- Dissolved solids: These include minerals such as calcium carbonate, magnesium sulfate, and sodium chloride.

- Organic matter: This includes plant and animal matter, as well as bacteria and other microorganisms.

- Heavy metals: These include lead, mercury, and cadmium.

- Microplastics: These are small pieces of plastic that can be harmful to marine life.

- Pharmaceuticals: These include drugs that have been flushed down the toilet or otherwise released into the environment.

- Personal care products: These include cosmetics, shampoo, and toothpaste.

The concentration of these impurities can vary depending on the location and time of year. In general, the filtrate of seawater is not safe to drink without further treatment.