Non-dioxin-like PCB and PBDE deposition on Zea mays L. leaves: modelled contamination in milk from dairy animals fed on silage.

Maize (Zea mays L.) can intercept airborne pollutants before their deposition on soil. Selected non-dioxin-like polychlorinated biphenyls (Σ6NDL-PCBs) and polybrominated diphenyl ethers (Σ8PBDEs) with feed and food safety relevance were measured on maize leaves harvested for silage in dairy animals from 28 fields in Italy. Analyses were carried out by gas chromatography coupled to high- and low-resolution mass spectrometry. Contamination ranged from 0.65 to 5.3 ng g(-1) with 12% moisture for Σ6NDL-PCBs, and from 2.7 to 6.2 for Σ8 PBDEs. Modelled contamination in cow's milk was estimated to fall within the range 0.27-16 ng g(-1) for PCBs, 0.17-1.9 for PBDE number 47, and 0.22-2.1 for PBDE number 99 on a lipid basis. The results indicate that maize silage alone may raise Σ6NDL-PCB contamination in dairy milk up to the 95th percentile in the European Union. Results are discussed in terms of air quality standards able to support food safety.