Microplastics reach Lut desert

July 12, 2021 - 17:6

TEHRAN – Recent studies by Iranian researchers have revealed the microplastic contamination in the soil of Kalout Shahdad and Lut deserts.

Identification of microplastics in desert and pristine areas indicates the spread, overuse, and mismanagement of plastics in the environment.

Humans are known to consume the tiny plastic particles via food and water, but the possible health effects on people and ecosystems have yet to be determined.

Microplastics found in the soil come from plastic waste, plastic-based mulch, the use of sewage sludge as fertilizer, river floods, road runoff, irrigation water, and atmospheric sediment.

Accordingly, researchers of Kerman University of Medical Sciences studied the soil of Kalout Shahdad and Lut deserts for microplastic presence.

The number of MPs identified in 300 g samples ranged from zero (not detected) in several yardang tops to 25 on some yardang hillsides, with an overall average abundance of about 0.02 MP g–1.

The majority of MPs were of a fibrous nature with a size distribution (≤100 μm to ≥1000 μm) skewed toward the lower end, and analysis of a selection of particles by μ-Raman spectroscopy showed that polyethylene terephthalate and Nylon (polyamide) were the principal polymers.

Scanning electron microscopy revealed intense degradation of some particles but limited weathering of others. With little evidence of meso- and macroplastics in the deserts, it appears that the majority of MPs are brought into these environments from distant sources via the wind, with smaller, seasonal contributions from runoff associated with the adjacent mountains.

It is proposed that some windborne MPs are transported through the deserts relatively rapidly, while others are subject to internal recycling and significant photo-oxidation and mechanical weathering.

Research by the National University of Singapore found more than 400 types of bacteria on 275 pieces of microplastic collected from local beaches. They included bugs that cause gastroenteritis and wound infections in humans, as well as those linked to the bleaching of coral reefs.

Defined as smaller than 5mm in size, microplastics are shed by synthetic clothing, vehicle tires, and the spillage of plastic pellets used by manufacturers. The physical breakdown of plastic litter also creates them. Rain washes them into rivers and the sea, but they can also be blown by the wind and end up in fields when treated sewage waste is used as fertilizer.

Hundreds of studies also show that plastic bags and packaging are the deadliest plastic materials in the oceans, killing marine organisms such as whales, dolphins, turtles, and seabirds around the globe.

------------- Plastic pollution

Plastic pollution is getting the whole world in hot water. In Iran, a total of 4 million plastic waste is generated annually.

Plastic bags constitute half a million tons of the whole plastic waste produced in the country annually. Every Iranian consumes an average of three plastic bags a day, 96 percent of which goes directly into the trash bin.

According to the World Population Review 2021, Iran is ranked 17th in the production of plastic waste.

The report also claims that approximately 500 billion plastic bags are used worldwide, and plastic pollution is a global catastrophe caused by humans.


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