Although these methods have been employed for years, problems can emerge once the treated water enters the distribution system, where pathogens are also present. For this reason, water is often over-chlorinated at the plant so that it remains in high enough concentrations in the pipes to neutralize pathogens. This explains why people living the closer to a treatment plant will be more likely to taste or smell the chemical than those farthest away from the plant, the researchers said. Additionally, chlorine can react with other organic matter in the system, leading to potentially harmful by-products.
UV light, while also effective in neutralizing pathogens at the plant, has no effect once the water is pumped out of the plant. Gunsch said that many pathogens are developing a resistance to the effects of chlorine and UV light, so newer options are needed.
We envision creating a system based on RNAi technology that would look from the outside just like the water filters commonly used now, Gunsch said. This approach would be especially attractive in less industrialized countries without water treatment systems. This point-of-use strategy would allow these countries to make safe water without the expense of water purification infrastructure.
The first prototypes would likely involve a filter seeded with RNAi that would eliminate pathogens as the water passed through it. These filters would likely need to be replaced regularly, Gunsch said, adding that she believes it would theoretically be possible to create a living, or self-replicating system, which would not require replacement.
The researchers are currently conducting additional experiments targeting other regions of the fungus genome. For their proof-of-concept experiments, they tested RNAi
|Contact: Richard Merritt|