Formaldehyde is a ubiquitous chemical found in virtually all indoor environments.
The major sources which have been reported and publicized include urea-formaldehyde
foam insulation (UFFI) and particle board or pressed wood products used
in manufacturing of the office furniture bought today. It is used in consumer
paper products which have been treated with UF resins, including grocery
bags, waxed papers, facial tissues and paper towels. Many common household
cleaning agents contain formaldehyde. UF resins are used as stiffeners,
wrinkle resisters, water repellents, fire retardants and adhesive binders
in floor coverings, carpet backings and permanent-press clothes. Other
sources of formaldehyde include heating and cooking fuels like natural
gas, kerosene, and cigarette smoke.
Formaldehyde irritates the mucous membranes of the eyes, nose and throat.
It is also a highly reactive chemical which combines with protein and can
cause allergic contact dermatitis. The most widely reported symptoms from
exposure to high levels of this chemical include irritation of the eyes
and headaches. Until recently, the most serious of the diseases attributed
to formaldehyde exposure was asthma. However, the Environmental Protection
Agency (EPA) has recently conducted research which has caused formaldehyde
to be strongly suspected of causing a rare type of throat cancer in long-term
occupants of mobile homes.
Benzene is a very commonly used solvent and is also present in many common
items including gasoline, inks, oils, paints, plastics, and rubber. In
addition it is used in the manufacture of detergents, explosives, pharmaceuticals,
and dyes. Benzene has long been known to irritate the skin and eyes. In
addition, it has been shown to be mutagenic to bacterial cell culture and
has shown embryotoxic activity and carcinogenicity in some tests. Evidence
also exists that benzene may be a contributing factor in chromosomal aberrations
and leukemia in humans.
Repeated skin contact with benzene will cause drying, inflammation, blistering
and dermatitis. Acute inhalation of high levels of benzene has been reported
to cause dizziness, weakness, euphoria, headache, nausea, blurred vision,
respiratory diseases, tremors, irregular heartbeat, liver and kidney damage,
paralysis and unconsciousness. In animal tests inhalation of benzene led
to cataract formation and diseases of the blood and lymphatic systems.
Chronic exposure to even relatively low levels causes headaches, loss of
appetite, drowsiness, nervousness, psychological disturbances and diseases
of the blood system, including anemia and bone marrow diseases.
Trichloroethylene (TCE) is a commercial product found in a wide variety
of industrial uses. Over 90 percent of the TCE produced is used in the
metal degreasing and dry cleaning industries. In addition, it is used in
printing inks, paints, lacquers, varnishes, and adhesives. In 1975 the
National Cancer Institute reported that an unusually high incidence of
hepatocellular carcinomas was observed in mice given TCE by gastric intubation
and now considers this chemical a potent liver carcinogen.