There are two fishing docks on the Nam Wan River and a cruise ship dock under construction.

Nan Zhiqiao and his party drove to the fishing boat wharf in the upper reaches of the Nam Wan River, intending to get off the car and board the boat there.

The CDC's field investigation vehicle followed the riverside road, passed through the town of South Bay, and stopped at the fishing boat wharf in the westernmost part of the town.

This fishing dock has a history of more than 100 years, and it has been rebuilt several times before it becomes what it is today.

The fishing boat pier is not large, and large and small fishing boats are busy coming in and out.

In the open area around the pier, many small trucks carrying seafood are parked.

The CDC's on-site investigation vehicle has a clear "CDC" sign on it, and it is very conspicuous when it is parked in a group of small trucks.

Getting off the scene investigation car, Ye Zhenzhen habitually checked the surrounding situation.

Many vendors around were surrounding the fishing boat that had just returned, in a noisy environment, Ye Zhenzhen felt the unique atmosphere of the coastal estuary wharf, smelling the humid air full of fishy smell, and suddenly, a black cat jumped out from behind.

The black cat that suddenly appeared came out of the green belt of bushes on the side of the pier.

The black cat walked unsteadily, swaying along the dirt road, hunched over its back, its limbs trembling and spasming.

I don't know if it was the smell of fish in the dock that attracted the black cat, or something else in the river, the black cat swayed to the edge of the dock bank.

"Plop!"

The black cat jumped into the water and committed suicide!

The sound of the black cat falling into the water was not obvious in the noisy dock environment, and it did not attract anyone's attention except Ye Zhenzhen.

"Senior Nan, there is a cat that committed suicide. ”

Ye Zhenzhen pointed to the corpse of the black cat drifting in the river, Nan Zhiqiao was carrying the sampling box at this time, and saw the black cat that had just jumped into the river, Nan Zhiqiao immediately said to Xiao Gong behind him: "Quickly salvage the black cat corpse." ”

Xiao Gong held a fishing net in his hand, which was originally used to collect aquatic specimens in the river, which came in handy at this time.

Standing on the shore of the pier, he fished up the corpse of the black cat that had not drifted away.

The black cat soaked in water, its fur was wet and sticking to its body, and its bony torso was slightly stiff.

Xiao Gong touched the black cat's corpse with gloves, "This cat is too thin, it lives near the fishing boat dock and will not lack food, but it is still so thin, is it sick?"

Nan Zhiqiao opened the sampling box, took out the sampling bag, and sealed the black cat corpse.

Xiao Gong watched Nan Zhiqiao finish his work, and asked curiously, "Director Nan, this cat will also be brought back for testing?"

"Well, the animals near the Nam Wan River are also the test subjects, and this cat lives nearby, and there are symptoms, so it is the focus of the test subjects. ”

Xiao Gong: "Oh, I remember, when Minamata disease in Japan, there were many poisoned cats who committed suicide by jumping into the river, and the situation is very similar to now. ”

Nan Zhiqiao: "Pay attention to the vicinity of the riverbank, if there are dead birds, dead dogs and other animal carcasses, they are also collected. ”

"Okay, we'll take notice. ”

——

In the river channel of the fishing boat wharf, an environmental monitoring boat is parked.

The outer surface of the ship is painted with several obvious big characters "Lianhai City Environmental Monitoring", the length of the ship is more than 20 meters, the width is about 5 meters, and the height is about 8 meters, which is divided into two layers, with a wheelhouse and a laboratory.

Nan Zhiqiao, Ye Zhenzhen, Xiao Gong, and two staff members of the Environmental Protection Bureau, a group of five people boarded the monitoring boat.

The monitoring vessel sailed slowly in the Nam Wan River, selecting sampling points at intervals.

Around the sampling point, the monitoring boat stopped, and everyone took out the sampler, sampled, bottled, labeled, and boxed.

More than two hours later, the monitoring vessel entered the Nanwan estuary wetland.

The monitoring vessel passed through an open body of water, startling a flock of waterfowl.

A flock of waterfowl flies, leaving two white waterfowl carcasses on the surface of the water.

Ye Zhenzhen's eyes were sharp, and she beckoned the driver to go near the carcass of the water bird.

After the carcasses were fished out of the river, an EPA staff member sealed the carcasses in bags and packed them into boxes.

Xiao Gong casually asked the staff of the Environmental Protection Bureau: "Do you usually have so many dead birds?"

"There are also dead birds, but in the last six months, the number of dead birds has increased a bit. ”

Xiao Gong: "This may also be caused by mercury poisoning." ”

"In our environmental water sample monitoring, mercury is a routine monitoring item, and the water quality of the Nam Van River has been no problem recently. ”

Xiao Gong also began to wonder, isn't it the problem of the water quality of the Nanwan River?

Nan Zhiqiao suggested on the side: "The water quality sampling points for environmental monitoring are all fixed, and we should increase the sampling points this time, and the shallow sea waters at the mouth of the Nanwan River should also be sampled." ”

After passing through the Nanwan Estuary Wetland, it enters the shallow sea waters of the estuary.

Seawater sampling is different from freshwater sampling, and after more than an hour of operation on the water in the shallow sea area, the specimens of marine organisms such as seawater, seaweed, and marine fish are all collected, and the monitoring ship returns home.

Back at the fishing boat wharf in the upper reaches of the Nam Wan River, everyone carried the collected samples off the boat and put them into the back compartment of the disease control vehicle parked in the parking lot of the wharf.

After sampling the Nanwan River, Nanzhiqiao also has to collect groundwater from Nanwan Town.

The staff of the Environmental Protection Bureau was a little embarrassed and explained to Nan Zhiqiao: "There are 45 groundwater monitoring points in Lianhai City, 29 shallow groundwater monitoring stations, 16 medium and deep groundwater monitoring stations, and there are only two monitoring stations in Nanwan Town, and they are all shallow water monitoring stations, which automatically collect water level, water temperature, and water quality information, and send it to the configuration sub-center through the GPRS channel, and the automatic monitoring items do not include mercury detection." ”

Xiao Gong: "What we want to check this time is mercury, and we can't monitor it automatically, so we will take samples manually, aren't they just two monitoring stations?"

Two shallow water monitoring stations are located around Nanwan Township, one in the upper reaches of the Nanwan River, which is to the west of Nanwan Township, and the other in the lower reaches of the Nanwan River, which is east of Nanwan Township, near the Nanwan Estuary Wetland.

It was very simple to collect water samples from the monitoring well, and when it was close to noon, all the samples were collected, and the group returned to Lianhai City by the same route as they were in the disease control on-site investigation vehicle.

The two groups of people were sampled separately, and the samples collected were also tested by the division of labor between the two units, the Environmental Protection Bureau was responsible for water sample testing, and the Center for Disease Control and Prevention was responsible for human specimen and food testing.

The test results soon came out, and in the environmental samples, the water quality between the wetland from the upstream to the downstream estuary of the Nam Wan River was normal, and when the Nam Wan River entered the estuary wetland, the water quality exceeded the mercury standard in the criss-crossed rivers in the wetland, and the algae, fish, shrimp and shellfish in the wetland also exceeded the mercury standard.

Mercury levels also exceeded the standard in the shallow waters of the Nam Wan estuary, with mercury levels decreasing to normal levels as the distance from the estuary progressed.

More than 400 people in the urine and hair and blood samples of the CDC have found excessive levels of mercury in their samples, more than 100 people show initial symptoms of mercury poisoning, and more than 20 people are hospitalized.

In the food test, the mercury levels of basic household foods such as rice, oil and salt in residents' homes were all at normal levels, and some types of fish, shrimp and shellfish eaten by fishermen had excessive mercury levels, and these foods with excessive mercury were all salvaged from the vicinity of the Nam Wan estuary.