Many of the VOC's involved were traced to household cleaners. The chemicals found in cleaning products cause both acute and chronic effects. An acute effect is caused by a single overexposure to a product or chemical. This is the type of danger cleaning product labels warn us about. Poisonings are the most common and well-known acute effect.
Chronic effects are much different.
They result from repeated low-level exposure to a chemical or product over a period of time. These types of exposures are more difficult to identify because it may take years for symptoms to develop. While cancer is the most well-documented result of chronic exposure to household chemicals, direct evidence connecting household cleaning chemicals to cancer is difficult to come by. There is however, enough anecdotal evidence to raise considerable alarm. For example, a fifteen-year study in Oregon compared women working outside the home to homemakers.