Earlier this week, I was listening to a report on the CBC about the safety of water hoses.
It was based on material obtained from a number of sources, including "HealthyStuff.org". I always have a little bit of trouble with organizations that say something to the effect of "the world is full of dangerous chemical compounds so buy our stuff instead".
Every compound - including oxygen and water - is a "dangerous chemical". Every compound on the planet has the potential to kill a human being.
Indeed, if one wants to get absurd about it, the principle cause of cancer is DNA. In 100% of all cases of cancer, DNA is involved. So why not argue to get rid of DNA?
Because life does not occur without it. Removing DNA from your cells is a quick death sentence. Our cells need their instruction manual.
The same could be said for, say, oxygen. I know that if I keep breathing oxygen long enough, I will die. I am just hoping to get a few more years before that happens. And, if I stopped breathing oxygen, I would die immediately.
Having said all that, HealthyStuff.org, and the organization behind it, very earnestly published the results of their studies arguing that you shouldn't drink from a garden hose.
"In 2013, we tested 21 new garden hose samples purchased from Lowe's, Home Depot, Walmart, Target, and K-Mart" they write. "One-third (8 of 21) of the garden hoses tested contained enough chemicals of concern to be ranked 'high concern' in our ranking system, which means we detected high levels of one or more chemical hazards."
It sounds bad. There are hoses on the market, sold by these major stores, with high levels of chemicals of concern. How can this be allowed to happen?
Except that is not what the web-site is actually saying. It takes a little more digging to try and find out what they have done.
It appears that they have not purchased "21 new garden hoses" but rather 4 different types of hoses. In an effort to perform "good science", they presumably have replicates of each of the four types of hoses. At least, they only present data from four different hoses. Who knows what they actually did?
The data they do present is somewhat misleading. They report that total phthalate content in the "five hoses tested" (they include data from a hose tested in 2012) range from 11% to 18%. They point out that these hoses contain "one or more phthalates which are banned by CPSC in children's products".
What they don't make clear is that the 11% to 18% is the total phthalate content of the hose and not the water in it. In other words, to get exposed to these levels of phthalates, a child would have to eat the garden hose.
Personally, if my child is eating the garden hose, I have bigger worries than whether or not there are phthalates in the plastic!
But HealthyStuff.org does move on to their "water leaching" tests. Finally, we have some data of relevance to the use of a garden water hose. After all, the central question should never be "what is the hose made from?" but "can the compounds in my hose get into the water within it?"
To answer this question, one needs to read a bit further into their experimental methodology.
To test for leaching, they completely filled the hoses with municipal water, clamped off the ends, and left the hoses in a yard in full sunlight for two days. The contents of the hose were collected in glass sample containers. They tested three samples - one from each hose and a faucet blank.
There are many problems with this procedure - many that one of our local science fair winners could point out. For example, HealthyStuff.org only did the experiment once on each hose. Who is to say that if they repeated their experiments that they would get even close to the same results?
There are so many uncontrolled variables - temperature, surroundings, water input, amount of sunlight, testing methodology - that the results are, at best, interesting and, at worse, misleading.
This is not to say that HealthyStuff.org is completely off-base. There are compounds in our environment and things that we use and consume on a daily basis that are not healthy for us. However, the science needs to be sound if the conclusions are to be useful.
In the case of garden hoses, the question of leaching is one which needs to be asked about water running through a hose and not water left to stagnate for 48 hours. Who would ever drink from a hose that had been left in the sun for two days?
No. When I drink from my garden hose, I want it to be running with cool, drinkable water from my house.
