oxides, oxygen and ketone give rise to PAN.

Photochemical smog forms when nitrogen oxides and volatile organic compounds react in sunlight, producing ozone as a secondary pollutant. This ground-level ozone is a key component of photochemical smog.

An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing gas (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.

1. The SPI (Society of the Plastics Industry) resin identification coding system is a set of symbols placed on plastics to identify the polymer type. The primary purpose of the codes is to allow efficient separation of different polymer types for recycling. Separation must be efficient because the plastics must be recycled separately.
   1. White pollution is improper disposal of rubbish such as food containers and wrapping paper along railway stations, rivers and any other corner of city streets. This term has been coined to describe the local and global effects of discarded plastic bags upon the environment.

Lichens are the indicator of pollution. By studying the behaviour of lichens the type of pollution can be detected. They are the most sensitive and die in SO₂ rich area.

Thermal power stations burn fossil fuels releasing CO2 and particulates. Nuclear plants produce radioactive waste (though minimal air pollution during normal operation). Cement factories release significant dust and CO2. Hydroelectric plants, however, use flowing water to generate electricity without combustion or emissions - they don't cause air pollution.