Lin Xiaoxiao likes this atmosphere of academic discussion.

Although the discussion was inconclusive at the end, several possibilities were listed, which really helped to focus on the on-site flow survey.

Li Bai circled a few key points on the whiteboard with a pen, "These aspects are what we should focus on when we conduct on-site investigations, okay, now let's go." ”

The emergency response team and two interns loaded the things needed for on-site sampling on-site on-site shunting and rushed to Fenghuang County People's Hospital first.

——

Fenghuang County People's Hospital.

The road was slippery on a snowy day, and by the time the municipal disease control emergency team arrived at the county people's hospital, it was already more than 2 o'clock in the afternoon.

The personnel of the county disease control site received Li Bai's notice and rushed to the county hospital in advance.

The director of the emergency department of the county hospital who reported the epidemic received Li Bai and his party.

Several poisoned patients were placed in a ward.

First look at the patient's medical record, and then look at the patient's specific symptoms in the ward.

What can be seen at a glance is the patient's skin symptoms.

Lin Xiaoxiao had only seen the symptoms of arsenic poisoning patients in textbooks before, but she didn't expect to see real patients for the first time when she came to the CDC internship, which was still different from the pictures in the book, and she felt slightly shocked.

All four patients had rice-like grains on their skin.

The nails also have off-white horizontal stripes.

The patient, Zhang Cui, had a nosebleed and a lump of cotton in her left nostril.

Just as Lin Xiaoxiao was staring at the patient to see the symptoms, Li Bai had already begun to ask the classic soul three questions.

Depending on the cause of the epidemic, the three questions of the soul are also different.

If it is a viral or bacterial infectious disease, the three questions of the soul are generally as follows: Where did you come from, where did you go, and what did you come into contact with?

If it is a poisoning incident, the three questions of the soul will become: Where have you been, what have you eaten, and what have you used?

However, Lin Xiaoxiao feels that all the tunes can basically be summarized into three general soul questions: where did you come from, where did you go, and what did you come into contact with?

Even if it is a poisoning incident, then the poisoning method may be divided into air contact, food intake, skin and mucosal contact, etc., which can be classified as what has been exposed.

At the end of Li Bai's three questions on his soul, he summarized the epidemiological history of the four patients.

The four are all villagers of Fenghuang Village, and their activities have been limited to Fenghuang Mountain since the beginning of winter.

Occasionally, I go to the Yamashita Market to buy some daily necessities.

The villagers are all tea farmers by profession.

There has been no recent action to spray tea plantations with pesticides.

There are also no metal smelters near Phoenix Mountain, and there is no contact with arsenic-related manufacturing.

However, in daily necessities, enamel products containing arsenic are not excluded.

The daily water source is the deep water wells of the house.

There is also a habit of burning coal in the patient's home.

In the autumn and winter, all 4 patients had headaches and brain fever symptoms and had taken medicines, but the types of medicines were different.

Judging from the flow data just asked, many common arsenic poisoning factors can be ruled out, but there are also many other clues.

The next thing to do is to go to the patient's home for on-site investigation, which is also the most important part of the on-site investigation.

——

Phoenix Village on Phoenix Mountain.

Because of the heavy snowfall just now, the road to Phoenix Mountain is extremely difficult to walk.

From the county people's hospital to the foot of Phoenix Mountain, it took more than an hour to drive.

The road up Phoenix Mountain is steep and covered with snow, so cars cannot enter, and the CDC group can only get out of the car and walk.

Carrying sampling boxes, air samplers and other on-site sampling tools, I stepped on the snow-covered bluestone road from the foot of the mountain to Fenghuang Village halfway up the mountain.

The most important targets of the on-site investigation were the homes and surroundings of the four patients, but other villagers in Fenghuang Village also had to be examined.

In order to prevent the villagers from having symptoms of arsenic poisoning but not going to the hospital, the CDC team also had to conduct physical examinations on other villagers.

First, find the village chief of Fenghuang Village, and he will inform all the villagers of Fenghuang Village about the purpose of the CDC's visit, and inform the villagers to wait for the CDC to go for a physical examination and check the surrounding environment of their homes.

As for the four patients who have been hospitalized, the village cadres led the disease control personnel to open their doors and enter the examination.

Li Bai also divided the city's CDC emergency team and the Fenghuang County CDC on-site dispatch personnel into two large action groups, one group led by Li Bai went to the homes of four patients, and the remaining group conducted physical examinations on all the villagers.

On the edge of the cliff, Li Jianguo's home.

The snow in the yard had not been cleared, leaving only a few rows of stray footprints.

In addition to the 5 main houses, there are also two east and west wings, and two people live here, which is very spacious.

Yu Fei, Gao Meng, and two interns followed Li Bai's group.

Gao Meng walked around the courtyard and shook his head, "In such a big place, it takes a lot of time to collect all the external environmental specimens. ”

Yu Fei had already squatted on the ground to open the sampling box, and skillfully took out all kinds of materials needed for on-site sampling, "Then speed up, it's almost dark, otherwise it will be affected when you go down the mountain." ”

There are three major elements of off-site environmental sampling: air, water, and soil.

Soil collection is easy to say, multi-point distribution collection is enough.

The air is collected by a special air sampler.

As for water, because Li Jianguo's family's drinking water mainly comes from their own deep wells, they have to turn on the deep well pumps to pump groundwater.

In the southwest corner of the courtyard, there is a deep well with a round mouth with a diameter of no more than 20 centimeters.

The wellhead is covered with stone slabs, and a water pipe exits the ground through a round hole in the stone slab.

The water pipe leads directly to a cement pool next to the well.

There is a washboard in the pool.

Yu Fei wanted to collect water samples, but couldn't find the well switch.

Deep wells like this one generally have a motor pump to go deep into the bottom of the well, and the switch must be found to pump the water out.

Fortunately, there were village cadres with him, and he opened the door of Li Jianguo's kitchen, where there was an electric switch, and when he reached out and pushed the electric switch, water came out.

The village cadres said, "Every household in Fenghuang Village now has a well, this kind of deep water well was drilled by the construction team invited by the village a few years ago, and tap water was used before, but because the terrain is too high and the water pressure is not good, then a tap water pool was built on the top of the mountain, and because it is too troublesome to divert water, it was changed to deep well water." ”

It's freezing outside, but the groundwater pumped out of the deep well is steaming.

The well water was pumped out of the pipe and into the nearby pool, and the mist drifted away.

After collecting water samples and entering the kitchen, Yu Fei found Li Bai looking around the extinguished coal stove.

Li Bai was also followed by Lin Xiaoxiao, and Yang Yufeng stood next to Lin Xiaoxiao.

"Could it be a problem with coal?" Lin Xiaoxiao expressed his opinion, "I see that Li Jianguo has a lot of coal stored in the backyard shed, according to the village cadres, every household in Fenghuang Village burns coal, and the villagers' illness is likely to be related to coal burning." However, the village cadres also said that their village has a long history of burning coal, and it did not get sick in the past, so why did some villagers suddenly get sick this year? I thought about it for a while, and it may have something to do with the source of coal, so I should ask where the villagers who spent the winter this year bought the coal from. ”

Yang Yufeng was puzzled and asked: "Isn't there obvious endemic to coal-fired arsenic poisoning?"

"It is local, and in our country mainly occurs in Guizhou, Shaanxi and other provinces, their arsenic poisoning is related to the local burning of coal arsenic content exceeds the standard, and most of these arsenic content exceeds the standard of coal mines from their local area, if there is this kind of substandard coal is transported to us, and the villagers buy and burn the use, then the possibility of arsenic poisoning is very large. ”

Lin Xiaoxiao's point of view coincides with Li Bai's thoughts.

Li Bai looked approvingly, and ordered, "Collect some coal and coal ash samples, and collect a little dust around the kitchen." ”

Most of the dust on kitchen furniture is dust from coal stoves, and people who live here for a long time inhale a large amount of this dust, and it makes sense to collect these dust samples for testing.