Manganese, less is not enough, more is harmful
For the human body, manganese is very similar to iron. Most people know that iron is an essential trace element for the human body. Iron deficiency can lead to a range of symptoms, such as lethargy, weakness and anemia, while too much iron can cause iron toxicity. According to WHO estimates, there are many people in iron deficiency worldwide, so "adding iron" is even promoted as a public **** health cause. "Iron pan stir-fry" is considered by many people is "iron" one of the ways, but there are experts rumors that the iron from the iron pan into the food is very little iron, "iron pan stir-fry" iron role can be ignored.
The case of manganese is similar. First, manganese is an essential trace element. It is a component of connective tissue, bone, clotting factors, sex hormones, etc. It is also indispensable for fat and carbohydrate metabolism, calcium absorption, and blood sugar regulation. Normal brain and nerve function, but also without its participation, manganese deficiency will affect the development of the nerve.
Like many mineral nutrients, too much manganese can be harmful to the human body. Excessive manganese inhibits iron absorption, and long-term overdose affects nervous system function -- the news scaremongering about "excessive manganese causing Parkinson's disease" isn't a stretch.
But as the old adage goes, "All talk of effects and harms without the dose is just a bunch of hooliganism." How much manganese does the human body need per day? How much manganese can the human body tolerate? Scientific data is not very uniform, the interpretation of the world's different countries, the recommended standards are different. For example, for adults, the "adequate amount" is 2-3 milligrams per day in the United States, 3.5 milligrams per day in China, and higher in Canada. This "Adequate Amount" means that eating this much per day is enough to meet your needs, and does not mean that exceeding it is harmful. The "maximum intake" is considered safe if you don't exceed it, and increases the risk if you do -- both China and the U.S. set the standard at about 10 milligrams a day.
Manganese is found in water, air, soil and food. The main route of manganese intake for the general population is food. The amount of manganese intake varies from country to country, but is generally in the range of a few milligrams. In other words, the average person is not "manganese deficient", but at the same time, there is still a considerable distance from the "safe upper limit of intake".
The real meaning of stainless steel cutlery "manganese exceeds the standard"
The news disclosed that the material used in Nepal's stainless steel cutlery was unqualified, and emphasized that "the manganese content exceeded the national standard by 4 times", so according to the "Long-term excessive intake of manganese increases the risk of Parkinson's disease", read these stainless steel tableware "harmful to health".
The state for stainless steel tableware used in the material requirements, which has a limit on the content of manganese. However, this limit is not based on "if the standard is exceeded, it will jeopardize food safety" and the development. It is only a specification for the steel itself. The "content in the steel" is not the same thing as the "amount that may be absorbed into the food". From the information reported in the news so far, Nepal has not denied the allegation that "the material does not comply with the national standard", but emphasized that its tableware is qualified in all indicators. They also cited foreign situations, arguing that the provisions of the current national standard are unreasonable and should allow for more materials.
The two are not contradictory. The current national standard specifies a number of stainless steel types and indicators, the implication being that if these steels are used, then they will be "qualified". On the other hand, as Nepal claims, the industry is always evolving, and many new, and perhaps even more suitable, steels are emerging, but they are not included in the national standard. It's also entirely possible to use these new steels to make tableware that meets all food safety standards.
So, Nepal's "manganese" tableware violates the national standard for materials. But this standard is not based on food safety. We can't use it to say "if it's over the limit, it's bad for your health" or "if it's over the limit, it's not bad for your health".
From the point of view of regulations, Nepal does not comply with the national standard. They believe that the current national standard is unreasonable and not in line with international practice. From a technical point of view, this is not surprising. If the national standard is revised in the future to allow the use of the steel they are currently using, it does not necessarily mean that it is "shady". However, until such time as the national standard is revised, their practices do not comply with the standard - or, at least, with all national standards. What kind of punishment should be imposed for this kind of "non-compliance" should be decided by the competent authorities. But it doesn't make sense for the media to crack down by hyping it up as a "food-safety incident".
"Manganese" tableware is harmful
Because manganese is an essential nutrient for the human body, and excessive intake is harmful, it is pointless to talk about whether or not it is harmful in terms of quantity.
If the amount of manganese precipitated from the tableware into the food is negligible, there is no need to worry. If the precipitation from tableware is not negligible, then there are three situations:
1. If a person does not get enough manganese from other sources, then such tableware even serves as a "manganese supplement";
2. If a person gets enough manganese from other sources, but there is still a big distance between it and the excess, and the precipitation from these tableware is not enough, then there is no need to worry about the amount of manganese.
Three, if a person's intake of manganese from other sources is already close to or exceeds the safe limit, then the manganese precipitated in the tableware is just adding insult to injury.
So, the manganese content is not the only determining factor in whether or not the tableware with "excessive manganese" is safe. The key factors are how much is "precipitated" and how much is "ingested by other means". Without these two indicators, it's all talk.
According to news reports, manganese intake among Chinese residents is roughly 6.8 milligrams per day. The test data provided by Nepal is that the steel used precipitates 0.05 milligrams per kilogram. If this is true, then the amount of manganese precipitated from these utensils would be negligible and would hardly change the total manganese intake. Alternatively, as in the second scenario above, the amount of manganese precipitated would not be sufficient to bring the average person's manganese intake up to the "safe limit".
Because of the nutritional and toxicological characteristics of manganese, international standards for manganese precipitation from tableware are generally not set. The sensitivity of the food safety issue prompted the National Center for Food Safety Risk Assessment to evaluate manganese precipitation in stainless steel tableware. Regardless of the outcome, this is always an improvement. Whether the previous national standard is reasonable or not, and no matter what the test data of Nepal, or let us wait and see what the Food Safety Risk Assessment Center assessment.