Old English broc garment for the legs and trunk; see breeches). The sense might reflect the breeches sense, on the notion of two limbs or of appliances used in pairs. The typographical bracket is first recorded 1750, so called for its resemblance to double supports in carpentry (a sense attested from 1610s). Senses affected by Latin brachium arm..
Carbon dioxide, a greenhouse gas, is the main pollutant that is warming Earth. Though living things emit carbon dioxide when they breathe, carbon dioxide is widely considered to be a pollutant when associated with cars, planes, power plants, and other human activities that involve the burning of fossil fuels such as gasoline and natural gas.
Point source pollution results when the contaminants come from a single location. Examples of point source pollution in the air, water and soil are given below. Air. A certain factory is producing chemicals. As part of the manufacturing process, certain poisonous chemicals and toxic gases result, such as benzene.nd, even if laws are followed now, these types of practices occurred in the past before the laws were enacted and the pollutants are still around. Non-point-source pollution results when contaminants are introduced into the environment over a large, widespread area. Some examples follow.