In article ,
"Ed Huntress" wrote:
"Joseph Gwinn" wrote in message
...
In article , "." wrote:
On 7/11/2011 7:49 PM, Ed Huntress wrote:
"Joseph wrote in message
...
In ,
"Ed wrote:
[snip]
look at it this way - would you rather have healthy rivers and cloudy
drinking glasses or nice clean drinking glasses and dead rivers? I
choose the former. And, I wash by hand so there has never been an issue
anyway.
This is a false dichotomy, and in addition fails back-of-the-envelope
reasonableness calculations.
The false dichotomy is the claim that we can have either clean rivers or
clean glasses. Actually, there is no reason not to have both, as
discussed next.
The main use of phosphate chemicals is fertilizer: "About 95% of the
phosphate rock mined is used to produce fertilizers, animal feeds and
pesticides." [1]
This leaves 5% for everything else, including dishwasher detergents.
Modern dishwashers use a few ounces of detergent per wash, while farms
use phosphate fertilizer by the ton. The difference is thus orders of
magnitude.
So even if we stopped washing dishes altogether, nothing much would
change.
Yeah, except when it does. Cumulative phosphate use from washing clothes, in
densly populated areas, can be a much higher percentage of the phosphate
load on rivers. I haven't seen the numbers for a while but I recall that it
was a high percentage in the Delaware at one time. There isn't as much ag
runoff in that river as in many others.
There are a few problems here.
First, we are talking about dishwashing, not clothes washing, which
makes for a big difference in detergent use, at least a factor of ten.
I don't know about others, but I have not been having any problems with
clothes washing detergents. The problem is with dishwashing detergents.
Second, Delaware is an outlier, being a very small state with a very
large fraction of non-farming households. The Delaware River promptly
flows into the Atlantic Ocean, joining the outflow from the rest of the
Eastern Seaboard. What matters is the aggregate.
Third, animals (including humans) excrete phosphorus in their excrement:
"However, where used, detergent phosphates contribute only 5 - 20% of
phosphates in sewage (most phosphate in sewage comes from human bodily
functions and food wastes), and sewage itself is only a minority source
of phosphate to the environment compared to agriculture." [2]
To summarize, 95% of phosphate goes into agriculture, and thus to
phosphate runoff. Of the remaining 5%, detergents are a fraction of
that 5%. Of detergents, something like 90% was for clothes washing, and
maybe 10% was for dishwashing. This was before the effort to remove
phosphates from detergents was undertaken, but even then only (5%)(10%)=
0.5% went into dishwashing detergents. After the removal effort, this
has been reduced to a fraction of 0.5%.
So, the focus would have to be on agriculture. The problem is that crop
plants cannot be convinced that they don't need phosphorus to grow.
Joe Gwinn
As I said above, The basic problem [with the EPA] is that they don't
know when to just stop, to just declare victory and move on.
Joe Gwinn
http://en.wikipedia.org/wiki/False_dilemma
[1] "World Phosphate Production: Overview and Prospects", L. CISSE and
T. MRABET, World Phosphate Institute, 3, Rue Abdelkader Al Mazini, 20001
Casablanca, Morocco, in Phosphorus Research Bulletin Vol. 15 (2004) p.
21-25, www.imphos.org/download/jena/cisse_prb-15.pdf.
[2] "Questions and Answers on the use of phosphate in detergents", 10
February 2011, CEEP (Centre Européen d¹Etudes sur les Polyphosphates),
http://www.ceep-phosphates.org/Files...%20detergent%2
0proposal%2010%20February%202011.pdf.