Air testing: scientific instruments can't replace "sniffs"

News background
Many years ago, there was a classic movie "Smell the Scented Woman" that touched countless fans. The memorable one in the play is not only a gorgeous tango dance, but what is more impressive is that Al Pacino played. The blind-eyed protagonists perceive the good things in life by relying on the superior sense of smell.

While watching the movie, perhaps many people think this is just a romantic story. "Smell smells people" is just a legend. However, what people do not know is that there are people around us today. Their profession is to use the nose to score points for our living environment and to constantly monitor the quality of the environment. However, unlike Al Pacino's smells, their noses are mainly used for "smelling smells" in their work. They are professionally referred to as "sniffs" and there is also a popular term called "smell smeller". .

It should be said that until today, the “sniffer” career is still mysterious and strange to the general public. Recently, the reporter walked into the Liaoning Provincial Environmental Monitoring Experimental Center and conducted a detailed understanding of the nature and tasks of the “Official Distinguishing Division”, and opened its mystery to readers.

Scientific instruments can't replace people's nose

"The task of the sniffing division is to fight the odorous pollutants in the environment." Dongming, a sniffing expert who worked for many years in the provincial Environmental Monitoring Experimental Center, told reporters.

Malodorous pollutants are all gaseous substances that stimulate the sense organs, cause unpleasantness, and damage the living environment. Of course, the odor contaminants here are not just odorous gases.

"Even if it is aroma, if it is too strong and affects the production and life of people around it, it must be counted as odor pollutants," Dongming said.

Odorous substances can cause nausea, vomiting, headaches and other symptoms to the stricken person. In severe cases, respiratory diseases can occur and endanger human health. In recent years, the concept of people’s lives has been transformed and promoted. They are more concerned about the environment and have higher requirements. The odor pollutant is a kind of public pollution and it is included in the world's seven major public hazards.

However, perhaps many people do not expect that today's advanced technology is still difficult to complete the detection of odor concentrations in modern instruments and equipment.

According to the "Emission Standard for Odor Pollutants," the odor pollutant control indicators include ammonia, trimethylamine, hydrogen sulfide, methyl mercaptan, dimethyl sulfide, dimethyl disulfide, carbon disulfide, styrene, and odor concentration. If the use of equipment, equipment, generally only measured the first eight single gas concentration indicators, the concentration of the ninth comprehensive odor is difficult to judge by the instrument.

"This requires sniffers to use olfactory experiments to test and determine the level of odor pollution." Dongming said, "In fact, people's sense of smell is more sensitive than the instrument to a certain extent, for trace odors, Sometimes even high-precision instruments cannot be measured, but trained professionals can smell it.”

The stench is a kind of sensory public hazard. It will bring unpleasant feelings and psychological reactions to people. Subjective factors are very strong. The odor pollution must not only rely on analytical instruments to come up with data, but also rely on human perception to evaluate and judge.

Therefore, sniffers are irreplaceable occupations for advanced machines. Sniffing and sniffing is currently a common international method of judging odor pollution.

How sniffers work

Speaking of this, you may think that the sniffers must be walking around the city every day and using their noses to find a source of urban smells.

Tung Ming said: "In fact, sniffers do not always have to go to the scene. In many cases, they collect stench and conduct identification and analysis in the laboratory."

In order to understand the complete process of smelling and smelling, on August 4, the reporter went to the Shenshuiwan Sewage Treatment Plant to collect odors and started a “sniffering trip” with the provincial Environmental Monitoring Laboratory.

At the edge of the Shenshuiwan Sewage Treatment Plant, Zhang Yiping, a member of the Provincial Environmental Monitoring Experimental Center, took out the sampling bottle to collect air. The reason why the gas is collected at the outer edge of the sewage treatment plant is that it can more effectively judge whether the sewage treatment plant has had a bad influence on the surrounding environment.

The staff then sent the collected gas samples back to the Provincial Environmental Monitoring Experimental Center. In the laboratory, the staff used sample injectors to draw gas from the sample bottles and inject them into 6 air bags at a certain dilution ratio. At the same time, they injected clean air into the 12 air bags. Each division sent 3 airbags and began sniffing work.

The olfactory division judges which air bag contains odor. After the olfactory discrimination is over, the next level dilution experiment is performed. The sniffing olfactory skeptics will be “eliminated out”. Repeat this cycle until all sniffers do not smell the odor and end the entire sniffing process. Finally, the sniffers summarize the results and calculate the odor concentration of the sample based on the formula specified in the test standard.

Tung Ming said: "In order to ensure that the sniffing results are more objective and accurate, the highest and lowest values ​​of the 6 sniffers will be deducted, and the rest will be weighted, and then the calculated results will be compared with the national odor standard if high. The national odor standard indicates that the odor in the air at the gas collection site exceeds the standard, and the environmental supervision department will order the relevant units to treat the odor source."

In the course of the experiment, there are special requirements. For example, sniffers cannot use any cosmetics, and even before the experiment, they cannot wash their hands with scented daily chemicals such as soap.

According to the regulations, if there is a task, the sniffing division should ensure that there are no colds and other diseases that affect the sense of smell. There are also many taboos in the daily diet. If you do not eat spicy, fried foods, avoid using onions, ginger, garlic , pepper and other spices and so on.

How did sniffers work out?

It is understood that the selection of sniffers has very strict procedures and that no one can be an olfactory judge.

The sniffing work is of course the protagonist from the nose. Therefore, how the sense of smell becomes a determinant of whether a person can work as a sniffer.

So what kind of nose can you have to be an olfactory judge? The answer may surprise you, that is, you must have a very "normal" nose.

"Because the smell of the sniffers must be representative of the general public's perception, it is not feasible to be too sensitive and insensitive, and it is necessary to take the median value," explained the olfactory practitioner Tung Ming. "The sniffing division's nose should not only be common enough, Sufficient to be "civilized" and healthy enough that a few problems with the olfactory organs are not suitable for olfactory work. For example, patients with rhinitis must be excluded from this work."

After the olfactory test is passed, a series of special trainings are also required. After passing the examination, the qualifications can be obtained.

The National Key Laboratory of Environmental Pollution Malodor Pollution Control in Tianjin is the national olfactory trainer training base. Most of the domestic sniffing experts are from here.

Dongming and her colleagues are the first sniffers in the province to attend training and obtain qualification certificates. Dong Ming told reporters that in the training to pass the theory test, the more critical is the on-site examination. In a well-ventilated, air-clean room, the examiner sent candidates several white slips of paper, including pieces of paper soaked in clean liquid, as well as odor soaks. Candidates must give correct judgments and tell them what the reason is. Odor. If you answer correctly, you are eligible to continue testing in the next room.

The content of the examination is also very interesting. It requires the examinee to distinguish the tastes of five substances, namely, floral, sweaty, sweet, ripe fruity, and odor-smelling.

"If you smell a slip of paper in the nose test, you will be brushed off." Dong Ming said, "The acquisition of the olfactory qualification requires a lot of clearance, and the olfactory qualification and university graduation certificate are for life. The usefulness is not the same, it is valid, and generally the validity period is 3 years." In addition, there is a limitation of age in the work of sniffers. In principle, it is not more than 45 years old because people's sense of smell will change with age. Decline in growth.

In the past, there were only several sniffers in the Provincial Environmental Monitoring Experimental Center in our province. Now that environmental protection is getting more and more important, the team of sniffers is also expanding. Environmental monitoring stations in Shenyang, Dalian, Fushun and Jinzhou are all Send people to participate in sniff training. At present, the number of people obtaining qualifications for sniffers in our province has increased to nearly 50 people.

From a national perspective, the number of sniffers in the past two years is also increasing, but even so, sniffers are still a very “niche” crowd, and even the majority of people in society still do not know that there is such a Occupation.

In fact, most sniffers do not do the job full time. They also perform other tasks in the environmental monitoring department.

Extended reading

The task of “smell odors” varies from country to country. In the world, the United States, Britain, the Netherlands, Belgium, Japan, and other countries all have “smelly odors”.

The mission of the United States “Smell Odor” is to walk through the bustling crowd every day, smell the odors emitted by pedestrians, and provide information for human body taste experiments.

The “smell smeller” in the Netherlands lived in the sheds on the edge of the industrial area and residential areas. From time to time, it sniffed out the window and monitored the air pollution.

Japan's “Smell Odor” has a job that specifically smells the smell of public toilets. Once odors are found to be excessive, managers must be notified to deodorize within a limited time. If the "smell smeller" recruited by the Tokyo environmental protection agency finds unusual smells in subways, stations, public toilets, etc., he must immediately report to the environmental protection authorities and instruct the relevant parties to deodorize in a limited time.