GAC:
Granular activated carbon is a highly adsorbent material used  in water filters to remove contamination from water. Activated carbon has been known as a miracle filter media by many researchers because of its unique ability to remove offensive tastes, odors, color, chlorine and volatile organic chemicals, pesticides and trihalomethanes (a group of suspected carcinogens). Briefly, activated carbon in a water filter acts like a sponge, with a large surface area to absorb contaminants in the water. The surface area of one pound of activated carbon is equal to 125 acres. Many scientists believe this is a result of an affinity that these chemicals have for carbon because of Van Der Waal forces. Activated carbon is the preferred treatment and method recommended by the EPA to remove a host of potentially hazardous and possibly carcinogenic chemicals in drinking water.

A partial list of chemicals that are reduced or removed by activated carbon are:

• Chlorobenzene 0.1 Used as a solvent for paint and metal manufacturing. Also used in insecticides. Affects nervous system, kidneys and liver.
• CIS-1,2  Dichloroethylene 0.07 Used as an industrial solvent in the manufacturing of dyes, perfumes  and lacquers Affects liver, and a nervous and circulatory systems. Probable cause of cancer.
• Dibromochloropropane 0.0002 Soil fumigant on soybeans, and cotton. Canceled in 1997. Cancer
• Dioxin 0.00000003 Chemical production by-product; impurity in herbicides. Affects lungs, liver and kidney. Probable cause of cancer.
• Epichlorohydrin 0 Used in epoxy resins and coating, and in flocculants. Affects nervous system, kidney and liver.
• Ethlbenzene 0.7 Used in the manufacture of gasoline, insecticides and  asphalt Probable cause of cancer
• Ethylene Dibromide 0.00005 Used as a gasoline additive and soil fumigant. Affects nervous system, kidneys and liver
• Monochlorobenzene 0.01 Used in manufacture of pesticides and as a metal cleaner and industrial solvent. Cancer
• PAHs 0.0002 Coal tar coating, burnings organic matter, volcanoes, fossil fuels. Cancer
• Phthalate (di(2-ethylhexyl)) 0.006
• Polychlorinated PVC and other plastics. Affects skin and liver. Causes nausea. Probable cause of cancer.
• Biophenyts (PCBs) 0.0005 Used in electrical transformers. Affect nervous system, kidneys and liver.
• Styrene 0.01 Used in manufacturing plastic, resins and foams. Affects nervous system. Probable cause of cancer and anesthesia
• Tetrachloroethylene 0.005 Used in dry cleaning and as a degreasing agent for metals. Also used for manufacturing rubber, waxes, paints and inks. Affects nervous system, liver and kidneys. Causes narcosis. Irritant to respiratory system.
• Toluene 1 Used in gasoline, paint thinners, lacquers and adhesives. Cancer
•  

Total Trihalomethanes
(THM's):

• Chloroform
• Bromoform
• Bromodichloromethane
• Dibromochloromethane
•  
•  0.01 Formed when water containing organic matter is treated with chlorine. ffects nervous system and muscles. Probable cause of cancer.
• 1,1 Dichloroethylene 0.007 Used in manufacturing dyes, plastic, perfumes, paints and adhesives Affects kidneys and liver and can cause nausea.
• 1,1,2-Trichloroethane 0.005 Solvent in rubber products, chemical production waste. Kidney, liver, nervous system damage
• 1,1,1-Trichloroethane 0.02 Used in manufacturing of pesticides, plastic and metals. Affects nervous system. Causes narcosis and probably cancer.
• 1,2 Dichlorobenzene 0.6 Used in the manufacturing of fumigants, insecticides, waxes, resins, rubber and asphalt Affects lungs, liver and kidneys.
• 1,2 Dichloroethane 0.005 Used in the manufacturing of gasoline, paint, varnish, metal degreasers and insecticide fumigants Damage kidney and liver can cause nausea
• 1,2 Dichloropropane 0.005 Used in insecticide fumigants, dry cleaning fluids and in manufacturing of resins, waxes and petroleum products Affects lungs, liver and kidneys.
• 1,2,4-Trichlorobenzene 0.07 Herbicide production; dye carrier. Liver, kidney damage
• 1,4 Dichlorobenzene 0.075 Used in moth repellent, germicides, pesticides and soil fumigants. Affects nervous system, liver and kidneys. Probable cause of cancer.
• Acrytamide 0 Flocculants used in sewage and wastewater treatment. Affect nervous system, probable cause of cancer.
• Adipates 0.4 Synthetic rubber, food packaging, cosmetics. Decreased body weight; liver and testes damage.
• Benzene 0.005 Used in fuels and as a solvent in manufacturing pharmaceuticals, plastics, pesticides and paints. Often traced to leaking underground storage tanks. Leukemia, anemia and possibly cancer
• Trans-1,2 Dichloroethylene 0.1 Used as an industrial solvent in the manufacturing of dyes, perfumes, lacquers and rubber. Affects liver, and nervous and circulatory systems
• Trichloroethylene 0.1 Used in dry cleaning and as a degreasing agent. Also used for manufacturing rubber, paints, adhesives, resins, oils and fumigants. Irritates body tissue. Affects nervous system. Probable cause of cancer.
• Vinyl Chloride 0.005 Used as a plastic adhesive and refrigerant. The main component of PVC pipe Affects nervous system. Probable cause of cancer.
• Xyienes 0.002  Used in manufacturing paint, ink, petroleum and detergents. Affects nervous system, kidneys, lungs, liver and mucous membranes.

Pesticides

• Aldicarb
• Aldicarb Sulfone
• Aldicarb Sulfoxide
• Carboturan
• Agricultural insecticide Affects nervous system, respiratory system, kidneys and liver. Probable cause of cancer.
• Chlordane 0.04 Used on rodents, insects, birds. Restricted since 1980. Affects nervous system, respiratory system, kidneys and liver. Probable cause of cancer
• Endrin 0.0002 Agricultural insecticide. Liver, kidneys, heart damage.
• Heptachlor 0.0004 Agricultural insecticide. Converts to expoxide by soil and water organisms Affects nervous system, respiratory system, kidneys and liver. Probable cause of cancer.
• Heptachlor Expoxide 0.0002 Pesticide production by-product. Affects nervous system, respiratory system, kidneys and liver. Probable cause of cancer.
• Hexachlorobenzene 0.001 Pesticide production by-product. Cancer
• Hexachlorocyclop -entadiene 0.05 Agricultural insecticide. Cancer
• Lindane 0.0002 Agricultural insecticide. Affects nervous system, respiratory system, kidneys and liver. Probable cause of cancer.
• Methoxychlor 0.04 Insecticide used on apples, potatoes, tomatoes. Affects nervous system, respiratory system, kidneys and liver. Probable cause of cancer.
• Oxamyl   Agricultural insecticide. Kidney damage.

Herbicides

•  
• 2,4-D
• 2,4,5-TP (silver)
• Alachlor
• Alrazine
• Agricultural  herbicides Affect nervous and reproductive system, respiratory system, kidneys, liver and heart. Causes anesthesia. Probable cause of cancer.
• Dalapon 0.2 Herbicide used on orchards, beans, coffee, lawn, roads and railway. Liver, kidney damage.
• Dinoseb 0.007 Runoff of herbicide from crop and non crop applications. Thyroid, reproduction organ damage.
• Diquat 0.02 Runoff of herbicide on land and aquatic weeds. Liver, kidneys, eye effects.
• Endothall 0.01 Used on crops, land and aquatic weeds. Liver, kidney and gastrointestinal damage. Activated carbon
• Glyphosphate 0.7 Used on grass, weeds, brush Liver, kidney damage Activated carbon
• Pentachlorophenol 0.001 Agricultural herbicide and wood preservative. Affects nervous and reproductive system, respiratory system, kidneys, liver and heart. Causes anesthesia. Probable cause of cancer.
• Picloram 0.5 Used on broadleaf and woody plants. Kidney, liver damage.
• Simazine 0.004 Used on grass sod, some crop, aquatic algae. Cancer.

Source: Water Technology, Directory Issue / 1995