Study Indicates That California Tap Water May Cause Many Different Types of Cancer

By Rehan Iqbal 

A study conducted by the Environmental Working Group (EWG) in 2019 indicates that the many contaminants commonly found in California's public water systems, such as:

…contribute to the development of cases of cancer throughout the state. In fact, it is speculated that as many as 15,500 cases of cancer might be attributed to use of California tap water in the course of a single generation.

The lead author of the study, Tasha Stoiber, says that it's very important to understand that the cancer risks are greater when the contaminants are combined. She further explained that testing is usually done on one contaminant at a time, but the contaminants do not typically occur in isolation.

Which Contaminants Are The Worst?

Of the four contaminants identified, arsenic is by far the most dangerous. Even when arsenic is at a very low level, it is a significant carcinogen and accounts for approximately 47% of cancer cases caused by water.

There is no safe level of arsenic in drinking water, and it can get into tap water naturally through the soil, or it can be introduced through agricultural and industrial activity.

How Was The Study Conducted? 

The study made a thorough evaluation of 2737 separate water systems throughout California. Researchers assessed the level of contaminants reported in each system.

These systems combined provide nearly 100% of the state’s drinking water. All are regulated federally in accordance with the Safe Drinking Water Act. All are monitored by state regulators.

Public water systems typically test for many different contaminants (unregulated and regulated) on a regular basis. The researchers reviewed the records kept by the systems from the years 2011 through 2015. They assessed the annual averages of all contaminants combined in order to calculate the cumulative risk.

Which Public Water Systems Are The Worst?

The next step was to categorize the water systems by risk. Four categories were identified, and researchers estimated that people drinking tap water from the highest risk providers had a one in 1000 likelihood of developing cancer in their lifetime.

Researchers determined that this would add up to approximately 4860 cancer diagnoses. Of the 2737 water systems evaluated, approximately 500 were identified as being in the high risk category.

It is worth noting that the American Cancer Society says that, water notwithstanding, about 40% of Americans overall will receive a diagnosis of cancer at some time in their lives.

The study determined that Californians who get their water from small public water systems are more likely to encounter arsenic as a contaminant because smaller utilities do not usually have the sophisticated treatment facilities necessary to remove arsenic from water.

How Can You Remove Contaminants from Your Tap water?

Luckily, it is possible to remove most contaminants, carcinogens and pathogens from tap water using carbon activated filters or reverse osmosis filters.

Something as simple as a water filtration pitcher can remove a significant amount of carcinogens and contaminants from water.

The study's authors say that faucet filters are a bit more effective than filtration pitchers, but whole house systems are the most effective.

In addition to the contaminants we've mentioned so far, you should realize that tap water can contain hundreds of other contaminants and chemicals. In fact, most tap water contains in excess of 300 different pollutants and chemicals according to EWG.

These include:

Heavy metals such as mercury and lead cause a wide variety of health problems.

Fluoride is a chemical that is frequently added to public drinking water because it has been shown to support healthy teeth; however, the fact that direct application to the teeth is effective, but drinking fluoride is not effective is not taken into account in this decision. Drinking fluoridated water can cause a wide variety of health problems including thyroid dysfunction.

Volatile Organic Chemicals (VOCs) which are frequently used in herbicides and pesticides that make their way into groundwater and eventually into tap water. VOCs can cause damage to your kidneys, liver, reproductive system and more.

Endocrine Disrupting Chemicals (EDCs) mimic the functions of normal hormones. Consuming EDCs on a regular basis can cause problems such as low sperm count in men, undescended testicles in young boys, ectopic pregnancies, breast cancer and prostate cancer.

How Can You Tell What's in Your Water?

Your local water supplier is required to provide a report annually. If you get your tap water from a large local water company, you may be able to access this report on the company's website. Otherwise, you should be able to submit a request for a copy, or the public utility may simply send you a copy annually.

Water Filtration Pitchers

If you're in a hurry to get started with water filtration and you don't have a lot of money to spend, a filtration pitcher is the answer for you. These units are available in most grocery stores, drug stores, department stores, big-box stores and online for under $30. Activated charcoal filters typically run about five dollars each and last about a month.

If you want start filtering your water as soon as you finish reading this article, you should go out and buy filtration pitcher. You may just want to do this is a stopgap measure, though. Filtration pitchers do remove chlorine and a number of other contaminants, but for the most part they do not remove VOCs, EDCs and fluoride. Some do remove heavy metals.

Faucet Mount External Filtration

You can also get a filter to mount on your kitchen sink faucet. Most of the same positives that apply to water filtration pitchers apply to faucet mount systems. They are easy and affordable to purchase and simple to install and use. They remove a lot of common chemicals, but may not remove some of the more dangerous pollutants and contaminants.

Water Filtration with Charcoal Sticks

If you don't like the idea of throwing away a plastic filter on a monthly basis, charcoal stick filters are a nice, eco-friendly alternative. With this method, you simply drop the stick into a pitcher of water and leave it for the amount of time recommended in the instructions.

 You can use charcoal sticks multiple times, and you can recharge them to extend their life even further. When a charcoal stick is completely used up, you can break it up and toss it into your compost heap or set it in your refrigerator as a natural deodorizer.

Reverse Osmosis Filtration (RO)

RO filtration uses a membrane that removes a great number of contaminants from tap water. It is usually used in conjunction with an activated charcoal filtration system which removes chlorine. This type of filtration system can be mounted under your kitchen sink and usually has a holding tank.

The membrane is semi-permeable and separates contaminants which have a larger particle size. The downside is that it also rejects and wastes a great deal of water along with the contaminants. Furthermore, the membrane removes minerals such as magnesium and calcium from the water.

Although RO filtration does remove fluoride, heavy metals, asbestos and arsenic, it is not an ecologically friendly choice because it wastes several gallons of water for every gallon that it filters. Furthermore, you'll need to take great care in supplementing your diet with necessary minerals to make up for their removal in the filtration process.

Water Distillation 

You can distill your tap water with a large and rather expensive system that heats it causing steam to rise into a cooling chamber where it condenses and drips into a holding tank leaving contaminants behind. This is an effective way of killing bacteria and removing heavy metals (and unfortunately minerals) from your water; however, it does not remove VOCs or EDCs.