Stephanie Angione, Ph.D.  |  Scientific Contributor

What Are Polychlorinated Biphenyls (PCBs)?

Polychlorinated Biphenyls (PCBs) are a class of industrial chemical that were widely manufactured in the US from the 1930s through the 1970s for use in electric equipment such as capacitors and transformers, and also as heat transfer fluids, plasticizers, adhesives, fire retardants, inks, lubricants, cutting oils, pesticide extenders, and in carbonless copy paper.
 
While PCB production slowed in the 1960s and was banned completely in the US in 1979, they are still found in industrial applications due to their chemical longevity. The US congressional ban was enacted due to the fact that PCBs are persistent organic pollutants, which create long lasting environmental toxicity and cause harmful health effects. Products that contain PCBs include old fluorescent lighting fixtures, PCB capacitors in old electrical appliances (pre-1978) and certain hydraulic fluids.
 
Nearly 2 million tons of PCBs have been produced since 1929, 10% of which persists in the environment today. Generally, environmental concentrations of PCBs are low, but due to their chemical inertness they are largely resistant to chemical breakdown or thermal destruction, and thus accumulate in the environment. Additionally, PCBs are highly fat soluble, resulting in the build up of PCBs in animal fat, resulting in higher concentrations of PCBs in top food chain consumers (e.g. predatory fish, large mammals, humans).
 

Where Are PCBs Found In The Environment?

Polychlorinated Biphenyls accumulate primarily in water sources, organic portions of surface soil, and in living organisms.
 

Water

Surface water that is contaminated with PCB waste generally has high levels of PCBs in sediment, as the PCBs attach to organic matter. PCBs can be slowly released from the sediment into the water and evaporate into the air, especially at higher temperatures.

Air

PCBs have been detected throughout the atmosphere, and can be transported globally through air. Concentrations of PCBs in the air are generally the lowest in rural areas and highest in large cites. Areas that are close to bodies of water that were highly contaminated with PCBs from industrial waste (e.g. Lake Michigan, Hudson River) can have higher air concentrations, due to evaporation of PCBs into the air over time.  

Living Organisms

PCBs accumulate in living organisms via bioaccumulation, or uptake from the environment, as well as biomagnification, from consumption along the food chain. Bioaccumulation is typically highest in aquatic species, with bottom feeding species having the highest levels of PCBs due to accumulation in sediment.  PCBs biomagnify up the food chain, as bottom feeders like shellfish are eaten by other species, and thus the greatest levels are found in large predatory fish. This process can also occur on land, as PCB contamination in soil is transferred up the food chain to insects, birds and mammals. Thus, one of the largest sources of PCB exposure and accumulation in humans is from food, specifically meat and fish.

How Do PCBs Impact Humans?

While PCBs have been classified as probable human carcinogens, there is no evidence that the low levels of PCBs in the environment cause cancer. Exposure to high levels of PCBs have primarily occurred through workplace exposure in people who work in plants that manufacture the chemicals. Studies of workers exposed to high PCB levels have shown association with certain types of cancer. These high levels of exposure have also been known to cause liver damage, skin lesions called chloracne, and respiratory problems.

Exposure to PCBs during pregnancy can result in developmental and behavioral deficits in newborns. Additionally, there is evidence that reproductive function can be disrupted due to PCB exposure. Women of childbearing age, or those who are pregnant or nursing should be aware of fish and shellfish advisories to limit consumption of PCB contaminated fish.
There are additional studies that suggest PCB exposure can cause health effects including thyroid dysfunction, liver dysfunction, as well as adverse cardiovascular, gastrointestinal, immune, musculoskeletal, and neurological effects.

How Are PCBs Regulated & Monitored In The US?

With so many sources of PCB exposure from food and water sources, the US government has guidelines on the amount of allowable environmental PCB contamination for each.  

Food

The FDA enforces a tolerance level in fish of 2 ppm, and overall 0.2 -3.0 ppm for all foods. PCBs in paper food packaging are limited to 10 ppm.
 
If fishing recreationally and you plan to eat your catch, check if any local fish consumption guidelines exist for your area. The EPA maintains a national database of fish and shellfish advisories issued by each state. These consumption advisories may recommend limiting the amount of a certain fish consumed, or from specific waters or water sources. As of 2011, five areas have advisories for PCBs in freshwater sources (Missouri, Minnesota, Maryland, Indiana, and District of Columbia) and nine states (Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, and Rhode Island) have PCB advisories for coastal waters.

Drinking Water

Under the Clean Water Act, industrial discharge of Polychlorinated Biphenyls in water is prohibited. The goal is to reach zero contamination in drinking water, but the enforceable maximum level is 0.0005 part per million (ppm).  Additionally, industries are required to report spills or accidental releases to the EPA. 

Routine monitoring of PCB levels in drinking water require the water supplier to maintain the limit enforced by the EPA and must make the data regarding water quality and contaminants public. Every year, the EPA requires water suppliers nationwide to provide a Consumer Confidence Report (CCR), which will include information about water treatment and any known contaminants. These reports are available on the EPA website and should be available on your water company’s website. Additionally, the supplier is required to alert customers of increased levels of PCB contamination as soon as possible.
 
If you get water from a household well, the local health department should have information about ground water quality and contaminants of concern, but it is often a good idea to have your water tested by a certified laboratory if you are worried about PCB (or other) contaminants. The EPA’s Safe Drinking Water Hotline (800-426-4791) can provide additional resources in your local area.

How Can I Remove PCBs From My Water?

If your water has high levels of PCBs in it,  the water should also not be used to drink, prepare or cook food,  or given to pets for consumption without first treating it.  Fortunately, PCBs are effectively removed from water by filters that use activated carbon as part of their active filtration media blend.
 
Hydroviv makes it our business to help you better understand your water.  As always, feel free to take advantage of our “help no matter what” approach to technical support!  Our water nerds will work to answer your questions, even if you have no intention of purchasing one of our water filters.  Reach out by dropping us an email (hello@hydroviv.com) or through our live chat. You can also find us on Twitter or Facebook!

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Why TDS Measurements Don't Tell You Anything About Water Quality

Eric Roy, Ph.D.  |  Scientific Founder

This past week, the Environmental Working Group (EWG) released a website where people punch in their zip code, and view contaminants found in their water. As a company that uses water quality data to optimize each customer’s water filter, we applaud EWG for putting in the enormous amount of time & effort to build the database so the public can learn about their water. Unfortunately, we are seeing that these data are being used to generate inflammatory headlines, which can leave consumers confused and unnecessarily panicked.

We will be updating this water quality database blog post as more questions come in. If you have your own question, please reach out to us (hello@hydroviv.com). One of our water nerds will do their best to get back to you very quickly, even if it’s outside of our business hours.

Frequently Asked Questions 

Updated July 31, 2017

Are All Potential Contaminants Listed In The EWG Tap Water Database?

No. The EWG Tap Water Database pulls data from municipal measurements, but municipalities are only required to test for certain things. Simply put, you can’t detect what you don’t look for. One example of this can be seen by punching in Zip Code 28402 (Wilmington, North Carolina) into the EWG Tap Water Database. GenX, a chemical that has been discharged into the Cape Fear River by Chemours since PFOA since 2010, is not listed, even though it’s been in the center of a huge topic of conversation for the past 2 months in the local media.

Why Is The “Health Guideline” Different Than The “Legal Limit?”

The two different thresholds use different criteria. For example, the “Health Guideline” cited by EWG for carcinogens is defined by the California Office of Environmental Health Hazard Assessment (OEHHA) as a one-in-a-million lifetime risk of cancer, while the “Legal Limit” refers to the MCL which is the limit that triggers a violation by EPA. The OEHHA's criteria are established by toxicological techniques, while the EPA limits are negotiated through political channels. We wrote an article that addresses this topic in much more detail for those who are interested.

Why Am I Just Learning About This Now?

The EPA's Safe Drinking Water Act requires municipalities to make water quality test data public in Consumer Confidence Reports. These reports are required to talk about the water's source, information about any regulated contaminants found in the water, health effects of any regulated contaminant found above the regulated limit, and a few other things. As discussed before, the data in the EWG report use different criteria than the EPA, and it's hard for people to make sense of what's what.

Are The Data Correct If My Water Comes From A Private Well?

No. The EWG Tap Water Database only has data for municipal tap water. Private wells are completely unregulated, and there's no requirement to conduct testing. If you'd like us to dig into our additional water quality databases to help you understand likely contaminants in your private well, we're happy to do so. We don't offer testing services, but we're happy to help you find an accredited lab in your area, give advice on which tests to run, and help you interpret the results! We offer this service for free.

What About My City's Water Quality?

Hydroviv makes it our business to help you better understand your water. As always, feel free to take advantage of our “help no matter what” approach to technical support! Our water nerds will work to answer your questions, even if you have no intention of purchasing one of our water filters. Reach out by dropping us an email (hello@hydroviv.com) or through our live chat. You can also find us on Twitter or Facebook!

Recommended For You

How Do I Filter Chromium 6 From Drinking Water?
Why Are So Many Schools Testing Positive for Lead?
Please Stop Using Cheap TDS Meters To Evaluate Water Quality! They Don't Tell You Anything!

Wendy Spicer, M.S.  |  Scientific Contributor
***Updated 10/27/2022 to include recent health studies and regulatory status. 

If you have seen the movie Erin Brockovich, you are familiar with chromium 6 (also known as hexavalent chromium and chromium VI). The film tells the story of a legal clerk turned activist who uncovers that a California utility company, Pacific Gas and Electric (PG&E), was knowingly dumping chromium 6 waste and contaminating the local water supply. Brockovich’s law firm, Masry and Vititoe, represented over 600 clients in a lawsuit against PG&E which settled for $333 million dollars in 1993. Despite the success and fame of this story, chromium 6 water contamination remains largely unregulated and problematic across the United States. The Environmental Working Group estimated that in 2015, water supplies serving over 218 million Americans were contaminated with chromium 6.

What Is Chromium?

It is important to note that there are 2 very different forms of chromium that are often grouped together when reporting contaminant levels. These two different types vary based on their oxidation states, meaning that they differ in the number of electrons surrounding the atom’s nucleus. Chromium (III), or trivalent chromium is a naturally occurring element that is an essential nutrient, and is beneficial, not toxic to humans. In fact, chromium(III) plays a role in glucose, fat, and protein metabolism by increasing the effect of insulin.

However, chromium 6 is the highly-toxic form of chromium. Industrial discharge is the largest source of chromium 6 in our environment and is released into air and wastewater by metal processing facilities, tannery facilities, chromate production, stainless steel welding, ferrochrome production, and pigment production. The major way that most people are exposed to chromium 6 is through contaminated food and water.

What Are The Adverse Health Effects Of Chromium in Water?

There is strong evidence that chromium 6 is a human carcinogen. The most recent EPA draft toxicity review states "Cr(VI) is likely to be carcinogenic to humans by the oral route of exposure.” 

Specifically, this study suggests that chromium 6 causes stomach cancer in humans, consistent with previous tumor results reported in rodent studies. Chromium 6 exposure is also known to cause multiorgan toxicity such as kidney damage, allergy, and asthma. This study compared the toxicity of chromium 3 to chromium 6 in kidney cells, and scientists observed toxic effects in cells treated with chromium 6 but not with chromium 3.

In addition to being a likely carcinogen, the most recent EPA draft toxicity review discusses negative health effects affecting organ systems  including gastrointestinal, liver, immune, hematologic, as well as the male reproductive system. In addition, the developing fetus is considered especially susceptible because Chromium 6 was determined as a likely cause of developmental toxicity in humans. 

Chromium 6 is also a known endocrine-disrupting chemical, and this study documented that environmental exposure to chromium 6 caused detrimental reproductive effects in women and negative health effects in infants in California. In fact, the scientists reported that women with occupational chromium 6 exposure experienced infertility, pregnancy loss, spontaneous abortion, and stillbirth.

Breathing high levels of chromium 6 can cause irritation to the lining of the nose, and nose ulcers. Lung and respiratory cancers are more common in industrial workers (where it is more likely to be inhaled) while gastrointestinal tumors are more common in humans and animals exposed to chromium 6 in drinking water. Accidental or intentional ingestion of extremely high doses of chromium 6 compounds can cause acute respiratory, cardiovascular, gastrointestinal, hematological, hepatic, renal, and neurological distress which may result in death.

Is Chromium 6 Regulated?

Chromium 6 in drinking water is not currently regulated by any State or at the Federal Level. However, the California Water Resources Control Board’s Drinking Water Program is the first in the nation to unveil a proposal to set a “maximum contaminant level” (MCL) of 10 parts per billion, or ppb, in water. The board is also proposing to set the “detection limit,” which would trigger reporting, at 0.05 ppb. The current Public Health Goal in California (the level below which there is no expected health issues) for Chromium-6 is 0.02 ppb.

Other Articles We Think You’ll Enjoy:

What You Need To Know About Chromium 6
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How To Tell If Your Home Has Lead Pipes

Eric Roy, Ph.D.  |  Scientific Founder

***Updated to include 2021 water quality data***

For Hydroviv’s assessment of Washington, D.C. drinking water, we aggregated water quality test data from D.C. Water (the public utility provider) and the U.S. Environmental Protection Agency (EPA), as well as from samples that we collect and analyze. We cross reference these data with toxicity studies in the scientific and medical literature, and look at upcoming regulatory changes. The custom water filters that build and sell for Washington, D.C. are optimized with these factors in mind.

Lead In DC Tap Water

Washington, D.C. is an old city with a lot of lead service lines, so it's not a huge surprise that D.C. has had such a big problem with lead in drinking water. Lead leaches from lead-containing pipes, solder, and fittings, unlike most contaminants which are found at the source. D.C. Water uses two sampling periods when testing for lead: January-June and July-December. In the 107 samples pulled during January-June period, the 90th percentile concentration for lead was 2 parts per billion, and 3 samples were above the 15 part per billion Action Level (AL). In the 105 samples pulled from the July-December sampling period, the 90th percentile concentration was 3 parts per billion, and one of the collected samples exceeded the action level. Although these results indicate that D.C. is in citywide compliance with federal water quality standards, it's important to point out that EPA, CDC and the American Academy of Pediatrics all agree that there is no safe level of lead for children. The bottom line is that the federal standards allow up to 10% of sampled taps to have lead concentrations over 15 parts per billion.

We highly recommend that Washington D.C. residents take a look at this map to see if their home has a lead service line, because those homes (and homes with plumbing that predates 1986) are most susceptible. We also highly recommend taking advantage of D.C. Water's free lead testing program, and any families with small children take steps to remove any lead from their water, even if they don't use a Hydroviv filter. It's important to remember that most pitchers and fridge filters do NOT remove lead from water. Hydroviv Undersink filters are NSF/ANSI 53 certified to remove lead from drinking water.

Detectable Levels of Unregulated Contaminants In DC Tap Water

One thing that has caused quite a bit of alarm from several people in this year's report is that several herbicides, VOC's and synthetic compounds were all found at detectable levels in D.C. drinking water. Herbicides such as Dalapon, shouldn't be a huge surprise seeing that D.C. draws water from near at the end of a river, so there is opportunity for agricultural runoff to enter the river. For anyone who is interested, The Maryland DEP has made the Source Water Assessment for the Potomac River (404 pages) publicly available. 

DC's Water Source: Potomac River

The Washington Aqueduct (operated by the Army Corps of Engineers) draws water from the Potomac River for treatment. District of Columbia Sewer and Water Authority (aka D.C. Water) purchases treated water from the Washington Aqueduct, and is responsible for distributing it throughout D.C. We also have a stand-alone article that entirely focuses on the Potomac River.

Left Out Of The Report: Chromium 6

We were a bit surprised to see Chromium 6 left out of the 2019 water quality report for Washington, D.C. Even though it's a known human carcinogen, chromium 6 is categorized as an "Emerging Contaminant" by EPA but is not regulated on its own. D.C. Water (and 6000 other municipalities) participate in the Unregulated Contaminant Monitoring Rule (UCMR3), which is a nationwide testing program to study "emerging" contaminants. UCMR acknowledges that contaminants on the list most likely cause adverse health effects, including cancer. The concentration in D.C. water average 86 parts per trillion. For perspective, these levels are roughly 4-5x higher than what The State Of California set as a public health goal. We believe that people should not wait for EPA to begin regulating chromium 6 on its own, and filter their water, even it they aren't using our product. It's important to remember that most pitchers and fridge filters do NOT remove chromium 6 from water.

Per and Polyfluoralkyl Substances (PFAS) In Washington, D.C. Drinking Water

PFAS are a category of chemicals found in various non-stick/stain resistant products, as well as fire fighting foam. PFAS are considered to be "emerging contaminants" because they are not currently regulated by EPA, but are known to be toxic and persistent in the environment. PFAS have been detected at surrounding military installments that are in close proximity to the Potomac River (DC's source water). Most municipalities are not required to test for, or remove, PFAS from drinking water. Not all filters are designed to remove PFAS from drinking water. If you'd like find water filters that remove PFAS from tap water, check out this Duke/NC State study.

Disinfectant

The primary disinfectant used to treat Washington DC's tap water is chloramine, except for a few weeks in the spring when DC switches over to chlorine. D.C. (and a growing number of municipalities) use chloramine instead of chlorine for a few reasons: for one, chloramine is more persistent than chlorine, so it maintains its ability to disinfect the water further away from the source. On the other side, chloramine does not quickly dissipate from water if left in a jug overnight. If you want to get it out of the water, you'll need a filter designed to remove chloramine, because a regular charcoal filter doesn't do a great job removing it.

If you want to learn more about Hydroviv's water filters, check out www.hydroviv.com, or drop us a line through live chat or email (hello@hydroviv.com). Even though we sell our products nationwide, Hydroviv is a DC company and we take care of our own backyard!

As always, feel free to take advantage of our "Help No Matter What" approach to technical support. We will answer your questions about water quality even if you have no desire to purchase one of our products. 

Other Articles We Think You'll Enjoy:

Please Stop Using a TDS Meter To Evaluate Your Home's Water Quality
Things To Know Before Replacing Your Home's Lead Service Line
How To Filter Chromium 6 From Drinking Water

What Are Heavy Metals?

Chemists categorize heavy metals as elements that are at least five times denser than water. Examples of heavy metals include: cobalt (Co), copper (Cu), chromium (Cr), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se), zinc (Zn), arsenic (As), mercury (Hg), and lead (Pb). Some heavy metals are essential minerals for healthy biochemical and physiological functions. Others, such as lead, chromium, arsenic, and mercury are toxic even when ingested in very small quantities. Elemental density and toxicity are interrelated. Arsenic, which is technically categorized as a metalloid (think of a metalloid as metal-like), is quite dense and is extremely toxic in very small quantities. Thus, toxicologists typically categorize arsenic as a heavy metal. Due to their shared high degree of toxicity, lead, cadmium, chromium, mercury, and arsenic are cause for significant public concern.

How Are We Exposed To Heavy Metals?

People can be exposed to heavy metals through ingestion, inhalation, or contact with skin. The severity of the health effects of heavy metals is related to the type and chemical form of each particular contaminant, and is also depends on the exposure time and dose.

Heavy metals have industrial, domestic, agricultural, medical and technological applications, and as a result they are now widespread in our environment. Heavy metal pollution in water is very high in areas where mining, smelters, metal processing refineries, wood preservation, and paper processing facilities are located. Human exposure to heavy metals as well as public concern for the associated health risks have both risen dramatically as a result of an exponential increase of their use in these various applications.

If Heavy Metals Are Toxic, Why Are They Found In Multi-Vitamins?

Some heavy metals including cobalt (Co), copper (Cu), chromium (Cr), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se) and zinc (Zn) are essential minerals that are necessary for various biochemical and physiological functions. They serve as components of several key enzymes and play important roles in various oxidation-reduction reactions in our bodies. Many of these metals are found naturally in the food we eat, while other foods are fortified with these minerals. For example, almost all grain products (cereal, bread, crackers, etc) are fortified with iron. Inadequate supply of these minerals can result in a variety of deficiency diseases. For example, anemia (red blood cell deficiency) can result from low iron. Supplements can prevent or treat diseases resulting from mineral deficiency.

Not all heavy metals are toxic in low quantities, however all heavy metals (yes, even the good ones) can be toxic if too much is ingested. Each heavy metal’s toxicity depends on dosage, method of exposure, age, gender, genetics, and nutritional status of the exposed individual. An excess amount of any particular heavy metal produces cellular and tissue damage leading to a variety of adverse effects and human diseases. For some including chromium and copper, there is a very narrow range of concentrations between beneficial and toxic effects, so be careful when taking supplements. Other metals such as aluminium (Al), antimony (Sb), arsenic (As), barium (Ba), beryllium (Be), bismuth (Bi), cadmium (Cd), gallium (Ga), germanium (Ge), gold (Au), indium (In), lead (Pb), lithium (Li), mercury (Hg), nickel (Ni), platinum (Pt), silver (Ag), strontium (Sr), tellurium (Te), thallium (Tl), tin (Sn), titanium (Ti), vanadium (V) and uranium (U) have no established biological functions and are considered non-essential metals in our diet.

What Is Heavy Metal Toxicity Or Heavy Metal Poisoning?

Each metal differs in how it behaves in our bodies, and exposure alone does not always cause disease or harm. Heavy metal-induced toxicity and carcinogenicity involves many biochemical processes, some of which are not clearly understood. The human body’s natural response to heavy metal exposure is to store them and slowly excrete them over time to minimize organ damage.

Acute heavy metal poisoning usually occurs when people are exposed to large amounts of one particular metal at a time. For example, a child swallowing a lead bullet can cause a large amount of lead exposure all at once. Acute exposures can quickly cause serious health effects or death.

Chronic or long-term exposure to lower levels of heavy metals can also cause health problems. The symptoms of chronic heavy metal poisoning can be severe, but are often less obvious and develop much more slowly over time than the symptoms caused by acute exposure. This is a topic of growing scientific evidence that needs to be better researched to clarify all the possible health implications. Chronic heavy metal poisoning can be challenging for both health care providers and patients because there are often many more questions than answers. Symptoms of chronic heavy metal toxicity can include but is not limited to headaches, fatigue, muscle and joint pain, and weakness. However, these same symptoms can be caused by many other health problems unrelated to heavy metal toxicity. True chronic heavy metal poisoning is rare but also difficult to diagnose.

What Are The Health Effects Of Heavy Metal Toxicity?

Even in very low quantities, lead, cadmium, chromium, mercury, and arsenic are known to induce cardiovascular diseases, developmental abnormalities, neurologic and neurobehavioral disorders, diabetes, hearing loss, hematologic and immunologic disorders. These heavy metals are also classified as human carcinogens (known or probable) according to the U.S. Environmental Protection Agency, and the International Agency for Research on Cancer.

Although the acute and chronic effects are known for some metals, little is known about the health impact of mixtures of heavy metals. Studies have shown that toxic heavy metals can interfere with absorption and use of nutritionally essential metals such as iron, calcium, copper, and zinc. However, the research on the combined effects of heavy metal exposure is very limited.

How Can I Minimize Exposure To Heavy Metals?

The best way to reduce heavy metal pollution is prevention. Identify sources of heavy metals in your home and remove them. Here are some helpful suggestions:

• Be aware of local fish advisories for mercury contamination.
• Test the water in your home for heavy metals and install a home water filtration system if necessary.
• Read labels on products coming in to your home.
• Store products containing heavy metals out of reach of children.