26 March 2008

Everything old (in plumbing) is new again?

Robyn asked below about some news about copper fixtures being antimicrobial. I thought I had seen it somewhere, and finally I tracked it down: a Bloomberg News story from yesterday.

Unfortunately the story seems to be based largely on a press release from the, wait for it, Copper Development Association. So it's just possible there may be a whiff of bias here.

The story says:
March 25 (Bloomberg) -- Copper doorknobs, bedrails and faucets can prevent the spread of deadly drug-resistant infections that have become a growing public-health threat in hospitals, according to a metal industry group.

The U.S. Environmental Protection Agency has found copper, brass and bronze can combat infections, including those caused by methicillin-resistant staphylococcus aureus, or MRSA, according to a statement today from the New York-based Copper Development Association.
Digging a little further, it seems the EPA on Tuesday ruled that metal-alloy manufacturers can make "health claims" about their products:
NEW YORK—The U.S. Environmental Protection Agency (EPA) has approved the registration of antimicrobial copper alloys, with public health claims. These public health claims acknowledge that copper, brass and bronze are capable of killing harmful, potentially deadly bacteria. Copper is the first solid surface material to receive this type of EPA registration, which is supported by extensive antimicrobial efficacy testing. ...

The following statements are included in the registration: "When cleaned regularly, antimicrobial copper alloys surfaces kill greater than 99.9% of (specific) bacteria within two hours, and continue to kill more than 99% of (these) bacteria even after repeated contamination," and "The use of a copper alloy surface is a supplement to and not a substitute for standard infection control practices; users must continue to follow all current infection control practices, including those practices related to cleaning and disinfection of environmental surfaces. The copper alloy surface material has been shown to reduce microbial contamination, but it does not necessarily prevent cross contamination."
There may be good science about some metals being sterilizing — there is at least one company producing silver-coated catheters to combat bloodstream infections — but I'm personally confused why this is an EPA ruling and not an FDA one, if the alloys are going to go into hospital fixtures. Perhaps bedrails and IV stands don't qualify as "devices"?

1 comment:

robyn said...

While we desperately need to find ways to stop the epidemic of resistant microbes, we must be careful not to substitute a Superbug with a Superfund.

The Berkeley Pit in Butte, MT is at the top of the EPA superfund sites. It's a copper mine and it is not only still not cleaned up, but is a growing crisis. The pit is 1.5 miles across and almost 2,000 feet deep. In 1982, the mining company left and turned off the lights behind them...including the pumps.

The pit has been filling with water ever since, dissolving the tailings and turning the pit into a toxic lake that has a pH of 2.5, similar to the acid in lemons. In 1995, a flock of snow geese landed on it and all 300 of them died in the water.

The pit WILL overflow into the nearby Blackfoot river, killing everything downstream and poisoning aquifers all along the way.

Yet, there is good news. Andrea and Don Stierle, two dedicated and clever scientists at Montana Tech university in Butte, have found living organisms in that toxic, acidic water--extremophiles. And they are finding that these bacteria, yeast and fungi can use those acids for nutrients. It's possible these microbes could be used to help filter the water.

Copper may kill most microbes, but I suspect there are some that could survive. Microbes have 3 billion years of trial and error on us.