Back in 2000, some of you may remember watching the film Erin Brockovich, starring Julia Roberts. In the movie, Roberts’ character becomes involved in a class action lawsuit against Pacific Gas and Electric Company (PG&E) regarding toxic groundwater caused by the carcinogen hexavalent chromium, or ‘chromium-6.’ You may not know this, but this story was based on a true story. Sadly, the toxic water issue still lives on today and continues to affect hundreds of millions of Americans.

A Brief History of Hexavalent Chromium aka Chromium-6

Before 1970, the federal government could not effectively monitor or enforce environmental regulations. It wasn’t until December 2, 1970 that the Environmental Protection Agency (EPA) was formed. About four years later, the Safe Drinking Water Act (SWDA) was passed. However, it was not until 1991 that the EPA added chromium to their list of maximum contaminant level (MCL) goals. Chromium is a tasteless and odorless element found in soil, plants, rocks, volcanic dust, and animals. Although it is a naturally occurring metallic element, industrial projects have contributed to higher-than-recommended quantities of chromium-6. This includes the manufacturing of stainless steel, textiles, anticorrosion coatings, leather tanning, and poor storage or waste disposal practices. As a result, this industrial pollution contaminates tap and drinking water. But it was not until the turn of the century that chromium-6 became truly mainstream, thanks to the retelling of the Erin Brockovich story.

Hexavalent Chromium: Then and Now

In 1991, the first MCL for chromium given by the EPA was 100 parts per billion (ppb). Over the last two and a half decades, environmental researchers and scientists have collected and analyzed data surrounding the cancer-linked carcinogen. In fact, all hexavalent chromium compounds are recognized as known human carcinogens. That said, there’s a definite lack of human studies, while most have been conducted on laboratory animals. However, in the ‘side effects’ listed below, we cite a few unfortunate cases where humans ingested hexavalent chromium compounds. In 2010, the Environmental Working Group analyzed samples of drinking water from 35 American cities. Researchers found 31 of those cities to contain measurable amounts of hexavalent chromium. On average, there was 0.18 ppb of chromium-6 in EWG’s tested tap water. The highest levels of chromium-6 were found in Norman, OK which measured 12.9 ppb; Honolulu, HA with 2.00 ppb; Riverside, CA at 1.69 ppb.  As it stands, the EPA has set the acceptable limit of hexavalent chromium to 100 ppb. But California’s EPA, unsatisfied with this limit, proposed a MCL goal of 0.2 ppb to reduce cancer risk, which was successfully established in 2011. That is 5,000 times higher than California’s new proposed limit for chromium-6. Between 2013 and 2015, the Environmental Working Group studied 60,000+ water utility samples from all fifty states. Unsurprisingly, the team still found levels of chromium-6 in over 75% of U.S. cities. Today, EWG and Erin Brockovich continue to push for the EPA to lower the MCL to reflect California’s proposed goal.

The Most Common Side Effects of Hexavalent Chromium 

Some of the adverse health effects associated with inhaling, not ingesting, hexavalent chromium can include:

  • Asthma
  • Eye irritation and damage
  • Perforated eardrums
  • Respiratory irritation
  • Kidney damage
  • Liver damage
  • Pulmonary congestion and edema
  • Upper abdominal pain
  • Nose irritation and damage
  • Respiratory (e.g., lung) cancer
  • Skin irritation
  • Erosion and discoloration of teeth

If all that can happen from inhalation, we must question the short or long-term effects of skin contact with or ingestion of hexavalent chromium. In fact, research has show that this kind of contact with chromium-6 may cause:

  • Non-allergic skin irritation, which can turn into ‘chrome ulcers’
  • Red, swelling, itchy skin rashes
  • Cancer in mice following oral ingestion, with increases in tumors at sites where tumors are rarely seen in laboratory animals

In extreme cases where humans ingested hexavalent chromium compounds, studies revealed the following adverse effects:

  • Abdominal pain and vomiting
  • Gastrointestinal hemorrhaging
  • Cardiovascular issues
  • DNA oxidative damage

How to Tell Your Hexavalent Chromium Risk

The Environmental Working Group has put together an interactive map, which states that the “’Erin Brockovich’ chemical taints tap water of 218 million Americans.” It incorporates all of their analysis to date. So far, it has found 1,370 U.S. county water supplies with levels of chromium-6 that exceed California’s ideal goal. Click on the map below to enlarge and interact. According to the EWG’s senior scientist David Andrews: “Americans deserve to know if there are potentially harmful levels of a cancer-causing chemical in their tap water… The difficulty with chromium-6 is how to set a standard to protect human health during windows of development.” But that isn’t the only issue. In a report from the Environmental Working Group, they wrote: “Cleaning up water supplies contaminated with chromium-6 will not be cheap,” the EWG report concluded. “But the answer to high costs is not allowing exposures at unsafe levels while pretending water is safe. And the fact that some unknown level of chromium-6 contamination comes from natural sources does not negate Americans’ need to be protected from a known carcinogen.”

But Here’s What You Can Do to Protect Yourself

According to the Environmental Working Group, the most effective and affordable prevention tool is a reverse osmosis filter, which works like a high-pressure coffee filter. To make your search easier, the EWG has put together a guide for finding the perfect water filter. While they apply to people working directly hexavalent chromium, the Occupational Safety and Health Administration (OSHA) has outlined steps to protect yourself:

  • Limit eight-hour time-weighted average hexavalent chromium exposure in the workplace to 5 micrograms or less per cubic meter of air.
  • Perform periodic monitoring at least every 6 months if initial monitoring shows employee exposure at or above the action level (2.5 micrograms per cubic meter of air calculated as an 8-hour time-weighted average).
  • Provide appropriate personal protective clothing and equipment when there is likely to be a hazard present from skin or eye contact.
  • Implement good personal hygiene and housekeeping practices to prevent hexavalent chromium exposure.
  • Prohibit employee rotation as a method to achieve compliance with the exposure limit (PEL).
  • Provide respiratory protection as specified in the standard.
  • Make available medical examinations to employees within 30 days of initial assignment, annually, to those exposed in an emergency situation, to those who experience signs or symptoms of adverse health effects associated with hexavalent chromium exposure, to those who are or may be exposed at or above the action level for 30 or more days a year, and at termination of employment.