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Table salt contains a shocking number of microplastics

A recent study led by Andalas University in Indonesia has raised concerns about the presence of microplastics in table salt, echoing similar findings in bottled water. 

The research, involving 21 table salt brands, revealed that each contained microplastics, including fragments, fibers, films, and pellets. These molecules are associated with serious health risks, including cancer, heart disease, dementia, and fertility issues.

Salt contamination

The study, published in the Global Journal of Environmental Science and Management, points out that the contamination of salt can occur during the extraction of seawater and manufacturing processes. 

The research is particularly relevant for the United States, Singapore, and the Czech Republic, as Indonesia exports most of its sea salt to these countries.

How the research was conducted 

The methodology of the study involved examining 50 grams of salt from each brand. The salt was mixed with water to remove organic impurities, heated, and stirred. 

After the salt dissolved, the remaining material was examined under a microscope. The team detected up to 33 microplastics per kilogram of table salt.

Key findings

The researchers identified four types of microplastics by shape, size, and color. They found that fragments were the most common type of microplastic, followed by fibers, films, and pellets. Black was the predominant color among the particles.

Additionally, the team identified four types of polymers present in the microplastics: polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and polyester. PE is commonly used in synthetic resins, PP in robust, heat-resistant plastics, PET in clothing fibers and containers for liquids and foods, and polyester in man-made fiber materials.

Growing collection of evidence

Notably, the study chose not to disclose the names of the salt brands tested to maintain privacy. This research is part of a growing body of evidence highlighting the widespread presence of microplastics in everyday products. 

A similar study conducted by the University of Alicante in 2017 found up to 280 molecules per kilogram of salt from Spain, another significant exporter of salt to the US.

Study implications 

These findings underscore the pervasive nature of microplastic pollution and its potential implications for human health. 

As microplastics are found in various sources, including food, water, and air, understanding their impact and finding ways to mitigate their presence in the environment and consumer products is becoming increasingly crucial.

Additional sources of salt contamination 

Salt contamination can occur from a variety of sources, often depending on how and where the salt is sourced and processed. Here are some common sources:

  • Environmental pollution: Industrial waste and agricultural runoff can contaminate seawater or underground brine with heavy metals like mercury, lead, arsenic, and cadmium. These pollutants can enter the salt during the evaporation process.
  • Natural contaminants: Certain naturally occurring elements, like fluoride or bromide, might be present in higher than desirable amounts in some salt deposits.
  • Manufacturing process: During the processing and refining of salt, contamination can occur from equipment or during the addition of anti-caking agents, which may contain impurities.
  • Microbial contamination: Sea salt, especially unrefined varieties, can sometimes be contaminated with microorganisms from seawater.
  • Storage and transportation: Salt can also be contaminated during storage or transportation if it comes into contact with contaminated materials.
  • Packaging materials: Certain types of packaging might leach chemicals into the salt, especially if stored in high heat or humidity conditions.

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