Asbestos is a carcinogenic naturally occurring mineral. Throughout most of the twentieth century, asbestos was considered a “miracle mineral”. It was lightweight, inexpensive, strong, and fire resistant. Not until the late 1970s did people realize it had a downside: asbestos causes many diseases and cancers. Some of these illnesses include lung cancer, mesothelioma, and asbestosis. The diseases are caused when asbestos is inhaled or ingested; despite this risk, there is no complete ban on asbestos in the United States, making the country one of the only world powers lacking an asbestos ban. Many products containing asbestos remain allowed, with a limit of asbestos percentage.

It was only in the late 1970s that asbestos risks were recognized; because of this products made after 1979 are much less likely to contain asbestos than those made before 1979. Because those made before 1979 were often made with asbestos cement, water pipes are one dangerous product. Now, decades later, many of the pipes are wearing down. Potentially, this contaminates drinking water with asbestos.

Why did drinking pipes include asbestos? Asbestos cement is cheap, strong, and resists corrosion. Beyond cement water pipes containing asbestos, there are a variety of ways asbestos can make its way into drinking water. Some of these are: if landslides move asbestos deposits into water supplies, if asbestos containing materials are improperly disposed, if airborne asbestos settles in water supplies, and if storms damage structures that have asbestos and are located near water.

How dangerous is asbestos in water? It is not clear. No level of asbestos is safe, but because asbestos in water is wet, it might not cause as much harm as airborne asbestos. Much research is still necessary to find out exactly how dangerous asbestos in water is. The World Health Organization estimates that most people living in the United States consume one million asbestos fibers per liter of water. The Environmental Protection Agency’s regulations for groundwater say that up to seven million fibers of asbestos per liter of water is safe, but any more than that is unsafe. The agency set that limit based on existing evidence. The goal of the regulation is to protect human health.

Multiple organizations have the job to prevent harmful exposure to asbestos. These organizations are: the World Health Organization, the Centers for Disease Control and Prevention, the Environmental Protection Agency, and the Agency for Toxic Substances and Disease Registry.

All drinking water goes through an extensive process to remove contaminants. There are many steps to this process, but the step that removes asbestos is the filtration step. In this step, water is typically filtered through fine granules, for example sand, gravel, or charcoal. Filtration happens before disinfection, which kills bacteria and germs. The water cleaning process isn’t always perfect, and sometimes more precautions are advised or preferred. Many people include filters in their homes just to be safe. If there has been a recent natural disaster, health professionals might advise those nearby to use bottled water for the time being.