This is scientific American's 60 second science.

I'm Christopher Intalyata.

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Here's a way to fight the ongoing drought in California.

Use more wastewater for irrigation. The state's water board suggested that

strategy a few years ago, but so far of the trillions of gallons of water used for

irrigation, only about 6% is wastewater. But in Israel, which is also notoriously dry, half the

country's irrigation water is reclaimed water. The question is, could pharmaceutical

residues, which are found in trace amounts in wastewater, make it into the veggies and onto your dinner plate.

Israeli scientists focused on an epilepsy drug called carbon mazepine, often found in wastewater. They detected trace

quantities in lettuce, parsley, peppers, and other wastewater-grown veggies.

They then fed volunteers either those veggies or organic ones grown in freshwater.

After a week the wastewater group did indeed have significantly higher levels of the

chemical in their urine compared to the freshwater group.

Switching to a freshwater-grown diet though quickly reverse the effect.

The finding is in the journal Environmental Science and Technology.

There's one huge caveat.

The amount of the drug in the volunteer's urine was some 40,000 times lower than would be found

after just one therapeutic dose of the drug.

And the researchers say it's unlikely exposure to such tiny quantities poses any risk. But the result does suggest

it's at least possible to ingest unwanted pharmaceuticals in your salad, something for public

health officials to investigate, as they weigh green water policy with what's in our greens.

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