Grandma Li cried so much that she was out of breath when she said this, and the mother of the child in the next bed was even more excited, and the doctor used a sedative to stabilize the child's mother's mood.

Dr. Zhang, director of the neurology department, whispered to the police officer Xiao Li to report the situation, "These two patients are two children who have died of biogas poisoning, and because they were not sent to the hospital, I can't see the symptoms, so I can't determine the cause of death." ”

Police officer Xiao Li: "Our police have sent people to do a scene investigation and case investigation, the two deceased have been transported back to the police forensic center, there will be a forensic doctor to conduct an autopsy on the deceased, if you need help from the hospital, we will contact you again." ”

Although the conversation between the doctor and the policeman Xiao Li was small, it was still heard by the child's father who was accompanying him.

The child's father was emotional and shouted, "How can it be biogas poisoning?" I don't have a biogas digester at home, where does the biogas come from? My two children are all wounded, they must have been killed by someone, you police and doctors can't just ignore people's lives and settle the case hastily! ”

The family members were emotional, and Gu Yanan and Lu Li stood outside the ward, already hearing the ins and outs of the matter.

Seeing this, Lu Li whispered beside Gu Yanan, "The patient was determined by the doctor to be poisoned by biogas, and the child is likely to be, but the parents said that there is no biogas digester at home, and they don't know what the specific situation in their home is and what conditions they have for biogas production." ”

"After a while, we will go to the patient's home to conduct an on-site flow survey to figure it out, and now we will first collect blood from two patients and let the colleagues in the laboratory do a biogas poison test in the blood."

The sound of Gu Yanan and Lu Li talking quietly alarmed the policemen Xiao Li and Doctor Zhang in the ward.

Dr. Zhang often came into contact with people from the CDC, knew Gu Yanan and Lu Li, and when he saw someone from the CDC, he was busy, "Director Gu came too timely, and the patient was diagnosed with biogas poisoning after clinical symptoms, but the patient himself felt that it was not, so we need laboratory confirmation evidence, and you CDC will help to do an analysis of biogas poison in the blood." ”

Gu Yanan instructed Lu Li to collect blood samples from the two patients.

The policeman Xiao Li also came to Gu Yanan, "sister-in-law......"

The title of "sister-in-law" has not been fully spoken, and the policeman Xiao Li hurriedly changed his words, "Director Gu, your Occupational Health Department of the CDC can do on-site biogas poison analysis, our police just received a case, suspected to be related to biogas poisoning, can you borrow your people to go to the scene?" ”

Gu Yanan understood what the policeman Xiao Li meant, and it just so happened that she was also going to the patient's home to conduct on-site investigation and help the police test the biogas poison at the scene, just by the way, "Okay, when do you go to the scene, our on-site flow transfer from disease control will be with you." ”

——

Deep in the Yuntai Mountains, Yuntai Village.

The second day after the death of Li Dashan and Li Xiaoshan.

At noon, the sun was shining brightly, and the temperature in Yuntai Village was close to 35 degrees Celsius.

The CDC's on-site flow shunting and the police's on-site investigation police car were parked at the entrance of Yuntai Village.

Nan Hanfei has already led a team to conduct an autopsy and investigation visit in Yuntai Village in advance.

A cordon was set up near the homes of the deceased Li Dashan and Li Xiaoshan, and there were many onlookers around them.

The group of disease control led by Gu Yanan carried a poison gas analyzer and a sampling box, and provoked a cordon to enter the scene of the crime.

The deceased's home is a typical Yuntai mountain house structure, a single-storey civil structure house distributed in the shape of an inverted "concave", with a kitchen in the middle, and a bedroom and a cowshed on both sides of the kitchen, and the place where the deceased died is in the cowshed.

It's a hot day, and there is a pungent smell coming from the cowshed.

Gu Yanan wore a gas mask and carried a poison gas analyzer into the cowshed, and found that there was a large amount of cow dung on the ground of the cowshed, which was covered with a thick layer of straw, and the environment in the cowshed was relatively closed and the air was not circulated.

A large amount of organic matter in a high-temperature confined environment, which already has the basic conditions for biogas production.

The toxic gas detector was activated on site, and harmful gases such as methane, hydrogen sulfide, and carbon monoxide were detected in the cattle shed.

After getting the test results, Gu Yanan withdrew from the cowshed, stood in the yard, and said to Lu Li and the policeman Xiao Li who were following him, "There is indeed biogas in the cowshed, according to the current gas composition, if someone is exposed to it for a short time, there will be symptoms of dizziness, nausea and vomiting like Mrs. Li's, and if you contact it for a long time, you will be in a coma." After the investigation of this case is completed, the cattle shed should be cleaned up, and at the same time, safety education should be carried out for other families in the village to eliminate the conditions for natural biogas production, otherwise similar poisoning incidents will occur. ”

Nan Hanfei also visited and completed the investigation, returned to the scene of the crime, and saw Gu Yanan and other disease control personnel, and the policeman Xiao Li hurriedly reported the situation of the disease control investigation to Nan Hanfei.

Nan Hanfei came to Gu Yanan's side and wanted to see the report sheet in Gu Yanan's hand, Gu Yanan happily handed it to Nan Hanfei and explained: "There is biogas in the cowshed, and the biogas contains toxic gases hydrogen sulfide and carbon monoxide. ”

Police officer Xiao Li said on the side the news he had just received from the forensic doctor, "Forensic autopsy: the deceased Li Dashan, male, 6 years old, had punctate hemorrhage under the ciliary membrane in both eyes, rice grains overflowing between the nasal cavities, a little white mucus flowing out of the corners of the mouth, cyanosis of the lips and ten nail beds, different degrees of subcutaneous hemorrhage on the left occipital, left forehead, and above the left eyebrow arch, and varying degrees of epidermal detachment on the outside of the left eyebrow arch, left lip corner, right earlobe, and right mandible.

The deceased Li Xiaoshan, male, 4 years old, was found on the body and was similar to the deceased Li Dashan.

The autopsy of the two deceased was basically similar, the blood was dark red and non-coagulated, there was no obvious bleeding in the muscular layer at the neck injury, there were no fractures of the thyroid cartilage, cricoid cartilage and hyoid bone, the trachea was completely filled with a large number of rice grains, reaching the deep part of the trachea, the gastric contents were consistent with the endotracheal filling, forming a filling shape, the surface of the heart and lungs was spotted with hemorrhage, and the bleeding point at the apex of the heart was fused into a piece.

Trace amounts of evidence were collected from the neck injuries and fingernails of the two deceased and sent for examination, but no DNA was detected.

The results of routine poison tests for the deceased's heart blood and gastric dissolved substances were negative. ”

Police officer Xiao Li said a bunch of forensic test results, Nan Hanfei combined the results of the investigation and the results of the on-site poison gas test of the disease control, and began to analyze the cause of death, "The cause of death of the two deceased ruled out homicide, the deceased was impaired by consciousness after inhalation of biogas poisoning, and the deceased still had respiratory activity after biogas poisoning, and when the irritating reflexes such as coughing disappeared, a large number of gastric contents were continuously vomited and regurgitated into the respiratory tract, causing trachea blockage and causing suffocation death." ”

Gu Yanan listened to what Nan Hanfei and police officer Xiao Li said, and also understood the general process of the case, Nan Hanfei and several other policemen began to reconstruct the scene, roughly restoring the process of the case.

The parents of the deceased went out that morning, and the two deceased felt sleepy after playing until lunchtime and returning to the kitchen to eat.

Because the bedroom door was locked, they could not enter to rest, and it was the time when the sun was at its strongest at noon, so the two deceased chose to rest in a relatively shady cowshed.

As the temperature rises, the biogas fermentation process in the barn is accelerated.

The two deceased were in a location with poor air circulation, and the deceased was a child, who was more sensitive to toxic gases, which eventually led to the deceased's biogas poisoning, inhaling a large amount of gastric reflux in a coma, resulting in suffocation and death.