Name: 鉛中毒仍然是一個巨大的問題，但可能有一個快速的解決方案。 (Lead Poisoning Is Still a Huge Problem, But There Could Be a Quick Fix)
Uploaded: 2021-01-14T09:58:45.000Z
Duration: 5 min 30 s
Description: 【看影片學英語】數萬部 YouTube 影片，搭配英漢字典即點即查，輕鬆掌握單字發音與用法，長久累積看電影不必再看字幕。

Zapping water with electricity could save your life.

Not something you thought we’d ever say?

By introducing an electric current into lead pipes filled with a harmless phosphate solution

researchers at UC Berkeley were able to rapidly form a protective coating around corroded

lead pipes, reducing leaching of this toxic element by roughly 99%.

Lead exposure is a huge public health issue, according to The World Health Organization.

Paint and dust laced with lead are the most common sources of exposure, but contaminated

In the U.S. alone, over 5,000 water systems violate the EPA’s Safe Drinking Water Act,

placing an estimated 18 million people at risk.

This chemical element (Pb) can accumulate in our body over time, leading to kidney damage,

reduced IQ, increased risk of cancer, stroke, and even death.

That’s all thanks to lead’s sneaky ability to mimic and inhibit calcium, break through

the blood-brain barrier, and result in the misfiring of neural signals, impairing our

Evidence suggests that ancient Romans knew their lead pipes were poisonous, but lead’s

dangers weren’t widely re-discovered until the period of industrialization in the 19th

century, when reports of lead poisoning began to pick up.

Decades of subsequent scientific investigation and their damming findings eventually prompted

many governments to distance themselves from sources of lead, like gasoline additives,

paint, and piping material, which was favored as a durable and long-lasting material well

But it takes time to redo the plumbing of entire cities, as was made painfully clear

when taps in Flint, Michigan began dispensing lead-contaminated water to residents in 2014.

One sample even had lead levels reaching 13,200 parts per billion!

So...we’re stuck with all this lead-laden water.

Water doesn’t contain much lead on its own, but it can be corrosive.

Once in contact with lead pipes, it can breakdown the metal and cause leaching.

To prevent this, inorganic phosphates are commonly added to public water supplies, where

they react with positively charged lead ions to form a protective, insoluble mineral scale

. But without maintaining tight control of the chemistry, that coating is quickly eaten

To fix a water supply that’s turned toxic, pipe replacement is by far the best solution,

Case in point: it took two years after Flint’s water crisis erupted for the city’s roughly

170 million dollar pipe replacement program to break ground.

And as of 2019, roughly 2,500 lines still need replacement.

So is there a better way to zap the situation?

ASHOK: In our work, we ask the question, "what can we do to rapidly stop a leaching lead

pipe so that the drinking water that passes through it will become safe all over again?"

The team specializes in drinking water treatment using electrochemistry, which is the science

of looking at how electricity interacts with materials.

It starts by introducing a threaded wire down the inside of a lead pipe into a tank of water

filled with phosphates, then switching on an electric circuit.

At first, the voltage causes lead ions to leach into the water, but as these ions react

with the phosphates, they begin to form insoluble lead phosphate.

Searching for somewhere to deposit, these minerals begin to settle on the lead pipe

ASHOK: As the lead phosphate lines the inside of the lead pipe for a given voltage, less

and less current can flow because the lead pipe becomes non-conducting...that's how we

know that our process is working.We can reduce the leaching of lead from those pipes by a

We have not tested it yet in the field, but we have a solution that works.

Their preliminary results found that once a charge is introduced, a mineral barrier

can accumulate on the pipe wall in less than 2 hours, effectively decreasing lead leaching

Any part of the lead pipe that’s left uncoated, the current self-tunes to go where it needs

There is also a sense of public responsibility in fixing the problem...replacing a pipe costs

about 100 dollars a foot if you fold in all the costs.

Our goal is to bring that cost down to, maybe, three dollars a foot.

Water chemistry varies by a lot.We haven't explored all that space of unknowns...to say

We need to test it out, but we are ready to do that very soon we think.

If all goes well, the team plans to try their technique in nearby schools as early as this

Once refined, this technology could act as a vital stopgap until communities are able

to replace lead pipes, as that ultimately remains the best solution.

And maybe a 5-star filter for your water tap.

Are you excited about this research to stop this toxin from polluting our tap?

Let us know in the comments below, and don’t forget to subscribe for more Seeker.

I’ll see you next time, thanks for watching.