美国国家公共电台 NPR Digging In The Mud To See What Toxic Substances Were Spread By Hurricane Harvey（在线收听）

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When Hurricane Harvey dumped 50 inches of rain on Houston, the floodwater a drain somewhere. Much of it went to the Houston Ship Channel, and it brought along a lot of contamination. Now scientists are sampling the channel mud to find what toxins were left behind. NPR's Rebecca Hersher reports.

REBECCA HERSHER, BYLINE: Lindsay Critides is kneeling on the deck of a small, beat-up research boat improbably nicknamed Big Daddy. It's 8 a.m. and the oceanography master's student is trying to fix a winch before the team heads out.

LINDSAY CRITIDES: I grabbed the T Allen wrenches, both sizes that would work.

HERSHER: They have to get everything ready before they leave the dock. The Houston Ship Channel is a really busy waterway. It's part of one of the biggest ports in the country. And this morning, barges and tanker ships are already passing each other in the wide, calm channel on their way to and from oil refineries.

TIM DELLAPENNA: Right here. This toolbox right here.

HERSHER: Tim Dellapenna is an associate professor of marine science and oceanography at Texas A&M. He's leading this expedition today, and he says after Harvey, a lot of mud ended up in this channel.

DELLAPENNA: The Port of Houston's saying that they had up to 10 feet of storm layer deposited in the ship channel. And then I - that had us going, well, we need to go up there and sample that as soon as we can. And that's why we're here.

HERSHER: The plan is to go to shallower parts of the channel and use winches and straight-up muscle to sink long tubes down into the mud then compare what's in the different layers. They think they might find pollution from things upstream.

DELLAPENNA: And, specifically, we're downstream from where the big dioxin pits are for the Superfund site.

HERSHER: That's the San Jacinto Waste Pits Superfund site, contaminated with toxic dioxin since the 1960s. It's already polluted the channel before, and now they're worried Harvey has made things worse. And it's not just old industrial sites. Some of the largest petrochemical facilities in the world line the channel. Many of them were affected by the storm.

DELLAPENNA: We're actually going to do a full screening for dioxins, heavy metals, polyaromatic hydrocarbons, called PAHs.

HERSHER: There are houses along the channel, too, which is one reason contamination here is a public health issue. People live here.

DELLAPENNA: OK.

HERSHER: The actual sampling is harder than it sounds. Their little boat has to dodge enormous ships.

CRITIDES: We're going to go a little faster.

HERSHER: And the team is concerned that the new sediment layer might be too soupy to stay in the tubes. They stop to take a sample in a shallow area surrounded by active oil wells.

DELLAPENNA: Ready? OK. Dellapenna and Critides lean over the side of the boat and sink a clear plastic tube deep into the mud.

CRITIDES: This mud is pretty soft.

DELLAPENNA: Is it coming? Yeah, it's coming. OK. You're good.

CRITIDES: Wow. Look at that. It's pretty.

DELLAPENNA: This is the storm layer right here, the light-colored stuff. That's still oxidized. That's the flood layer that we have here in this core.

HERSHER: The sandy mud left by Hurricane Harvey is about 6 inches deep here. Critides saws off the extra end of the tube, labels it, and the team moves on to the next area, making their way up the ship channel. At the end of the day five of these teams will go back to Galveston, where they'll be divided up and toxicologists will start analyzing what's in the layers. The whole process will take a few months. Rebecca Hersher, NPR News.