This research is the first of its scale to look at contaminant levels of the geographical spread of sea salt and its correlation with environmental discharge and pollution levels of plastics.
The news will be of interest to the water sector which has been researching and assessing the role of wastewater treatment plants to filter out microplastics.
Salt sourced from Asia contained the highest level of microplastics, the study found, with researchers finding the largest number of quantities in a sample from Indonesia – a country considered to be the second worst plastic emitter into the world’s oceans.
Only three brands of investigated salts – Taiwan (refined sea salt), China mainland (refined rock salt), France (unrefined sea salt produced by solar evaporation) – did not contain any microplastic particles in both replicate samples.
Assuming intake of 10 grams per day of salt, the average adult consumer could ingest approximately 2000 microplastics each year through salt alone, the study suggests.