According to a report from the UN’s Food and Agriculture Organisation (FAO), the way in which plastic is used in farming across the world is threatening food safety and potentially human health.

The soil contains more microplastic pollution than the oceans and therefore we need to better manage the millions of tonnes of plastics used in the food and farming system each year. Microplastics are formed as larger plastics are broken down, which are then consumed by people and wildlife, some of which contain toxic additives and may carry pathogens. It is also known that some marine animals are harmed by eating plastics, but little is known about the impact on land animals or people.

There are several benefits to using plastic in the farming industry, from bale wrap to irrigation and even tree guards, but the FAO said the use of plastics had become pervasive and that most were currently single-use and were buried, burned or lost after use.

“Despite the many benefits, agricultural plastics also pose a serious risk of pollution and harm to human and ecosystem health when they are damaged, degraded or discarded in the environment,” the report says.

The FAO report, which was reviewed by external experts, estimates 12.5m tonnes of plastic products were used in plant and animal production in 2019, and a further 37.3m in food packaging.

“The report serves as a loud call for decisive action to curb the disastrous use of plastics across the agricultural sectors,” said Maria Helena Semedo, deputy director general at the FAO.

“Soils are one of the main receptors of agricultural plastics and are known to contain larger quantities of microplastics than oceans,” she said. “Microplastics can accumulate in food chains, threatening food security, food safety and potentially human health.”

Microplastic pollution is a global issue, and global soils are the sourse of all life on land. In December 2020, the FAO warned that their future looked bleak without action to halt degradation.

There is limited data on the use of plastic. but Asia was estimated to be the largest user, accounting for about half of global usage. The global demand for major products such as greenhouse, mulching and silage films is also expected to rise by 50% by 2030.

Prof Jonathan Leake, at the University of Sheffield in the UK and a panel member of the UK Sustainable Soils Alliance, said: “Plastic pollution of agricultural soils is a pervasive, persistent problem that threatens soil health throughout much of the world.”

He said the impact of plastic was poorly understood, although adverse effects had been seen on earthworms, which played a crucial role in keeping soils and crops healthy.

“We are currently adding large amounts of these unnatural materials into agricultural soils without understanding their long-term effects,” he said. “In the UK the problems are especially serious because of our applications of large amounts of plastic-contaminated sewage sludges and composts. We need to remove the plastics [from these] before they are added to land, as it is impossible to remove them afterwards.”

As a solution, the FAO report cites “the 6R model” – refuse, redesign, reduce, reuse, recycle, and recover. This means adopting farming practices that avoid plastic use, substituting plastic products with natural or biodegradable alternatives, promoting reusable plastic products and improving plastic waste management.