Pollution - Environmental Science - page 158

found in older buildings and furniture. Mercury also can become airborne indoors, and mercury fumes
can occur from the use of latex paints.
• Biological threats, such as mold, dust mites, and pet dander, are often found indoors. They are not uni-
versally toxic, but some people are sensitive to these allergens.
• Carbon monoxide (CO) is a colorless, odorless gas that is emitted from broken or incorrectly used heat-
ing appliances such as clothes driers and water heaters. It is also emitted in vehicle exhaust and the com-
bustion of wood.
• Wood-burning emits particulate matter and carbon monoxide.
• Volatile organic compounds (VOCs) can be released as gases from a wide variety of products including
carpeting, paints, aerosol sprays, cleaning products, building supplies, pesticides, printers, glues, wood
preservatives, mothballs, and air fresheners. Some VOCs are also used in dry cleaning processes.
• Polybrominated biphenyl ether (PBDEs) are chemicals that are used as flame-retardants in household
items such as televisions, furniture, fabrics, wire insulation, drapes, small appliances, and other electron-
ics. During manufacture, PBDEs are mixed with materials in order to raise the temperature at which they
burn, but unfortunately they are released into the air in small quantities throughout the life of the
product. Some forms of PCDEs have been banned in places such as the United States and the United
Kingdom, but others are still in use.
Noise Pollution
Noise pollution encompasses all human activities that produce enough sound to be considered a nuisance.
Common sources of noise pollution consist of vehicle traffic, railways, aircraft, car alarms, machinery, barking
dogs, yard equipment, loud motorcycles, and music. Poor urban planning can result in an increased amount of
aggravating noise for the people who reside or work in these locations.
This issue is serious enough that federal laws have been enacted in response to noise pollution. Such laws in-
clude the Noise Pollution and Abatement Act of 1970 and the Noise Control Act of 1972.
Light Pollution
Light pollution results from the excessive use of artificial light and can cause glare, over-illumination, sky
glow, and decreased night visibility, and can consume excessive amounts of energy. In addition to being a dis-
traction and an annoyance, light pollution can block terrestrial views of the night sky, interfering with organ-
isms that depend on this view. Reducing light pollution requires conscious conservation efforts by all.
Genetic Pollution
Genetic pollution is a new concern that refers to the unintended spread of altered genetic information from ge-
netically engineered organisms to natural organisms. Genetically engineered organisms are organisms that
have had their DNA intentionally altered by combining their genetic material with that of another, most com-
monly in hopes of creating traits that are commercially desirable, including size, growth, or disease resistance.
The use of these genetically engineered organisms is quickly increasing, especially in industrialized agricul-
ture, in which genetically modified seeds are used to grow crops. This process has proponents and opponents
and is seen to have both positive and negative impacts. Benefits of genetically engineered foods can include in-
creased yield and crop efficiency. Dangers of these organisms include their potential to leak into the wild due
to pollination or wind, where they may out-compete native species. Another concern is that only a few com-