In our last article, we introduced the topic of volatile organic compounds (VOCs). We described their chemical composition, and gave some examples of common household, commercial and industrial products that contain VOCs. We concluded with a look at how these chemical contaminants find their way into the environment, and specifically into our drinking water supply. Now let’s turn our attention to what happens once VOCs enter our homes. What are the health effects of VOCs? And what can we do to filter VOCs from our drinking water?
Spread of VOCs in the home
Volatile organic compounds can easily evaporate into indoor air when you use your water for any purpose, such as drinking, cooking, showering, and washing dishes, especially if the water is heated. Your water, however, is not the only source of VOC contamination in your home. The VOCs known as chlorinated solvents come into your home through a variety of common household products: cleaners, degreasers, office supplies and freshly dry-cleaned clothing. VOCs known as fuel components come into your indoor air through cigarette smoke, gasoline or heating oils stored in the basement or attached garage, and some hobby or craft supplies.
Effects of VOCS on our health
The U.S. Environmental Protection Agency (EPA) estimates that volatile organic compounds are present in one-fifth of the nation’s water supplies. Since January 2011, the EPA has been studying further limits on eight currently regulated compounds (benzene; carbon tetrachloride; 1,2- dichloroethane; 1,2-dichloropropane; dichloromethane; tetrachloroethylene; trichloroethylene; vinyl chloride) and eight unregulated compounds (aniline; benzyl chloride; 1,3-butadiene; 1,1-dichloroethane; nitrobenzene; oxirane methyl; 1,2,3-trichloropropane and urethane). All of these VOCs are known or suspected to cause cancer.
VOCs vary considerably in their harmful consquences. VOCs are typically not acutely toxic, but instead have compounding long-term health effects. Because VOC concentrations are usually low and the symptoms slow to develop, research into VOCs and their effects can be difficult. Researchers collect information about VOCs and human health primarily from animals studies, and from studies of workers who are exposed to large quantities of chemicals in the workplace.
VOCs may cause irritation when they contact the skin, or may irritate mucous membranes if they are inhaled. High amounts of chlorinated solvents have been found to cause dizziness, to reduce concentration and memory, and to damage the nervous system. They can also produce an irregular heartbeat in people who are exposed in the workplace and in laboratory animals. Fuel components can cause drowsiness, dizziness, and headaches at high doses. Long-term exposure to high levels of toluene or xylene may lead to liver and kidney damage. Benzene is the most toxic of the fuel components and can seriously alter blood cells. Industrial workers exposed to high levels of benzene in the air were at higher risk of developing low red and white blood cell counts than other unexposed workers.
A New Jersey Department of Health and Senior Services (NJDHSS) study, and two studies in Massachusetts, suggested that the geographic pattern of tetrachloroethylene (PCE) and trichloroethylene (TCE) in drinking water was related to increases in the occurrence of certain types of leukemia and lymphoma. Other studies in New Jersey and California have also connected these chemicals in drinking water with an increased occurrence of certain birth defects (congenital heart and neural tube defects) and low birth weight.
Filtering VOCs from our drinking water
Granular activated carbon (GAC) filters are typically used to reduce VOC levels effectively in home drinking water if they are properly installed and maintained. Filtration systems may be installed for point-of-use treatment at the faucet, or point-of-entry treatment where water comes into the house. Because VOCs may enter the body through skin absorption or through inhalation of water vapor, point-of-entry systems are preferred. That way, you can provide your household with safe water for bathing and washing, as well as for cooking and drinking.