Heavy metals are those elements that have a density at least 5 times greater than that of water. While some, such as Chromium, Selenium and Iron are required by the human body in trace amounts, others, such as Arsenic and Lead are extremely dangerous, and even a minimal level of exposure to them is unsafe.
In order to decide the best way to remove heavy metals from your water, it is important to know the different types of heavy metals commonly found in our water supplies, how to detect them, and what the safe consumption guidelines are. The last point about knowing water safety standards, according to me is the most crucial.
However, before I go forward, here’s a brief table of contents, in case you’re interested in skipping to a particular section.
- Commonly Found Heavy Metals To Watch Out For
- How do heavy metals get into water?
- Health effects of Heavy Metals in Water
- Existing Regulations on Heavy Metals
- How To Test For Heavy Metals At Home
- My Recommendation For Testing Heavy Metals At Home
- How To Remove Heavy Metals From Drinking Water
Few of the dangerous heavy metals that have no biological use for humans are:
Even heavy metals that are needed such as Chromium, Iron, Zinc, etc can cause adverse effects if their levels in the human body become excessive.
- Vehicular pollution– According to Nato Science For Peace and Security book , heavy metals like lead, cadmium and mercury are released into the air by vehicular emissions. These add to the pollutants in the air, which contaminate rainwater as it falls down and percolates into the ground.
- Acid Rain: Tying in with the point above, air pollution turns rainwater acidic as the pollutants mix into it. When this water comes into contact with the soil, it may release any trapped heavy metals which further contaminate this water
- Source Water contamination– In some areas, heavy metals are naturally present in groundwater. This news story in the US cited excessive lead levels were found in almost 2000 water systems across 50 US states
- Agricultural runoff: Pesticides sprayed on crops contains heavy metals. If the farm is situated up-slope from a water source, there is a high probability that excess pesticidal spray may have contaminated the water at some point or the other.
- Incorrect Pesticide Spraying Practices: Another common cause of contamination is due to incorrect spraying practices which contaminates water sources nearby
- Industrial Runoff: Waste from factories and industrial plants contains multiple heavy metals in high concentrations. If not correctly disposed, it can easily contaminate water bodies nearby
- Lead Plumbing: There are multiple sources of lead in our plumbing through which it can enter the water supply. Read this article for more on how to identify if you have lead plumbing
Acute heavy metal poisoning, where you ingest a high dose of heavy metal(s) at once, can lead to serious health issues. However, it is easier to diagnose than chronic heavy metal toxicity. Chronic heavy metal toxicity refers to the scenario where someone consumes just a little bit of heavy metal(s) through a contaminated water source everyday.
The second case is tougher to diagnose for doctors because the symptoms are quite generic and the progression of side effects is quite slow. This is because heavy metals accumulate in the body over time and may not start causing adverse effects till a later date. According to hydroviv.com:
“Symptoms of chronic heavy metal toxicity can include but are not limited to headaches, fatigue, muscle and joint pain, and weakness.”
According to the US Environmental protection Agency(USEPA) Regulations, here are the permissible limits in water for few of the common heavy metals:
- Lead: 150 ppb(parts per billion)
- Antimony: 6 ppb
- Arsenic: 10 ppb
- Mercury: 2 ppb
- Barium: 2000 ppb
- Beryllium: 4 ppb
- Cadmium: 5 ppb
- Chromium: 100 ppb
- Fluoride: 4000 ppb
- Selenium: 50 ppb
Drawback of EPA Regulations on Heavy Metals in Water:
According to me, it is best to completely filter out all heavy metals because heavy metals tend to accumulate in our bodies over time and continual exposure, even at small concentrations can lead to serious health problems later on.
The biggest barrier to identifying heavy metals at home is that most of them have no particular odor or taste, nor do they impart any color to the water.
Secondly, they become dangerous at parts per billion levels(ppb) which can’t be picked up by TDS meters-calibrated to parts per million(ppm).
Having said that, there are a few things you can do to check for heavy metals at home:
According to Dr. Sarah Carnes, this method is unreliable because heavy metals remain in the bloodstream only for a few weeks until they either are excreted or stored in the body. At that point, even if one gets a blood test done and the blood test comes clear, heavy metal poisoning still can’t be ruled out, since they might’ve accumulated inside.
For acute cases though, where a clear source of ingestion of heavy metals is identified(such as kids chewing on lead car keys) and a rapid progression of symptoms comes in, blood tests are effective.
The thing with heavy meals is, once they’re inside the human body, they are usually excreted through hair, sweat, urine, stool, menses, etc. However, if the body isn’t able to excrete them(could be due to many other health reasons, such as a weakened immune system) they get stored inside our tissues, bones and organs.
This is why heavy metals are called bioaccumulators- they tend to accumulate in the body over time.
Similar to blood tests, hair tests are also unreliable in most cases because the results don’t give a conclusive answer. Here’s why:
If the results show low concentration of heavy metals, it can mean that either:
- There aren’t a lot of heavy metals in the body
- There are a high concentration of heavy metals, but the body isn’t excreting them properly
Similarly, if the results show a high concentration of heavy metals, it can mean that either:
- The body is excreting them efficiently and very little heavy metals remain inside the body
- That the body is excreting a lot of heavy metals but a high concentration of heavy metals still exist in the body
Also, washing hair makes this testing unreliable. US people should get theirs tested at Trace Elements
Has the same pitfalls as the hair tests, as there are really no conclusive answers. The best way to test that seemed to make logical sense to me was to get a normal or ‘unprovoked’ urine test as a baseline, and then get a ‘provoked’ urine test- which basically means ingesting a chelating or binding agent that flushes out all the heavy metals through the kidneys in the form of urine.
When the ‘unprovoked’ and ‘provoked’ test results are compared, an accurate assessment can be made by the doctors. This shouldn’t be attempted without a doctor’s advice, however, because it is quite dangerous for the kidneys.
Normal/Unprovoked urine tests for heavy metals can be easily ordered online, such as this one by Everly Well
Water Testing Kits:
As a first step before you go for the more expensive heavy metal tests, I’d say it’s better to buy a home water test kit. They are very easy to use- consisting of strips that can be dipped in water and turn a certain color to indicate which contaminant it contains.
There aren’t a lot of comprehensive home test kits that for heavy metals, though. I found this one on Amazon that tests for Lead, Copper and Iron.
Water suppliers in the US are required to publish an annual water quality report and provide the same to all consumers. You can look it up online for your particular supplier or even request them for it.
The best way to know your current water quality though, would be to get a water test done from a local lab. If you’ve been experiencing some of the heavy metal associated symptoms listed above, it might be a good idea to invest in a lab test.
As a preliminary step, you could get an at-home test kit for heavy metals, and then if the results seem alarming, you could go for a lab test.
As for the hair, urine and blood test options- they may give inconclusive results, so take them only as a preliminary test. Best to take the doctor’s advice when it comes to interpreting the results.
RO Water Filters:
There are many water filtration technologies that you could go for, but if you’re really concerned about the heavy metal concentration in your water, I’d suggest going for a RO water filter, such as this one on Amazon. While they waste a lot of water, they are the most effective water filtration technology in the market, as they virtually remove all contaminants in water.
You can read more about RO purifiers in this comparison post I wrote about the 3 main water filter technologies today – RO Vs UV Vs UF
Whole house heavy metal water filters:
If you’re thinking long term and have correctly identified heavy metal contamination in your water, getting a whole house filter might make sense, especially because of how expensive they are(usually in the range of $600-$1000+). A lot of them are designed to remove the common heavy metals, chlorine, chloramines etc from water, as well as last a long time- such as this one on Amazon, that is supposed to last 10 years!
If you want to know the exact specifications, it’s best to check out the manufacturer’s website or speak to their representatives on the phone.
Removing heavy metals from water can be a costly process. Keep in mind that heavy metals are dangerous whether they’re present in your drinking water or even the water you shower and wash your hands in.
If you can afford it, getting a whole house water filter makes sense, and solves all problems in one go.However, if you cannot, here’s what I recommend:
- Get a RO water purifier for drinking purposes
- Get a KDF shower and tap filter, such as this one on Amazon– removes upto 98% of water soluble heavy metals, among other common contaminants.
- Use filtered water for washing clothes
Hope you enjoyed the article, and if you found this helpful, do share it with a friend who you think might need it. Or at least tell them what you learned!