• Brass manufacturing creates a number of pollutants.Brass image by travesty from Fotolia.com
  
  Brass is composed of copper and zinc; as such, it's often considered a kind of copper alloy. Since 3000 B.C., humans have been melting together copper and tin to make bronze, another copper alloy that contains tin instead of zinc. By 20 B.C., metalworkers could recognize and isolate zinc, forming brass into coins. Now brass manufacturing take place all around the world, with the finished product used for such varied items as pipes, architectural trim, musical instruments and screws. However, the process of combining copper and zinc into brass releases a number of pollutants, with potentially damaging effects on nearby air and water.
  
  

Fugitive Dust

• Both the first stage of brass production, when scrap materials are sorted, and the final stage, when the alloy material is cast, create what is termed "fugitive dust". Fugitive dust refers to general, non-specific air pollution, that is, small airborne particles that derive from a range of sources. For example, driving over an unpaved road creates a good deal of fugitive dust; construction sites and agricultural farmland are other common sources.
  
  

Metal Oxides

• Two stages of brass making create metal oxides: the preliminary "sweating" process and the final melting stage. Metal oxides are compounds composed of metal cations, or positively charged ions, and oxide anions, or negatively charged ions. When they are exposed to water, metal oxides typically react by forming alkaline bases, altering the water's pH level.
  
  

Fluoride

• During pre-treatment, directly before the melting stage, brass making creates fluoride, or sodium fluoride. Fluoride is a form of the highly reactive gaseous element fluorine, which is extremely difficult to isolate from the compounds it forms. When isolated, fluorine is a yellow, poisonous gas. Fluoride is the same element that's caused controversy over it being added in small quantities to public water systems to help prevent tooth decay.
  
  

Aldehydes

• You may have heard of one of the most well-known aldehydes, formaldehyde. A common pollutant from many manfacturing processes, aldehydes are produced during an early stage of brass making. They can be harmful to the environment, irritating the eyes and mucous membranes of humans and animals and either directly or indirectly harming plant species. Aldehydes also react with other compounds to form ozone and peroxides.
  
  

Chloride

• A negatively charged form of chlorine, chloride is produced during an intermediary stage of brass production, when brass and bronze are formed. Chloride is a very common pollutant from manufacturing and industry. Therefore, environmentalists and ecologists sometimes measure chloride levels to extrapolate the general pollution levels in an area.