Dr Oz talks about drinking Water
Lead in your drinking water: don’t rely on tests!
This report from the Chicago Tribune is alarming to say the least. In tests of 29 homes’ drinking water, half showed unacceptable lead levels. The test was significant because for the first time, testers took more than the one litre the present testing requires. In most cases a one litre test was ‘clean’ but as they drew more litres from the tap, the problem of lead showed more clearly.
I’m amazed that they ever allowed the old testing regimen. It’s common knowledge that old homes with copper pipes and brazed joints have lead in the joints, which, if the water is acidic, are slowly eaten away by stationary water overnight. So it only makes sense that any test has to be first thing in the morning and that the tap should be run long enough for that concentration of lead-laded water to come out.
Of course it’s not so easy to rip out all of your old plumbing – especially when it’s built into a wall! But some modern water filters have the ability to filter lead. Look for KDF in the media mix of the water filter. It’s a proprietary media that has this ability, as well as the ability to remove other heavy metals, and to neutralise bacteria.
Giardia; A very tricky parasite in drinking water
Giardia parasites can change the proteins on their surface, which helps them to evade the immune system, but only one protein is on the surface at any one time. This Giardia parasite has been engineered to exhibit two proteins on its surface, shown in green and red.
Dr Hugo D. Luján of Catholic University of Córdoba in Argentina and the Howard Hughes Medical Institute, has found that the Giardia lamblia parasite changes its shape when meeting the human immune system. The parasite causes about 200 million cases of diarrhea each year, and the research into its function is helping to develop a genetically modified strain that can serve as a possible vaccine for the disease.
The Giardia genome contains nearly 200 genes that code for surface antigens. Despite the large number of genes, each parasite displays only a single antigen—derived from a single gene—on its surface at any given time. Normally, the RNA instructions for each gene are copied from the parasite’s DNA then run through the cell’s internal machinery to create proteins, including surface antigens. As Luján and his group delved into this mystery, he discovered that the molecular machinery in the parasite actually reads and transcribes most of the 200 surface antigen genes, but only one antigenic protein makes it to the outer coat on the parasite’s surface.
That observation suggested to Luján that the RNA instructions—called messenger RNA—had been created and were inside the organism, but something was stopping the RNA from being translated into proteins and expressed on the cell’s surface. “That was a surprise,” Luján said. “Because it takes a lot of energy for the organism to transcribe all of those genes into messenger RNA.”So Luján sought to find out why most of the parasite’s RNA never gets translated into a working surface antigen. Something must be interfering with that process for Giardia’s surface antigens.
He suspected that a powerful cellular mechanism called RNA interference, or RNAi, might be the cause of the holdup. Discovered a decade ago, RNAi identifies short segments of RNA and then destroys all RNA that matches the segments. The result: None of the protein that would have been created by that RNA is released into the cell. Researchers originally found that RNAi is a protective mechanism that helps cells fight off invading viruses. But as the new work by Luján shows, the process can also control which genes are switched on and off in Giardia.
In a series of experiments, Luján found that the cellular machinery involved in RNAi squelches most of the RNA in Giardia that codes for surface antigens. At any given time, in fact, only the RNA for a single type of antigen is left untouched. The rest is destroyed. “At that point, we realized RNAi was strongly linked to antigenic variation,” Luján said.
Next, Luján inhibited the enzymes involved in RNAi in Giardia. Again, he made a surprising discovery: The cells with defective RNAi machinery displayed many surface antigens simultaneously—a kind of parasitic Technicolor dream coat. “That was the direct link between enzymes involved in the RNAi pathway and antigenic variation in Giardia that we had been looking for,” Luján said.
Full story at HHMI: New Research Reveals How Giardia Parasite Changes Its Appearance …
Pharmaceuticals in our water; Repeat Offender
We’ve heard all about traces of drugs in our drinking water.
Unfortunately, that may seem pretty minor in comparison if you happen to live near a drug production plant that’s located on a waterway. According to a Pharmalot report, Merck violated the Clean Water Act with three chemical discharges into the water supplies of Pennsylvania, in the US. One of these discharges was so extreme that the entire city of Philadelphia had to shut down drinking water temporarily.
Nice.
For that little misstep, Merck paid a fine of more than $20 million in 2007.
So… lesson learned?
Not quite.
The same year that fine was paid, a Merck facility in Pennsylvania dumped ammonia and ethylene glycol into the water and neglected to inform the Environmental Protection Agency (EPA). That violation, coupled with a similar 2004 abuse recently cost the company another $1.5 million in fines.
What we have here, apparently, is a repeat offender. So if you had to bet, would you bet it won’t happen again?
Not me.
