Is edible salt unsafe? Can eating iodized salt protect against radiation? Let the experts explain

On August 24, Japan started discharging contaminated water from the Fukushima nuclear power plant into the sea, which attracted global attention and heated discussions. It also triggered panic among people about salt, and a "salt rush" swept across many places.

Some people are worried that the nuclear contaminated water from Fukushima will contaminate table salt after being discharged into the sea, while others believe that iodized salt can prevent radiation. So, is table salt really unsafe? Can iodized salt prevent radiation? Is it necessary to stock up on salt?

Before answering these questions, let’s take a look at where sea salt comes from↓↓↓

1. How does seawater become salt? Is it safe?

Relevant data shows that 1 kg of seawater contains about 35 grams of salt, which is called sea salt, of which only 27 grams is table salt for seasoning. In addition to sodium chloride (table salt), seawater also contains substances such as magnesium chloride.

So where does the salt in the sea come from? The salt in the sea comes from the rocks that cover the earth. Raindrops fall on the rocks, and the rain dissolves certain substances contained in the rocks. This water (plus spring water) slowly turns into rivers and flows into the sea.

Sea salt is produced by introducing seawater into the salt pond on the beach, evaporating the water through sunlight, and then purifying it to make edible sea salt. It accounts for about 15%-20% of the total salt. The main sea salt producing areas in my country are Liaoning, Hebei, Tianjin, Shandong, Jiangsu and other places. In addition, Hainan, Guangdong and other places also produce some sea salt, usually called southern sea salt, with lower production.

▲Workers working in the sea salt crystallization pool (Photo source: Fujian Daily)

In response to public concerns about the impact of seawater pollution on salt safety, a relevant person in charge of a certain Salt Administration stated that China's salt production must undergo three rigorous testing and inspection processes at the primary, intermediate and advanced levels, and only after meeting the inspection standards will it enter the finished salt production stage ; after the finished salt is produced, it must pass moisture and standard tests before it can be sold on the market, ensuring that each batch of salt enters the market safely.

2. In addition to sea salt, there are many other salts to choose from in my country

Salt resources are widely distributed in nature. There are abundant salt in seawater, salt lakes, salt wells and salt mines. my country is the world's largest producer of raw salt. About 10 million tons of raw salt in my country is used to make table salt. In recent years, my country's annual salt production has stabilized at about 12 million tons.

According to the source, in addition to sea salt, there are also well salt and lake salt.

In fact, well salt is the main type of edible salt for the Chinese people .

Well salt is made from rock salt or underground natural brine (excluding coastal underground brine), which accounts for about 70%-75% of the total salt. Surface water is injected into underground salt mines to dissolve rock salt ore to form saturated brine, which is then introduced into vacuum salt making equipment to evaporate the water and make salt. The main production areas of well salt are Sichuan, Hubei, Hunan, Shaanxi, Jiangsu, Henan and Jiangxi.

(Photo from the Internet) Lake salt is salt mined from salt lakes or made from salt lake brine. It accounts for about 5%-10% of the total salt production, and is mainly produced in Qinghai, Xinjiang, Inner Mongolia and Gansu.

In addition, according to the processing technology, it can be divided into ordinary table salt (including refined salt, crushed washing salt, sun-dried salt, etc.) and multi-variety table salt (including low sodium salt, reduced sodium salt, seasoning salt, special process salt, etc.), which play different uses in our lives.

3. Can eating iodized salt prevent radiation?

Many people are worried that the Fukushima nuclear contaminated water will contaminate table salt after being discharged into the sea, while some people believe that iodized salt can prevent radiation.

In response to this, Zhang Yu, deputy director of the office of the Institute of Nutrition and Health at the Chinese Center for Disease Control and Prevention, wrote an article in Science Popularization China pointing out that the content of iodine and potassium iodide in iodized salt is not high, neither of them has anti-radiation effects , and excessive intake of iodine and potassium iodide can easily lead to iodine poisoning and even endanger life.

Data shows that iodine is an essential trace nutrient for metabolism and growth and development, and is the main raw material for the human body to synthesize thyroid hormones. The common table salt we have includes iodized salt, which is table salt fortified with iodine nutrients to prevent the occurrence of iodine deficiency.

In addition, according to the latest data released by China National Salt Corporation, the current product structure of edible salt in my country is 87% of well salt, 10% of sea salt, and 3% of lake salt. The production of well salt and lake salt is not affected by the nuclear pollution in Japan. Zhang Yu said that the production process of edible salt must comply with food safety regulations. The relevant departments have launched the monitoring of seawater radioactivity in relevant areas. The public does not need to worry too much. Salt is a condiment and should not be purchased in excess. Improper storage conditions or too long a storage time may also affect the quality of iodized salt, which is not worth the loss.

4. Experts: No need to stock up on salt

Wang Xiaoqing, president of the China Salt Industry Association, said that in general, China imports more and exports less, with more imports and less exports, and the imported raw salt is mainly used as chemical raw materials in industry. China's edible salt production can meet demand .

Public data shows that China is the country with the largest raw salt production capacity and output in the world. The salt production areas are divided into sea salt production areas, well salt production areas, and lake salt production areas. In 2022, China's raw salt production capacity reached 115.85 million tons and its output reached 83.9 million tons; in 2022, the apparent consumption of raw salt in the country reached 58.3 million tons, with a consumption structure of caustic soda 51.86%, soda ash 36.85%, and others 11.29%; 713,000 tons of raw salt were exported and 9.425 million tons were imported. Among the raw salt consumption destinations, about 70% of the raw salt is used in salt chemical industry, and the rest is used for food and other purposes.

Zhang Jinliang, a professor at the Chinese Academy of Environmental Sciences, said in an interview that if consumers are very worried about the radioactivity of discharged nuclear wastewater, they need to be careful when purchasing and try to avoid buying sea salt; in addition, management departments should strengthen the monitoring of radioactivity of edible salt and establish radioactivity limits for edible salt.

Source: Beijing Science and Technology News, Science Refutes Rumors, CCTV News, Beijing News