Name: 为什么我们仍然使用铅管？！（Why Do We STILL Use Lead Pipes?!）
Uploaded: 2021-04-30T09:14:47.000Z
Duration: 4 min 4 s
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情態副詞

Lead is poisonous and it can leach into water, so you probably wouldn't gulp from a cup

Yet today, hundreds of millions of us worldwide get our water from plumbing that contains

We've actually had a complicated relationship with lead for a long time.

Scholars first recognized its dangers in ancient times, yet for the next 2000 years, we relied

After all, lead is plentiful, and since it has a low melting point, it's easy to extract.

It's a super-soft metal, so it can easily be formed into pipe-y shapes, and it can last

for centuries - far longer than other plumbing contenders.

Lead is such an ideal water-transporter that the word “plumbing” literally came from

And while people have known for a long time that lead could make us sick, it was tricky

to nail down how big a risk it actually was.

It can take years to see the effects of lead on our bodies, and even then, its symptoms

can be mistaken for lots of other maladies.

But what really *led* to confusion was that in some places, lead pipes didn't seem to

Generally, lead can leach right out of a pipe and into the water rushing through it, poisoning

But in places where water has lots of dissolved minerals, a hard, scaly crust builds up inside

pipes, which separates the water from the lead, keeping most of it out of our cups.

By 1900, we had figured out these quirks and fully understood the dangers lead pipes posed,

but two thousand years of plumbing had given lead some serious inertia.

By then more than 70 percent of large US cities used lead water lines.

Pipefitters and plumbers still preferred plumbum for their plumbing work.

And in some places, the powerful lead industry worked hard to keep promoting lead pipes for

All in all, it took many countries until the late 20th century - or longer - to ban the

But there were still lots of lead pipes already out there, and replacing them would be incredibly

But we could put to work one of the things that had initially confused us about lead

pipes; we started adding dissolved minerals to water that didn't naturally contain them,

artificially forming that protective crust that makes lead pipes safe...well, safe-ER.

Occasionally, disaster happens - like when a drought in England caused the protective

barrier in a town's pipes to crumble, poisoning hundreds of people when water started flowing

again; or when officials in Flint, Michigan neglected to add minerals to the town's

water, exposing tens of thousands of households to lead.

It's time to get over the cost and effort of removing and replacing all that plumbum,

so that safe plumbing is no longer just a pipe dream.

In the US, instead of replacing lead pipes, the Environmental Protection Agency has tried

to monitor and limit lead levels in drinking water.

But here's the thing: their flawed testing method systematically misses high lead levels

What's more, the lead limit the EPA has adopted isn't actually based on what's best

These not-so-minor details mean that tens of millions of Americans are currently at

For more information about what's actually going on here, you can check out Buried Lead;

the result of a collaboration by APM Reports and The Water Main, the sponsor of this video

and an initiative of American Public Media that's working to build public will for

You can read the story at apmreports.org/water.

Thanks to the Water Main for helping us make this video, and for trying to make sure the

water we're drinking is plentiful and safe.