As soon as the test results came back, members of the entire mercury poisoning emergency response team came together to analyze the source of the contamination and discuss countermeasures.

Nan Zhiqiao, Ye Zhenzhen, Liang Lei, Xiao Gong, Xiao Zhao, and two staff members of the Environmental Protection Bureau gathered in the conference room on the top floor of the main building of the Lianhai CDC.

Xiao Gong took the test report and was the first to start analyzing: "It is certain that the Nanwan River is polluted, but this polluted area is very strange, the water area with excessive mercury only starts at the mouth of the lower reaches of the Nanwan River, the entire estuarine wetland, and the shallow sea area of the estuary." ”

Xiao Zhao continued: "Mercury-contaminated aquatic products are also mainly concentrated in the lower reaches of the Nam Van River and the estuary area, but there are no chemical factories there, so what is the source of pollution?"

A staff member from the Environmental Protection Bureau, in his 40s, wearing a pair of black-rimmed glasses, surnamed Zhuang, known to everyone as Section Chief Zhuang, also participated in sampling the Nanwan River at that time, and Section Chief Zhuang followed Xiao Zhao's words and said: "There are four factories in the upper reaches of the Nanwan River, and the environmental protection department will do regular testing of the sewage from chemical plants, and there is no problem." ”

Xiao Gong frowned and speculated, "Could it be that the chemical plant secretly discharged toxic industrial wastewater into the Nanwan River when your environmental protection department was not inspecting?"

Another staff member of the Environmental Protection Bureau is a young man in his twenties, Section Chief Zhuang calls him Xiao Zheng, who looks a little similar to Liang Lei, with a strong figure and a darkened complexion, Xiao Zheng retorted to Xiao Gong and said: "No, if they discharge toxic industrial wastewater, then the entire Nanwan River will be polluted, how can only the section of the estuary be polluted?"

Xiao Zhao also echoed and said: "Yes, those chemical factories will never pack the daily industrial wastewater, send it to the lower reaches of the Nanwan River and then dump it, which is too troublesome, and it comes and goes like this, the target is big, and it is easy to be discovered." ”

Xiao Gong: "Maybe the chemical plant used other methods to get the wastewater downstream, but we haven't thought of it yet." ”

As a colleague in the same unit and the same department, Xiao Zhao stared at Xiao Gong and asked rhetorically: "Gong Fang, why do you always suspect those chemical plants?"

Xiao Gong replied confidently: "Because they have a criminal record, have you forgotten about the previous two years?"

Xiao Gong's "antecedent" is that two years ago, a factory manufacturing electrical appliances in the upper reaches of the Nam Van River discharged untreated industrial wastewater directly into the Nam Van River, and this industrial wastewater contains a variety of heavy metal elements, and the wastewater also emits a foul smell.

The wastewater flows directly into the Nam Van River along a small ditch outside the factory.

The water in the waste ditch glows pale green and emits a foul smell.

The electrical appliance factory is five or six hundred meters away from the river bank, and the waste water flows into the Nam Wan River along the half-meter-wide waste water ditch.

When a resident of a small town went fishing in the upper reaches of the Nam Wan River, he found that the surface of the river where the wastewater was flowing was a strange blue and green color, and after going ashore, he found a waste ditch hidden in the gravel and soil, and the finder reported the situation to the local environmental protection department.

After receiving the report, the environmental protection department investigated the electrical appliance factory and found that the wastewater of the factory was discharged directly without treatment, and the production process used mercuric chloride and mercury sulfate as catalysts, and the production process was backward, and the wastewater contained a large amount of mercury.

The electrical appliance factory was ordered to suspend production for rectification, improve production processes, and build sewage equipment.

It was not until a year ago that the home appliance factory restarted production after the acceptance of the standard.

Two years ago, the industrial wastewater pollution incident did not have much impact on the environment of the Nam Van River because it was discovered in time, and since then, the chemical plants in the upper reaches of the Nam Van River have been the focus of environmental inspections.

In the past year, there have been no substandard wastewater treatment standards.

Thinking about the incident two years ago, Xiao Zhao looked at Section Chief Zhuang and Xiao Zheng of the Environmental Protection Bureau, who explained: "Since the industrial wastewater pollution incident two years ago, we have stepped up our monitoring efforts, and there is no similar situation in the factories in the upper reaches of the Nam Wan River, so they should have nothing to do with this mercury poisoning incident." ”

Section Chief Zhuang looked at the comprehensive inspection report with a serious face, "Could it be caused by someone dumping garbage in the lower reaches of the Nanwan River, I see that there is a large garbage pile near the estuary wetland." ”

Liang Lei answered the analysis and said: "The garbage heap has always been there, for more than a year, it is the construction waste of the nearby real estate, the relevant departments have contacted the developer, they are ready to clean up in the near future, but the construction waste, there will be no mercury exceedance, and the location of the garbage heap is two kilometers away from the first water quality mercury exceedance point, the construction waste heap will not be the source of pollution." ”

If it's not an upstream chemical plant, it's not a downstream garbage dump, so where will the source of pollution be?

When everyone was at a loss for the source of pollution, they all thought of Nan Zhiqiao, an expert from the national disease control and control.

Nan Zhiqiao didn't say a word at this discussion meeting, and everyone's eyes were focused on Nan Zhiqiao.

At this time, Nan Zhiqiao was looking at the information on the laptop.

Ye Zhenzhen sat next to Nan Zhiqiao, her body slightly sideways, and turned her head to look at the information on the screen of Nan Zhiqiao's notebook.

That's a map of the distribution of groundwater in Lianhai City.

"Senior Nan, do you suspect that there is a problem with the groundwater?" Ye Zhenzhen asked softly.

Nan no Qiao projected the materials from his laptop on the big screen in the conference room through slides.

There are two data maps on the big screen, one is the distribution of residents with symptoms of mercury poisoning, and the other is the distribution of groundwater in Nanwan Town.

Nan Zhiqiao pointed to the two pictures on the screen with a laser pointer, "Do you see any similarities between these two pictures?"

Everyone's eyes were focused on the data map on the big screen, and Ye Zhenzhen was the first to react, exclaiming: "Residents with symptoms of mercury poisoning live around that deep underground water line!"

was reminded by Ye Zhenzhen, and everyone else also understood.

Two seemingly unrelated data maps, linked by mercury poisoning patients.

Liang Lei: "Mr. Nan, the distribution area of this mercury poisoning patient really coincides with the line of deep groundwater, how did you come up with the idea of putting these two maps together? There must be an inevitability in the coincidence, and there must be something wrong with this deep groundwater line." ”

The eyes of the section chief of the Environmental Protection Bureau have been fixed on the groundwater distribution map, and after looking at it for a while, he said: "There are 23 groundwater routine monitoring projects, of which mercury is a mandatory project, and there are 45 groundwater monitoring wells in the entire Lianhai City, of which two in Nanwan Town are not on this deep groundwater line, in the first half of the year, our Environmental Protection Bureau has just applied to build a deep groundwater monitoring well on this waterline, which has been approved, and construction can only start in the first half of next year." ”

Liang Lei: "In other words, we don't have the monitoring data of this deep groundwater, and we haven't collected water samples there. ”

Xiao Zheng: "Well, at present, the monitoring data of groundwater in Nanwan Town are all shallow groundwater, and if you want the monitoring data of deep groundwater, you have to dig wells and sample them again. ”