A-Over time, even with good teeth cleaning, plaque and tartar can attach to the teeth similar to lime build-up in a kettle or iron. The saliva fluids in our mouths contain calcium and bacteria.-According to oral hygiene standards, it is recommended that patients visit the dentist every six months for an oral health check-up, to discuss any medical changes such as new medications that can affect oral wellbeing, and to have teeth cleaned with scaling and polishing where necessary.
Industrial smog occurs when the smoke and sulfur dioxide produced from burning coal merges with fog and creates a yellowish-brown-colored haze close to ground level. Photoch â¦ emical smog forms as the result of increased usage of all fossil fuels, including gasoline and the burning of trees and organic waste.
Some petroleum industry operations have been responsible for water pollution through by-products of refining and oil spills. The industry is the largest industrial source of emissions of volatile organic compounds (VOCs), a group of chemicals that contribute to the formation of ground-level ozone (smog).he United States consumed 25% of the oil produced in 2007. The production, distribution, refining, and retailing of petroleum taken as a whole represents the world's largest industry in terms of dollar value.