Monday, May 31, 2021

Removing fluoride and chlorine from tap water

After my interview by CNA, some questions came in about the removal of chlorine and fluoride from tap water. 

 

Unlike other substances in tap water, chlorine and fluoride are added into tap water by the water treatment process. Chlorine is supposed to keep water free of pathogens as the water is conveyed from the water treatment through kilometres of piping (with many other equipment in between) to your home. On the other hand, fluoride is supposed to maintain dental health as the locals here tend to have tooth decay issues in the years after independence. I have written about chlorine and fluoride previously - fluoride & other contaminants in beer, Do we really need water filters?, Evaluating the necessity and usefulness of water filters for domestic tap water, Advice on water filtration in Singapore: alumina, boiling, gravity fed vs. counter-top.


 In recent years, much health concerns have been raised about these 2 additives in our drinking water. Are they safe at the concentrations in tap water? Are they even necessary? As with a lot of health issues, there are arguments on both sides. A lot of times, it comes down to the consumer to decide on getting a water filtration system to remove them for good, old peace of mind. To me, this is perfectly fine as I can attest to the importance of peace of mind from personal experience. What I do have issue with is the selection of an effective water filtration system (aka water filter), if one even exists.

3 points to consider in selecting a water filter

Those who have watched my interview with CNA (CNA has somehow left out these 3 points in their print version) should recall that I have expressed 3 factors to consider in getting a water filter.
  1. Know what you want to remove (or add) from your water.
  2. Find a water filter certified to remove those contaminants
  3. Make sure you can spare the time and money for maintenance

A more comprehensive guide can be found in my article - 3 Critical Questions to Choosing Your Water Filter which can be downloaded for free.

Which water filter can remove chlorine and fluoride then?

Some readers have mentioned their confusion by the vast assortment of water filters in the market. Without going into laborious scientific research, are there any water filters that I can recommend to remove chlorine and fluoride? 

 

In general, most brands of water filters do not show certification from a reputable source e.g. NSF/ANSI. Furthermore, they do not display evidence of extensive testing of their filters either. Most claims to remove this contaminant and that pollutant are just that - claims.

Naturally, quite a few brands have slick marketing campaigns and impressive designs. In fact, their designs can actually be aesthetically pleasant and functional in piping tap water under the sink to a sleek looking but unobtrusive faucet on the tabletop. However, the question still remains - can the filter perform the job you want it to - removing chlorine and fluoride from tap water? In the majority of cases, I am not confident enough to say they are capable of it.

But I still want a water filter for peace of mind

Yes, I understand the importance of peace of mind so I shall make a recommendation here. 

 

I strongly suggest getting a Big Berkey fitted with their Black Berkey filter elements + fluoride reduction attachments. (No links provided here. I am sure you can find it easily on the Internet.) Though not actually certified by NSF/ANSI, their filters are extensively tested under NSF/ANSI standards and the detailed results with testing protocols are published on their website. That is a lot more than what the majority of brands can provide to the consumer.

 

Nevertheless, a caveat is in order - NSF/ANSI standards are not exactly Singapore tap water standards. The most obvious difference is Singapore's tap water has chlorine and fluoride in much lower concentrations. How much can a filter further reduce their concentrations? We did tests on certain water filters in the past and the reduction is in general not fantastic. And unfortunately, Singapore is too small a market for anyone to actually conduct testing of water filters for their effectiveness in treating Singapore tap water.


With that in mind, dear consumer, go ahead and choose your water filter!

Figure: Big Berkey replacement filter elements


Should you boil your tap water?

After my interview by CNA, some questions came in about the necessity of boiling tap water. 

Are there benefits to it? Does boiling mitigate the effects of contaminants from piping and water tanks?

  1. First off, let's be clear that boiling water has been a tradition in Singapore for a long time, probably dating to before independence, and for good reasons. In the old days, not everyone had access to tap water. Whatever water sources (rivers, ponds, wells) in those days were probably low in sanitary standards, if any. Imagine someone bathing and defecating into the river that you obtain your drinking water from. Piping and water tanks were probably poorly maintained.

    This combination of conditions were recipes for outbreaks of water borne diseases like cholera, dysentery etc. The main culprits were of course pathogenic microbes transmitted via contaminated water and food. The good news is such microbes can be killed by boiling. As long the boiled water does not get recontaminated, you are safe from these nasty water borne diseases with colourful nicknames like bloody diarrhea or rice water-like stools. Not surprisingly, boiling water has become a standard practice that persists even after every household on the mainland is served by tap water.

    Check out this post by Rice Media: A brief history of lao sai, explained if you want to get down and dirty for the details.

  2.  However... boiling does nothing to the rest of the non-microbial contaminants in the tap water. If your piping and water tanks are rusty, rust will go into your tap water. Not that rust is a real health concern, it is just that boiling does not remove it. Neither does boiling remove heavy metals, pesticides or most radioactive substances. It certainly does not remove fluoride (hey, we need fluoride to REMAIN in the water for healthy teeth, remember?) and only removes a small percentage of chlorine.

  3. Is boiling necessary then?

    If we go by the study by CNA of which my interview is part of the programme, the bacteria count is either undetected or low in the tap water. Please keep in mind that these bacteria are probably harmless. Of course, if you are concerned about the maintenance of the water tanks, equipment and piping leading to your household, by all means, go ahead and boil your tap water. Maintenance is ultimately performed by humans and there is always a possibility of human error.

    As mentioned above, if you decide to boil your water, make sure your boiled water does not become recontaminated in whatever container you are using. 
 
Figure: Boiling water in this vintage kettle from the old days

 
 
 
 
 

Friday, May 14, 2021

Being Interviewed on Talking Point shown on Channel 5, 13 May 2021: Do I really need a water filter?

I was approached by the producer for Talking Point to be interviewed for my views on water filters in the context of the home user in Singapore. I ended doing a show-and-tell of three different types of water filtration processes in addition to the interview. Shooting took place a month before the programme was aired on TV though the MeWatch version appeared earlier.


For my part, the programme essentially covered my demonstration of how activated carbon (AC), ion exchange resin and alkaline water ioniser work, as well as my tips to the viewer on choosing a water filter. As per CNA's practice for Talking Point, various subject matter experts were interviewed on pertinent aspects of tap water, water filters and alkaline water. Overall, given the limited duration (20min), the programme provided a rather interesting and balanced take on the controversial issue of water filters for home use in Singapore.

 

Go ahead and watch it on MeWatch!

 

Updated on 28 May 2021: The print version is available now: 

Can filtered water help to prevent cancer? Talking Point gets the answer from a food scientist.
Can filtered water help to prevent cancer? Talking Point gets the answer from a food scientist.https://www.channelnewsasia.com/news/cnainsider/why-filtered-water-may-not-be-as-clean-beneficial-you-think-tap-14901036?cid=FBcna

Why filtered water may not be as clean or beneficial as you think

Updated on 18 May 2021: The YouTube version is available now.


 

This scene with Steven Chia was shot during my filming session with CNA but it was ultimately left out in the final version.
Figure: This scene with Steven Chia was shot during my filming session with CNA but it was ultimately left out in the final version.