Our drinking water is regulated by the Drinking Water Ordinance through limits. However, it frequently happens that tap water is contaminated with pollutants such as heavy metals for various reasons. Excessive concentrations of various metals can have long-term effects and, in critical quantities, can lead to health problems, especially in young children. So, what can you do about heavy metal contamination in drinking water? In this guide, we provide you with an overview of all dangerous heavy metals and how you can counteract them:
How do heavy metals get into our drinking water?
To understand the extent to which heavy metals can affect nature and our health, we must first understand what heavy metals actually are and where they come from:
Heavy metals are…
...metals that accumulate in the Earth's crust in the form of chemical compounds. They are a natural part of our environment. Any metal with a density greater than 5 grams per cubic centimeter is classified as a heavy metal. These metals can quickly appear in our groundwater if they seep deeper and deeper into the soil through erosion. Once heavy metals are present in the groundwater, they become part of our water cycle and can be difficult to remove.
To prevent heavy metals from easily ending up in our drinking water, the Drinking Water Ordinance sets strict limits for heavy metals such as copper, lead, and cadmium. Waterworks must ensure that these limits are adhered to during water treatment. However, when the supposedly clean water reaches our homes after its long journey, elevated levels of heavy metals can still appear in the drinking water. This is due, among other things, to the fact that from the point of connection to the house, everyone is responsible for their own water quality. It is therefore entirely possible that pipes or fittings contaminate the tap water with metals.
Metals are less soluble in hard water (limescale water), so regions with soft water are particularly affected by heavy metals in drinking water.
What heavy metals are there?
To help you know which metals in drinking water you should be particularly careful of, we provide you with an overview of all the heavy metals that can be harmful to your health and can be found in drinking water:
- Lead: If you ingest lead daily through drinking water, it can lead to chronic poisoning or developmental disorders (in young children) over time. Lead can also disrupt the formation of red blood cells and is therefore suspected of causing cancer. Chronic lead poisoning can cause symptoms such as anemia, digestive disorders, or fatigue. Lead in drinking water can be traced back to galvanized pipes, fixtures, or fittings. Zinc often reacts with the chemically similar lead, causing these harmful health effects. The limit value for lead is 0.01 mg/l. If you have galvanized or even old lead pipes, you should let your tap water run for a longer period of time before use, not just if it has been standing for a long time, but also at least let it drain for a longer period of time before use, or better yet, use a high-quality water filter to reliably remove any heavy metal residues.
- Cadmium: This metal is not necessary for our metabolism and should therefore be avoided at all costs. Long-term exposure to small amounts of cadmium in drinking water becomes dangerous when it settles in the kidneys and liver, and at high concentrations, can lead to kidney damage. Caution: Young children and pregnant women are particularly affected, as they absorb cadmium more rapidly due to a slight iron deficiency. The limit value (including cadmium compounds absorbed during stagnation in pipes) is 0.003 mg/l. However, if the cadmium concentration in your drinking water is greater than 0.001 mg/l, we strongly recommend filtering the water before use to safely remove this contaminant.
- Iron: Iron in drinking water is not necessarily hazardous to health and should primarily be avoided for other reasons. Even low levels of iron can cause discoloration, cloudiness, or a metallic taste. This occurs because the iron ions precipitate when they come into contact with oxygen. Many users therefore consider elevated iron levels a nuisance and can remove them with a water filter. Iron concentrations can enter our drinking water either through groundwater or iron-containing pipes. The limit is 0.2 mg/l.
- Copper: This metal is a vital trace element for us, but can be harmful in large quantities. High copper intake can lead to acute gastrointestinal problems with side effects such as vomiting or abdominal pain. Higher copper concentrations are to be expected, especially in new pipelines. Although 2 mg/l is permitted, we recommend filtering drinking water before consumption if your concentration is higher than 1 mg/l. Caution: Infants and young children, in particular, store copper in their livers, which can lead to liver poisoning in the long term.
- Nickel: Nickel is not dangerous in conventional drinking water due to its low concentration. Only very high concentrations can cause intestinal problems or brain damage. The TVO permits a limit of 0.02 mg/l. Caution: Nickel is often used in faucets. Therefore, if water is in prolonged contact with the surface, the nickel content increases significantly.
- Uranium: In some areas, uranium occurs naturally in the soil and therefore also in plants and groundwater. It can have a negative impact on the kidneys if it is present in high concentrations in drinking water. This can happen near mining, phosphate industries (including phosphate-containing fertilizers), or landfills. Therefore, as a precaution, you should keep a close eye on your drinking water and, ideally, filter it to remove all heavy metals. The TVO permits a limit of 0.01 mg/l.
- Zinc: Like copper, this metal is a vital trace element and, in the right amounts, non-toxic. A daily intake of 7–15 mg is recommended. However, a high overdose can lead to nausea and vomiting. Furthermore, a high zinc content increases the harmful effects of the heavy metals cadmium and lead. Zinc enters drinking water from natural sources and from galvanized materials, particularly pipes. The WHO considers a maximum value of 5 mg/l in drinking water to be safe; the current TVO does not specify a specific limit for zinc. Very high levels of zinc salts in drinking water can lead to cloudiness and an unpleasant change in the taste of the water. Zinc can react with the contaminant nitrate to form the toxic nitrite. This occurs when high nitrate levels occur in tap water.
Why are heavy metals in water so dangerous?
Heavy metals can have very different effects on the body and health. Each metal has a different effect. This makes it difficult to identify a general threat. However, it is clear that all heavy metals, in high concentrations, pose a threat to our cells and our immune system.
If the amounts are very high, the metal ions block many processes in the body:
- Heavy metals bind to proteins due to their high affinity for sulfur. Once bound, the protein structure can change and impair various enzyme functions. This blocks important metabolic processes. Such structural changes also increase the development of autoimmune diseases.
- Heavy metals block mechanisms that regulate central systems, such as the immune and nervous systems. This occurs when heavy metals damage cell structures.
- Heavy metals interact with substances such as calcium, iron, and zinc, reducing the body's absorption of these important nutrients. This can lead to metabolic disorders.
But how can I protect myself against such chronic changes in my body? There are two ways to prevent heavy metal levels in drinking water:
- Selected bottled water , in which the heavy metal content has been tested and is even lower. But of course, bottled water has to be extracted, bottled, transported, and marketed at great expense—and ultimately, paid for and hauled home from the market...
- High-quality water filters such as Carbonit block filters or reverse osmosis systems remove 90-100% of the heavy metals present in the water. This protects both your health and that of your children. The goal of such filters is not just to achieve the limits set by the Drinking Water Ordinance, but to achieve the lowest possible levels!
Water filters against heavy metals: different filters compared
Water filters are a reliable method for removing heavy metals from drinking water. However, not every filter can do this. We've created a list to give you an overview of which filters filter out heavy metal residues and which aren't:
Activated carbon filters: There are three different types of filters that utilize the adsorption power of activated carbon. All three types can filter different pollutants and contaminants from drinking water, but not all of them remove heavy metals.
A conventional jug filter that uses activated carbon granules does NOT remove heavy metals.
Even a simple activated carbon filter with poured or extruded activated carbon does not remove heavy metals or does not do so demonstrably.
A complex, baked block filter (sintered activated carbon) is effective at removing heavy metals. Although the exact process cannot yet be explained, all measurements demonstrate its high, reliable, and sustainable effectiveness. After purification, the clean water flows into the tap. Activated carbon block filters can be used to remove heavy metals in the home, in the beverage industry, or in drinking water treatment. Although activated carbon block filters are very reliable at filtering out heavy metals, they are unable to remove limescale. A reverse osmosis system is ideal for this purpose.
Reverse osmosis system: In reverse osmosis, the water to be filtered is forced through a fine membrane under high pressure. The membrane consists of a densely meshed network through which only small water molecules can pass under pressure. The significantly larger heavy metal ions and all other contaminants are safely retained. Reverse osmosis systems are characterized by their extremely high degree of purification and, unlike activated carbon block filters, also remove limescale from drinking water. Even though such a filter system can be somewhat more expensive, it is still worthwhile because it completely removes all substances that could endanger your health. Reverse osmosis systems also have a wide range of applications: producing clean drinking water at home, for use in aquariums, or in commercial applications (tea kitchens in offices and businesses, laboratories, and much more).
Ion exchange: This type of filtration can also remove heavy metals from drinking water. The heavy metal ions are replaced by other ions, such as sodium, which increases the amount of sodium in the water accordingly. Furthermore, an ion exchange is not always suitable for all heavy metals; it can usually only remove certain heavy metals. For reliable removal of all heavy metals, an activated carbon block filter or a reverse osmosis system proves to be significantly more effective.
How can I take action against heavy metals myself?
You can take some steps at home to clean your drinking water of possible heavy metal contamination and protect yourself.
- If the water has been standing in the pipe for a long time (for example, overnight), you should let it run for a while before using it. This allows you to "flush away" the heavy metal leaching that occurs during long periods of standing in the pipe.
- To be on the safe side, you can replace old piping systems. The amount of heavy metals in pipes is significantly reduced by using new stainless steel or plastic pipes. However, there are a few things to keep in mind when replacing entire pipelines: Do not use stainless steel pipes in conjunction with other materials, as the less noble materials will corrode quickly.
- To minimize heavy metal concentrations, it's worthwhile to use a filter in the long term. For private households, fine-pored and sintered activated carbon block filters (monoblock filters) and reverse osmosis systems are ideal. Visit our online shop or ask our experts for advice.
H2O water charging against heavy metals – this is what we offer
Activated carbon block filter: The activated carbon block filter from CARBONIT is particularly affordable in this value package with a filter cartridge. You simply screw the diverter valve onto the faucet, and the installation is complete! The filter can safely remove heavy metals from drinking water when used with cold water, thus protecting you from heavy metal contamination. The premium block filter is used in various CARBONIT filter units, including under-sink units.
Reverse osmosis system: The H2O Economy reverse osmosis system is perfect for the whole family. This convenient system from ROWA is wastewater-saving and economical. The three-stage filter system removes all contaminants, including heavy metals, from tap water. To install, connect the system to the cold water line under your sink. The process also requires a connection to your kitchen sink's wastewater line and a separate tap.
Conclusion
Using water filters to safely remove heavy metals from tap water promises higher water quality and protects you and your family from heavy metal contamination. However, the final decision regarding the filtration method is yours. Some filter options, such as ion exchange or conventional activated carbon filters, are not well-suited or comprehensive for removing heavy metals. To ensure that all heavy metals are truly removed from tap water, use a reverse osmosis system or a sintered activated carbon block filter.
Take a detailed look at our online offering or consult with our specialist staff. We look forward to hearing from you.
Your water shop
