Water, water, everywhere … but is it safe to drink?

“Over the last couple of generations, there has been a massive quantity of groundwater pollution worldwide, and this has had a negative effect on our drinking water source,” states Barbara Sherwood Lollar, Canada Research Chair in Isotope Geochemistry of the Earth and the Environment in the University of Toronto.Sherwood Lollar took a part at AAAS from the THINK CANADA Press Breakfast Sunday.

Her study examines society’s efforts to reverse and stop groundwater pollution, and the effectiveness of bioremediation technology — using microbes to clean up organic contaminants like petroleum hydrocarbons (petroleum, gasoline or petrol) or compounds used in the electronics or transportation industries.Though now the disposal of those organic contaminants has been well regulated, this has not been the situation. Lax enforcement and regulations during the period immediately after the Second World War has left a legacy of past contamination to Europe and North America.

“This pollution has had a pervasive effect on the surroundings,” says Sherwood Lollarsaid “It’s still on the market, and it ought to be taken care of.”Such as Sherwood Lollar , many techniques used to clean up groundwater contamination have harnessed the energy of microbiology and also the work of geochemists over the last ten years. “We are not genetically engineering microbes,” she clarifies. “In most settings, naturally occurring microbes feed off the natural contaminants and, in the process, convert them to non invasive end solutions.”Until today, the difficulty has been in proving that the microbes are cleaning up the contaminants and that the method exists.

Sherwood Lollar has developed techniques which reveal where the cleanup is currently occurring and, just as importantly, where it isn’t.”Elements like carbon have different stable isotopes: Carbon-12 and Carbon-13. One is a bit heavier than the other, and the germs tend to feed on the lighter one. The proportion of carbon may change when the microbes have been working for some time. It is this shift — referred to as an isotopic signature — which lets us understand the water is being cleaned up,” says Sherwood Lollar.