My Science School

Can you believe that we are swallowing plastic along with the food and drink we consume every day? But how do microplastics infiltrate our food? Read on to fund out..

Did you know that microplastics, tiny bits of plastic invisible to the naked eye are taken up by the roots of plants and eventually end up in the fruits and vegetables we eat?

Microplastics are everywhere. They have been found in Antarctica. buried in the sea ice and in the stomachs of creatures living in the deepest ocean trenches According to a recent study, there are around 24 trillion fragments of microplastics adrift in the world's oceans.

 

Food front

The unpalatable truth is that not only are microplastics present in Earth's water bodies they are on land too. in the soil in which we grow our food. In fact, we are swallowing plastic along with the food and drink we consume every day, including tra salt milk honey, sugar, vegetables fruits drut soft strides Tap water contains plastic and bottled water oven m The main reason why food crops airsorb microplastics is the use of sewage sludge as an alternative to chemical fertilizers by farmers. Sewage Since sludge contains sludge is left behind after a number of nutrients beneficial to soil it is used as organic fertilizer. wastewater is cleaned. Since it is costly to dispose of sludge and it contains a number of nutrients beneficial to soil, the sludge is used as organic fertilizer

From soil to food

Microplastics can remain in the soil for a long time. leaching harmful chemicals into it Ploughing also enables the plastic to reach areas where sludge is not applied in fact. scientists say that the amount of microplastic particles in agricultural soil is equal to what is found in surface ocean waters. Rainwater run-off containing topsoil and irrigation run-off also contribute in a big way to microplastic pollution in rivers, seas and in groundwater.

Research shows that crops absorb the particles from surrounding water and soil through tiny cracks in their roots. Most of the plastic collects in the roots with only a tiny amount travelling up to the shoots and leaves. Root vegetables such as carrots, radishes and turips may thus pose a bigger health risk when consumed. In leafy vegetables such as lettuce and cabbage, the concentrations are very low.

A surprising finding is that microplastics can stunt the growth of and lead to weight loss in earthworms! Microplastics may clog up the earthworms digestive tracts, hampering their ability to absorb nutrients. It is a well-known fact that earthworms are important for soil health.

Though the impact is not fully understood yet, studies show that the chemicals added during the manufacture of plastics can disrupt the hormone-producing endocrine system and cause other health problems and diseases.

Some European countries have banned sludge on farmland, but that may not be the best solution. It may force farmers to use synthetic fertilizers. Depositing it in landfills or burning it also poses environmental hazards.

Worth of sludge

Also called biosolids, treated sewage sludge has elements such as nitrogen, phosphorus and potassium, which are essential for plant health. The U.S. and countries in Europe have used sludge for decades on farmland.

In Europe, it is part of an EU (European Union) directive to promote a circular waste economy. Around 10 million tonnes of sludge is produced annually, of which 40 per cent is spread on fields. Researchers estimate that due to this practice, 31.000-42.000 tonnes of microplastics could be contaminating European farmland every year. This works out to 86 million to 720 million particles of microplastics! About 650 million microplastic particles, measuring 1 mm to 5 mm in size. entered one wastewater treatment plant in the UK on a single day and almost all of these ended up in the sewage sludge. forming one per cent of its total weight

In the US, an analysis by an environmental non-profit group in 2022 found that sewage sludge had contaminated 20 million acres of cropland. The contaminants were PFAS in plastic products that don't break down easily. They are termed forever chemicals

*PFAS is short for perfluoroalkyl and polyfluoroalkyl substances which are a group of man-made chemicals.

Picture Credit: Google