From soil to fork: Are mulch films releasing additives to the soil and contaminating our food?

Climate change and rising food demand have increased plastic mulch use to boost yields; however, mulches release additives like phthalates, potentially contaminating soil and crops. This study examined additive transfer from conventional and biodegradable mulches to soil and strawberries over a two year-cycle. Substrates were collected at four times: before mulching (T0), first harvest (T1), six months after mulching (T2), second harvest (T3). Phthalate levels peaked at T2 (up to 746.18 ± 33.33 μg/kg) and declined at T3. Contrary to their eco-friendly image, PBAT released additives at levels comparable to polyethylene. Polypropylene and oxo-degradable polyethylene mulch consistently led to the highest contamination. Significant differences in di(2-ethylhexyl)-phthalate, dibutyl-phthalate, and diethyl-phthalate concentrations were found between treatments and controls. In strawberries, only dibutyl-phthalate (up to 164.32 ± 81.58 μg/kg) and acetyl-tributyl-citrate (up to 8.37 ± 2.68 μg/kg) were detected, with low estimated noncarcinogenic risk. The study urges assessment of mulch pollution and shows film types differ in additive release.