Plastic films have
become an integral part of fruit and vegetable
production systems, but their release of phthalate acid esters (PAEs)
is a threat to human health. The release kinetics of PAEs and measures
of risk are still not well understood. We investigated 50 agricultural
films, with concentrations ranging from 2.59 to 282,000 mg kg–1. The seven commercially available film types included
were polyvinylchloride (PVC), metallocene polyethylene (mPE), ethylene
vinyl acetate (EVA), polyolefin (PO), and three mulch films. Bis(2-ethylhexyl)
phthalate (DEHP) was detected in most of films, and its release fitted
well into the first-order kinetic model. The release rate of DEHP
was negatively related to the film thickness. The potential carcinogenic
risks of DEHP in the air of six kinds of plastic greenhouses to human
health were estimated. We found that the carcinogenic risks associated
with PVC and mPE greenhouse films warrant greater attention. Though
EVA, PO greenhouse, and mulch films were lower risk, we advise keeping
plastic greenhouses well ventilated during the first month of use
to reduce direct human exposure to volatile PAEs.