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Unsafe Lead Levels in Tap Water Not Limited to Flint

nytimes.com

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Re: Unsafe Lead Levels in Tap Water Not Limited to Flint

#61

Post by colin_mccabe »

manachar wrote: post #16
staunch wrote: post #2

Ancient Romans knew that lead water pipes were unhealthy and so they preferred terracotta pipes. It's hard to imagine why the U.S. ever had a single lead water pipe, let alone huge numbers of them. Updated with a reference for the downvoters: Sheets of lead were used to line Roman aqueducts (as was cement) and lead pipes to convey water. But lead also was known to be unwholesome and, for that reason, pipes made of cl…

Most houses in the U.S. built prior to a few decades ago have lead paint and many have asbestos. Then there's the whole leaded gasoline fiasco. The world has known of the danger of lead and many other dangerous substances, but often still chooses to use the dangerous substance. Sometimes it's because there weren't alternative substances that could do what needed to be done. Sometimes it was just a matter of expense.…

Course, then there are cases like the leaded gasoline that should be considered one of the greatest crimes of all time.

Yep, and it's still going on. Some small planes still use leaded fuels. http://ehp.niehs.nih.gov/121-a54/

Re: Unsafe Lead Levels in Tap Water Not Limited to Flint

#62

Post by prions »

ohthanks wrote: post #18
overcast wrote: post #5

Earlier quoted context omitted.

Drinking distilled water is not a good idea, which is basically what reverse osmosis gives you stripping out essential minerals. It's also an incredibly wasteful 4:1 process. Look into three stage filtering, that's all you need.

Carbon filtration will not remove dissolved solids (lead, heavy metals) without added ion-exchange resins. RO is generally the most effective broad spectrum treatment method for drinking water. The mineral issue is pretty much bunk, if the lack of trace minerals in your water is a concern you need to see a doctor. Food is your body's preferred source of minerals, you have to drink a lot to have much effect on your da…

I'm a water treatment engineer. Carbon filtration will remove dissolved solids and heavy metals, and with high efficiency if done correctly. Most GAC columns designed to remove lead and heavy metals are enriched with sulfide ions to increase the removal efficiency as well. People prefer to use ion exchange resins to remove heavy metals because they can be regenerated more easily and efficiently. Also ion exchange resins allow you to recover any absorbed minerals.

http://ascelibrary.org/doi/10.1061/%28ASCE%290733-9372%28199...

Re: Unsafe Lead Levels in Tap Water Not Limited to Flint

#63

Post by akg_67 »

prewett wrote: post #53
akg_67 wrote: post #15

Earlier quoted context omitted.

Default to not drinking from taps directly. I live in Seattle. We only use tap water after filtering with a Brita Filter for drinking and cooking. When we are outside home, we either bring filtered water with us or buy bottled water. At restaurants, if in doubt we ask if water is directly from tap. Since the flint lead news, I have been exploring how can I get my tap water tested on a routine.

> Default to not drink from taps directly Why?? Tap water is highly regulated, and 1000 times cheaper than bottled water. It does not produce tons of plastic waste (much of which is not recycled). It does not leach possible carcinogens like BPA, DEHA, or BBP. Furthermore, much of the bottled water comes from municipal tap water! The Mayo Clinic says that tap water and bottled water are about equally safe. If you can'…

Water quality is one aspect. The water delivery mechanism is another, often ignored, aspect.

Flint issue has more to do with delivery.

Re: Unsafe Lead Levels in Tap Water Not Limited to Flint

#64

Post by Laforet »

thescriptkiddie wrote: post #56
ohthanks wrote: post #18

Earlier quoted context omitted.

Carbon filtration will not remove dissolved solids (lead, heavy metals) without added ion-exchange resins. RO is generally the most effective broad spectrum treatment method for drinking water. The mineral issue is pretty much bunk, if the lack of trace minerals in your water is a concern you need to see a doctor. Food is your body's preferred source of minerals, you have to drink a lot to have much effect on your da…

Sorry, but you really don't want to be drinking true deionized water. It isn't a about long term mineral loss, it is about the immediate discomfort of drinking it. It's fine for the first cup or two, but after that it starts to burn. Wash your hands with it and you'll find you skin is dry and cracking. You'll notice that reverse osmosis systems intended for producing drinking water have a much lower standard of purit…

>It's fine for the first cup or two, but after that it starts to burn. Wash your hands with it and you'll find you skin is dry and cracking.

I have handled and, against my better judgement, quaffed many types of deionised water: triple glass distilled, reverse osmosis, ion exchange, etc. They taste more or less the same to store-bought distilled water and I have not yet had any of the ailments in your complaint. There is also a certain coworker who developed a pechant for the MilliQ water machine and regularly filled her drink bottle with ultrapure (>18.2 megaohms) water there. Suffice to say she is still doing it.

>But really, get over it, 99% of the US has safe tap water

This is not necesarily true given the state of water infrastructure in the US. The water leaving a treatment plant is not the same as water coming out of a tap.

Re: Unsafe Lead Levels in Tap Water Not Limited to Flint

#65

Post by matthewbauer »

ohthanks wrote: post #18
overcast wrote: post #5

Earlier quoted context omitted.

Drinking distilled water is not a good idea, which is basically what reverse osmosis gives you stripping out essential minerals. It's also an incredibly wasteful 4:1 process. Look into three stage filtering, that's all you need.

Carbon filtration will not remove dissolved solids (lead, heavy metals) without added ion-exchange resins. RO is generally the most effective broad spectrum treatment method for drinking water. The mineral issue is pretty much bunk, if the lack of trace minerals in your water is a concern you need to see a doctor. Food is your body's preferred source of minerals, you have to drink a lot to have much effect on your da…

Why is the mineral issue bunk?

According to this WHO report[1], it seems like a real concern:

"Low-mineral water markedly: 1.) increased diuresis (almost by 20%, on average), body water volume, and serum sodium concentrations, 2.) decreased serum potassium concentration, and 3.) increased the elimination of sodium, potassium, chloride, calcium and magnesium ions from the body. It was thought that low-mineral water acts on osmoreceptors of the gastrointestinal tract, causing an increased flow of sodium ions into the intestinal lumen and slight reduction in osmotic pressure in the portal venous system with subsequent enhanced release of sodium into the blood as an adaptation response. This osmotic change in the blood plasma results in the redistribution of body water; that is, there is an increase in the total extracellular fluid volume and the transfer of water from erythrocytes and interstitial fluid into the plasma and between intracellular and interstitial fluids."

It might not be enough to outweigh the benefits of highly filtered water, but just because you have enough minerals from food doesn't mean that minerals in water aren't having an effect.

[1]: http://www.who.int/water_sanitation_health/dwq/nutrientschap...

Re: Unsafe Lead Levels in Tap Water Not Limited to Flint

#66

Post by snowwrestler »

the_mitsuhiko wrote: post #40
djrogers wrote: post #31

Earlier quoted context omitted.

If I travel to Europe, how do I know if the local knows the water is safe to drink? Unless you're in Flint, or a paranoiac, tap water in the US is safe. Period. Flint's problem is not endemic, it was isolated. The article is really reaching - they cite 3 instances over ~15 years of problems in city water supplies. In 2 of the 3 cases it was caught and rectified quickly - Flint is the exception.

> Unless you're in Flint, or a paranoiac, tap water in the US is safe. Period. Given the size of the United States that's a very brave statement. Water quality in Europe is typically measured on on commune level and even in countries like Austria which pride themselves for drinkable tap water there are incidents which cause tap water to not be drinkable at times.

The U.S. is huge but it's also filled with a lot of people and a lot of local governments, state governments, and of course a federal government.

If you want one independent source of proof that U.S. water is safe, consider that almost every U.S. child has blood work done on an annual basis. If elevated levels of lead are a problem, they would be detected at that time, as they were in Flint.

Re: Unsafe Lead Levels in Tap Water Not Limited to Flint

#67

Post by such_a_casual »

tn13 wrote: post #32

You can cheap water testing kits on amazon which you can use. Also not water is 100% safe and it makes a lot of sense to diversify the water sources. We use tap water for cooking, bottled water from different brands at home and workplace. That probably is good enough. I have tested water at home for lead and pesticides and found it to be safe to drink. [Sunnyvale]

Google says 45% of bottled water is just tap water. I will never understand this phenomena.

Re: Unsafe Lead Levels in Tap Water Not Limited to Flint

#68

Post by Laforet »

matthewbauer wrote: post #65
ohthanks wrote: post #18

Earlier quoted context omitted.

Carbon filtration will not remove dissolved solids (lead, heavy metals) without added ion-exchange resins. RO is generally the most effective broad spectrum treatment method for drinking water. The mineral issue is pretty much bunk, if the lack of trace minerals in your water is a concern you need to see a doctor. Food is your body's preferred source of minerals, you have to drink a lot to have much effect on your da…

Why is the mineral issue bunk? According to this WHO report[1], it seems like a real concern: "Low-mineral water markedly: 1.) increased diuresis (almost by 20%, on average), body water volume, and serum sodium concentrations, 2.) decreased serum potassium concentration, and 3.) increased the elimination of sodium, potassium, chloride, calcium and magnesium ions from the body. It was thought that low-mineral water ac…

This particular report cites a number of rather fringe sources as well as many non-English journal artiles that cannot be easily verified. Overall I find the author's conclusions hard to believe.

>It was thought that low-mineral water acts on osmoreceptors of the gastrointestinal tract

This is not how osmolarity sensing works.

Re: Unsafe Lead Levels in Tap Water Not Limited to Flint

#69

Post by tn13 »

maxxxxx wrote: post #58
tn13 wrote: post #32

You can cheap water testing kits on amazon which you can use. Also not water is 100% safe and it makes a lot of sense to diversify the water sources. We use tap water for cooking, bottled water from different brands at home and workplace. That probably is good enough. I have tested water at home for lead and pesticides and found it to be safe to drink. [Sunnyvale]

Do you have an amazon link for one of those?

http://www.amazon.com/First-Alert-WT1-Drinking-Water/dp/B000...

Re: Unsafe Lead Levels in Tap Water Not Limited to Flint

#70

Post by ohthanks »

prions wrote: post #62
ohthanks wrote: post #18

Earlier quoted context omitted.

Carbon filtration will not remove dissolved solids (lead, heavy metals) without added ion-exchange resins. RO is generally the most effective broad spectrum treatment method for drinking water. The mineral issue is pretty much bunk, if the lack of trace minerals in your water is a concern you need to see a doctor. Food is your body's preferred source of minerals, you have to drink a lot to have much effect on your da…

I'm a water treatment engineer. Carbon filtration will remove dissolved solids and heavy metals, and with high efficiency if done correctly. Most GAC columns designed to remove lead and heavy metals are enriched with sulfide ions to increase the removal efficiency as well. People prefer to use ion exchange resins to remove heavy metals because they can be regenerated more easily and efficiently. Also ion exchange res…

This is totally correct. It is also not very applicable to drinking water & whole house systems that homeowners are interested in.

There are carbon cartridges with ion-exchanges resins blended into the block that seem to be effective for lead removal at low flow rates. They tend to have lower flow-rates and capacity than is ideal.

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