Recently, the relevant reports on 9 nitrosamines detected in drinking water in China have aroused people's concern about various phenomena of exposure to nitrosamines in life. What are nitrosamines? What about the daily contact? Undoubtedly, it is a matter of great concern to people.
Nitrosamines are a class of organic compounds with the structure of - N - N=O, which have been discovered for more than 100 years. In 1937, Freund reported for the first time two cases of occupational exposure to N-nitrosodimethylamine (NDMA) in the nitrosamine family, and the patient showed toxic liver damage. In 1956, British scientists Magee and Barnes found that, NDMA has a strong carcinogenic activity on experimental animals. Since then, nitrosamines have attracted extensive attention. At present, researchers have found nearly 300 kinds of nitrosamines, and it has been confirmed that 90% of nitrosamines can induce tumors in different organs of animals. The pollutant risk information integration system managed by the US Environmental Protection Agency classifies nitrosamines as B2 carcinogens, that is, substances with insufficient evidence of carcinogenicity to humans and sufficient evidence of carcinogenicity to experimental animals.
Nitrosamines are easily formed by the reaction of secondary amine and nitrite, whether under natural conditions and in the process of laboratory research, or in human and other animals
In order to pursue health, it is essential for people to insist on physical exercise, which requires sports venues. Whether it is a professional or popular sports place, the development of its site materials is always accompanied by the improvement of social and technological level, economic level and sports level. The first materials used for sports track are usually soil, turf, cinder and other types. The U-shaped track of Panathinaiko Stadium for the Athens Olympic Games in 1896 was made of rolled soil, and the athletes' technical exertion was restricted regardless of the surface flatness and soft and hard uniformity; The track of the Paris Olympic Games in 1900 used turf, and it was difficult for athletes to create excellent results because of the soft and sliding on the track; In 1904, the first cinder track was paved at the St. Louis Olympic Games in the United States, and its water permeability and friction were improved. Until the 1960s, the runway materials basically followed the "formula" of mixing coal cinder, sand and lime.
In the late 1930s, German chemist O Bayer and his colleagues developed the synthesis method and processing technology of diisocyanate for the first time. The polyurethane material synthesized by isocyanate, polyol and coordination additives has become one of the fastest growing materials today with its excellent performance and wide range of uses. In 1961, the Minnesota Mining Manufacturing Company (3M Company) of the United States first paved a 200m racetrack with polyurethane materials
Recently, media reported that a jury in Missouri, the United States, ruled that Johnson&Johnson must pay 72 million dollars (about 470 million yuan) to the family of a woman who died of ovarian cancer. The report pointed out that the patient had used Johnson&Johnson baby talcum powder for more than 30 years, and identified the talcum powder in its products as carcinogenic.
What is talcum powder? The main component of talc is magnesium silicate, which can be selected, crushed and dried into talc powder. In the process of talc mineralization, due to different metallogenic conditions in different regions, other ores are often associated in talc ore, such as asbestos components such as serpentine, calcite, dolomite, magnesite and mica.
What is the use of talcum powder? The application of talc related products is often encountered in our daily life. Talc and talc powder are both components of traditional Chinese medicine, and their medicinal value involves diuresis, relieving rheumatism, clearing away heat, removing dampness and astringing sores, etc. Cosmetic grade talcum powder is used for various moisturizing powder, beauty powder, talcum powder, etc; Pharmaceutical and food grade talc powder is used for pharmaceutical tablets, sugar coating, Chinese medicine prescriptions, food additives, isolating agents, etc; Industrial applications involve production fields such as coatings, paints, paper making, plastics, rubber, cables, ceramics, waterproof materials, etc.
Low back pain）， Also called low back pain, it refers to a group of subjective feelings of pain in the lower back, lumbosacral, sacroiliac, buttocks or legs. Lower back pain is a group of symptoms, It is not the diagnostic name of a disease. WHO defines lower back pain as a group of symptoms or syndromes represented by back pain, whose main clinical manifestations are local pain or sciatica, which can affect lower limb activities radially. Research has found that 80% of people have suffered from lower back pain in their life, which is one of the most important causes of incapacity of all occupational groups.
There are many causes of lower back pain, but work-related lower back pain is often related to the following factors:
one Heavy physical load The causal relationship between heavy physical load and low back pain is almost recognized by all researchers.
2. Poor working posture Repeated or static bad posture, such as bending or body twisting, will increase the pressure on the spine and cause uneven stress on the spine, which is the main risk factor for lower back pain.
three whole
(2015-01-13 10:42)
Popcorn, as a kind of puffed food, is deeply loved by many people. It is believed that few people have ever eaten popcorn in their life. I don't know when, watching movies in cinemas and eating popcorn has become a fashion for young people, which has become a ubiquitous scene in modern urban life.
It is believed that eating popcorn while watching movies in cinemas originated from the input of American culture. In the mid-19th century, popcorn has become a household snack in the United States. But at that time, the cinema played silent movies, and the plot was all expressed by subtitles. The audience of the cinema was still in the "upper class society". The audience eating popcorn would make unpleasant noise, and was therefore prohibited by the cinema. In the 1920s, movies entered the era of sound, and sound effects became an important part of movie playing. By the 1930s, the number of Americans who watched movies in cinemas every week had reached 90 million. At that time, the perfect combination of cinemas and popcorn industry had brought significant positive effects to the United States in the Great Depression. People pour into cinemas in search of cheap consumption and entertainment; The popcorn made and sold in the hall there is another kind of complementarity of good quality and low price.
Recently, the media reported that the popcorn sold in supermarkets and cinemas contained lead. In this regard, media reporters bought 6 kinds of popcorn in cinemas and supermarkets respectively
(2014-07-01 10:46)
The media reported that at about 4:50 a.m. on June 30, 2014, an argon leakage accident occurred in Nanjing Iron and Steel Plant, which resulted in the death of three workers. What kind of poison is argon? Why can it quickly kill people?
In 1894, William Ramsay, a Scottish chemist, and his colleagues obtained nitrogen after removing oxygen, carbon dioxide, water vapor and other components from the air sample. When they compared it with the nitrogen decomposed from ammonia, they found that the nitrogen decomposed from ammonia was 1.5% lighter than the nitrogen obtained from air. Although the difference is small, it can indicate the existence of an unknown gas, which is argon.
Argon is the first noble gas discovered by people, and its chemical symbol is Ar. The content of argon in the atmosphere is 0.934% by volume and 1.29% by mass. Argon is an inert gas, which means "inactive" in Greek. Argon, whether gaseous or liquid, is colorless and tasteless, and has no significant toxicity.
Argon is used in many industrial production fields due to its non combustion, non combustion supporting and low heat transfer rate. Argon is stable in nature, generally does not react with any chemical substances, and is often used as various protective gases or gas colors
(2014-02-11 17:50)
According to media reports, Subway, a global fast food chain, has attracted much attention because of its use of azoformamide as a food additive in the production of bread. It is also reported that bread contains rubber sole ingredients, which has caused concern among consumers. After all, bread is a popular food.
In response to this incident, Subway China said that its bread suppliers were Asian and local suppliers completely different from those in North America, and all suppliers in Greater China had confirmed that they had not used this chemical ingredient. Whether Chinese consumers can be sure that they are "lucky" to not eat azoformamide.
In recent years, various baked foods have become an indispensable part of people's daily diet. The protein in flour is mainly composed of glutenin and glutenin. The former is spherical, with good flow and extensibility, but lacks elasticity, while the latter is fibrous and elastic; In order to make the two proteins reach a more appropriate ratio and cross-linking, oxidants need to be added to adjust. In the past decades, potassium bromate has been used in the global food baking industry as a cheap and effective oxidant. The dissolution rate of potassium bromate is slow. With the increase of dough fermentation acidity and baking temperature, it is beneficial to produce elastic bread.
In the 1980s, researchers found that potassium bromate had carcinogenic effect on animals under experimental conditions. In the whole
(2013-11-04 13:24)
Everyone has a love of beauty. With the improvement of people's living standards, cosmetics have become a popular necessity. Especially for women, the daily expenditure of cosmetics is growing rapidly. In recent years, the sales volume of China's cosmetics market has increased at an average rate of more than 20% every year, reaching more than 40% in the highest year. The growth rate is far higher than the average growth rate of the national economy, and has considerable development potential.
There are so many kinds of cosmetics that I forgot to see a star character's description of lipstick in a short article: "If only one cosmetics is allowed in my bag, it is lipstick". This may represent the choice of many women to some extent, indicating that the use of lipstick is extremely popular among women.
Do you know lipstick? Although women do not need to become lipstick experts, they should know some basic lipstick use knowledge, which not only refers to the choice of brand, color and price, but also includes the necessary knowledge of healthy use. For example, in recent years, the media has repeatedly reported that lipstick contains lead, which really makes many people feel embarrassed: "If I use lipstick, my health may be threatened; but if I give up lipstick, my face will be more threatened!".
The media reported that an independent laboratory in the United States sampled 33 brands of red lipsticks in the United States market in September 2007, and the test results showed that 61% of lipsticks contained lead, with the content ranging from 0.03ppm to 0.65ppm, but no lipstick was labeled on the package
(2013-06-18 18:13)
On June 14, 2013, CCTV's "Morning News", "News 30 Minutes" and other columns exposed that several egg processing plants in Nanchang County, Jiangxi Province used industrial copper sulfate to pickle preserved eggs. As preserved egg is a popular food, the safety of eating preserved egg has aroused widespread concern after the program is broadcast.
Can copper sulfate be used to pickle preserved eggs? According to the relevant provisions of the National Food Safety Law, copper sulfate is listed as a processing aid in the food industry to replace lead oxide in processing preserved eggs, which helps to reduce the lead content in preserved eggs. Therefore, enterprises can use the food additive copper sulfate to pickle preserved eggs, but they must use food grade copper sulfate instead of industrial copper sulfate.
What is the difference between industrial copper sulfate and food grade copper sulfate? At present, it is believed that the purity of industrial copper sulfate is not enough, and it may contain harmful elements such as lead, arsenic and cadmium. If it is used to process preserved eggs, it will cause potential harm to human body. It can be concluded that the use of industrial copper sulfate to pickle preserved eggs violates the relevant provisions of the Food Safety Law of the People's Republic of China, which is an illegal act. Therefore, the local government requires the relevant preserved egg production and processing enterprises to stop production, confiscate the copper sulfate raw materials and send them to the authoritative department for inspection, and send the preserved eggs produced by the copper sulfate process for inspection, which is the current remedial measure.
The disclosure of the tainted egg incident was mainly due to the fact that the reporter found the existence of industrial copper sulfate at the production and processing enterprise site. As a regular means of supervision, can the relevant departments start with the detection of preserved eggs to determine which kind of copper sulfate is used by the production and processing enterprises, so as to
(2013-06-04 11:28)
Yesterday morning, I saw from the Internet that a particularly serious production safety accident occurred at 6:00 am on June 3 at Jilin Baoyuanfeng Poultry Co., Ltd. in Dehui City, Jilin Province, causing serious loss of life and property. As of 20:00 on June 3, 120 people had been killed and 70 injured in the accident. In addition to management oversight, what are the main causes of casualties?
Since the investigation team of the State Council has not yet released an authoritative accident investigation report, there is still controversy about whether the main cause of casualties is fire or acute ammonia poisoning. Yesterday, the local fire department initially determined that the cause of the accident was the explosion caused by the leakage of liquid ammonia; According to the on-site medical staff, the causes of death from injuries include burns, ammonia poisoning, etc. The main cause of death is respiratory edema caused by ammonia poisoning. According to the official micro blog of CCTV News on June 4, Jilin Baoyuanfeng Poultry Co., Ltd. had a particularly serious burning accident. The judgment of accident causes involves the follow-up clinical treatment of the injured.
Ammonia (NH3) is a colorless gas with strong pungent smell under normal temperature and pressure; Ammonia is very soluble in water. Under normal temperature and pressure, one volume of water can dissolve about 700 volumes of ammonia to form ammonia water; When ammonia is cooled to - 33.5 ℃ under normal pressure or pressurized to 700KPa to 800KPa under normal temperature, gaseous ammonia can be converted into liquid ammonia. When liquid ammonia is vaporized, it needs to absorb a lot of heat, which makes the surrounding temperature drop sharply. Therefore, liquid ammonia is often used as a refrigerant
