The Guardian view on microplastics: harmful pollution must be curbed | Editorial

New evidence of particles damaging crops strengthens the case for an international plastics treatyNew and concerning findings from environmental scientists about the impact of microplastics on crops and marine algae add to a growing body of evidence about the disruption caused to living systems by plastic pollution. The results, from a team led by Prof Huan Zhong at Nanjing University, China, are not definitive and require corroboration. But analysis showing that plastics could limit photosynthesis (the conversion of sunlight into chemical energy) must be taken seriously. If the researchers are correct, and staple crops are being reduced by about 12%, there are huge implications for global agriculture and food supplies. This could inject new urgency into efforts to tackle plastic pollution.There is no single route by which microplastic particles inhibit plants from growing. The overall effect is attributed to a combination of blocked sunlight and nutrients, and damage to soil and cells. This can lead to reduced levels of chlorophyll - the pigment enabling photosynthesis. When the researchers modelled the crop losses caused by an effect of this size, they found Asia was hardest hit, potentially contributing to food insecurity and worsening hunger. Continue reading...