Cooking food in microwavable plastic containers: in situ formation of a new chemical substance and increased migration of polypropylene polymers

Hydrolysis of plasma-polymerized poly(ethylene glycol)/ZnO nanocomposites in food simulants: Identification of components and potential toxicity

Plasma polymerization at atmospheric pressure provides an eco-friendly alternative to wet chemistry for creating antibacterial coatings for food packaging. However, the degradation of these coatings in contact with food remains underexplored. This study employs an aerosol-assisted atmospheric plasma system to deposit polyethylene glycol (PEG)-like coatings with 1 wt% zinc oxide (ZnO) nanoparticles on a polymer substrate. Fourteen degradation products, differ mainly in the number of ethylene oxide groups were identified in food simulants, with the highest releases associated with C6H14O4 and C10H22O5. Increasing plasma input power from 200 to 350 W enhanced crosslinking and increased ZnO nanoparticle content from 1.6 ± 0.3 to 5.9 ± 0.8 at. %, resulting in lower release of the degradation products. Toxicity evaluations, including Daphnia magna LC50 (48 h) and oral rat LD50 tests, confirmed the non-toxic nature of these substances. These findings suggest that plasma-polymerized coatings are safe and effective for antibacterial food packaging.

One sampler to see it all: The use of APIStrips for beehive characterization and pesticide residue evaluation based on mass spectrometry

Environmental monitoring is crucial for assessing the overall state of the ecosystems in terms of contaminant impact and chemical landscape. The use of honey bee (Apis mellifera) colonies considerably eases the sampling activities, as honey bees are exposed to a wide range of substances that are transported and accumulated within the beehives. In this work, combining low-resolution and high-resolution mass spectrometry, the APIStrip passive sampler has been employed to evaluate the presence of pesticide residues and the overall characterization of beehive environments. A total of 180 APIStrips have been deployed in 10 Danish apiaries, located in different landscapes, during a five-month sampling period. The targeted methodology for pesticide analysis was based on gas and liquid chromatography coupled with triple quadrupole mass spectrometry, covering 430 pesticide residues. A total of 29 pesticide residues were identified (fluopyram and azoxystrobin being the most frequently detected), with remarkable differences in the pesticide load between apiaries. For its part, the use of non-targeted approaches through liquid chromatography coupled with an Orbitrap mass spectrometer allowed the detection of unknown compounds that were specific of certain environments. Natural products such as eupatilin and gnaphaliin, which are derived from plant sources, were present exclusively in one of the apiaries. Additionally, the detection of drimane sesquiterpenoids, including compounds potentially originating from the Aspergillus genus, suggests the capability of APIStrips to early detect fungal contamination within beehives. This dual approach of low- and high-resolution mass spectrometry maximizes the analytical potential of APIStrips as a tool capable of detecting a wide range of substances with implications for both agricultural practices and ecological health.

Evaluation of the sorption/desorption processes of pesticides in biodegradable mulch films used in agriculture

Microplastics from mulch films can be a source of chemical contamination to agricultural soils. In this context, biodegradable films have been widely positioned as a greener choice. However, their sorption/desorption capabilities, in contrast to the conventional plastic types remain understudied. It is for this reason that objective evaluation of their interactions with residual agricultural contaminants becomes important. Our findings reveal that polyethylene (PE) mulch films retained lower amounts of pesticide residues and demonstrated a higher desorption/release [median desorption = 71.86 μg/L or about 50%], while polybutylene adipate terephthalate (PBAT) mulch films retained higher amounts of pesticide residues onto their surface and demonstrated a much lower desorption [median desorption = 24.27 μg/L or about 17%] after a spraying event. A higher ambient temperature had no significant effect on final desorption amounts in both PE [median = 65.27 μg/L at 20 °C and 74.23 μg/L at 40 °C] and PBAT [median = 24.26 μg/L at 20 °C and 24.78 μg/L at 40 °C] mulch films. However, it did favour a faster desorption pace in PE films. Desorption in PBAT and PE plastic types was correlated with the log Kow value [Spearman's correlation: 0.857 and 0.837 respectively, p < 0.05]. However, only a moderate correlation with pKa was observed in PBAT [Spearman's correlation: 0.478, p < 0.05], while none for PE plastic type. Sorption of pesticides onto biodegradable PBAT microplastics were best explained by Elovich [R2: 0.937-0.959] and pseudo-second order kinetics [R2: 0.942-0.987], suggesting the presence of chemisorption. Furthermore, Weber Morris plots suggested the presence of a multi-step process and Boyd plots indicated that film diffusion or chemical bond formation was the rate-limiting step governing this phenomenon.

Consumers' practices and safety perceptions regarding the use of materials for food preparation and storage: Analyses by age group

Food Contact Materials (FCM) are those intended to be in contact with food, during its production, handling, and storage. FCM contain chemicals that could migrate to the foodstuff, posing potential health concerns, and usage practices influence the level of migration. This study assesses the preferences, safety perceptions, and usage practices of Portuguese consumers regarding FCM used for cooking and food storage (cookware). An observational, quantitative, and transversal study was performed through an online survey created for this purpose, which involved 1179 Portuguese adults. Results were analyzed according to age. Safety was the factor considered most important when choosing cookware materials, although the choice criteria varied with age. The majority of respondents recognize the risk of food contamination through cookware. Stainless steel and glass were considered the safest materials for cooking. The materials most used to reserve food are glass and plastic. Older individuals carry out more maintenance of cookware and have greater knowledge about how to wash and store it. Regarding the FCM symbology, there is a general lack of knowledge. Our study demonstrates the need to disseminate reliable information to the general public about cookware, contributing to greater literacy in health and to less exposure to food contact chemicals.

Exploring sorption of pesticides and PAHs in microplastics derived from plastic mulch films used in modern agriculture

The sorption and vector effect of microplastics on the transfer of pesticides and polycyclic aromatic hydrocarbons (PAHs), as well as its impact on agriculture remain largely unexplored. This comparative study is first to investigate the sorption behavior of different pesticides and PAHs at environmentally realistic concentrations by model microplastics and microplastics derived from polyethylene mulch films. Sorption was found to be up to 90% higher in the case of microplastics derived from mulch films as opposed to pure polyethylene microspheres. For microplastics from mulch films, the sorption percentages for pesticides in media containing CaCl₂ were reported to be: pyridate (75.68% and 52.44%), fenazaquin (48.54% and 32.02%), pyridaben (45.04% and 56.70%), bifenthrin (74.27% and 25.88%), etofenprox (82.16% and 54.16%) and pyridalyl (97.00% and 29.74%) at 5 μg/L and 200 μg/L pesticide concentration levels respectively. For PAHs, the sorption amounts were: naphthalene (22.03% and 48.00%), fluorene (38.99% and 39.00%), anthracene (64.62% and 68.02%) and pyrene (75.65% and 86.38%) at 5 μg/L and 200 μg/L PAH concentration levels respectively. Sorption was influenced by the octanol-water partition coefficient (log K_ow) and ionic strength. Kinetics of the process in the case of sorption of pesticides were best explained by pseudo-first order kinetic model (R² between 0.90 and 0.98) while the best fitting isotherm model was Dubinin-Radushkevich (R² between 0.92 and 0.99). Results suggest the presence of surface level physi-sorption through a micropore volume filling mechanism and the role of hydrophobic and electrostatic forces. Pesticide desorption data in polyethylene mulch films indicate that pesticides with high log K_ow were almost completely retained in mulch films, while those with lower log K_ow were desorbed rapidly into the surrounding media. Our study highlights the role of microplastics from plastic mulch films as vectors for pesticide and PAH transport at environmentally realistic concentrations and the factors that influence it.